com.awrtechnologies.valor.valorfireplace.hlistview.widget.HListView.java Source code

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Here is the source code for com.awrtechnologies.valor.valorfireplace.hlistview.widget.HListView.java

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/*
 * Author: alessandro crugnola
 * alessandro.crugnola@gmail.com
 * 
 * Fork based on the google opensource framework
 * 
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.awrtechnologies.valor.valorfireplace.hlistview.widget;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.util.SparseArrayCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.FocusFinder;
import android.view.KeyEvent;
import android.view.SoundEffectConstants;
import android.view.View;
import android.view.ViewDebug;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.ArrayAdapter;
import android.widget.Checkable;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RemoteViews.RemoteView;
import android.widget.WrapperListAdapter;

import com.awrtechnologies.valor.valorfireplace.R;

import java.util.ArrayList;

/*
 * Implementation Notes:
 *
 * Some terminology:
 *
 *     index    - index of the items that are currently visible
 *     position - index of the items in the cursor
 */

/**
 * A view that shows items in a vertically scrolling list. The items come from the {@link ListAdapter} associated with this view.
 * 
 * <p>
 * See the <a href="{@docRoot}guide/topics/ui/layout/listview.html">List View</a> guide.
 * </p>
 * 
 * @attr ref android.R.styleable#ListView_entries
 * @attr ref android.R.styleable#ListView_divider
 * @attr ref android.R.styleable#ListView_dividerHeight
 * @attr ref android.R.styleable#ListView_headerDividersEnabled
 * @attr ref android.R.styleable#ListView_footerDividersEnabled
 */
@RemoteView
public class HListView extends AbsHListView {

    /**
     * Used to indicate a no preference for a position type.
     */
    static final int NO_POSITION = -1;

    /**
     * When arrow scrolling, ListView will never scroll more than this factor times the height of the list.
     */
    private static final float MAX_SCROLL_FACTOR = 0.33f;

    /**
     * When arrow scrolling, need a certain amount of pixels to preview next items. This is usually the fading edge, but if that is
     * small enough, we want to make sure we preview at least this many pixels.
     */
    private static final int MIN_SCROLL_PREVIEW_PIXELS = 2;

    private static final String LOG_TAG = "HListView";

    /**
     * A class that represents a fixed view in a list, for example a header at the top or a footer at the bottom.
     */
    public static class FixedViewInfo {

        /** The view to add to the list */
        public View view;
        /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */
        public Object data;
        /** <code>true</code> if the fixed view should be selectable in the list */
        public boolean isSelectable;
    }

    private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>();
    private ArrayList<FixedViewInfo> mFooterViewInfos = new ArrayList<FixedViewInfo>();

    Drawable mDivider;
    int mDividerWidth;
    int mMeasureWithChild;

    Drawable mOverScrollHeader;
    Drawable mOverScrollFooter;

    private boolean mIsCacheColorOpaque;
    private boolean mDividerIsOpaque;

    private boolean mHeaderDividersEnabled;
    private boolean mFooterDividersEnabled;

    private boolean mAreAllItemsSelectable = true;

    private boolean mItemsCanFocus = false;

    // used for temporary calculations.
    private final Rect mTempRect = new Rect();
    private Paint mDividerPaint;

    // the single allocated result per list view; kinda cheesey but avoids
    // allocating these thingies too often.
    private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult();

    // Keeps focused children visible through resizes
    private FocusSelector mFocusSelector;

    public HListView(Context context) {
        this(context, null);
    }

    public HListView(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.hlv_listViewStyle);
    }

    public HListView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

        if (LOG_ENABLED) {
            Log.i(LOG_TAG, "defStyle: " + defStyle);
        }

        final Resources.Theme theme = context.getTheme();
        TypedArray array = theme.obtainStyledAttributes(attrs, R.styleable.HListView, defStyle, 0);

        CharSequence[] entries = null;
        Drawable dividerDrawable = null;
        Drawable overscrollHeader = null;
        Drawable overscrollFooter = null;
        int dividerWidth = 0;

        boolean headerDividersEnabled = true;
        boolean footerDividersEnabled = true;
        int measureWithChild = -1;

        if (null != array) {
            entries = array.getTextArray(R.styleable.HListView_android_entries);
            dividerDrawable = array.getDrawable(R.styleable.HListView_android_divider);
            overscrollHeader = array.getDrawable(R.styleable.HListView_hlv_overScrollHeader);
            overscrollFooter = array.getDrawable(R.styleable.HListView_hlv_overScrollFooter);
            dividerWidth = array.getDimensionPixelSize(R.styleable.HListView_hlv_dividerWidth, 0);
            headerDividersEnabled = array.getBoolean(R.styleable.HListView_hlv_headerDividersEnabled, true);
            footerDividersEnabled = array.getBoolean(R.styleable.HListView_hlv_footerDividersEnabled, true);
            measureWithChild = array.getInteger(R.styleable.HListView_hlv_measureWithChild, -1);
            array.recycle();

            if (LOG_ENABLED) {
                Log.d(LOG_TAG, "divider: " + dividerDrawable);
                Log.d(LOG_TAG, "overscrollHeader: " + overscrollHeader);
                Log.d(LOG_TAG, "overscrollFooter: " + overscrollFooter);
                Log.d(LOG_TAG, "dividerWith: " + dividerWidth);
                Log.d(LOG_TAG, "headerDividersEnabled: " + headerDividersEnabled);
                Log.d(LOG_TAG, "footerDividersEnabled: " + footerDividersEnabled);
                Log.d(LOG_TAG, "measureWithChild: " + measureWithChild);
            }
        }

        if (entries != null) {
            setAdapter(new ArrayAdapter<CharSequence>(context, android.R.layout.simple_list_item_1, entries));
        }

        if (dividerDrawable != null) {
            // If a divider is specified use its intrinsic height for divider height
            setDivider(dividerDrawable);
        }

        if (overscrollHeader != null) {
            setOverscrollHeader(overscrollHeader);
        }

        if (overscrollFooter != null) {
            setOverscrollFooter(overscrollFooter);
        }

        // Use the height specified, zero being the default
        if (dividerWidth != 0) {
            setDividerWidth(dividerWidth);
        }

        mHeaderDividersEnabled = headerDividersEnabled;
        mFooterDividersEnabled = footerDividersEnabled;
        mMeasureWithChild = measureWithChild;

    }

    /**
     * @return The maximum amount a list view will scroll in response to an arrow event.
     */
    public int getMaxScrollAmount() {
        return (int) (MAX_SCROLL_FACTOR * (getRight() - getLeft()));
    }

    /**
     * Make sure views are touching the top or bottom edge, as appropriate for our gravity
     */
    private void adjustViewsLeftOrRight() {
        final int childCount = getChildCount();
        int delta;

        if (childCount > 0) {
            View child;

            if (!mStackFromRight) {
                // Uh-oh -- we came up short. Slide all views up to make them
                // align with the top
                child = getChildAt(0);
                delta = child.getLeft() - mListPadding.left;
                if (mFirstPosition != 0) {
                    // It's OK to have some space above the first item if it is
                    // part of the vertical spacing
                    delta -= mDividerWidth;
                }
                if (delta < 0) {
                    // We only are looking to see if we are too low, not too high
                    delta = 0;
                }
            } else {
                // we are too high, slide all views down to align with bottom
                child = getChildAt(childCount - 1);
                delta = child.getRight() - (getWidth() - mListPadding.right);

                if (mFirstPosition + childCount < mItemCount) {
                    // It's OK to have some space below the last item if it is
                    // part of the vertical spacing
                    delta += mDividerWidth;
                }

                if (delta > 0) {
                    delta = 0;
                }
            }

            if (delta != 0) {
                offsetChildrenLeftAndRight(-delta);
            }
        }
    }

    /**
     * Add a fixed view to appear at the top of the list. If addHeaderView is called more than once, the views will appear in the
     * order they were added. Views added using this call can take focus if they want.
     * <p>
     * NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that will also account
     * for header and footer views.
     *
     * @param v
     *           The view to add.
     * @param data
     *           Data to associate with this view
     * @param isSelectable
     *           whether the item is selectable
     */
    public void addHeaderView(View v, Object data, boolean isSelectable) {

        if (mAdapter != null && !(mAdapter instanceof HeaderViewListAdapter)) {
            throw new IllegalStateException(
                    "Cannot add header view to list -- setAdapter has already been called.");
        }

        FixedViewInfo info = new FixedViewInfo();
        info.view = v;
        info.data = data;
        info.isSelectable = isSelectable;
        mHeaderViewInfos.add(info);

        // in the case of re-adding a header view, or adding one later on,
        // we need to notify the observer
        if (mAdapter != null && mDataSetObserver != null) {
            mDataSetObserver.onChanged();
        }
    }

    /**
     * Add a fixed view to appear at the top of the list. If addHeaderView is called more than once, the views will appear in the
     * order they were added. Views added using this call can take focus if they want.
     * <p>
     * NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that will also account
     * for header and footer views.
     *
     * @param v
     *           The view to add.
     */
    public void addHeaderView(View v) {
        addHeaderView(v, null, true);
    }

    @Override
    public int getHeaderViewsCount() {
        return mHeaderViewInfos.size();
    }

    /**
     * Removes a previously-added header view.
     *
     * @param v
     *           The view to remove
     * @return true if the view was removed, false if the view was not a header view
     */
    public boolean removeHeaderView(View v) {
        if (mHeaderViewInfos.size() > 0) {
            boolean result = false;
            if (mAdapter != null && ((HeaderViewListAdapter) mAdapter).removeHeader(v)) {
                if (mDataSetObserver != null) {
                    mDataSetObserver.onChanged();
                }
                result = true;
            }
            removeFixedViewInfo(v, mHeaderViewInfos);
            return result;
        }
        return false;
    }

    private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) {
        int len = where.size();
        for (int i = 0; i < len; ++i) {
            FixedViewInfo info = where.get(i);
            if (info.view == v) {
                where.remove(i);
                break;
            }
        }
    }

    /**
     * Add a fixed view to appear at the bottom of the list. If addFooterView is called more than once, the views will appear in the
     * order they were added. Views added using this call can take focus if they want.
     * <p>
     * NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that will also account
     * for header and footer views.
     *
     * @param v
     *           The view to add.
     * @param data
     *           Data to associate with this view
     * @param isSelectable
     *           true if the footer view can be selected
     */
    public void addFooterView(View v, Object data, boolean isSelectable) {

        // NOTE: do not enforce the adapter being null here, since unlike in
        // addHeaderView, it was never enforced here, and so existing apps are
        // relying on being able to add a footer and then calling setAdapter to
        // force creation of the HeaderViewListAdapter wrapper

        FixedViewInfo info = new FixedViewInfo();
        info.view = v;
        info.data = data;
        info.isSelectable = isSelectable;
        mFooterViewInfos.add(info);

        // in the case of re-adding a footer view, or adding one later on,
        // we need to notify the observer
        if (mAdapter != null && mDataSetObserver != null) {
            mDataSetObserver.onChanged();
        }
    }

    /**
     * Add a fixed view to appear at the bottom of the list. If addFooterView is called more than once, the views will appear in the
     * order they were added. Views added using this call can take focus if they want.
     * <p>
     * NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied cursor with one that will also account
     * for header and footer views.
     *
     *
     * @param v
     *           The view to add.
     */
    public void addFooterView(View v) {
        addFooterView(v, null, true);
    }

    @Override
    public int getFooterViewsCount() {
        return mFooterViewInfos.size();
    }

    /**
     * Removes a previously-added footer view.
     *
     * @param v
     *           The view to remove
     * @return true if the view was removed, false if the view was not a footer view
     */
    public boolean removeFooterView(View v) {
        if (mFooterViewInfos.size() > 0) {
            boolean result = false;
            if (mAdapter != null && ((HeaderViewListAdapter) mAdapter).removeFooter(v)) {
                if (mDataSetObserver != null) {
                    mDataSetObserver.onChanged();
                }
                result = true;
            }
            removeFixedViewInfo(v, mFooterViewInfos);
            return result;
        }
        return false;
    }

    /**
     * Returns the adapter currently in use in this ListView. The returned adapter might not be the same adapter passed to
     * {@link #setAdapter(ListAdapter)} but might be a {@link WrapperListAdapter}.
     *
     * @return The adapter currently used to display data in this ListView.
     *
     * @see #setAdapter(ListAdapter)
     */
    @Override
    public ListAdapter getAdapter() {
        return mAdapter;
    }

    /**
     * Sets the data behind this ListView.
     *
     * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, depending on the ListView features currently
     * in use. For instance, adding headers and/or footers will cause the adapter to be wrapped.
     *
     * @param adapter
     *           The ListAdapter which is responsible for maintaining the data backing this list and for producing a view to
     *           represent an item in that data set.
     *
     * @see #getAdapter()
     */
    @Override
    public void setAdapter(ListAdapter adapter) {
        if (mAdapter != null && mDataSetObserver != null) {
            mAdapter.unregisterDataSetObserver(mDataSetObserver);
        }

        resetList();
        mRecycler.clear();

        if (mHeaderViewInfos.size() > 0 || mFooterViewInfos.size() > 0) {
            mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter);
        } else {
            mAdapter = adapter;
        }

        mOldSelectedPosition = INVALID_POSITION;
        mOldSelectedColId = INVALID_COL_ID;

