Java tutorial
/* 50AH-code ========= 50 Android Hacks (http://manning.com/sessa/) book source code Copyright (c) 2012 Manning Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /* * Copyright (C) 2007 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.actionbarsherlock.internal.widget; import static android.view.ViewGroup.LayoutParams.MATCH_PARENT; import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT; import com.actionbarsherlock.R; import android.content.Context; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.content.res.TypedArray; import android.database.DataSetObserver; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.view.Gravity; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.PopupWindow; import android.widget.SpinnerAdapter; /** * A view that displays one child at a time and lets the user pick among them. * The items in the Spinner come from the {@link Adapter} associated with * this view. * * <p>See the <a href="{@docRoot}resources/tutorials/views/hello-spinner.html">Spinner * tutorial</a>.</p> * * @attr ref android.R.styleable#Spinner_prompt */ public class IcsSpinner extends IcsAbsSpinner implements OnClickListener { //private static final String TAG = "Spinner"; // Only measure this many items to get a decent max width. private static final int MAX_ITEMS_MEASURED = 15; /** * Use a dialog window for selecting spinner options. */ //public static final int MODE_DIALOG = 0; /** * Use a dropdown anchored to the Spinner for selecting spinner options. */ public static final int MODE_DROPDOWN = 1; /** * Use the theme-supplied value to select the dropdown mode. */ //private static final int MODE_THEME = -1; private SpinnerPopup mPopup; private DropDownAdapter mTempAdapter; int mDropDownWidth; private int mGravity; private boolean mDisableChildrenWhenDisabled; private Rect mTempRect = new Rect(); public IcsSpinner(Context context, AttributeSet attrs) { this(context, attrs, R.attr.actionDropDownStyle); } /** * Construct a new spinner with the given context's theme, the supplied attribute set, * and default style. * * @param context The Context the view is running in, through which it can * access the current theme, resources, etc. * @param attrs The attributes of the XML tag that is inflating the view. * @param defStyle The default style to apply to this view. If 0, no style * will be applied (beyond what is included in the theme). This may * either be an attribute resource, whose value will be retrieved * from the current theme, or an explicit style resource. */ public IcsSpinner(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SherlockSpinner, defStyle, 0); DropdownPopup popup = new DropdownPopup(context, attrs, defStyle); mDropDownWidth = a.getLayoutDimension(R.styleable.SherlockSpinner_android_dropDownWidth, ViewGroup.LayoutParams.WRAP_CONTENT); popup.setBackgroundDrawable(a.getDrawable(R.styleable.SherlockSpinner_android_popupBackground)); final int verticalOffset = a .getDimensionPixelOffset(R.styleable.SherlockSpinner_android_dropDownVerticalOffset, 0); if (verticalOffset != 0) { popup.setVerticalOffset(verticalOffset); } final int horizontalOffset = a .getDimensionPixelOffset(R.styleable.SherlockSpinner_android_dropDownHorizontalOffset, 0); if (horizontalOffset != 0) { popup.setHorizontalOffset(horizontalOffset); } mPopup = popup; mGravity = a.getInt(R.styleable.SherlockSpinner_android_gravity, Gravity.CENTER); mPopup.setPromptText(a.getString(R.styleable.SherlockSpinner_android_prompt)); mDisableChildrenWhenDisabled = true; a.recycle(); // Base constructor can call setAdapter before we initialize mPopup. // Finish setting things up if this happened. if (mTempAdapter != null) { mPopup.setAdapter(mTempAdapter); mTempAdapter = null; } } @Override public void setEnabled(boolean enabled) { super.setEnabled(enabled); if (mDisableChildrenWhenDisabled) { final int count = getChildCount(); for (int i = 0; i < count; i++) { getChildAt(i).setEnabled(enabled); } } } /** * Describes how the selected item view is positioned. Currently only the horizontal component * is used. The default is determined by the current theme. * * @param gravity See {@link android.view.Gravity} * * @attr ref android.R.styleable#Spinner_gravity */ public void setGravity(int gravity) { if (mGravity != gravity) { if ((gravity & Gravity.HORIZONTAL_GRAVITY_MASK) == 0) { gravity |= Gravity.LEFT; } mGravity = gravity; requestLayout(); } } @Override public void setAdapter(SpinnerAdapter adapter) { super.setAdapter(adapter); if (mPopup != null) { mPopup.setAdapter(new DropDownAdapter(adapter)); } else { mTempAdapter = new DropDownAdapter(adapter); } } @Override public int getBaseline() { View child = null; if (getChildCount() > 0) { child = getChildAt(0); } else if (mAdapter != null && mAdapter.getCount() > 0) { child = makeAndAddView(0); mRecycler.put(0, child); removeAllViewsInLayout(); } if (child != null) { final int childBaseline = child.getBaseline(); return childBaseline >= 0 ? child.getTop() + childBaseline : -1; } else { return -1; } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mPopup != null && mPopup.isShowing()) { mPopup.dismiss(); } } /** * <p>A spinner does not support item click events. Calling this method * will raise an exception.</p> * * @param l this listener will be ignored */ @Override public void setOnItemClickListener(OnItemClickListener l) { throw new RuntimeException("setOnItemClickListener cannot be used with a spinner."); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (mPopup != null && MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.AT_MOST) { final int measuredWidth = getMeasuredWidth(); setMeasuredDimension( Math.min(Math.max(measuredWidth, measureContentWidth(getAdapter(), getBackground())), MeasureSpec.getSize(widthMeasureSpec)), getMeasuredHeight()); } } /** * @see android.view.View#onLayout(boolean,int,int,int,int) * * Creates and positions all views * */ @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); mInLayout = true; layout(0, false); mInLayout = false; } /** * Creates and positions all views for this Spinner. * * @param delta Change in the selected position. +1 moves selection is moving to the right, * so views are scrolling to the left. -1 means selection is moving to the left. */ @Override void layout(int delta, boolean animate) { int childrenLeft = mSpinnerPadding.left; int childrenWidth = getRight() - getLeft() - mSpinnerPadding.left - mSpinnerPadding.right; if (mDataChanged) { handleDataChanged(); } // Handle the empty set by removing all views if (mItemCount == 0) { resetList(); return; } if (mNextSelectedPosition >= 0) { setSelectedPositionInt(mNextSelectedPosition); } recycleAllViews(); // Clear out old views removeAllViewsInLayout(); // Make selected view and position it mFirstPosition = mSelectedPosition; View sel = makeAndAddView(mSelectedPosition); int width = sel.getMeasuredWidth(); int selectedOffset = childrenLeft; switch (mGravity & Gravity.HORIZONTAL_GRAVITY_MASK) { case Gravity.CENTER_HORIZONTAL: selectedOffset = childrenLeft + (childrenWidth / 2) - (width / 2); break; case Gravity.RIGHT: selectedOffset = childrenLeft + childrenWidth - width; break; } sel.offsetLeftAndRight(selectedOffset); // Flush any cached views that did not get reused above mRecycler.clear(); invalidate(); checkSelectionChanged(); mDataChanged = false; mNeedSync = false; setNextSelectedPositionInt(mSelectedPosition); } /** * Obtain a view, either by pulling an existing view from the recycler or * by getting a new one from the adapter. If we are animating, make sure * there is enough information in the view's layout parameters to animate * from the old to new positions. * * @param position Position in the spinner for the view to obtain * @return A view that has been added to the spinner */ private View makeAndAddView(int position) { View child; if (!mDataChanged) { child = mRecycler.get(position); if (child != null) { // Position the view setUpChild(child); return child; } } // Nothing found in the recycler -- ask the adapter for a view child = mAdapter.getView(position, null, this); // Position the view setUpChild(child); return child; } /** * Helper for makeAndAddView to set the position of a view * and fill out its layout paramters. * * @param child The view to position */ private void setUpChild(View child) { // Respect layout params that are already in the view. Otherwise // make some up... ViewGroup.LayoutParams lp = child.getLayoutParams(); if (lp == null) { lp = generateDefaultLayoutParams(); } addViewInLayout(child, 