src/com/android/dialer/list/PhoneFavoriteListView.java - platform/packages/apps/Dialer - Git at Google

 /*
  * Copyright (C) 2012 Google Inc.
  * Licensed to 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.android.dialer.list;

 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
 import android.os.Handler;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.DragEvent;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewConfiguration;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.ListView;

 import com.android.dialer.R;
 import com.android.dialer.list.PhoneFavoritesTileAdapter.ContactTileRow;
 import com.android.dialer.list.SwipeHelper.OnItemGestureListener;
 import com.android.dialer.list.SwipeHelper.SwipeHelperCallback;

 /**
  * The ListView composed of {@link ContactTileRow}.
  * This ListView handles both
  * - Swiping, which is borrowed from packages/apps/UnifiedEmail (com.android.mail.ui.Swipeable)
  * - Drag and drop
  */
 public class PhoneFavoriteListView extends ListView implements SwipeHelperCallback {

     public static final String LOG_TAG = PhoneFavoriteListView.class.getSimpleName();

     private SwipeHelper mSwipeHelper;
     private boolean mEnableSwipe = true;

     private OnItemGestureListener mOnItemGestureListener;
     private OnDragDropListener mOnDragDropListener;

     private float mDensityScale;
     private float mTouchSlop;

     private int mTopScrollBound;
     private int mBottomScrollBound;
     private int mLastDragY;

     private Handler mScrollHandler;
     private final long SCROLL_HANDLER_DELAY_MILLIS = 5;
     private final int DRAG_SCROLL_PX_UNIT = 10;

     private boolean mIsDragScrollerRunning = false;
     private int mTouchDownForDragStartX;
     private int mTouchDownForDragStartY;

     private Bitmap mDragShadowBitmap;
     private ImageView mDragShadowOverlay;
     private int mAnimationDuration;

     // X and Y offsets inside the item from where the user grabbed to the
     // child's left coordinate. This is used to aid in the drawing of the drag shadow.
     private int mTouchOffsetToChildLeft;
     private int mTouchOffsetToChildTop;

     private int mDragShadowLeft;
     private int mDragShadowTop;

     private final float DRAG_SHADOW_ALPHA = 0.7f;

     /**
      * {@link #mTopScrollBound} and {@link mBottomScrollBound} will be
      * offseted to the top / bottom by {@link #getHeight} * {@link #BOUND_GAP_RATIO} pixels.
      */
     private final float BOUND_GAP_RATIO = 0.2f;

     private final Runnable mDragScroller = new Runnable() {
         @Override
         public void run() {
             if (mLastDragY <= mTopScrollBound) {
                 smoothScrollBy(-DRAG_SCROLL_PX_UNIT, (int) SCROLL_HANDLER_DELAY_MILLIS);
             } else if (mLastDragY >= mBottomScrollBound) {
                 smoothScrollBy(DRAG_SCROLL_PX_UNIT, (int) SCROLL_HANDLER_DELAY_MILLIS);
             }
             mScrollHandler.postDelayed(this, SCROLL_HANDLER_DELAY_MILLIS);
         }
     };

     private final AnimatorListenerAdapter mDragShadowOverAnimatorListener =
             new AnimatorListenerAdapter() {
         @Override
         public void onAnimationEnd(Animator animation) {
             if (mDragShadowBitmap != null) {
                 mDragShadowBitmap.recycle();
                 mDragShadowBitmap = null;
             }
             mDragShadowOverlay.setVisibility(GONE);
             mDragShadowOverlay.setImageBitmap(null);
         }
     };

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

     public PhoneFavoriteListView(Context context, AttributeSet attrs) {
         this(context, attrs, -1);
     }

     public PhoneFavoriteListView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         mAnimationDuration = context.getResources().getInteger(R.integer.fade_duration);
         mDensityScale = getResources().getDisplayMetrics().density;
         mTouchSlop = ViewConfiguration.get(context).getScaledPagingTouchSlop();
         mSwipeHelper = new SwipeHelper(context, SwipeHelper.X, this,
                 mDensityScale, mTouchSlop);
         setItemsCanFocus(true);
     }