        // AbsListView#setAdapter will update choice mode states.
        super.setAdapter(adapter);

        if (mAdapter != null) {
            mAreAllItemsSelectable = mAdapter.areAllItemsEnabled();
            mOldItemCount = mItemCount;
            mItemCount = mAdapter.getCount();
            checkFocus();

            mDataSetObserver = new AdapterDataSetObserver();
            mAdapter.registerDataSetObserver(mDataSetObserver);

            mRecycler.setViewTypeCount(mAdapter.getViewTypeCount());

            int position;
            if (mStackFromRight) {
                position = lookForSelectablePosition(mItemCount - 1, false);
            } else {
                position = lookForSelectablePosition(0, true);
            }
            setSelectedPositionInt(position);
            setNextSelectedPositionInt(position);

            if (mItemCount == 0) {
                // Nothing selected
                checkSelectionChanged();
            }
        } else {
            mAreAllItemsSelectable = true;
            checkFocus();
            // Nothing selected
            checkSelectionChanged();
        }

        requestLayout();
    }

    /**
     * The list is empty. Clear everything out.
     */
    @Override
    protected void resetList() {
        // The parent's resetList() will remove all views from the layout so we need to
        // cleanup the state of our footers and headers
        clearRecycledState(mHeaderViewInfos);
        clearRecycledState(mFooterViewInfos);

        super.resetList();

        mLayoutMode = LAYOUT_NORMAL;
    }

    private void clearRecycledState(ArrayList<FixedViewInfo> infos) {
        if (infos != null) {
            final int count = infos.size();

            for (int i = 0; i < count; i++) {
                final View child = infos.get(i).view;
                final LayoutParams p = (LayoutParams) child.getLayoutParams();
                if (p != null) {
                    p.recycledHeaderFooter = false;
                }
            }
        }
    }

    /**
     * @return Whether the list needs to show the top fading edge
     */
    private boolean showingLeftFadingEdge() {
        final int listLeft = getScrollX() + mListPadding.left;
        return (mFirstPosition > 0) || (getChildAt(0).getLeft() > listLeft);
    }

    /**
     * @return Whether the list needs to show the bottom fading edge
     */
    private boolean showingRightFadingEdge() {
        final int childCount = getChildCount();
        final int rightOfRightChild = getChildAt(childCount - 1).getRight();
        final int lastVisiblePosition = mFirstPosition + childCount - 1;

        final int listRight = getScrollX() + getWidth() - mListPadding.right;

        return (lastVisiblePosition < mItemCount - 1) || (rightOfRightChild < listRight);
    }

    @Override
    public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) {

        int rectLeftWithinChild = rect.left;

        // offset so rect is in coordinates of the this view
        rect.offset(child.getLeft(), child.getTop());
        rect.offset(-child.getScrollX(), -child.getScrollY());

        final int width = getWidth();
        int listUnfadedLeft = getScrollX();
        int listUnfadedRight = listUnfadedLeft + width;
        final int fadingEdge = getHorizontalFadingEdgeLength();

        if (showingLeftFadingEdge()) {
            // leave room for top fading edge as long as rect isn't at very top
            if ((mSelectedPosition > 0) || (rectLeftWithinChild > fadingEdge)) {
                listUnfadedLeft += fadingEdge;
            }
        }

        int childCount = getChildCount();
        int rightOfRightChild = getChildAt(childCount - 1).getRight();

        if (showingRightFadingEdge()) {
            // leave room for bottom fading edge as long as rect isn't at very bottom
            if ((mSelectedPosition < mItemCount - 1) || (rect.right < (rightOfRightChild - fadingEdge))) {
                listUnfadedRight -= fadingEdge;
            }
        }

        int scrollXDelta = 0;

        if (rect.right > listUnfadedRight && rect.left > listUnfadedLeft) {
            // need to MOVE DOWN to get it in view: move down just enough so
            // that the entire rectangle is in view (or at least the first
            // screen size chunk).

            if (rect.width() > width) {
                // just enough to get screen size chunk on
                scrollXDelta += (rect.left - listUnfadedLeft);
            } else {
                // get entire rect at bottom of screen
                scrollXDelta += (rect.right - listUnfadedRight);
            }

            // make sure we aren't scrolling beyond the end of our children
            int distanceToRight = rightOfRightChild - listUnfadedRight;
            scrollXDelta = Math.min(scrollXDelta, distanceToRight);
        } else if (rect.left < listUnfadedLeft && rect.right < listUnfadedRight) {
            // need to MOVE UP to get it in view: move up just enough so that
            // entire rectangle is in view (or at least the first screen
            // size chunk of it).

            if (rect.width() > width) {
                // screen size chunk
                scrollXDelta -= (listUnfadedRight - rect.right);
            } else {
                // entire rect at top
                scrollXDelta -= (listUnfadedLeft - rect.left);
            }

            // make sure we aren't scrolling any further than the top our children
            int left = getChildAt(0).getLeft();
            int deltaToLeft = left - listUnfadedLeft;
            scrollXDelta = Math.max(scrollXDelta, deltaToLeft);
        }

        final boolean scroll = scrollXDelta != 0;
        if (scroll) {
            scrollListItemsBy(-scrollXDelta);
            positionSelector(INVALID_POSITION, child);
            mSelectedLeft = child.getTop();
            invalidate();
        }
        return scroll;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void fillGap(boolean down) {
        final int count = getChildCount();
        if (down) {
            int paddingLeft = 0;
            // if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK ) {
            // paddingTop = getListPaddingTop();
            // }
            final int startOffset = count > 0 ? getChildAt(count - 1).getRight() + mDividerWidth : paddingLeft;
            fillRight(mFirstPosition + count, startOffset);
            correctTooWide(getChildCount());
        } else {
            int paddingRight = 0;
            // if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK ) {
            // paddingBottom = getListPaddingBottom();
            // }
            final int startOffset = count > 0 ? getChildAt(0).getLeft() - mDividerWidth : getWidth() - paddingRight;
            fillLeft(mFirstPosition - 1, startOffset);
            correctTooSmall(getChildCount());
        }
    }

    /**
     * Fills the list from pos down to the end of the list view.
     *
     * @param pos
     *           The first position to put in the list
     *
     * @param nextLeft
     *           The location where the left of the item associated with pos should be drawn
     *
     * @return The view that is currently selected, if it happens to be in the range that we draw.
     */
    private View fillRight(int pos, int nextLeft) {
        View selectedView = null;

        int end = (getRight() - getLeft());
        // if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK ) {
        // end -= mListPadding.bottom;
        // }

        while (nextLeft < end && pos < mItemCount) {
            // is this the selected item?
            boolean selected = pos == mSelectedPosition;
            View child = makeAndAddView(pos, nextLeft, true, mListPadding.top, selected);

            nextLeft = child.getRight() + mDividerWidth;
            if (selected) {
                selectedView = child;
            }
            pos++;
        }

        setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1);
        return selectedView;
    }

    /**
     * Fills the list from pos up to the top of the list view.
     *
     * @param pos
     *           The first position to put in the list
     *
     * @param nextRight
     *           The location where the right of the item associated with pos should be drawn
     *
     * @return The view that is currently selected
     */
    private View fillLeft(int pos, int nextRight) {
        View selectedView = null;

        int end = 0;
        // if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK ) {
        // end = mListPadding.top;
        // }

        while (nextRight > end && pos >= 0) {
            // is this the selected item?
            boolean selected = pos == mSelectedPosition;
            View child = makeAndAddView(pos, nextRight, false, mListPadding.top, selected);
            nextRight = child.getLeft() - mDividerWidth;
            if (selected) {
                selectedView = child;
            }
            pos--;
        }

        mFirstPosition = pos + 1;
        setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1);
        return selectedView;
    }

    /**
     * Fills the list from top to bottom, starting with mFirstPosition
     *
     * @param nextLeft
     *           The location where the left of the first item should be drawn
     *
     * @return The view that is currently selected
     */
    private View fillFromLeft(int nextLeft) {
        mFirstPosition = Math.min(mFirstPosition, mSelectedPosition);
        mFirstPosition = Math.min(mFirstPosition, mItemCount - 1);
        if (mFirstPosition < 0) {
            mFirstPosition = 0;
        }
        return fillRight(mFirstPosition, nextLeft);
    }

    /**
     * Put mSelectedPosition in the middle of the screen and then build up and down from there. This method forces mSelectedPosition
     * to the center.
     *
     * @param childrenLeft
     *           Left of the area in which children can be drawn, as measured in pixels
     * @param childrenRight
     *           Right of the area in which children can be drawn, as measured in pixels
     * @return Currently selected view
     */
    private View fillFromMiddle(int childrenLeft, int childrenRight) {
        int width = childrenRight - childrenLeft;

        int position = reconcileSelectedPosition();

        View sel = makeAndAddView(position, childrenLeft, true, mListPadding.top, true);
        mFirstPosition = position;

        int selWidth = sel.getMeasuredWidth();
        if (selWidth <= width) {
            sel.offsetLeftAndRight((width - selWidth) / 2);
        }

        fillBeforeAndAfter(sel, position);

        if (!mStackFromRight) {
            correctTooWide(getChildCount());
        } else {
            correctTooSmall(getChildCount());
        }

        return sel;
    }

    /**
     * Once the selected view as been placed, fill up the visible area above and below it.
     *
     * @param sel
     *           The selected view
     * @param position
     *           The position corresponding to sel
     */
    private void fillBeforeAndAfter(View sel, int position) {
        final int dividerWidth = mDividerWidth;
        if (!mStackFromRight) {
            fillLeft(position - 1, sel.getLeft() - dividerWidth);
            adjustViewsLeftOrRight();
            fillRight(position + 1, sel.getRight() + dividerWidth);
        } else {
            fillRight(position + 1, sel.getRight() + dividerWidth);
            adjustViewsLeftOrRight();
            fillLeft(position - 1, sel.getLeft() - dividerWidth);
        }
    }

    /**
     * Fills the grid based on positioning the new selection at a specific location. The selection may be moved so that it does not
     * intersect the faded edges. The grid is then filled upwards and downwards from there.
     *
     * @param selectedLeft
     *           Where the selected item should be
     * @param childrenLeft
     *           Where to start drawing children
     * @param childrenRight
     *           Last pixel where children can be drawn
     * @return The view that currently has selection
     */
    private View fillFromSelection(int selectedLeft, int childrenLeft, int childrenRight) {
        int fadingEdgeLength = getHorizontalFadingEdgeLength();
        final int selectedPosition = mSelectedPosition;

        View sel;

        final int leftSelectionPixel = getLeftSelectionPixel(childrenLeft, fadingEdgeLength, selectedPosition);
        final int rightSelectionPixel = getRightSelectionPixel(childrenRight, fadingEdgeLength, selectedPosition);

        sel = makeAndAddView(selectedPosition, selectedLeft, true, mListPadding.top, true);

        // Some of the newly selected item extends below the bottom of the list
        if (sel.getRight() > rightSelectionPixel) {
            // Find space available above the selection into which we can scroll
            // upwards
            final int spaceBefore = sel.getLeft() - leftSelectionPixel;

            // Find space required to bring the bottom of the selected item
            // fully into view
            final int spaceAfter = sel.getRight() - rightSelectionPixel;
            final int offset = Math.min(spaceBefore, spaceAfter);

            // Now offset the selected item to get it into view
            sel.offsetLeftAndRight(-offset);
        } else if (sel.getLeft() < leftSelectionPixel) {
            // Find space required to bring the top of the selected item fully
            // into view
            final int spaceBefore = leftSelectionPixel - sel.getLeft();

            // Find space available below the selection into which we can scroll
            // downwards
            final int spaceAfter = rightSelectionPixel - sel.getRight();
            final int offset = Math.min(spaceBefore, spaceAfter);

            // Offset the selected item to get it into view
            sel.offsetLeftAndRight(offset);
        }

        // Fill in views above and below
        fillBeforeAndAfter(sel, selectedPosition);

        if (!mStackFromRight) {
            correctTooWide(getChildCount());
        } else {
            correctTooSmall(getChildCount());
        }

        return sel;
    }

    /**
     * Calculate the bottom-most pixel we can draw the selection into
     *
     * @param childrenRight
     *           Right pixel were children can be drawn
     * @param fadingEdgeLength
     *           Length of the fading edge in pixels, if present
     * @param selectedPosition
     *           The position that will be selected
     * @return The bottom-most pixel we can draw the selection into
     */
    private int getRightSelectionPixel(int childrenRight, int fadingEdgeLength, int selectedPosition) {
        int rightSelectionPixel = childrenRight;
        if (selectedPosition != mItemCount - 1) {
            rightSelectionPixel -= fadingEdgeLength;
        }
        return rightSelectionPixel;
    }

    /**
     * Calculate the left-most pixel we can draw the selection into
     *
     * @param childrenLeft
     *           Left pixel were children can be drawn
     * @param fadingEdgeLength
     *           Length of the fading edge in pixels, if present
     * @param selectedPosition
     *           The position that will be selected
     * @return The left-most pixel we can draw the selection into
     */
    private int getLeftSelectionPixel(int childrenLeft, int fadingEdgeLength, int selectedPosition) {
        // first pixel we can draw the selection into
        int leftSelectionPixel = childrenLeft;
        if (selectedPosition > 0) {
            leftSelectionPixel += fadingEdgeLength;
        }
        return leftSelectionPixel;
    }

    /**
     * Smoothly scroll to the specified adapter position. The view will scroll such that the indicated position is displayed.
     *
     * @param position
     *           Scroll to this adapter position.
     */
    @Override
    public void smoothScrollToPosition(int position) {
        super.smoothScrollToPosition(position);
    }

    /**
     * Smoothly scroll to the specified adapter position offset. The view will scroll such that the indicated position is displayed.
     *
     * @param offset
     *           The amount to offset from the adapter position to scroll to.
     */
    @Override
    public void smoothScrollByOffset(int offset) {
        super.smoothScrollByOffset(offset);
    }

    /**
     * Fills the list based on positioning the new selection relative to the old selection. The new selection will be placed at,
     * above, or below the location of the new selection depending on how the selection is moving. The selection will then be pinned
     * to the visible part of the screen, excluding the edges that are faded. The list is then filled upwards and downwards from
     * there.
     *
     * @param oldSel
     *           The old selected view. Useful for trying to put the new selection in the same place
     * @param newSel
     *           The view that is to become selected. Useful for trying to put the new selection in the same place
     * @param delta
     *           Which way we are moving
     * @param childrenLeft
     *           Where to start drawing children
     * @param childrenRight
     *           Last pixel where children can be drawn
     * @return The view that currently has selection
     */
    private View moveSelection(View oldSel, View newSel, int delta, int childrenLeft, int childrenRight) {
        int fadingEdgeLength = getHorizontalFadingEdgeLength();
        final int selectedPosition = mSelectedPosition;

