Java tutorial
/* * Copyright (C) 2011 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 edu.usf.cutr.opentripplanner.android.util; import android.content.Context; import android.os.Bundle; import android.os.Handler; import android.support.v4.app.Fragment; import android.view.ContextMenu; import android.view.ContextMenu.ContextMenuInfo; import android.view.Gravity; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnCreateContextMenuListener; import android.view.ViewGroup; import android.view.animation.AnimationUtils; import android.widget.AdapterView; import android.widget.ExpandableListAdapter; import android.widget.ExpandableListView; import android.widget.FrameLayout; import android.widget.LinearLayout; import android.widget.ProgressBar; import android.widget.TextView; /** * @author Khoa Tran * @see android.support.v4.app.ListFragment * @see android.app.ExpandableListActivity */ public class ExpandableListFragment extends Fragment implements OnCreateContextMenuListener, ExpandableListView.OnChildClickListener, ExpandableListView.OnGroupCollapseListener, ExpandableListView.OnGroupExpandListener { static final int INTERNAL_EMPTY_ID = 0x00ff0001; static final int INTERNAL_PROGRESS_CONTAINER_ID = 0x00ff0002; static final int INTERNAL_LIST_CONTAINER_ID = 0x00ff0003; final private Handler mHandler = new Handler(); final private Runnable mRequestFocus = new Runnable() { public void run() { mExpandableList.focusableViewAvailable(mExpandableList); } }; final private AdapterView.OnItemClickListener mOnClickListener = new AdapterView.OnItemClickListener() { public void onItemClick(AdapterView<?> parent, View v, int position, long id) { onListItemClick((ExpandableListView) parent, v, position, id); } }; ExpandableListAdapter mAdapter; ExpandableListView mExpandableList; boolean mFinishedStart = false; View mEmptyView; TextView mStandardEmptyView; View mProgressContainer; View mExpandableListContainer; CharSequence mEmptyText; boolean mExpandableListShown; public ExpandableListFragment() { } /** * Provide default implementation to return a simple list view. Subclasses * can override to replace with their own layout. If doing so, the * returned view hierarchy <em>must</em> have a ListView whose id * is {@link android.R.id#list android.R.id.list} and can optionally * have a sibling view id {@link android.R.id#empty android.R.id.empty} * that is to be shown when the list is empty. * * <p>If you are overriding this method with your own custom content, * consider including the standard layout {@link android.R.layout#list_content} * in your layout file, so that you continue to retain all of the standard * behavior of ListFragment. In particular, this is currently the only * way to have the built-in indeterminant progress state be shown. */ @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { final Context context = getActivity(); FrameLayout root = new FrameLayout(context); // ------------------------------------------------------------------ LinearLayout pframe = new LinearLayout(context); pframe.setId(INTERNAL_PROGRESS_CONTAINER_ID); pframe.setOrientation(LinearLayout.VERTICAL); pframe.setVisibility(View.GONE); pframe.setGravity(Gravity.CENTER); ProgressBar progress = new ProgressBar(context, null, android.R.attr.progressBarStyleLarge); pframe.addView(progress, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)); root.addView(pframe, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); // ------------------------------------------------------------------ FrameLayout lframe = new FrameLayout(context); lframe.setId(INTERNAL_LIST_CONTAINER_ID); TextView tv = new TextView(getActivity()); tv.setId(INTERNAL_EMPTY_ID); tv.setGravity(Gravity.CENTER); lframe.addView(tv, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); ExpandableListView lv = new ExpandableListView(getActivity()); lv.setId(android.R.id.list); lv.setDrawSelectorOnTop(false); lframe.addView(lv, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); root.addView(lframe, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); // ------------------------------------------------------------------ root.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); return root; } /** * Attach to list view once the view hierarchy has been created. */ @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); ensureList(); } /** * Detach from list view. */ @Override public void onDestroyView() { mHandler.removeCallbacks(mRequestFocus); mExpandableList = null; mExpandableListShown = false; mEmptyView = mProgressContainer = mExpandableListContainer = null; mStandardEmptyView = null; super.onDestroyView(); } /** * This method will be called when an item in the list is selected. * Subclasses should override. Subclasses can call * getListView().getItemAtPosition(position) if they need to access the * data associated with the selected item. * * @param l The ListView where the click happened * @param v The view that was clicked within the ListView * @param position The position of the view in the list * @param id The row id of the