     @Override
     protected void onConfigurationChanged(Configuration newConfig) {
         super.onConfigurationChanged(newConfig);
         mDensityScale= getResources().getDisplayMetrics().density;
         mTouchSlop = ViewConfiguration.get(getContext()).getScaledPagingTouchSlop();
         mSwipeHelper.setDensityScale(mDensityScale);
         mSwipeHelper.setPagingTouchSlop(mTouchSlop);
     }

     /**
      * Enable swipe gestures.
      */
     public void enableSwipe(boolean enable) {
         mEnableSwipe = enable;
     }

     public boolean isSwipeEnabled() {
         return mEnableSwipe && mOnItemGestureListener.isSwipeEnabled();
     }

     public void setOnItemSwipeListener(OnItemGestureListener listener) {
         mOnItemGestureListener = listener;
     }

     public void setOnDragDropListener(OnDragDropListener listener) {
         mOnDragDropListener = listener;
     }

     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         if (ev.getAction() == MotionEvent.ACTION_DOWN) {
             mTouchDownForDragStartX = (int) ev.getX();
             mTouchDownForDragStartY = (int) ev.getY();
         }
         if (isSwipeEnabled()) {
             return mSwipeHelper.onInterceptTouchEvent(ev) || super.onInterceptTouchEvent(ev);
         } else {
             return super.onInterceptTouchEvent(ev);
         }
     }

     @Override
     public boolean onTouchEvent(MotionEvent ev) {
         if (mOnItemGestureListener != null) {
             mOnItemGestureListener.onTouch();
         }
         if (isSwipeEnabled()) {
             return mSwipeHelper.onTouchEvent(ev) || super.onTouchEvent(ev);
         } else {
             return super.onTouchEvent(ev);
         }
     }

     @Override
     public View getChildAtPosition(MotionEvent ev) {
         final View view = getViewAtPosition((int) ev.getX(), (int) ev.getY());
         if (view != null &&
                 SwipeHelper.isSwipeable(view) &&
                 view.getVisibility() != GONE) {
             // If this view is swipable in this listview, then return it. Otherwise
             // return a null view, which will simply be ignored by the swipe helper.
             return view;
         }
         return null;
     }

     @Override
     public View getChildContentView(View view) {
         return view.findViewById(R.id.contact_favorite_card);
     }

     @Override
     public void onScroll() {}

     @Override
     public boolean canChildBeDismissed(View v) {
         return SwipeHelper.isSwipeable(v);
     }

     @Override
     public void onChildDismissed(final View v) {
         if (v != null) {
             if (mOnItemGestureListener != null) {
                 mOnItemGestureListener.onSwipe(v);
             }
         }
     }

     @Override
     public void onDragCancelled(View v) {}

     @Override
     public void onBeginDrag(View v) {
         final View tileRow = (View) v.getParent();

         // We do this so the underlying ScrollView knows that it won't get
         // the chance to intercept events anymore
         requestDisallowInterceptTouchEvent(true);
     }