        View sel;

        final int leftSelectionPixel = getLeftSelectionPixel(childrenLeft, fadingEdgeLength, selectedPosition);
        final int rightSelectionPixel = getRightSelectionPixel(childrenLeft, fadingEdgeLength, selectedPosition);

        if (delta > 0) {
            /*
             * Case 1: Scrolling down.
             */

            /*
             * Before After | | | | +-------+ +-------+ | A | | A | | 1 | => +-------+ +-------+ | B | | B | | 2 | +-------+ +-------+
             * | | | |
             *
             * Try to keep the top of the previously selected item where it was. oldSel = A sel = B
             */

            // Put oldSel (A) where it belongs
            oldSel = makeAndAddView(selectedPosition - 1, oldSel.getLeft(), true, mListPadding.top, false);

            final int dividerWidth = mDividerWidth;

            // Now put the new selection (B) below that
            sel = makeAndAddView(selectedPosition, oldSel.getRight() + dividerWidth, true, mListPadding.top, true);

            // Some of the newly selected item extends below the bottom of the list
            if (sel.getRight() > rightSelectionPixel) {

                // Find space available above the selection into which we can scroll upwards
                int spaceBefore = sel.getLeft() - leftSelectionPixel;

                // Find space required to bring the bottom of the selected item fully into view
                int spaceAfter = sel.getRight() - rightSelectionPixel;

                // Don't scroll more than half the height of the list
                int halfHorizontalSpace = (childrenRight - childrenLeft) / 2;
                int offset = Math.min(spaceBefore, spaceAfter);
                offset = Math.min(offset, halfHorizontalSpace);

                // We placed oldSel, so offset that item
                oldSel.offsetLeftAndRight(-offset);
                // Now offset the selected item to get it into view
                sel.offsetLeftAndRight(-offset);
            }

            // Fill in views above and below
            if (!mStackFromRight) {
                fillLeft(mSelectedPosition - 2, sel.getLeft() - dividerWidth);
                adjustViewsLeftOrRight();
                fillRight(mSelectedPosition + 1, sel.getRight() + dividerWidth);
            } else {
                fillRight(mSelectedPosition + 1, sel.getRight() + dividerWidth);
                adjustViewsLeftOrRight();
                fillLeft(mSelectedPosition - 2, sel.getLeft() - dividerWidth);
            }
        } else if (delta < 0) {
            /*
             * Case 2: Scrolling up.
             */

            /*
             * Before After | | | | +-------+ +-------+ | A | | A | +-------+ => | 1 | | B | +-------+ | 2 | | B | +-------+ +-------+
             * | | | |
             *
             * Try to keep the top of the item about to become selected where it was. newSel = A olSel = B
             */

            if (newSel != null) {
                // Try to position the top of newSel (A) where it was before it was selected
                sel = makeAndAddView(selectedPosition, newSel.getLeft(), true, mListPadding.top, true);
            } else {
                // If (A) was not on screen and so did not have a view, position
                // it above the oldSel (B)
                sel = makeAndAddView(selectedPosition, oldSel.getLeft(), false, mListPadding.top, true);
            }

            // Some of the newly selected item extends above the top of the list
            if (sel.getLeft() < leftSelectionPixel) {
                // Find space required to bring the top of the selected item fully into view
                int spaceBefore = leftSelectionPixel - sel.getLeft();

                // Find space available below the selection into which we can scroll downwards
                int spaceAfter = rightSelectionPixel - sel.getRight();

                // Don't scroll more than half the height of the list
                int halfHorizontalSpace = (childrenRight - childrenLeft) / 2;
                int offset = Math.min(spaceBefore, spaceAfter);
                offset = Math.min(offset, halfHorizontalSpace);

                // Offset the selected item to get it into view
                sel.offsetLeftAndRight(offset);
            }

            // Fill in views above and below
            fillBeforeAndAfter(sel, selectedPosition);
        } else {

            int oldLeft = oldSel.getLeft();

            /*
             * Case 3: Staying still
             */
            sel = makeAndAddView(selectedPosition, oldLeft, true, mListPadding.top, true);

            // We're staying still...
            if (oldLeft < childrenLeft) {
                // ... but the top of the old selection was off screen.
                // (This can happen if the data changes size out from under us)
                int newRight = sel.getRight();
                if (newRight < childrenLeft + 20) {
                    // Not enough visible -- bring it onscreen
                    sel.offsetLeftAndRight(childrenLeft - sel.getLeft());
                }
            }

            // Fill in views above and below
            fillBeforeAndAfter(sel, selectedPosition);
        }

        return sel;
    }

    private class FocusSelector implements Runnable {

        private int mPosition;
        private int mPositionLeft;

        public FocusSelector setup(int position, int left) {
            mPosition = position;
            mPositionLeft = left;
            return this;
        }

        @Override
        public void run() {
            setSelectionFromLeft(mPosition, mPositionLeft);
        }
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        if (getChildCount() > 0) {
            View focusedChild = getFocusedChild();
            if (focusedChild != null) {
                final int childPosition = mFirstPosition + indexOfChild(focusedChild);
                final int childRight = focusedChild.getRight();
                final int offset = Math.max(0, childRight - (w - getPaddingLeft()));
                final int left = focusedChild.getLeft() - offset;
                if (mFocusSelector == null) {
                    mFocusSelector = new FocusSelector();
                }
                post(mFocusSelector.setup(childPosition, left));
            }
        }
        super.onSizeChanged(w, h, oldw, oldh);
    }

    @TargetApi(11)
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // Sets up mListPadding
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        int widthMode = View.MeasureSpec.getMode(widthMeasureSpec);
        int heightMode = View.MeasureSpec.getMode(heightMeasureSpec);
        int widthSize = View.MeasureSpec.getSize(widthMeasureSpec);
        int heightSize = View.MeasureSpec.getSize(heightMeasureSpec);

        int childWidth = 0;
        int childHeight = 0;
        int childState = 0;

        mItemCount = mAdapter == null ? 0 : mAdapter.getCount();

        if (mItemCount > 0
                && (widthMode == View.MeasureSpec.UNSPECIFIED || heightMode == View.MeasureSpec.UNSPECIFIED)) {
            if (LOG_ENABLED) {
                Log.d(LOG_TAG, "let's measure a scrap child");
            }

            final View child = obtainView(0, mIsScrap);

            measureScrapChildWidth(child, 0, heightMeasureSpec);

            childWidth = child.getMeasuredWidth();
            childHeight = child.getMeasuredHeight();

            if (android.os.Build.VERSION.SDK_INT >= 11) {
                childState = combineMeasuredStates(childState, child.getMeasuredState());
            }

            if (recycleOnMeasure()
                    && mRecycler.shouldRecycleViewType(((LayoutParams) child.getLayoutParams()).viewType)) {
                mRecycler.addScrapView(child, -1);
            }
        }

        if (heightMode == View.MeasureSpec.UNSPECIFIED) {
            heightSize = mListPadding.top + mListPadding.bottom + childHeight + getHorizontalScrollbarHeight();
        } else if (heightMode == View.MeasureSpec.AT_MOST && mItemCount > 0 && mMeasureWithChild > -1) {

            // TODO: need a better way in case of "wrap_content"
            int[] result = measureWithLargeChildren(heightMeasureSpec, mMeasureWithChild, mMeasureWithChild,
                    widthSize, heightSize, -1);
            heightSize = result[1];

        } else { // match_parent, dimension
            if (android.os.Build.VERSION.SDK_INT >= 11) {
                heightSize |= (childState & MEASURED_STATE_MASK);
            }
        }

        if (widthMode == View.MeasureSpec.UNSPECIFIED) {
            widthSize = mListPadding.left + mListPadding.right + childWidth + getHorizontalFadingEdgeLength() * 2;
        }

        if (widthMode == View.MeasureSpec.AT_MOST) {
            widthSize = measureWidthOfChildren(heightMeasureSpec, 0, NO_POSITION, widthSize, -1);
        }

        if (LOG_ENABLED) {
            Log.d(LOG_TAG, "final size: " + widthSize + "x" + heightSize);
        }

        setMeasuredDimension(widthSize, heightSize);
        mHeightMeasureSpec = heightMeasureSpec;
    }

    private void measureScrapChildWidth(View child, int position, int heightMeasureSpec) {
        LayoutParams p = (LayoutParams) child.getLayoutParams();
        if (p == null) {
            p = (AbsHListView.LayoutParams) generateDefaultLayoutParams();
            child.setLayoutParams(p);
        }
        p.viewType = mAdapter.getItemViewType(position);
        p.forceAdd = true;

        int childHeightSpec = ViewGroup.getChildMeasureSpec(heightMeasureSpec,
                mListPadding.top + mListPadding.bottom, p.height);
        int lpWidth = p.width;
        int childWidthSpec;
        if (lpWidth > 0) {
            childWidthSpec = View.MeasureSpec.makeMeasureSpec(lpWidth, View.MeasureSpec.EXACTLY);
        } else {
            childWidthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        }
        child.measure(childWidthSpec, childHeightSpec);
    }

    public int[] measureChild(View child) {
        measureItem(child);

        int w = child.getMeasuredWidth();
        int h = child.getMeasuredHeight();

        return new int[] { w, h };
    }

    /**
     * @return True to recycle the views used to measure this ListView in UNSPECIFIED/AT_MOST modes, false otherwise.
     * @hide
     */
    @ViewDebug.ExportedProperty(category = "list")
    protected boolean recycleOnMeasure() {
        return true;
    }

    /**
     * Measures the height of the given range of children (inclusive) and returns the height with this ListView's padding and divider
     * heights included. If maxHeight is provided, the measuring will stop when the current height reaches maxHeight.
     *
     * @param heightMeasureSpec
     *           The height measure spec to be given to a child's {@link View#measure(int, int)}.
     * @param startPosition
     *           The position of the first child to be shown.
     * @param endPosition
     *           The (inclusive) position of the last child to be shown. Specify {@link #NO_POSITION} if the last child should be the
     *           last available child from the adapter.
     * @param maxWidth
     *           The maximum height that will be returned (if all the children don't fit in this value, this value will be returned).
     * @param disallowPartialChildPosition
     *           In general, whether the returned height should only contain entire children. This is more powerful--it is the first
     *           inclusive position at which partial children will not be allowed. Example: it looks nice to have at least 3
     *           completely visible children, and in portrait this will most likely fit; but in landscape there could be times when
     *           even 2 children can not be completely shown, so a value of 2 (remember, inclusive) would be good (assuming
     *           startPosition is 0).
     * @return The height of this ListView with the given children.
     */
    final int measureWidthOfChildren(int heightMeasureSpec, int startPosition, int endPosition, final int maxWidth,
            int disallowPartialChildPosition) {
        if (LOG_ENABLED) {
            Log.i(LOG_TAG, "measureWidthOfChildren, from " + startPosition + " to " + endPosition);
        }

        final ListAdapter adapter = mAdapter;
        if (adapter == null) {
            return mListPadding.left + mListPadding.right;
        }

        // Include the padding of the list
        int returnedWidth = mListPadding.left + mListPadding.right;
        final int dividerWidth = ((mDividerWidth > 0) && mDivider != null) ? mDividerWidth : 0;
        // The previous height value that was less than maxHeight and contained
        // no partial children
        int prevWidthWithoutPartialChild = 0;
        int i;
        View child;

        // mItemCount - 1 since endPosition parameter is inclusive
        endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition;
        final AbsHListView.RecycleBin recycleBin = mRecycler;
        final boolean recyle = recycleOnMeasure();
        final boolean[] isScrap = mIsScrap;

        for (i = startPosition; i <= endPosition; ++i) {
            child = obtainView(i, isScrap);

            measureScrapChildWidth(child, i, heightMeasureSpec);

            if (i > 0) {
                // Count the divider for all but one child
                returnedWidth += dividerWidth;
            }

            // Recycle the view before we possibly return from the method
            if (recyle && recycleBin.shouldRecycleViewType(((LayoutParams) child.getLayoutParams()).viewType)) {
                recycleBin.addScrapView(child, -1);
            }

            returnedWidth += child.getMeasuredWidth();

            if (returnedWidth >= maxWidth) {
                // We went over, figure out which height to return. If returnedHeight > maxHeight,
                // then the i'th position did not fit completely.
                return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1)
                        && (i > disallowPartialChildPosition) // We've past the min pos
                        && (prevWidthWithoutPartialChild > 0) // We have a prev height
                        && (returnedWidth != maxWidth) // i'th child did not fit completely
                                ? prevWidthWithoutPartialChild
                                : maxWidth;
            }

            if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) {
                prevWidthWithoutPartialChild = returnedWidth;
            }
        }

        // At this point, we went through the range of children, and they each
        // completely fit, so return the returnedHeight
        return returnedWidth;
    }

    final int[] measureWithLargeChildren(int heightMeasureSpec, int startPosition, int endPosition,
            final int maxWidth, final int maxHeight, int disallowPartialChildPosition) {
        if (LOG_ENABLED) {
            Log.i(LOG_TAG, "measureWithLargeChildren, from " + startPosition + " to " + endPosition);
        }

        final ListAdapter adapter = mAdapter;
        if (adapter == null) {
            return new int[] { mListPadding.left + mListPadding.right, mListPadding.top + mListPadding.bottom };
        }

        // Include the padding of the list
        int returnedWidth = mListPadding.left + mListPadding.right;
        int returnedHeight = mListPadding.top + mListPadding.bottom;

        final int dividerWidth = ((mDividerWidth > 0) && mDivider != null) ? mDividerWidth : 0;

        int childWidth = 0;
        int childHeight = 0;

        int i;
        View child;