item that was clicked */ public void onListItemClick(ExpandableListView l, View v, int position, long id) { } /** * Provide the cursor for the list view. */ public void setListAdapter(ExpandableListAdapter adapter) { boolean hadAdapter = mAdapter != null; mAdapter = adapter; if (mExpandableList != null) { mExpandableList.setAdapter(adapter); if (!mExpandableListShown && !hadAdapter) { // The list was hidden, and previously didn't have an // adapter. It is now time to show it. setListShown(true, getView().getWindowToken() != null); } } } /** * Set the currently selected list item to the specified * position with the adapter's data */ public void setSelection(int position) { ensureList(); mExpandableList.setSelection(position); } /** * Get the position of the currently selected list item. */ public int getSelectedItemPosition() { ensureList(); return mExpandableList.getSelectedItemPosition(); } /** * Get the cursor row ID of the currently selected list item. */ public long getSelectedItemId() { ensureList(); return mExpandableList.getSelectedItemId(); } /** * Get the activity's list view widget. */ public ExpandableListView getListView() { ensureList(); return mExpandableList; } /** * The default content for a ListFragment has a TextView that can * be shown when the list is empty. If you would like to have it * shown, call this method to supply the text it should use. */ public void setEmptyText(CharSequence text) { ensureList(); if (mStandardEmptyView == null) { throw new IllegalStateException("Can't be used with a custom content view"); } mStandardEmptyView.setText(text); if (mEmptyText == null) { mExpandableList.setEmptyView(mStandardEmptyView); } mEmptyText = text; } /** * Control whether the list is being displayed. You can make it not * displayed if you are waiting for the initial data to show in it. During * this time an indeterminant progress indicator will be shown instead. * * <p>Applications do not normally need to use this themselves. The default * behavior of ListFragment is to start with the list not being shown, only * showing it once an adapter is given with setListAdapter(ListAdapter). * If the list at that point had not been shown, when it does get shown * it will be do without the user ever seeing the hidden state. * * @param shown If true, the list view is shown; if false, the progress * indicator. The initial value is true. */ public void setListShown(boolean shown) { setListShown(shown, true); } /** * Like {@link #setListShown(boolean)}, but no animation is used when * transitioning from the previous state. */ public void setListShownNoAnimation(boolean shown) { setListShown(shown, false); } /** * Control whether the list is being displayed. You can make it not * displayed if you are waiting for the initial data to show in it. During * this time an indeterminant progress indicator will be shown instead. * * @param shown If true, the list view is shown; if false, the progress * indicator. The initial value is true. * @param animate If true, an animation will be used to transition to the * new state. */ private void setListShown(boolean shown, boolean animate) { ensureList(); if (mProgressContainer == null) { throw new IllegalStateException("Can't be used with a custom content view"); } if (mExpandableListShown == shown) { return; } mExpandableListShown = shown; if (shown) { if (animate) { mProgressContainer .startAnimation(AnimationUtils.loadAnimation(getActivity(), android.R.anim.fade_out)); mExpandableListContainer .startAnimation(AnimationUtils.loadAnimation(getActivity(), android.R.anim.fade_in)); } else { mProgressContainer.clearAnimation(); mExpandableListContainer.clearAnimation(); } mProgressContainer.setVisibility(View.GONE); mExpandableListContainer.setVisibility(View.VISIBLE); } else { if (animate) { mProgressContainer .startAnimation(AnimationUtils.loadAnimation(getActivity(), android.R.anim.fade_in)); mExpandableListContainer .startAnimation(AnimationUtils.loadAnimation(getActivity(), android.R.anim.fade_out)); } else { mProgressContainer.clearAnimation(); mExpandableListContainer.clearAnimation(); } mProgressContainer.setVisibility(View.VISIBLE); mExpandableListContainer.setVisibility(View.GONE); } } /** * Get the ListAdapter associated with this activity's ListView. */ public ExpandableListAdapter getListAdapter() { return mAdapter; } private void ensureList() { if (mExpandableList != null) { return; } View root = getView(); if (root == null) { throw new IllegalStateException("Content view not yet created"); } if (root instanceof ExpandableListView) { mExpandableList = (ExpandableListView) root; } else { mStandardEmptyView = (TextView) root.findViewById(INTERNAL_EMPTY_ID); if (mStandardEmptyView == null) { mEmptyView = root.findViewById(android.R.id.empty); } else { mStandardEmptyView.setVisibility(View.GONE); } mProgressContainer = root.findViewById(INTERNAL_PROGRESS_CONTAINER_ID); mExpandableListContainer = root.findViewById(INTERNAL_LIST_CONTAINER_ID); View rawExpandableListView = root.findViewById(android.R.id.list); if (!