     @Override
     public boolean dispatchDragEvent(DragEvent event) {
         final int action = event.getAction();
         final int eX = (int) event.getX();
         final int eY = (int) event.getY();
         switch (action) {
             case DragEvent.ACTION_DRAG_STARTED:
                 if (!handleDragStarted(mTouchDownForDragStartX, mTouchDownForDragStartY)) {
                     return false;
                 };
                 break;
             case DragEvent.ACTION_DRAG_LOCATION:
                 mLastDragY = eY;
                 handleDragHovered(eX, eY);
                 // Kick off {@link #mScrollHandler} if it's not started yet.
                 if (!mIsDragScrollerRunning &&
                         // And if the distance traveled while dragging exceeds the touch slop
                         (Math.abs(mLastDragY - mTouchDownForDragStartY) >= 4 * mTouchSlop)) {
                     mIsDragScrollerRunning = true;
                     ensureScrollHandler();
                     mScrollHandler.postDelayed(mDragScroller, SCROLL_HANDLER_DELAY_MILLIS);
                 }
                 break;
             case DragEvent.ACTION_DRAG_ENTERED:
                 final int boundGap = (int) (getHeight() * BOUND_GAP_RATIO);
                 mTopScrollBound = (getTop() + boundGap);
                 mBottomScrollBound = (getBottom() - boundGap);
                 break;
             case DragEvent.ACTION_DRAG_EXITED:
             case DragEvent.ACTION_DRAG_ENDED:
             case DragEvent.ACTION_DROP:
                 ensureScrollHandler();
                 mScrollHandler.removeCallbacks(mDragScroller);
                 mIsDragScrollerRunning = false;
                 // Either a successful drop or it's ended with out drop.
                 if (action == DragEvent.ACTION_DROP || action == DragEvent.ACTION_DRAG_ENDED) {
                     handleDragFinished(eX, eY);
                 }
                 break;
             default:
                 break;
         }
         // This ListView will consumer the drag events on behalf of its children.
         return true;
     }

     public void setDragShadowOverlay(ImageView overlay) {
         mDragShadowOverlay = overlay;
     }

     /**
      * Find the view under the pointer.
      */
     private View getViewAtPosition(int x, int y) {
         final int count = getChildCount();
         View child;
         for (int childIdx = 0; childIdx < count; childIdx++) {
             child = getChildAt(childIdx);
             if (y >= child.getTop() && y <= child.getBottom()) {
                 return child;
             }
         }
         return null;
     }

     private void ensureScrollHandler() {
         if (mScrollHandler == null) {
             mScrollHandler = getHandler();
         }
     }

     /**
      * @return True if the drag is started.
      */
     private boolean handleDragStarted(int x, int y) {
         final View child = getViewAtPosition(x, y);
         if (!(child instanceof ContactTileRow)) {
             // Bail early.
             return false;
         }

         final ContactTileRow tile = (ContactTileRow) child;

         if (tile.getTileAdapter().hasPotentialRemoveEntryIndex()) {
             return false;
         }

         final int itemIndex = tile.getItemIndex(x, y);
         if (itemIndex != -1 && mOnDragDropListener != null) {
             final PhoneFavoriteTileView tileView =
                     (PhoneFavoriteTileView) tile.getViewAtPosition(x, y);
             if (mDragShadowOverlay == null) {
                 return false;
             }

             mDragShadowOverlay.clearAnimation();
             mDragShadowBitmap = createDraggedChildBitmap(tileView);
             if (mDragShadowBitmap == null) {
                 return false;
             }

             if (tileView instanceof PhoneFavoriteRegularRowView) {
                 mDragShadowLeft = tile.getLeft();
                 mDragShadowTop = tile.getTop();
             } else {
                 // Square tile is relative to the contact tile,
                 // and contact tile is relative to this list view.
                 mDragShadowLeft = tileView.getLeft() + tileView.getParentRow().getLeft();
                 mDragShadowTop = tileView.getTop() + tileView.getParentRow().getTop();
             }

             mDragShadowOverlay.setImageBitmap(mDragShadowBitmap);
             mDragShadowOverlay.setVisibility(VISIBLE);
             mDragShadowOverlay.setAlpha(DRAG_SHADOW_ALPHA);

             mDragShadowOverlay.setX(mDragShadowLeft);
             mDragShadowOverlay.setY(mDragShadowTop);

             // x and y passed in are the coordinates of where the user has touched down, calculate
             // the offset to the top left coordinate of the dragged child.  This will be used for
             // drawing the drag shadow.
             mTouchOffsetToChildLeft = x - mDragShadowLeft;
             mTouchOffsetToChildTop = y - mDragShadowTop;