        // mItemCount - 1 since endPosition parameter is inclusive
        endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition;
        final AbsHListView.RecycleBin recycleBin = mRecycler;
        final boolean recyle = recycleOnMeasure();
        final boolean[] isScrap = mIsScrap;

        for (i = startPosition; i <= endPosition; ++i) {
            child = obtainView(i, isScrap);

            measureScrapChildWidth(child, i, heightMeasureSpec);

            // Recycle the view before we possibly return from the method
            if (recyle && recycleBin.shouldRecycleViewType(((LayoutParams) child.getLayoutParams()).viewType)) {
                recycleBin.addScrapView(child, -1);
            }

            childWidth = Math.max(childWidth, child.getMeasuredWidth() + dividerWidth);
            childHeight = Math.max(childHeight, child.getMeasuredHeight());
        }

        returnedWidth += childWidth;
        returnedHeight += childHeight;

        return new int[] { Math.min(returnedWidth, maxWidth), Math.min(returnedHeight, maxHeight) };
    }

    @Override
    protected int findMotionCol(int x) {
        int childCount = getChildCount();
        if (childCount > 0) {
            if (!mStackFromRight) {
                for (int i = 0; i < childCount; i++) {
                    View v = getChildAt(i);
                    if (x <= v.getRight()) {
                        return mFirstPosition + i;
                    }
                }
            } else {
                for (int i = childCount - 1; i >= 0; i--) {
                    View v = getChildAt(i);
                    if (x >= v.getLeft()) {
                        return mFirstPosition + i;
                    }
                }
            }
        }
        return INVALID_POSITION;
    }

    /**
     * Put a specific item at a specific location on the screen and then build up and down from there.
     *
     * @param position
     *           The reference view to use as the starting point
     * @param left
     *           Pixel offset from the left of this view to the top of the reference view.
     *
     * @return The selected view, or null if the selected view is outside the visible area.
     */
    private View fillSpecific(int position, int left) {
        boolean tempIsSelected = position == mSelectedPosition;
        View temp = makeAndAddView(position, left, true, mListPadding.top, tempIsSelected);
        // Possibly changed again in fillUp if we add rows above this one.
        mFirstPosition = position;

        View before;
        View after;

        final int dividerWidth = mDividerWidth;
        if (!mStackFromRight) {
            before = fillLeft(position - 1, temp.getLeft() - dividerWidth);
            // This will correct for the top of the first view not touching the top of the list
            adjustViewsLeftOrRight();
            after = fillRight(position + 1, temp.getRight() + dividerWidth);
            int childCount = getChildCount();
            if (childCount > 0) {
                correctTooWide(childCount);
            }
        } else {
            after = fillRight(position + 1, temp.getRight() + dividerWidth);
            // This will correct for the bottom of the last view not touching the bottom of the list
            adjustViewsLeftOrRight();
            before = fillLeft(position - 1, temp.getLeft() - dividerWidth);
            int childCount = getChildCount();
            if (childCount > 0) {
                correctTooSmall(childCount);
            }
        }

        if (tempIsSelected) {
            return temp;
        } else if (before != null) {
            return before;
        } else {
            return after;
        }
    }

    /**
     * Check if we have dragged the right of the list too wide (we have pushed the left element off the left of the screen when we did
     * not need to). Correct by sliding everything back down.
     *
     * @param childCount
     *           Number of children
     */
    private void correctTooWide(int childCount) {
        // First see if the last item is visible. If it is not, it is OK for the
        // top of the list to be pushed up.
        int lastPosition = mFirstPosition + childCount - 1;
        if (lastPosition == mItemCount - 1 && childCount > 0) {

            // Get the last child ...
            final View lastChild = getChildAt(childCount - 1);

            // ... and its bottom edge
            final int lastRight = lastChild.getRight();

            // This is bottom of our drawable area
            final int end = (getRight() - getLeft()) - mListPadding.right;

            // This is how far the bottom edge of the last view is from the bottom of the
            // drawable area
            int rightOffset = end - lastRight;
            View firstChild = getChildAt(0);
            final int firstLeft = firstChild.getLeft();

            // Make sure we are 1) Too high, and 2) Either there are more rows above the
            // first row or the first row is scrolled off the top of the drawable area
            if (rightOffset > 0 && (mFirstPosition > 0 || firstLeft < mListPadding.top)) {
                if (mFirstPosition == 0) {
                    // Don't pull the top too far down
                    rightOffset = Math.min(rightOffset, mListPadding.top - firstLeft);
                }
                // Move everything down
                offsetChildrenLeftAndRight(rightOffset);
                if (mFirstPosition > 0) {
                    // Fill the gap that was opened above mFirstPosition with more rows, if
                    // possible
                    fillLeft(mFirstPosition - 1, firstChild.getLeft() - mDividerWidth);
                    // Close up the remaining gap
                    adjustViewsLeftOrRight();
                }

            }
        }
    }

    /**
     * Check if we have dragged the right of the list too low (we have pushed the right element off the right of the screen when
     * we did not need to). Correct by sliding everything back up.
     *
     * @param childCount
     *           Number of children
     */
    private void correctTooSmall(int childCount) {
        // First see if the first item is visible. If it is not, it is OK for the
        // bottom of the list to be pushed down.
        if (mFirstPosition == 0 && childCount > 0) {

            // Get the first child ...
            final View firstChild = getChildAt(0);

            // ... and its top edge
            final int firstLeft = firstChild.getLeft();

            // This is top of our drawable area
            final int start = mListPadding.left;

            // This is bottom of our drawable area
            final int end = (getRight() - getLeft()) - mListPadding.right;

            // This is how far the top edge of the first view is from the top of the
            // drawable area
            int leftOffset = firstLeft - start;
            View lastChild = getChildAt(childCount - 1);
            final int lastRight = lastChild.getRight();
            int lastPosition = mFirstPosition + childCount - 1;

            // Make sure we are 1) Too low, and 2) Either there are more rows below the
            // last row or the last row is scrolled off the bottom of the drawable area
            if (leftOffset > 0) {
                if (lastPosition < mItemCount - 1 || lastRight > end) {
                    if (lastPosition == mItemCount - 1) {
                        // Don't pull the bottom too far up
                        leftOffset = Math.min(leftOffset, lastRight - end);
                    }
                    // Move everything up
                    offsetChildrenLeftAndRight(-leftOffset);
                    if (lastPosition < mItemCount - 1) {
                        // Fill the gap that was opened below the last position with more rows, if
                        // possible
                        fillRight(lastPosition + 1, lastChild.getRight() + mDividerWidth);
                        // Close up the remaining gap
                        adjustViewsLeftOrRight();
                    }
                } else if (lastPosition == mItemCount - 1) {
                    adjustViewsLeftOrRight();
                }
            }
        }
    }

    @Override
    protected void layoutChildren() {
        final boolean blockLayoutRequests = mBlockLayoutRequests;
        if (!blockLayoutRequests) {
            mBlockLayoutRequests = true;
        } else {
            return;
        }

        try {
            super.layoutChildren();

            invalidate();

            if (mAdapter == null) {
                resetList();
                invokeOnItemScrollListener();
                return;
            }

            int childrenLeft = mListPadding.left;
            int childrenRight = getRight() - getLeft() - mListPadding.right;

            int childCount = getChildCount();
            int index = 0;
            int delta = 0;

            View sel;
            View oldSel = null;
            View oldFirst = null;
            View newSel = null;

            View focusLayoutRestoreView = null;

            // AccessibilityNodeInfo accessibilityFocusLayoutRestoreNode = null;
            // View accessibilityFocusLayoutRestoreView = null;
            // int accessibilityFocusPosition = INVALID_POSITION;

            // Remember stuff we will need down below
            switch (mLayoutMode) {
            case LAYOUT_SET_SELECTION:
                index = mNextSelectedPosition - mFirstPosition;
                if (index >= 0 && index < childCount) {
                    newSel = getChildAt(index);
                }
                break;
            case LAYOUT_FORCE_LEFT:
            case LAYOUT_FORCE_RIGHT:
            case LAYOUT_SPECIFIC:
            case LAYOUT_SYNC:
                break;
            case LAYOUT_MOVE_SELECTION:
            default:
                // Remember the previously selected view
                index = mSelectedPosition - mFirstPosition;
                if (index >= 0 && index < childCount) {
                    oldSel = getChildAt(index);
                }

                // Remember the previous first child
                oldFirst = getChildAt(0);

                if (mNextSelectedPosition >= 0) {
                    delta = mNextSelectedPosition - mSelectedPosition;
                }

                // Caution: newSel might be null
                newSel = getChildAt(index + delta);
            }

            boolean dataChanged = mDataChanged;
            if (dataChanged) {
                handleDataChanged();
            }

            // Handle the empty set by removing all views that are visible
            // and calling it a day
            if (mItemCount == 0) {
                resetList();
                invokeOnItemScrollListener();
                return;
            } else if (mItemCount != mAdapter.getCount()) {
                throw new IllegalStateException("The content of the adapter has changed but "
                        + "ListView did not receive a notification. Make sure the content of "
                        + "your adapter is not modified from a background thread, but only "
                        + "from the UI thread. [in ListView(" + getId() + ", " + getClass() + ") with Adapter("
                        + mAdapter.getClass() + ")]");
            }

            setSelectedPositionInt(mNextSelectedPosition);

            // Pull all children into the RecycleBin.
            // These views will be reused if possible
            final int firstPosition = mFirstPosition;
            final RecycleBin recycleBin = mRecycler;

            // reset the focus restoration
            View focusLayoutRestoreDirectChild = null;

            // Don't put header or footer views into the Recycler. Those are
            // already cached in mHeaderViews;
            if (dataChanged) {
                for (int i = 0; i < childCount; i++) {
                    recycleBin.addScrapView(getChildAt(i), firstPosition + i);
                }
            } else {
                recycleBin.fillActiveViews(childCount, firstPosition);
            }

            // take focus back to us temporarily to avoid the eventual
            // call to clear focus when removing the focused child below
            // from messing things up when ViewAncestor assigns focus back
            // to someone else
            final View focusedChild = getFocusedChild();
            if (focusedChild != null) {
                // TODO: in some cases focusedChild.getParent() == null

                // we can remember the focused view to restore after relayout if the
                // data hasn't changed, or if the focused position is a header or footer
                if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) {
                    focusLayoutRestoreDirectChild = focusedChild;
                    // remember the specific view that had focus
                    focusLayoutRestoreView = findFocus();
                    if (focusLayoutRestoreView != null) {
                        // tell it we are going to mess with it
                        focusLayoutRestoreView.onStartTemporaryDetach();
                    }
                }
                requestFocus();
            }

            /*
             * // Remember which child, if any, had accessibility focus. final ViewRootImpl viewRootImpl = getViewRootImpl(); if (
             * viewRootImpl != null ) { final View accessFocusedView = viewRootImpl.getAccessibilityFocusedHost(); if (
             * accessFocusedView != null ) { final View accessFocusedChild = findAccessibilityFocusedChild( accessFocusedView ); if (
             * accessFocusedChild != null ) { if ( !dataChanged || isDirectChildHeaderOrFooter( accessFocusedChild ) ) { // If the
             * views won't be changing, try to maintain // focus on the current view host and (if // applicable) its virtual view.
             * accessibilityFocusLayoutRestoreView = accessFocusedView; accessibilityFocusLayoutRestoreNode = viewRootImpl
             * .getAccessibilityFocusedVirtualView(); } else { // Otherwise, try to maintain focus at the same // position.
             * accessibilityFocusPosition = getPositionForView( accessFocusedChild ); } } } }
             */

            // Clear out old views
            detachAllViewsFromParent();
            recycleBin.removeSkippedScrap();

            switch (mLayoutMode) {
            case LAYOUT_SET_SELECTION:
                if (newSel != null) {
                    sel = fillFromSelection(newSel.getLeft(), childrenLeft, childrenRight);
                } else {
                    sel = fillFromMiddle(childrenLeft, childrenRight);
                }
                break;
            case LAYOUT_SYNC:
                sel = fillSpecific(mSyncPosition, mSpecificLeft);
                break;
            case LAYOUT_FORCE_RIGHT:
                sel = fillLeft(mItemCount - 1, childrenRight);
                adjustViewsLeftOrRight();
                break;
            case LAYOUT_FORCE_LEFT:
                mFirstPosition = 0;
                sel = fillFromLeft(childrenLeft);
                adjustViewsLeftOrRight();
                break;
            case LAYOUT_SPECIFIC:
                sel = fillSpecific(reconcileSelectedPosition(), mSpecificLeft);
                break;
            case LAYOUT_MOVE_SELECTION:
                sel = moveSelection(oldSel, newSel, delta, childrenLeft, childrenRight);
                break;
            default:
                if (childCount == 0) {
                    if (!mStackFromRight) {
                        final int position = lookForSelectablePosition(0, true);
                        setSelectedPositionInt(position);
                        sel = fillFromLeft(childrenLeft);
                    } else {
                        final int position = lookForSelectablePosition(mItemCount - 1, false);
                        setSelectedPositionInt(position);
                        sel = fillLeft(mItemCount - 1, childrenRight);
                    }
                } else {
                    if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) {
                        sel = fillSpecific(mSelectedPosition, oldSel == null ? childrenLeft : oldSel.getLeft());
                    } else if (mFirstPosition < mItemCount) {
                        sel = fillSpecific(mFirstPosition, oldFirst == null ? childrenLeft : oldFirst.getLeft());
                    } else {
                        sel = fillSpecific(0, childrenLeft);
                    }
                }
                break;
            }