0, lp); child.setSelected(hasFocus()); if (mDisableChildrenWhenDisabled) { child.setEnabled(isEnabled()); } // Get measure specs int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec, mSpinnerPadding.top + mSpinnerPadding.bottom, lp.height); int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, mSpinnerPadding.left + mSpinnerPadding.right, lp.width); // Measure child child.measure(childWidthSpec, childHeightSpec); int childLeft; int childRight; // Position vertically based on gravity setting int childTop = mSpinnerPadding.top + ((getMeasuredHeight() - mSpinnerPadding.bottom - mSpinnerPadding.top - child.getMeasuredHeight()) / 2); int childBottom = childTop + child.getMeasuredHeight(); int width = child.getMeasuredWidth(); childLeft = 0; childRight = childLeft + width; child.layout(childLeft, childTop, childRight, childBottom); } @Override public boolean performClick() { boolean handled = super.performClick(); if (!handled) { handled = true; if (!mPopup.isShowing()) { mPopup.show(); } } return handled; } public void onClick(DialogInterface dialog, int which) { setSelection(which); dialog.dismiss(); } /** * Sets the prompt to display when the dialog is shown. * @param prompt the prompt to set */ public void setPrompt(CharSequence prompt) { mPopup.setPromptText(prompt); } /** * Sets the prompt to display when the dialog is shown. * @param promptId the resource ID of the prompt to display when the dialog is shown */ public void setPromptId(int promptId) { setPrompt(getContext().getText(promptId)); } /** * @return The prompt to display when the dialog is shown */ public CharSequence getPrompt() { return mPopup.getHintText(); } int measureContentWidth(SpinnerAdapter adapter, Drawable background) { if (adapter == null) { return 0; } int width = 0; View itemView = null; int itemType = 0; final int widthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); final int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); // Make sure the number of items we'll measure is capped. If it's a huge data set // with wildly varying sizes, oh well. int start = Math.max(0, getSelectedItemPosition()); final int end = Math.min(adapter.getCount(), start + MAX_ITEMS_MEASURED); final int count = end - start; start = Math.max(0, start - (MAX_ITEMS_MEASURED - count)); for (int i = start; i < end; i++) { final int positionType = adapter.getItemViewType(i); if (positionType != itemType) { itemType = positionType; itemView = null; } itemView = adapter.getView(i, itemView, this); if (itemView.getLayoutParams() == null) { itemView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)); } itemView.measure(widthMeasureSpec, heightMeasureSpec); width = Math.max(width, itemView.getMeasuredWidth()); } // Add background padding to measured width if (background != null) { background.getPadding(mTempRect); width += mTempRect.left + mTempRect.right; } return width; } /** * <p>Wrapper class for an Adapter. Transforms the embedded Adapter instance * into a ListAdapter.</p> */ private static class DropDownAdapter implements ListAdapter, SpinnerAdapter { private SpinnerAdapter mAdapter; private ListAdapter mListAdapter; /** * <p>Creates a new ListAdapter wrapper for the specified adapter.</p> * * @param adapter the Adapter to transform into a ListAdapter */ public DropDownAdapter(SpinnerAdapter adapter) { this.mAdapter = adapter; if (adapter instanceof ListAdapter) { this.mListAdapter = (ListAdapter) adapter; } } public int getCount() { return mAdapter == null ? 0 : mAdapter.getCount(); } public Object getItem(int position) { return mAdapter == null ? null : mAdapter.getItem(position); } public long getItemId(int position) { return mAdapter == null ? -1 : mAdapter.getItemId(position); } public View getView(int position, View convertView, ViewGroup parent) { return getDropDownView(position, convertView, parent); } public View getDropDownView(int position, View convertView, ViewGroup parent) { return mAdapter == null ? null : mAdapter.getDropDownView(position, convertView, parent); } public boolean hasStableIds() { return mAdapter != null && mAdapter.hasStableIds(); } public void registerDataSetObserver(DataSetObserver observer) { if (mAdapter != null) { mAdapter.registerDataSetObserver(observer); } } public void