             // invalidate to trigger a redraw of the drag shadow.
             invalidate();

             mOnDragDropListener.onDragStarted(itemIndex);
         }

         return true;
     }

     private void handleDragHovered(int x, int y) {
         // Update the drag shadow location.
         mDragShadowLeft = x - mTouchOffsetToChildLeft;
         mDragShadowTop = y - mTouchOffsetToChildTop;
         // Draw the drag shadow at its last known location if the drag shadow exists.
         if (mDragShadowOverlay != null) {
             mDragShadowOverlay.setX(mDragShadowLeft);
             mDragShadowOverlay.setY(mDragShadowTop);
         }

         final View child = getViewAtPosition(x, y);
         if (!(child instanceof ContactTileRow)) {
             // Bail early.
             return;
         }

         final ContactTileRow tile = (ContactTileRow) child;
         final int itemIndex = tile.getItemIndex(x, y);
         if (itemIndex != -1 && mOnDragDropListener != null) {
             mOnDragDropListener.onDragHovered(itemIndex);
         }
     }

     private void handleDragFinished(int x, int y) {
         // Update the drag shadow location.
         mDragShadowLeft = x - mTouchOffsetToChildLeft;
         mDragShadowTop = y - mTouchOffsetToChildTop;

         if (mDragShadowOverlay != null) {
             mDragShadowOverlay.clearAnimation();
             mDragShadowOverlay.animate().alpha(0.0f)
                     .setDuration(mAnimationDuration)
                     .setListener(mDragShadowOverAnimatorListener)
                     .start();
         }

         if (mOnDragDropListener != null) {
             mOnDragDropListener.onDragFinished();
         }
     }

     private Bitmap createDraggedChildBitmap(View view) {
         view.setDrawingCacheEnabled(true);
         final Bitmap cache = view.getDrawingCache();

         Bitmap bitmap = null;
         if (cache != null) {
             try {
                 bitmap = cache.copy(Bitmap.Config.ARGB_8888, false);
             } catch (final OutOfMemoryError e) {
                 Log.w(LOG_TAG, "Failed to copy bitmap from Drawing cache", e);
                 bitmap = null;
             }
         }

         view.destroyDrawingCache();
         view.setDrawingCacheEnabled(false);

         return bitmap;
     }

     public interface OnDragDropListener {
         public void onDragStarted(int itemIndex);
         public void onDragHovered(int itemIndex);
         public void onDragFinished();
     }
 }
	/*
	* Copyright (C) 2012 Google Inc.
	* Licensed to 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.android.dialer.list;

	import android.animation.Animator;
	import android.animation.AnimatorListenerAdapter;
	import android.content.Context;
	import android.content.res.Configuration;
	import android.graphics.Bitmap;
	import android.os.Handler;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.DragEvent;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.ViewConfiguration;
	import android.widget.FrameLayout;
	import android.widget.ImageView;
	import android.widget.ListView;

	import com.android.dialer.R;
	import com.android.dialer.list.PhoneFavoritesTileAdapter.ContactTileRow;
	import com.android.dialer.list.SwipeHelper.OnItemGestureListener;
	import com.android.dialer.list.SwipeHelper.SwipeHelperCallback;

	/**
	* The ListView composed of {@link ContactTileRow}.
	* This ListView handles both
	* - Swiping, which is borrowed from packages/apps/UnifiedEmail (com.android.mail.ui.Swipeable)
	* - Drag and drop
	*/
	public class PhoneFavoriteListView extends ListView implements SwipeHelperCallback {

	public static final String LOG_TAG = PhoneFavoriteListView.class.getSimpleName();

	private SwipeHelper mSwipeHelper;
	private boolean mEnableSwipe = true;

	private OnItemGestureListener mOnItemGestureListener;
	private OnDragDropListener mOnDragDropListener;

	private float mDensityScale;
	private float mTouchSlop;

	private int mTopScrollBound;
	private int mBottomScrollBound;
	private int mLastDragY;

	private Handler mScrollHandler;
	private final long SCROLL_HANDLER_DELAY_MILLIS = 5;
	private final int DRAG_SCROLL_PX_UNIT = 10;

	private boolean mIsDragScrollerRunning = false;
	private int mTouchDownForDragStartX;
	private int mTouchDownForDragStartY;

	private Bitmap mDragShadowBitmap;
	private ImageView mDragShadowOverlay;
	private int mAnimationDuration;