            // Flush any cached views that did not get reused above
            recycleBin.scrapActiveViews();

            if (sel != null) {
                // the current selected item should get focus if items
                // are focusable
                if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) {
                    final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild
                            && focusLayoutRestoreView != null && focusLayoutRestoreView.requestFocus())
                            || sel.requestFocus();
                    if (!focusWasTaken) {
                        // selected item didn't take focus, fine, but still want
                        // to make sure something else outside of the selected view
                        // has focus
                        final View focused = getFocusedChild();
                        if (focused != null) {
                            focused.clearFocus();
                        }
                        positionSelector(INVALID_POSITION, sel);
                    } else {
                        sel.setSelected(false);
                        mSelectorRect.setEmpty();
                    }
                } else {
                    positionSelector(INVALID_POSITION, sel);
                }
                mSelectedLeft = sel.getLeft();
            } else {
                if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) {
                    View child = getChildAt(mMotionPosition - mFirstPosition);
                    if (child != null)
                        positionSelector(mMotionPosition, child);
                } else {
                    mSelectedLeft = 0;
                    mSelectorRect.setEmpty();
                }

                // even if there is not selected position, we may need to restore
                // focus (i.e. something focusable in touch mode)
                if (hasFocus() && focusLayoutRestoreView != null) {
                    focusLayoutRestoreView.requestFocus();
                }
            }

            // Attempt to restore accessibility focus.
            // if ( accessibilityFocusLayoutRestoreNode != null ) {
            // accessibilityFocusLayoutRestoreNode.performAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS );
            // } else if ( accessibilityFocusLayoutRestoreView != null ) {
            // this method is marked as hidden. Shame on you google!
            // accessibilityFocusLayoutRestoreView.requestAccessibilityFocus();
            // } else if ( accessibilityFocusPosition != INVALID_POSITION ) {
            // Bound the position within the visible children.
            // final int position = MathUtils.constrain( ( accessibilityFocusPosition - mFirstPosition ), 0, ( getChildCount() - 1 ) );
            // final View restoreView = getChildAt( position );
            // if ( restoreView != null ) {
            // this method is marked as hidden. Shame on you google!
            // restoreView.requestAccessibilityFocus();
            // }
            // }

            // tell focus view we are done mucking with it, if it is still in
            // our view hierarchy.
            if (focusLayoutRestoreView != null && focusLayoutRestoreView.getWindowToken() != null) {
                focusLayoutRestoreView.onFinishTemporaryDetach();
            }

            mLayoutMode = LAYOUT_NORMAL;
            mDataChanged = false;
            if (mPositionScrollAfterLayout != null) {
                post(mPositionScrollAfterLayout);
                mPositionScrollAfterLayout = null;
            }
            mNeedSync = false;
            setNextSelectedPositionInt(mSelectedPosition);

            updateScrollIndicators();

            if (mItemCount > 0) {
                checkSelectionChanged();
            }

            invokeOnItemScrollListener();
        } finally {
            if (!blockLayoutRequests) {
                mBlockLayoutRequests = false;
            }
        }
    }

    /**
     * @param focusedView
     *           the view that has accessibility focus.
     * @return the direct child that contains accessibility focus.
     */
    @SuppressWarnings("unused")
    private View findAccessibilityFocusedChild(View focusedView) {
        ViewParent viewParent = focusedView.getParent();
        while ((viewParent instanceof View) && (viewParent != this)) {
            focusedView = (View) viewParent;
            viewParent = viewParent.getParent();
        }
        if (!(viewParent instanceof View)) {
            return null;
        }
        return focusedView;
    }

    /**
     * @param child
     *           a direct child of this list.
     * @return Whether child is a header or footer view.
     */
    private boolean isDirectChildHeaderOrFooter(View child) {

        final ArrayList<FixedViewInfo> headers = mHeaderViewInfos;
        final int numHeaders = headers.size();
        for (int i = 0; i < numHeaders; i++) {
            if (child == headers.get(i).view) {
                return true;
            }
        }
        final ArrayList<FixedViewInfo> footers = mFooterViewInfos;
        final int numFooters = footers.size();
        for (int i = 0; i < numFooters; i++) {
            if (child == footers.get(i).view) {
                return true;
            }
        }
        return false;
    }

    /**
     * Obtain the view and add it to our list of children. The view can be made fresh, converted from an unused view, or used as is
     * if it was in the recycle bin.
     *
     * @param position
     *           Logical position in the list
     * @param x
     *           Left or right edge of the view to add
     * @param flow
     *           If flow is true, align left edge to x. If false, align right edge to x.
     * @param childrenTop
     *           Top edge where children should be positioned
     * @param selected
     *           Is this position selected?
     * @return View that was added
     */
    private View makeAndAddView(int position, int x, boolean flow, int childrenTop, boolean selected) {
        View child;

        if (!mDataChanged) {
            // Try to use an existing view for this position
            child = mRecycler.getActiveView(position);
            if (child != null) {
                // Found it -- we're using an existing child
                // This just needs to be positioned
                setupChild(child, position, x, flow, childrenTop, selected, true);

                return child;
            }
        }

        // Make a new view for this position, or convert an unused view if possible
        child = obtainView(position, mIsScrap);

        // This needs to be positioned and measured
        setupChild(child, position, x, flow, childrenTop, selected, mIsScrap[0]);

        return child;
    }

    /**
     * Add a view as a child and make sure it is measured (if necessary) and positioned properly.
     *
     * @param child
     *           The view to add
     * @param position
     *           The position of this child
     * @param x
     *           The x position relative to which this view will be positioned
     * @param flowDown
     *           If true, align left edge to x. If false, align right edge to x.
     * @param childrenTop
     *           Top edge where children should be positioned
     * @param selected
     *           Is this position selected?
     * @param recycled
     *           Has this view been pulled from the recycle bin? If so it does not need to be remeasured.
     */
    @TargetApi(11)
    private void setupChild(View child, int position, int x, boolean flowDown, int childrenTop, boolean selected,
            boolean recycled) {
        final boolean isSelected = selected && shouldShowSelector();
        final boolean updateChildSelected = isSelected != child.isSelected();
        final int mode = mTouchMode;
        final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && mMotionPosition == position;
        final boolean updateChildPressed = isPressed != child.isPressed();
        final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested();

        // Respect layout params that are already in the view. Otherwise make some up...
        // noinspection unchecked
        AbsHListView.LayoutParams p = (AbsHListView.LayoutParams) child.getLayoutParams();
        if (p == null) {
            p = (AbsHListView.LayoutParams) generateDefaultLayoutParams();
        }
        p.viewType = mAdapter.getItemViewType(position);

        if ((recycled && !p.forceAdd)
                || (p.recycledHeaderFooter && p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) {
            attachViewToParent(child, flowDown ? -1 : 0, p);
        } else {
            p.forceAdd = false;
            if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) {
                p.recycledHeaderFooter = true;
            }
            addViewInLayout(child, flowDown ? -1 : 0, p, true);
        }

        if (updateChildSelected) {
            child.setSelected(isSelected);
        }

        if (updateChildPressed) {
            child.setPressed(isPressed);
        }

        if (mChoiceMode != ListView.CHOICE_MODE_NONE && mCheckStates != null) {
            if (child instanceof Checkable) {
                ((Checkable) child).setChecked(mCheckStates.get(position, false));
            } else if (android.os.Build.VERSION.SDK_INT >= 11) {
                child.setActivated(mCheckStates.get(position, false));
            }
        }

        if (needToMeasure) {
            int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec,
                    mListPadding.top + mListPadding.bottom, p.height);
            int lpWidth = p.width;
            int childWidthSpec;
            if (lpWidth > 0) {
                childWidthSpec = View.MeasureSpec.makeMeasureSpec(lpWidth, View.MeasureSpec.EXACTLY);
            } else {
                childWidthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
            }
            child.measure(childWidthSpec, childHeightSpec);
        } else {
            cleanupLayoutState(child);
        }

        final int w = child.getMeasuredWidth();
        final int h = child.getMeasuredHeight();
        final int childLeft = flowDown ? x : x - w;

        if (needToMeasure) {
            final int childBottom = childrenTop + h;
            final int childRight = childLeft + w;
            child.layout(childLeft, childrenTop, childRight, childBottom);
        } else {
            child.offsetLeftAndRight(childLeft - child.getLeft());
            child.offsetTopAndBottom(childrenTop - child.getTop());
        }

        if (mCachingStarted && !child.isDrawingCacheEnabled()) {
            child.setDrawingCacheEnabled(true);
        }

        if (android.os.Build.VERSION.SDK_INT >= 11) {
            if (recycled
                    && (((AbsHListView.LayoutParams) child.getLayoutParams()).scrappedFromPosition) != position) {
                child.jumpDrawablesToCurrentState();
            }
        }
    }

    @Override
    protected boolean canAnimate() {
        return super.canAnimate() && mItemCount > 0;
    }

    /**
     * Sets the currently selected item. If in touch mode, the item will not be selected but it will still be positioned
     * appropriately. If the specified selection position is less than 0, then the item at position 0 will be selected.
     *
     * @param position
     *           Index (starting at 0) of the data item to be selected.
     */
    @Override
    public void setSelection(int position) {
        setSelectionFromLeft(position, 0);
    }

    /**
     * Sets the selected item and positions the selection x pixels from the left edge of the ListView. (If in touch mode, the item
     * will not be selected but it will still be positioned appropriately.)
     *
     * @param position
     *           Index (starting at 0) of the data item to be selected.
     * @param x
     *           The distance from the left edge of the ListView (plus padding) that the item will be positioned.
     */
    public void setSelectionFromLeft(int position, int x) {
        if (mAdapter == null) {
            return;
        }

        if (!isInTouchMode()) {
            position = lookForSelectablePosition(position, true);
            if (position >= 0) {
                setNextSelectedPositionInt(position);
            }
        } else {
            mResurrectToPosition = position;
        }

        if (position >= 0) {
            mLayoutMode = LAYOUT_SPECIFIC;
            mSpecificLeft = mListPadding.left + x;

            if (mNeedSync) {
                mSyncPosition = position;
                mSyncColId = mAdapter.getItemId(position);
            }

            if (mPositionScroller != null) {
                mPositionScroller.stop();
            }
            requestLayout();
        }
    }

    /**
     * Makes the item at the supplied position selected.
     *
     * @param position
     *           the position of the item to select
     */
    @Override
    public void setSelectionInt(int position) {
        setNextSelectedPositionInt(position);
        boolean awakeScrollbars = false;

        final int selectedPosition = mSelectedPosition;

        if (selectedPosition >= 0) {
            if (position == selectedPosition - 1) {
                awakeScrollbars = true;
            } else if (position == selectedPosition + 1) {
                awakeScrollbars = true;
            }
        }

        if (mPositionScroller != null) {
            mPositionScroller.stop();
        }

        layoutChildren();

        if (awakeScrollbars) {
            awakenScrollBars();
        }
    }

    /**
     * Find a position that can be selected (i.e., is not a separator).
     *
     * @param position
     *           The starting position to look at.
     * @param lookDown
     *           Whether to look down for other positions.
     * @return The next selectable position starting at position and then searching either up or down. Returns
     *         {@link #INVALID_POSITION} if nothing can be found.
     */
    @Override
    protected int lookForSelectablePosition(int position, boolean lookDown) {
        final ListAdapter adapter = mAdapter;
        if (adapter == null || isInTouchMode()) {
            return INVALID_POSITION;
        }

        final int count = adapter.getCount();
        if (!mAreAllItemsSelectable) {
            if (lookDown) {
                position = Math.max(0, position);
                while (position < count && !adapter.isEnabled(position)) {
                    position++;
                }
            } else {
                position = Math.min(position, count - 1);
                while (position >= 0 && !adapter.isEnabled(position)) {
                    position--;
                }
            }

            if (position < 0 || position >= count) {
                return INVALID_POSITION;
            }
            return position;
        } else {
            if (position < 0 || position >= count) {
                return INVALID_POSITION;
            }
            return position;
        }
    }

    /**
     * setSelectionAfterHeaderView set the selection to be the first list item after the header views.
     */
    public void setSelectionAfterHeaderView() {
        final int count = mHeaderViewInfos.size();
        if (count > 0) {
            mNextSelectedPosition = 0;
            return;
        }

        if (mAdapter != null) {
            setSelection(count);
        } else {
            mNextSelectedPosition = count;
            mLayoutMode = LAYOUT_SET_SELECTION;
        }

    }

    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        // Dispatch in the normal way
        boolean handled = super.dispatchKeyEvent(event);
        if (!handled) {
            // If we didn't handle it...
            View focused = getFocusedChild();
            if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) {
                // ... and our focused child didn't handle it
                // ... give it to ourselves so we can scroll if necessary
                handled = onKeyDown(event.getKeyCode(), event);
            }
        }
        return handled;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        return commonKey(keyCode, 1, event);
    }

    @Override
    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) {
        return commonKey(keyCode, repeatCount, event);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        return commonKey(keyCode, 1, event);
    }

    @TargetApi(11)
    private boolean commonKey(int keyCode, int count, KeyEvent event) {
        if (mAdapter == null || !mIsAttached) {
            return false;
        }

        if (mDataChanged) {
            layoutChildren();
        }

        if (android.os.Build.VERSION.SDK_INT < 11) {
            return false;
        }

        boolean handled = false;
        int action = event.getAction();

        if (action != KeyEvent.ACTION_UP) {
            switch (keyCode) {
            case KeyEvent.KEYCODE_DPAD_LEFT:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded();
                    if (!handled) {
                        while (count-- > 0) {
                            if (arrowScroll(FOCUS_UP)) {
                                handled = true;
                            } else {
                                break;
                            }
                        }
                    }
                } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
                    handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP);
                }
                break;

            case KeyEvent.KEYCODE_DPAD_RIGHT:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded();
                    if (!handled) {
                        while (count-- > 0) {
                            if (arrowScroll(FOCUS_DOWN)) {
                                handled = true;
                            } else {
                                break;
                            }
                        }
                    }
                } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
                    handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN);
                }
                break;

            case KeyEvent.KEYCODE_DPAD_UP:
                if (event.hasNoModifiers()) {
                    handled = handleHorizontalFocusWithinListItem(View.FOCUS_UP);
                }
                break;

            case KeyEvent.KEYCODE_DPAD_DOWN:
                if (event.hasNoModifiers()) {
                    handled = handleHorizontalFocusWithinListItem(View.FOCUS_DOWN);
                }
                break;

            case KeyEvent.KEYCODE_DPAD_CENTER:
            case KeyEvent.KEYCODE_ENTER:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded();
                    if (!handled && event.getRepeatCount() == 0 && getChildCount() > 0) {
                        keyPressed();
                        handled = true;
                    }
                }
                break;

            case KeyEvent.KEYCODE_SPACE:

                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_DOWN);
                } else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) {
                    handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_UP);
                }
                handled = true;
                break;

            case KeyEvent.KEYCODE_PAGE_UP:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_UP);
                } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
                    handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP);
                }
                break;

            case KeyEvent.KEYCODE_PAGE_DOWN:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_DOWN);
                } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) {
                    handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN);
                }
                break;

            case KeyEvent.KEYCODE_MOVE_HOME:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP);
                }
                break;

            case KeyEvent.KEYCODE_MOVE_END:
                if (event.hasNoModifiers()) {
                    handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN);
                }
                break;

            case KeyEvent.KEYCODE_TAB:
                break;
            }
        }

        if (handled) {
            return true;
        }

        switch (action) {
        case KeyEvent.ACTION_DOWN:
            return super.onKeyDown(keyCode, event);

        case KeyEvent.ACTION_UP:
            return super.onKeyUp(keyCode, event);

        case KeyEvent.ACTION_MULTIPLE:
            return super.onKeyMultiple(keyCode, count, event);

        default: // shouldn't happen
            return false;
        }
    }

    /**
     * Scrolls left or right by the number of items currently present on screen.
     *
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
     * @return whether selection was moved
     */
    boolean pageScroll(int direction) {
        int nextPage = -1;
        boolean down = false;

        if (direction == FOCUS_UP) {
            nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1);
        } else if (direction == FOCUS_DOWN) {
            nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1);
            down = true;
        }

        if (nextPage >= 0) {
            int position = lookForSelectablePosition(nextPage, down);
            if (position >= 0) {
                mLayoutMode = LAYOUT_SPECIFIC;
                mSpecificLeft = getPaddingLeft() + getHorizontalFadingEdgeLength();

                if (down && position > mItemCount - getChildCount()) {
                    mLayoutMode = LAYOUT_FORCE_RIGHT;
                }

                if (!down && position < getChildCount()) {
                    mLayoutMode = LAYOUT_FORCE_LEFT;
                }

                setSelectionInt(position);
                invokeOnItemScrollListener();
                if (!awakenScrollBars()) {
                    invalidate();
                }

                return true;
            }
        }

        return false;
    }

    /**
     * Go to the last or first item if possible (not worrying about panning across or navigating within the internal focus of the
     * currently selected item.)
     *
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
     *
     * @return whether selection was moved
     */
    boolean fullScroll(int direction) {
        boolean moved = false;
        if (direction == FOCUS_UP) {
            if (mSelectedPosition != 0) {
                int position = lookForSelectablePosition(0, true);
                if (position >= 0) {
                    mLayoutMode = LAYOUT_FORCE_LEFT;
                    setSelectionInt(position);
                    invokeOnItemScrollListener();
                }
                moved = true;
            }
        } else if (direction == FOCUS_DOWN) {
            if (mSelectedPosition < mItemCount - 1) {
                int position = lookForSelectablePosition(mItemCount - 1, true);
                if (position >= 0) {
                    mLayoutMode = LAYOUT_FORCE_RIGHT;
                    setSelectionInt(position);
                    invokeOnItemScrollListener();
                }
                moved = true;
            }
        }

        if (moved && !awakenScrollBars()) {
            awakenScrollBars();
            invalidate();
        }

        return moved;
    }

    /**
     * To avoid horizontal focus searches changing the selected item, we manually focus search within the selected item (as
     * applicable), and prevent focus from jumping to something within another item.
     *
     * @param direction
     *           one of {View.FOCUS_LEFT, View.FOCUS_RIGHT}
     * @return Whether this consumes the key event.
     */
    private boolean handleHorizontalFocusWithinListItem(int direction) {
        // TODO: implement this
        if (direction != View.FOCUS_UP && direction != View.FOCUS_DOWN) {
            throw new IllegalArgumentException("direction must be one of" + " {View.FOCUS_UP, View.FOCUS_DOWN}");
        }

        final int numChildren = getChildCount();
        if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) {
            final View selectedView = getSelectedView();
            if (selectedView != null && selectedView.hasFocus() && selectedView instanceof ViewGroup) {

                final View currentFocus = selectedView.findFocus();
                final View nextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) selectedView,
                        currentFocus, direction);
                if (nextFocus != null) {
                    // do the math to get interesting rect in next focus' coordinates
                    currentFocus.getFocusedRect(mTempRect);
                    offsetDescendantRectToMyCoords(currentFocus, mTempRect);
                    offsetRectIntoDescendantCoords(nextFocus, mTempRect);
                    if (nextFocus.requestFocus(direction, mTempRect)) {
                        return true;
                    }
                }
                // we are blocking the key from being handled (by returning true)
                // if the global result is going to be some other view within this
                // list. this is to acheive the overall goal of having
                // horizontal d-pad navigation remain in the current item.
                final View globalNextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) getRootView(),
                        currentFocus, direction);
                if (globalNextFocus != null) {
                    return isViewAncestorOf(globalNextFocus, this);
                }
            }
        }
        return false;
    }

    /**
     * Scrolls to the next or previous item if possible.
     *
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}
     *
     * @return whether selection was moved
     */
    boolean arrowScroll(int direction) {
        try {
            mInLayout = true;
            final boolean handled = arrowScrollImpl(direction);
            if (handled) {
                playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
            }
            return handled;
        } finally {
            mInLayout = false;
        }
    }

    /**
     * Handle an arrow scroll going up or down. Take into account whether items are selectable, whether there are focusable items
     * etc.
     *
     * @param direction
     *           Either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}.
     * @return Whether any scrolling, selection or focus change occured.
     */
    private boolean arrowScrollImpl(int direction) {
        if (getChildCount() <= 0) {
            return false;
        }

        View selectedView = getSelectedView();
        int selectedPos = mSelectedPosition;

        int nextSelectedPosition = lookForSelectablePositionOnScreen(direction);
        int amountToScroll = amountToScroll(direction, nextSelectedPosition);

        // if we are moving focus, we may OVERRIDE the default behavior
        final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null;
        if (focusResult != null) {
            nextSelectedPosition = focusResult.getSelectedPosition();
            amountToScroll = focusResult.getAmountToScroll();
        }

        boolean needToRedraw = focusResult != null;
        if (nextSelectedPosition != INVALID_POSITION) {
            handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null);
            setSelectedPositionInt(nextSelectedPosition);
            setNextSelectedPositionInt(nextSelectedPosition);
            selectedView = getSelectedView();
            selectedPos = nextSelectedPosition;
            if (mItemsCanFocus && focusResult == null) {
                // there was no new view found to take focus, make sure we
                // don't leave focus with the old selection
                final View focused = getFocusedChild();
                if (focused != null) {
                    focused.clearFocus();
                }
            }
            needToRedraw = true;
            checkSelectionChanged();
        }

        if (amountToScroll > 0) {
            scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll);
            needToRedraw = true;
        }

        // if we didn't find a new focusable, make sure any existing focused
        // item that was panned off screen gives up focus.
        if (mItemsCanFocus && (focusResult == null) && selectedView != null && selectedView.hasFocus()) {
            final View focused = selectedView.findFocus();
            if (!isViewAncestorOf(focused, this) || distanceToView(focused) > 0) {
                focused.clearFocus();
            }
        }

        // if the current selection is panned off, we need to remove the selection
        if (nextSelectedPosition == INVALID_POSITION && selectedView != null
                && !isViewAncestorOf(selectedView, this)) {
            selectedView = null;
            hideSelector();

            // but we don't want to set the ressurect position (that would make subsequent
            // unhandled key events bring back the item we just scrolled off!)
            mResurrectToPosition = INVALID_POSITION;
        }

        if (needToRedraw) {
            if (selectedView != null) {
                positionSelector(selectedPos, selectedView);
                mSelectedLeft = selectedView.getLeft();
            }
            if (!awakenScrollBars()) {
                invalidate();
            }
            invokeOnItemScrollListener();
            return true;
        }

        return false;
    }

    /**
     * When selection changes, it is possible that the previously selected or the next selected item will change its size. If so, we
     * need to offset some folks, and re-layout the items as appropriate.
     *
     * @param selectedView
     *           The currently selected view (before changing selection). should be <code>null</code> if there was no previous
     *           selection.
     * @param direction
     *           Either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}.
     * @param newSelectedPosition
     *           The position of the next selection.
     * @param newFocusAssigned
     *           whether new focus was assigned. This matters because when something has focus, we don't want to show selection
     *           (ugh).
     */
    private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition,
            boolean newFocusAssigned) {
        if (newSelectedPosition == INVALID_POSITION) {
            throw new IllegalArgumentException("newSelectedPosition needs to be valid");
        }

        // whether or not we are moving down or up, we want to preserve the
        // top of whatever view is on top:
        // - moving down: the view that had selection
        // - moving up: the view that is getting selection
        View leftView;
        View rightView;
        int leftViewIndex, rightViewIndex;
        boolean leftSelected = false;
        final int selectedIndex = mSelectedPosition - mFirstPosition;
        final int nextSelectedIndex = newSelectedPosition - mFirstPosition;

        if (direction == View.FOCUS_UP) {
            leftViewIndex = nextSelectedIndex;
            rightViewIndex = selectedIndex;
            leftView = getChildAt(leftViewIndex);
            rightView = selectedView;
            leftSelected = true;
        } else {
            leftViewIndex = selectedIndex;
            rightViewIndex = nextSelectedIndex;
            leftView = selectedView;
            rightView = getChildAt(rightViewIndex);
        }

        final int numChildren = getChildCount();

        // start with top view: is it changing size?
        if (leftView != null) {
            leftView.setSelected(!newFocusAssigned && leftSelected);
            measureAndAdjustRight(leftView, leftViewIndex, numChildren);
        }

        // is the bottom view changing size?
        if (rightView != null) {
            rightView.setSelected(!newFocusAssigned && !leftSelected);
            measureAndAdjustRight(rightView, rightViewIndex, numChildren);
        }
    }

    /**
     * Re-measure a child, and if its height changes, lay it out preserving its top, and adjust the children below it appropriately.
     *
     * @param child
     *           The child
     * @param childIndex
     *           The view group index of the child.
     * @param numChildren
     *           The number of children in the view group.
     */
    private void measureAndAdjustRight(View child, int childIndex, int numChildren) {
        int oldWidth = child.getWidth();
        measureItem(child);
        if (child.getMeasuredWidth() != oldWidth) {
            // lay out the view, preserving its top
            relayoutMeasuredItem(child);

            // adjust views below appropriately
            final int widthDelta = child.getMeasuredWidth() - oldWidth;
            for (int i = childIndex + 1; i < numChildren; i++) {
                getChildAt(i).offsetLeftAndRight(widthDelta);
            }
        }
    }

    /**
     * Measure a particular list child. TODO: unify with setUpChild.
     *
     * @param child
     *           The child.
     */
    private void measureItem(View child) {
        ViewGroup.LayoutParams p = child.getLayoutParams();
        if (p == null) {
            p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                    ViewGroup.LayoutParams.MATCH_PARENT);
        }

        int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec,
                mListPadding.top + mListPadding.bottom, p.height);
        int lpWidth = p.width;
        int childWidthSpec;
        if (lpWidth > 0) {
            childWidthSpec = View.MeasureSpec.makeMeasureSpec(lpWidth, View.MeasureSpec.EXACTLY);
        } else {
            childWidthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        }
        child.measure(childWidthSpec, childHeightSpec);
    }

    /**
     * Layout a child that has been measured, preserving its top position. TODO: unify with setUpChild.
     *
     * @param child
     *           The child.
     */
    private void relayoutMeasuredItem(View child) {
        final int w = child.getMeasuredWidth();
        final int h = child.getMeasuredHeight();

        final int childTop = mListPadding.top;
        final int childBottom = childTop + h;

        final int childLeft = child.getLeft();
        final int childRight = childLeft + w;

        child.layout(childLeft, childTop, childRight, childBottom);
    }

    /**
     * @return The amount to preview next items when arrow srolling.
     */
    private int getArrowScrollPreviewLength() {
        return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getHorizontalFadingEdgeLength());
    }

    /**
     * Determine how much we need to scroll in order to get the next selected view visible, with a fading edge showing below as
     * applicable. The amount is capped at {@link #getMaxScrollAmount()} .
     *
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}.
     * @param nextSelectedPosition
     *           The position of the next selection, or {@link #INVALID_POSITION} if there is no next selectable position
     * @return The amount to scroll. Note: this is always positive! Direction needs to be taken into account when actually scrolling.
     */
    private int amountToScroll(int direction, int nextSelectedPosition) {
        final int listRight = getWidth() - mListPadding.right;
        final int listLeft = mListPadding.left;

        final int numChildren = getChildCount();

        if (direction == View.FOCUS_DOWN) {
            int indexToMakeVisible = numChildren - 1;
            if (nextSelectedPosition != INVALID_POSITION) {
                indexToMakeVisible = nextSelectedPosition - mFirstPosition;
            }

            final int positionToMakeVisible = mFirstPosition + indexToMakeVisible;
            final View viewToMakeVisible = getChildAt(indexToMakeVisible);

            int goalRight = listRight;
            if (positionToMakeVisible < mItemCount - 1) {
                goalRight -= getArrowScrollPreviewLength();
            }

            if (viewToMakeVisible.getRight() <= goalRight) {
                // item is fully visible.
                return 0;
            }

            if (nextSelectedPosition != INVALID_POSITION
                    && (goalRight - viewToMakeVisible.getLeft()) >= getMaxScrollAmount()) {
                // item already has enough of it visible, changing selection is good enough
                return 0;
            }

            int amountToScroll = (viewToMakeVisible.getRight() - goalRight);

            if ((mFirstPosition + numChildren) == mItemCount) {
                // last is last in list -> make sure we don't scroll past it
                final int max = getChildAt(numChildren - 1).getRight() - listRight;
                amountToScroll = Math.min(amountToScroll, max);
            }

            return Math.min(amountToScroll, getMaxScrollAmount());
        } else {
            int indexToMakeVisible = 0;
            if (nextSelectedPosition != INVALID_POSITION) {
                indexToMakeVisible = nextSelectedPosition - mFirstPosition;
            }
            final int positionToMakeVisible = mFirstPosition + indexToMakeVisible;
            final View viewToMakeVisible = getChildAt(indexToMakeVisible);
            int goalLeft = listLeft;
            if (positionToMakeVisible > 0) {
                goalLeft += getArrowScrollPreviewLength();
            }
            if (viewToMakeVisible.getLeft() >= goalLeft) {
                // item is fully visible.
                return 0;
            }

            if (nextSelectedPosition != INVALID_POSITION
                    && (viewToMakeVisible.getRight() - goalLeft) >= getMaxScrollAmount()) {
                // item already has enough of it visible, changing selection is good enough
                return 0;
            }

            int amountToScroll = (goalLeft - viewToMakeVisible.getLeft());
            if (mFirstPosition == 0) {
                // first is first in list -> make sure we don't scroll past it
                final int max = listLeft - getChildAt(0).getLeft();
                amountToScroll = Math.min(amountToScroll, max);
            }
            return Math.min(amountToScroll, getMaxScrollAmount());
        }
    }