(rawExpandableListView instanceof ExpandableListView)) { if (rawExpandableListView == null) { throw new RuntimeException( "Your content must have a ListView whose id attribute is " + "'android.R.id.list'"); } throw new RuntimeException( "Content has view with id attribute 'android.R.id.list' " + "that is not a ListView class"); } mExpandableList = (ExpandableListView) rawExpandableListView; if (mEmptyView != null) { mExpandableList.setEmptyView(mEmptyView); } else if (mEmptyText != null) { mStandardEmptyView.setText(mEmptyText); mExpandableList.setEmptyView(mStandardEmptyView); } } mExpandableListShown = true; mExpandableList.setOnItemClickListener(mOnClickListener); if (mAdapter != null) { ExpandableListAdapter adapter = mAdapter; mAdapter = null; setListAdapter(adapter); } else { // We are starting without an adapter, so assume we won't // have our data right away and start with the progress indicator. if (mProgressContainer != null) { setListShown(false, false); } } mHandler.post(mRequestFocus); } /** * Override this to populate the context menu when an item is long pressed. menuInfo * will contain an {@link android.widget.ExpandableListView.ExpandableListContextMenuInfo} * whose packedPosition is a packed position * that should be used with {@link ExpandableListView#getPackedPositionType(long)} and * the other similar methods. * <p> * {@inheritDoc} */ @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { } /** * Override this for receiving callbacks when a child has been clicked. * <p> * {@inheritDoc} */ public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) { return false; } /** * Override this for receiving callbacks when a group has been collapsed. */ public void onGroupCollapse(int groupPosition) { } /** * Override this for receiving callbacks when a group has been expanded. */ public void onGroupExpand(int groupPosition) { } // /** // * Ensures the expandable list view has been created before Activity restores all // * of the view states. // * // *@see Activity#onRestoreInstanceState(Bundle) // */ // @Override // protected void onRestoreInstanceState(Bundle state) { // ensureList(); // super.onRestoreInstanceState(state); // } /** * Updates the screen state (current list and other views) when the * content changes. * * @see Activity.onContentChanged() */ public void onContentChanged() { // super.onContentChanged(); View emptyView = getView().findViewById(android.R.id.empty); mExpandableList = (ExpandableListView) getView().findViewById(android.R.id.list); if (mExpandableList == null) { throw new RuntimeException( "Your content must have a ExpandableListView whose id attribute is " + "'android.R.id.list'"); } if (emptyView != null) { mExpandableList.setEmptyView(emptyView); } mExpandableList.setOnChildClickListener(this); mExpandableList.setOnGroupExpandListener(this); mExpandableList.setOnGroupCollapseListener(this); if (mFinishedStart) { setListAdapter(mAdapter); } mFinishedStart = true; } /** * Get the activity's expandable list view widget. This can be used to get the selection, * set the selection, and many other useful functions. * * @see ExpandableListView */ public ExpandableListView getExpandableListView() { ensureList(); return mExpandableList; } /** * Get the ExpandableListAdapter associated with this activity's * ExpandableListView. */ public ExpandableListAdapter getExpandableListAdapter() { return mAdapter; } /** * Gets the ID of the currently selected group or child. * * @return The ID of the currently selected group or child. */ public long getSelectedId() { return mExpandableList.getSelectedId(); } /** * Gets the position (in packed position representation) of the currently * selected group or child. Use * {@link ExpandableListView#getPackedPositionType}, * {@link ExpandableListView#getPackedPositionGroup}, and * {@link ExpandableListView#getPackedPositionChild} to unpack the returned * packed position. * * @return A packed position representation containing the currently * selected group or child's position and type. */ public long getSelectedPosition() { return mExpandableList.getSelectedPosition(); } /** * Sets the selection to the specified child. If the child is in a collapsed * group, the group will only be expanded and child subsequently selected if * shouldExpandGroup is set to true, otherwise the method will return false. * * @param groupPosition The position of the group that contains the child. * @param childPosition The position of the child within the group. * @param shouldExpandGroup Whether the child's group should be expanded if * it is collapsed. * @return Whether the selection was successfully set on the child. */ public boolean setSelectedChild(int groupPosition, int childPosition, boolean shouldExpandGroup) { return mExpandableList.setSelectedChild(groupPosition, childPosition, shouldExpandGroup); } /** * Sets the selection to the specified group. * * @param groupPosition The position of the group that should be selected. */ public void setSelectedGroup(int groupPosition) { mExpandableList.setSelectedGroup(groupPosition); } }