unregisterDataSetObserver(DataSetObserver observer) { if (mAdapter != null) { mAdapter.unregisterDataSetObserver(observer); } } /** * If the wrapped SpinnerAdapter is also a ListAdapter, delegate this call. * Otherwise, return true. */ public boolean areAllItemsEnabled() { final ListAdapter adapter = mListAdapter; if (adapter != null) { return adapter.areAllItemsEnabled(); } else { return true; } } /** * If the wrapped SpinnerAdapter is also a ListAdapter, delegate this call. * Otherwise, return true. */ public boolean isEnabled(int position) { final ListAdapter adapter = mListAdapter; if (adapter != null) { return adapter.isEnabled(position); } else { return true; } } public int getItemViewType(int position) { return 0; } public int getViewTypeCount() { return 1; } public boolean isEmpty() { return getCount() == 0; } } /** * Implements some sort of popup selection interface for selecting a spinner option. * Allows for different spinner modes. */ private interface SpinnerPopup { public void setAdapter(ListAdapter adapter); /** * Show the popup */ public void show(); /** * Dismiss the popup */ public void dismiss(); /** * @return true if the popup is showing, false otherwise. */ public boolean isShowing(); /** * Set hint text to be displayed to the user. This should provide * a description of the choice being made. * @param hintText Hint text to set. */ public void setPromptText(CharSequence hintText); public CharSequence getHintText(); } /* private class DialogPopup implements SpinnerPopup, DialogInterface.OnClickListener { private AlertDialog mPopup; private ListAdapter mListAdapter; private CharSequence mPrompt; public void dismiss() { mPopup.dismiss(); mPopup = null; } public boolean isShowing() { return mPopup != null ? mPopup.isShowing() : false; } public void setAdapter(ListAdapter adapter) { mListAdapter = adapter; } public void setPromptText(CharSequence hintText) { mPrompt = hintText; } public CharSequence getHintText() { return mPrompt; } public void show() { AlertDialog.Builder builder = new AlertDialog.Builder(getContext()); if (mPrompt != null) { builder.setTitle(mPrompt); } mPopup = builder.setSingleChoiceItems(mListAdapter, getSelectedItemPosition(), this).show(); } public void onClick(DialogInterface dialog, int which) { setSelection(which); dismiss(); } } */ private class DropdownPopup extends IcsListPopupWindow implements SpinnerPopup { private CharSequence mHintText; private ListAdapter mAdapter; public DropdownPopup(Context context, AttributeSet attrs, int defStyleRes) { super(context, attrs, 0, defStyleRes); setAnchorView(IcsSpinner.this); setModal(true); setPromptPosition(POSITION_PROMPT_ABOVE); setOnItemClickListener(new OnItemClickListener() { @SuppressWarnings("rawtypes") public void onItemClick(AdapterView parent, View v, int position, long id) { IcsSpinner.this.setSelection(position); dismiss(); } }); } @Override public void setAdapter(ListAdapter adapter) { super.setAdapter(adapter); mAdapter = adapter; } public CharSequence getHintText() { return mHintText; } public void setPromptText(CharSequence hintText) { // Hint text is ignored for dropdowns, but maintain it here. mHintText = hintText; } @Override public void show() { final int spinnerPaddingLeft = IcsSpinner.this.getPaddingLeft(); if (mDropDownWidth == WRAP_CONTENT) { final int spinnerWidth = IcsSpinner.this.getWidth(); final int spinnerPaddingRight = IcsSpinner.this.getPaddingRight(); setContentWidth(Math.max(measureContentWidth((SpinnerAdapter) mAdapter, getBackground()), spinnerWidth - spinnerPaddingLeft - spinnerPaddingRight)); } else if (mDropDownWidth == MATCH_PARENT) { final int spinnerWidth = IcsSpinner.this.getWidth(); final int spinnerPaddingRight = IcsSpinner.this.getPaddingRight(); setContentWidth(spinnerWidth - spinnerPaddingLeft - spinnerPaddingRight); } else { setContentWidth(mDropDownWidth); } final Drawable background = getBackground(); int bgOffset = 0; if (background != null) { background.getPadding(mTempRect); bgOffset = -mTempRect.left; } setHorizontalOffset(bgOffset + spinnerPaddingLeft); setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED); super.show(); getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE); setSelection(IcsSpinner.this.getSelectedItemPosition()); } } }