    /**
     * Holds results of focus aware arrow scrolling.
     */
    static private class ArrowScrollFocusResult {

        private int mSelectedPosition;
        private int mAmountToScroll;

        /**
         * How {@link com.needapps.hlistview.widget.HListView#arrowScrollFocused} returns its values.
         */
        void populate(int selectedPosition, int amountToScroll) {
            mSelectedPosition = selectedPosition;
            mAmountToScroll = amountToScroll;
        }

        public int getSelectedPosition() {
            return mSelectedPosition;
        }

        public int getAmountToScroll() {
            return mAmountToScroll;
        }
    }

    /**
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}.
     * @return The position of the next selectable position of the views that are currently visible, taking into account the fact
     *         that there might be no selection. Returns {@link #INVALID_POSITION} if there is no selectable view on screen in the
     *         given direction.
     */
    private int lookForSelectablePositionOnScreen(int direction) {
        final int firstPosition = mFirstPosition;
        if (direction == View.FOCUS_DOWN) {
            int startPos = (mSelectedPosition != INVALID_POSITION) ? mSelectedPosition + 1 : firstPosition;
            if (startPos >= mAdapter.getCount()) {
                return INVALID_POSITION;
            }
            if (startPos < firstPosition) {
                startPos = firstPosition;
            }

            final int lastVisiblePos = getLastVisiblePosition();
            final ListAdapter adapter = getAdapter();
            for (int pos = startPos; pos <= lastVisiblePos; pos++) {
                if (adapter.isEnabled(pos) && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) {
                    return pos;
                }
            }
        } else {
            int last = firstPosition + getChildCount() - 1;
            int startPos = (mSelectedPosition != INVALID_POSITION) ? mSelectedPosition - 1
                    : firstPosition + getChildCount() - 1;
            if (startPos < 0 || startPos >= mAdapter.getCount()) {
                return INVALID_POSITION;
            }
            if (startPos > last) {
                startPos = last;
            }

            final ListAdapter adapter = getAdapter();
            for (int pos = startPos; pos >= firstPosition; pos--) {
                if (adapter.isEnabled(pos) && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) {
                    return pos;
                }
            }
        }
        return INVALID_POSITION;
    }

    /**
     * Do an arrow scroll based on focus searching. If a new view is given focus, return the selection delta and amount to scroll via
     * an {@link ArrowScrollFocusResult}, otherwise, return null.
     *
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}.
     * @return The result if focus has changed, or <code>null</code>.
     */
    private ArrowScrollFocusResult arrowScrollFocused(final int direction) {
        final View selectedView = getSelectedView();
        View newFocus;
        if (selectedView != null && selectedView.hasFocus()) {
            View oldFocus = selectedView.findFocus();
            newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction);
        } else {
            if (direction == View.FOCUS_DOWN) {
                final boolean leftFadingEdgeShowing = (mFirstPosition > 0);
                final int listLeft = mListPadding.left
                        + (leftFadingEdgeShowing ? getArrowScrollPreviewLength() : 0);
                final int xSearchPoint = (selectedView != null && selectedView.getLeft() > listLeft)
                        ? selectedView.getLeft()
                        : listLeft;
                mTempRect.set(xSearchPoint, 0, xSearchPoint, 0);
            } else {
                final boolean rightFadingEdgeShowing = (mFirstPosition + getChildCount() - 1) < mItemCount;
                final int listRight = getWidth() - mListPadding.right
                        - (rightFadingEdgeShowing ? getArrowScrollPreviewLength() : 0);
                final int xSearchPoint = (selectedView != null && selectedView.getRight() < listRight)
                        ? selectedView.getRight()
                        : listRight;
                mTempRect.set(xSearchPoint, 0, xSearchPoint, 0);
            }
            newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction);
        }

        if (newFocus != null) {
            final int positionOfNewFocus = positionOfNewFocus(newFocus);

            // if the focus change is in a different new position, make sure
            // we aren't jumping over another selectable position
            if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) {
                final int selectablePosition = lookForSelectablePositionOnScreen(direction);
                if (selectablePosition != INVALID_POSITION
                        && ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus)
                                || (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) {
                    return null;
                }
            }

            int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus);

            final int maxScrollAmount = getMaxScrollAmount();
            if (focusScroll < maxScrollAmount) {
                // not moving too far, safe to give next view focus
                newFocus.requestFocus(direction);
                mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll);
                return mArrowScrollFocusResult;
            } else if (distanceToView(newFocus) < maxScrollAmount) {
                // Case to consider:
                // too far to get entire next focusable on screen, but by going
                // max scroll amount, we are getting it at least partially in view,
                // so give it focus and scroll the max ammount.
                newFocus.requestFocus(direction);
                mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount);
                return mArrowScrollFocusResult;
            }
        }
        return null;
    }

    /**
     * @param newFocus
     *           The view that would have focus.
     * @return the position that contains newFocus
     */
    private int positionOfNewFocus(View newFocus) {
        final int numChildren = getChildCount();
        for (int i = 0; i < numChildren; i++) {
            final View child = getChildAt(i);
            if (isViewAncestorOf(newFocus, child)) {
                return mFirstPosition + i;
            }
        }
        throw new IllegalArgumentException("newFocus is not a child of any of the" + " children of the list!");
    }

    /**
     * Return true if child is an ancestor of parent, (or equal to the parent).
     */
    private boolean isViewAncestorOf(View child, View parent) {
        if (child == parent) {
            return true;
        }

        final ViewParent theParent = child.getParent();
        return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent);
    }

    /**
     * Determine how much we need to scroll in order to get newFocus in view.
     *
     * @param direction
     *           either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}.
     * @param newFocus
     *           The view that would take focus.
     * @param positionOfNewFocus
     *           The position of the list item containing newFocus
     * @return The amount to scroll. Note: this is always positive! Direction needs to be taken into account when actually scrolling.
     */
    private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) {
        int amountToScroll = 0;
        newFocus.getDrawingRect(mTempRect);
        offsetDescendantRectToMyCoords(newFocus, mTempRect);
        if (direction == View.FOCUS_UP) {
            if (mTempRect.left < mListPadding.left) {
                amountToScroll = mListPadding.left - mTempRect.left;
                if (positionOfNewFocus > 0) {
                    amountToScroll += getArrowScrollPreviewLength();
                }
            }
        } else {
            final int listRight = getWidth() - mListPadding.right;
            if (mTempRect.bottom > listRight) {
                amountToScroll = mTempRect.right - listRight;
                if (positionOfNewFocus < mItemCount - 1) {
                    amountToScroll += getArrowScrollPreviewLength();
                }
            }
        }
        return amountToScroll;
    }

    /**
     * Determine the distance to the nearest edge of a view in a particular direction.
     *
     * @param descendant
     *           A descendant of this list.
     * @return The distance, or 0 if the nearest edge is already on screen.
     */
    private int distanceToView(View descendant) {
        int distance = 0;
        descendant.getDrawingRect(mTempRect);
        offsetDescendantRectToMyCoords(descendant, mTempRect);
        final int listRight = getRight() - getLeft() - mListPadding.right;
        if (mTempRect.right < mListPadding.left) {
            distance = mListPadding.left - mTempRect.right;
        } else if (mTempRect.left > listRight) {
            distance = mTempRect.left - listRight;
        }
        return distance;
    }

    /**
     * Scroll the children by amount, adding a view at the end and removing views that fall off as necessary.
     *
     * @param amount
     *           The amount (positive or negative) to scroll.
     */
    private void scrollListItemsBy(int amount) {
        offsetChildrenLeftAndRight(amount);

        final int listRight = getWidth() - mListPadding.right;
        final int listLeft = mListPadding.left;
        final AbsHListView.RecycleBin recycleBin = mRecycler;

        if (amount < 0) {
            // shifted items up

            // may need to pan views into the bottom space
            int numChildren = getChildCount();
            View last = getChildAt(numChildren - 1);
            while (last.getRight() < listRight) {
                final int lastVisiblePosition = mFirstPosition + numChildren - 1;
                if (lastVisiblePosition < mItemCount - 1) {
                    last = addViewAfter(last, lastVisiblePosition);
                    numChildren++;
                } else {
                    break;
                }
            }

            // may have brought in the last child of the list that is skinnier
            // than the fading edge, thereby leaving space at the end. need
            // to shift back
            if (last.getBottom() < listRight) {
                offsetChildrenLeftAndRight(listRight - last.getRight());
            }

            // top views may be panned off screen
            View first = getChildAt(0);
            while (first.getRight() < listLeft) {
                AbsHListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams();
                if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
                    detachViewFromParent(first);
                    recycleBin.addScrapView(first, mFirstPosition);
                } else {
                    removeViewInLayout(first);
                }
                first = getChildAt(0);
                mFirstPosition++;
            }
        } else {
            // shifted items down
            View first = getChildAt(0);

            // may need to pan views into top
            while ((first.getLeft() > listLeft) && (mFirstPosition > 0)) {
                first = addViewBefore(first, mFirstPosition);
                mFirstPosition--;
            }

            // may have brought the very first child of the list in too far and
            // need to shift it back
            if (first.getLeft() > listLeft) {
                offsetChildrenLeftAndRight(listLeft - first.getLeft());
            }

            int lastIndex = getChildCount() - 1;
            View last = getChildAt(lastIndex);

            // bottom view may be panned off screen
            while (last.getLeft() > listRight) {
                AbsHListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams();
                if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
                    detachViewFromParent(last);
                    recycleBin.addScrapView(last, mFirstPosition + lastIndex);
                } else {
                    removeViewInLayout(last);
                }
                last = getChildAt(--lastIndex);
            }
        }
    }

    private View addViewBefore(View theView, int position) {
        int abovePosition = position - 1;
        View view = obtainView(abovePosition, mIsScrap);
        int edgeOfNewChild = theView.getLeft() - mDividerWidth;
        setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.top, false, mIsScrap[0]);
        return view;
    }

    private View addViewAfter(View theView, int position) {
        int belowPosition = position + 1;
        View view = obtainView(belowPosition, mIsScrap);
        int edgeOfNewChild = theView.getRight() + mDividerWidth;
        setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.top, false, mIsScrap[0]);
        return view;
    }

    /**
     * Indicates that the views created by the ListAdapter can contain focusable items.
     *
     * @param itemsCanFocus
     *           true if items can get focus, false otherwise
     */
    public void setItemsCanFocus(boolean itemsCanFocus) {
        mItemsCanFocus = itemsCanFocus;
        if (!itemsCanFocus) {
            setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
        }
    }

    /**
     * @return Whether the views created by the ListAdapter can contain focusable items.
     */
    public boolean getItemsCanFocus() {
        return mItemsCanFocus;
    }

    @Override
    public boolean isOpaque() {
        boolean retValue = (mCachingActive && mIsCacheColorOpaque && mDividerIsOpaque) || super.isOpaque();
        if (retValue) {
            // only return true if the list items cover the entire area of the view
            final int listLeft = mListPadding != null ? mListPadding.left : getPaddingLeft();
            View first = getChildAt(0);
            if (first == null || first.getLeft() > listLeft) {
                return false;
            }
            final int listRight = getWidth() - (mListPadding != null ? mListPadding.right : getPaddingRight());
            View last = getChildAt(getChildCount() - 1);
            if (last == null || last.getRight() < listRight) {
                return false;
            }
        }
        return retValue;
    }

    @Override
    public void setCacheColorHint(int color) {
        final boolean opaque = (color >>> 24) == 0xFF;
        mIsCacheColorOpaque = opaque;
        if (opaque) {
            if (mDividerPaint == null) {
                mDividerPaint = new Paint();
            }
            mDividerPaint.setColor(color);
        }
        super.setCacheColorHint(color);
    }

    void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) {
        final int width = drawable.getMinimumWidth();

        canvas.save();
        canvas.clipRect(bounds);

        final int span = bounds.right - bounds.left;
        if (span < width) {
            bounds.left = bounds.right - width;
        }

        drawable.setBounds(bounds);
        drawable.draw(canvas);

        canvas.restore();
    }

    void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) {
        final int width = drawable.getMinimumWidth();

        canvas.save();
        canvas.clipRect(bounds);

        final int span = bounds.right - bounds.left;
        if (span < width) {
            bounds.right = bounds.left + width;
        }

        drawable.setBounds(bounds);
        drawable.draw(canvas);

        canvas.restore();
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        if (mCachingStarted) {
            mCachingActive = true;
        }