	// X and Y offsets inside the item from where the user grabbed to the
	// child's left coordinate. This is used to aid in the drawing of the drag shadow.
	private int mTouchOffsetToChildLeft;
	private int mTouchOffsetToChildTop;

	private int mDragShadowLeft;
	private int mDragShadowTop;

	private final float DRAG_SHADOW_ALPHA = 0.7f;

	/**
	* {@link #mTopScrollBound} and {@link mBottomScrollBound} will be
	* offseted to the top / bottom by {@link #getHeight} * {@link #BOUND_GAP_RATIO} pixels.
	*/
	private final float BOUND_GAP_RATIO = 0.2f;

	private final Runnable mDragScroller = new Runnable() {
	@Override
	public void run() {
	if (mLastDragY <= mTopScrollBound) {
	smoothScrollBy(-DRAG_SCROLL_PX_UNIT, (int) SCROLL_HANDLER_DELAY_MILLIS);
	} else if (mLastDragY >= mBottomScrollBound) {
	smoothScrollBy(DRAG_SCROLL_PX_UNIT, (int) SCROLL_HANDLER_DELAY_MILLIS);
	}
	mScrollHandler.postDelayed(this, SCROLL_HANDLER_DELAY_MILLIS);
	}
	};

	private final AnimatorListenerAdapter mDragShadowOverAnimatorListener =
	new AnimatorListenerAdapter() {
	@Override
	public void onAnimationEnd(Animator animation) {
	if (mDragShadowBitmap != null) {
	mDragShadowBitmap.recycle();
	mDragShadowBitmap = null;
	}
	mDragShadowOverlay.setVisibility(GONE);
	mDragShadowOverlay.setImageBitmap(null);
	}
	};

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

	public PhoneFavoriteListView(Context context, AttributeSet attrs) {
	this(context, attrs, -1);
	}

	public PhoneFavoriteListView(Context context, AttributeSet attrs, int defStyle) {
	super(context, attrs, defStyle);
	mAnimationDuration = context.getResources().getInteger(R.integer.fade_duration);
	mDensityScale = getResources().getDisplayMetrics().density;
	mTouchSlop = ViewConfiguration.get(context).getScaledPagingTouchSlop();
	mSwipeHelper = new SwipeHelper(context, SwipeHelper.X, this,
	mDensityScale, mTouchSlop);
	setItemsCanFocus(true);
	}

	@Override
	protected void onConfigurationChanged(Configuration newConfig) {
	super.onConfigurationChanged(newConfig);
	mDensityScale= getResources().getDisplayMetrics().density;
	mTouchSlop = ViewConfiguration.get(getContext()).getScaledPagingTouchSlop();
	mSwipeHelper.setDensityScale(mDensityScale);
	mSwipeHelper.setPagingTouchSlop(mTouchSlop);
	}

	/**
	* Enable swipe gestures.
	*/
	public void enableSwipe(boolean enable) {
	mEnableSwipe = enable;
	}

	public boolean isSwipeEnabled() {
	return mEnableSwipe && mOnItemGestureListener.isSwipeEnabled();
	}

	public void setOnItemSwipeListener(OnItemGestureListener listener) {
	mOnItemGestureListener = listener;
	}

	public void setOnDragDropListener(OnDragDropListener listener) {
	mOnDragDropListener = listener;
	}

	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
	if (ev.getAction() == MotionEvent.ACTION_DOWN) {
	mTouchDownForDragStartX = (int) ev.getX();
	mTouchDownForDragStartY = (int) ev.getY();
	}
	if (isSwipeEnabled()) {
	return mSwipeHelper.onInterceptTouchEvent(ev) \|\| super.onInterceptTouchEvent(ev);
	} else {
	return super.onInterceptTouchEvent(ev);
	}
	}