        // Draw the dividers
        final int dividerWidth = mDividerWidth;
        final Drawable overscrollHeader = mOverScrollHeader;
        final Drawable overscrollFooter = mOverScrollFooter;
        final boolean drawOverscrollHeader = overscrollHeader != null;
        final boolean drawOverscrollFooter = overscrollFooter != null;
        final boolean drawDividers = dividerWidth > 0 && mDivider != null;

        if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) {
            // Only modify the top and bottom in the loop, we set the left and right here
            final Rect bounds = mTempRect;
            bounds.top = getPaddingTop();
            bounds.bottom = getBottom() - getTop() - getPaddingBottom();

            final int count = getChildCount();
            final int headerCount = mHeaderViewInfos.size();
            final int itemCount = mItemCount;
            final int footerLimit = itemCount - mFooterViewInfos.size() - 1;
            final boolean headerDividers = mHeaderDividersEnabled;
            final boolean footerDividers = mFooterDividersEnabled;
            final int first = mFirstPosition;
            final boolean areAllItemsSelectable = mAreAllItemsSelectable;
            final ListAdapter adapter = mAdapter;
            // If the list is opaque *and* the background is not, we want to
            // fill a rect where the dividers would be for non-selectable items
            // If the list is opaque and the background is also opaque, we don't
            // need to draw anything since the background will do it for us
            final boolean fillForMissingDividers = isOpaque() && !super.isOpaque();

            if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) {
                mDividerPaint = new Paint();
                mDividerPaint.setColor(getCacheColorHint());
            }
            final Paint paint = mDividerPaint;

            int effectivePaddingLeft = 0;
            int effectivePaddingRight = 0;
            // if ( ( mGroupFlags & CLIP_TO_PADDING_MASK ) == CLIP_TO_PADDING_MASK ) {
            // effectivePaddingTop = mListPadding.top;
            // effectivePaddingBottom = mListPadding.bottom;
            // }

            final int listRight = getRight() - getLeft() - effectivePaddingRight + getScrollX();
            if (!mStackFromRight) {
                int right = 0;

                // Draw top divider or header for overscroll
                final int scrollX = getScrollX();
                if (count > 0 && scrollX < 0) {
                    if (drawOverscrollHeader) {
                        bounds.right = 0;
                        bounds.left = scrollX;
                        drawOverscrollHeader(canvas, overscrollHeader, bounds);
                    } else if (drawDividers) {
                        bounds.right = 0;
                        bounds.left = -dividerWidth;
                        drawDivider(canvas, bounds, -1);
                    }
                }

                for (int i = 0; i < count; i++) {
                    if ((headerDividers || first + i >= headerCount)
                            && (footerDividers || first + i < footerLimit)) {
                        View child = getChildAt(i);
                        right = child.getRight();
                        // Don't draw dividers next to items that are not enabled

                        if (drawDividers && (right < listRight && !(drawOverscrollFooter && i == count - 1))) {
                            if ((areAllItemsSelectable || (adapter.isEnabled(first + i)
                                    && (i == count - 1 || adapter.isEnabled(first + i + 1))))) {
                                bounds.left = right;
                                bounds.right = right + dividerWidth;
                                drawDivider(canvas, bounds, i);
                            } else if (fillForMissingDividers) {
                                bounds.left = right;
                                bounds.right = right + dividerWidth;
                                canvas.drawRect(bounds, paint);
                            }
                        }
                    }
                }

                final int overFooterBottom = getRight() + getScrollX();
                if (drawOverscrollFooter && first + count == itemCount && overFooterBottom > right) {
                    bounds.left = right;
                    bounds.right = overFooterBottom;
                    drawOverscrollFooter(canvas, overscrollFooter, bounds);
                }
            } else {
                int left;

                final int scrollX = getScrollX();

                if (count > 0 && drawOverscrollHeader) {
                    bounds.left = scrollX;
                    bounds.right = getChildAt(0).getLeft();
                    drawOverscrollHeader(canvas, overscrollHeader, bounds);
                }

                final int start = drawOverscrollHeader ? 1 : 0;
                for (int i = start; i < count; i++) {
                    if ((headerDividers || first + i >= headerCount)
                            && (footerDividers || first + i < footerLimit)) {
                        View child = getChildAt(i);
                        left = child.getLeft();
                        // Don't draw dividers next to items that are not enabled
                        if (left > effectivePaddingLeft) {
                            if ((areAllItemsSelectable || (adapter.isEnabled(first + i)
                                    && (i == count - 1 || adapter.isEnabled(first + i + 1))))) {
                                bounds.left = left - dividerWidth;
                                bounds.right = left;
                                // Give the method the child ABOVE the divider, so we
                                // subtract one from our child
                                // position. Give -1 when there is no child above the
                                // divider.
                                drawDivider(canvas, bounds, i - 1);
                            } else if (fillForMissingDividers) {
                                bounds.left = left - dividerWidth;
                                bounds.right = left;
                                canvas.drawRect(bounds, paint);
                            }
                        }
                    }
                }

                if (count > 0 && scrollX > 0) {
                    if (drawOverscrollFooter) {
                        final int absListRight = getRight();
                        bounds.left = absListRight;
                        bounds.right = absListRight + scrollX;
                        drawOverscrollFooter(canvas, overscrollFooter, bounds);
                    } else if (drawDividers) {
                        bounds.left = listRight;
                        bounds.right = listRight + dividerWidth;
                        drawDivider(canvas, bounds, -1);
                    }
                }
            }
        }

        // Draw the indicators (these should be drawn above the dividers) and children
        super.dispatchDraw(canvas);
    }

    @Override
    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
        boolean more = super.drawChild(canvas, child, drawingTime);
        if (mCachingActive /* && child.mCachingFailed */) {
            mCachingActive = false;
        }
        return more;
    }

    /**
     * Draws a divider for the given child in the given bounds.
     *
     * @param canvas
     *           The canvas to draw to.
     * @param bounds
     *           The bounds of the divider.
     * @param childIndex
     *           The index of child (of the View) above the divider. This will be -1 if there is no child above the divider to be
     *           drawn.
     */
    void drawDivider(Canvas canvas, Rect bounds, int childIndex) {
        // This widget draws the same divider for all children
        final Drawable divider = mDivider;

        divider.setBounds(bounds);
        divider.draw(canvas);
    }

    /**
     * Returns the drawable that will be drawn between each item in the list.
     *
     * @return the current drawable drawn between list elements
     */
    public Drawable getDivider() {
        return mDivider;
    }

    /**
     * Sets the drawable that will be drawn between each item in the list. If the drawable does not have an intrinsic height, you
     * should also call {@link #setDividerHeight(int)}
     *
     * @param divider
     *           The drawable to use.
     */
    public void setDivider(Drawable divider) {
        if (LOG_ENABLED) {
            Log.i(LOG_TAG, "setDivider: " + divider);
        }

        if (divider != null) {
            mDividerWidth = divider.getIntrinsicWidth();
        } else {
            mDividerWidth = 0;
        }
        mDivider = divider;
        mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE;
        requestLayout();
        invalidate();
    }

    /**
     * @return Returns the height of the divider that will be drawn between each item in the list.
     */
    public int getDividerWidth() {
        return mDividerWidth;
    }

    /**
     * Sets the height of the divider that will be drawn between each item in the list. Calling this will override the intrinsic
     * height as set by {@link #setDivider(Drawable)}
     *
     * @param height
     *           The new height of the divider in pixels.
     */
    public void setDividerWidth(int width) {
        if (LOG_ENABLED) {
            Log.i(LOG_TAG, "setDividerWidth: " + width);
        }
        mDividerWidth = width;
        requestLayout();
        invalidate();
    }

    /**
     * Enables or disables the drawing of the divider for header views.
     *
     * @param headerDividersEnabled
     *           True to draw the headers, false otherwise.
     *
     * @see #setFooterDividersEnabled(boolean)
     * @see #addHeaderView(View)
     */
    public void setHeaderDividersEnabled(boolean headerDividersEnabled) {
        mHeaderDividersEnabled = headerDividersEnabled;
        invalidate();
    }

    /**
     * Enables or disables the drawing of the divider for footer views.
     *
     * @param footerDividersEnabled
     *           True to draw the footers, false otherwise.
     *
     * @see #setHeaderDividersEnabled(boolean)
     * @see #addFooterView(View)
     */
    public void setFooterDividersEnabled(boolean footerDividersEnabled) {
        mFooterDividersEnabled = footerDividersEnabled;
        invalidate();
    }

    /**
     * Sets the drawable that will be drawn above all other list content. This area can become visible when the user overscrolls the
     * list.
     * 
     * @param header
     *           The drawable to use
     */
    public void setOverscrollHeader(Drawable header) {
        mOverScrollHeader = header;
        if (getScrollX() < 0) {
            invalidate();
        }
    }

    /**
     * @return The drawable that will be drawn above all other list content
     */
    public Drawable getOverscrollHeader() {
        return mOverScrollHeader;
    }

    /**
     * Sets the drawable that will be drawn below all other list content. This area can become visible when the user overscrolls the
     * list, or when the list's content does not fully fill the container area.
     * 
     * @param footer
     *           The drawable to use
     */
    public void setOverscrollFooter(Drawable footer) {
        mOverScrollFooter = footer;
        invalidate();
    }

    /**
     * @return The drawable that will be drawn below all other list content
     */
    public Drawable getOverscrollFooter() {
        return mOverScrollFooter;
    }

    @Override
    protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) {
        super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);

        final ListAdapter adapter = mAdapter;
        int closetChildIndex = -1;
        int closestChildLeft = 0;
        if (adapter != null && gainFocus && previouslyFocusedRect != null) {
            previouslyFocusedRect.offset(getScrollX(), getScrollY());

            // Don't cache the result of getChildCount or mFirstPosition here,
            // it could change in layoutChildren.
            if (adapter.getCount() < getChildCount() + mFirstPosition) {
                mLayoutMode = LAYOUT_NORMAL;
                layoutChildren();
            }

            // figure out which item should be selected based on previously
            // focused rect
            Rect otherRect = mTempRect;
            int minDistance = Integer.MAX_VALUE;
            final int childCount = getChildCount();
            final int firstPosition = mFirstPosition;

            for (int i = 0; i < childCount; i++) {
                // only consider selectable views
                if (!adapter.isEnabled(firstPosition + i)) {
                    continue;
                }

                View other = getChildAt(i);
                other.getDrawingRect(otherRect);
                offsetDescendantRectToMyCoords(other, otherRect);
                int distance = getDistance(previouslyFocusedRect, otherRect, direction);

                if (distance < minDistance) {
                    minDistance = distance;
                    closetChildIndex = i;
                    closestChildLeft = other.getLeft();
                }
            }
        }

        if (closetChildIndex >= 0) {
            setSelectionFromLeft(closetChildIndex + mFirstPosition, closestChildLeft);
        } else {
            requestLayout();
        }
    }

    /*
     * (non-Javadoc)
     * 
     * Children specified in XML are assumed to be header views. After we have parsed them move them out of the children list and
     * into mHeaderViews.
     */
    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();

        int count = getChildCount();
        if (count > 0) {
            for (int i = 0; i < count; ++i) {
                addHeaderView(getChildAt(i));
            }
            removeAllViews();
        }
    }

    /*
     * @Override protected View findViewByPredicateTraversal( Predicate<View> predicate, View childToSkip ) { View v; v =
     * super.findViewByPredicateTraversal( predicate, childToSkip ); if ( v == null ) { v = findViewByPredicateInHeadersOrFooters(
     * mHeaderViewInfos, predicate, childToSkip ); if ( v != null ) { return v; }
     * 
     * v = findViewByPredicateInHeadersOrFooters( mFooterViewInfos, predicate, childToSkip ); if ( v != null ) { return v; } } return
     * v; }
     */

    /*
     * View findViewByPredicateInHeadersOrFooters( ArrayList<FixedViewInfo> where, Predicate<View> predicate, View childToSkip ) { if
     * ( where != null ) { int len = where.size(); View v;
     * 
     * for ( int i = 0; i < len; i++ ) { v = where.get( i ).view;
     * 
     * if ( v != childToSkip && !v.isRootNamespace() ) { v = v.findViewByPredicate( predicate );
     * 
     * if ( v != null ) { return v; } } } } return null; }
     */

    /**
     * Returns the set of checked items ids. The result is only valid if the choice mode has not been set to
     * {@link #CHOICE_MODE_NONE}.
     * 
     * @return A new array which contains the id of each checked item in the list.
     * 
     * @deprecated Use {@link #getCheckedItemIds()} instead.
     */
    @Deprecated
    public long[] getCheckItemIds() {
        // Use new behavior that correctly handles stable ID mapping.
        if (mAdapter != null && mAdapter.hasStableIds()) {
            return getCheckedItemIds();
        }

        // Old behavior was buggy, but would sort of work for adapters without stable IDs.
        // Fall back to it to support legacy apps.
        if (mChoiceMode != ListView.CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) {
            final SparseArrayCompat<Boolean> states = mCheckStates;
            final int count = states.size();
            final long[] ids = new long[count];
            final ListAdapter adapter = mAdapter;

            int checkedCount = 0;
            for (int i = 0; i < count; i++) {
                if (states.valueAt(i)) {
                    ids[checkedCount++] = adapter.getItemId(states.keyAt(i));
                }
            }

            // Trim array if needed. mCheckStates may contain false values
            // resulting in checkedCount being smaller than count.
            if (checkedCount == count) {
                return ids;
            } else {
                final long[] result = new long[checkedCount];
                System.arraycopy(ids, 0, result, 0, checkedCount);

                return result;
            }
        }
        return new long[0];
    }

    @Override
    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
        super.onInitializeAccessibilityEvent(event);
        event.setClassName(HListView.class.getName());
    }

    @TargetApi(14)
    @Override
    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
        super.onInitializeAccessibilityNodeInfo(info);
        info.setClassName(HListView.class.getName());
    }

    @Override
    public void onGlobalLayout() {
    }
}