	@Override
	public boolean onTouchEvent(MotionEvent ev) {
	if (mOnItemGestureListener != null) {
	mOnItemGestureListener.onTouch();
	}
	if (isSwipeEnabled()) {
	return mSwipeHelper.onTouchEvent(ev) \|\| super.onTouchEvent(ev);
	} else {
	return super.onTouchEvent(ev);
	}
	}

	@Override
	public View getChildAtPosition(MotionEvent ev) {
	final View view = getViewAtPosition((int) ev.getX(), (int) ev.getY());
	if (view != null &&
	SwipeHelper.isSwipeable(view) &&
	view.getVisibility() != GONE) {
	// If this view is swipable in this listview, then return it. Otherwise
	// return a null view, which will simply be ignored by the swipe helper.
	return view;
	}
	return null;
	}

	@Override
	public View getChildContentView(View view) {
	return view.findViewById(R.id.contact_favorite_card);
	}

	@Override
	public void onScroll() {}

	@Override
	public boolean canChildBeDismissed(View v) {
	return SwipeHelper.isSwipeable(v);
	}

	@Override
	public void onChildDismissed(final View v) {
	if (v != null) {
	if (mOnItemGestureListener != null) {
	mOnItemGestureListener.onSwipe(v);
	}
	}
	}

	@Override
	public void onDragCancelled(View v) {}

	@Override
	public void onBeginDrag(View v) {
	final View tileRow = (View) v.getParent();

	// We do this so the underlying ScrollView knows that it won't get
	// the chance to intercept events anymore
	requestDisallowInterceptTouchEvent(true);
	}

	@Override
	public boolean dispatchDragEvent(DragEvent event) {
	final int action = event.getAction();
	final int eX = (int) event.getX();
	final int eY = (int) event.getY();
	switch (action) {
	case DragEvent.ACTION_DRAG_STARTED:
	if (!handleDragStarted(mTouchDownForDragStartX, mTouchDownForDragStartY)) {
	return false;
	};
	break;
	case DragEvent.ACTION_DRAG_LOCATION:
	mLastDragY = eY;
	handleDragHovered(eX, eY);
	// Kick off {@link #mScrollHandler} if it's not started yet.
	if (!mIsDragScrollerRunning &&
	// And if the distance traveled while dragging exceeds the touch slop
	(Math.abs(mLastDragY - mTouchDownForDragStartY) >= 4 * mTouchSlop)) {
	mIsDragScrollerRunning = true;
	ensureScrollHandler();
	mScrollHandler.postDelayed(mDragScroller, SCROLL_HANDLER_DELAY_MILLIS);
	}
	break;
	case DragEvent.ACTION_DRAG_ENTERED:
	final int boundGap = (int) (getHeight() * BOUND_GAP_RATIO);
	mTopScrollBound = (getTop() + boundGap);
	mBottomScrollBound = (getBottom() - boundGap);
	break;
	case DragEvent.ACTION_DRAG_EXITED:
	case DragEvent.ACTION_DRAG_ENDED:
	case DragEvent.ACTION_DROP:
	ensureScrollHandler();
	mScrollHandler.removeCallbacks(mDragScroller);
	mIsDragScrollerRunning = false;
	// Either a successful drop or it's ended with out drop.
	if (action == DragEvent.ACTION_DROP \|\| action == DragEvent.ACTION_DRAG_ENDED) {
	handleDragFinished(eX, eY);
	}
	break;
	default:
	break;
	}
	// This ListView will consumer the drag events on behalf of its children.
	return true;
	}

	public void setDragShadowOverlay(ImageView overlay) {
	mDragShadowOverlay = overlay;
	}

	/**
	* Find the view under the pointer.
	*/
	private View getViewAtPosition(int x, int y) {
	final int count = getChildCount();
	View child;
	for (int childIdx = 0; childIdx < count; childIdx++) {
	child = getChildAt(childIdx);
	if (y >= child.getTop() && y <= child.getBottom()) {
	return child;
	}
	}
	return null;
	}

	private void ensureScrollHandler() {
	if (mScrollHandler == null) {
	mScrollHandler = getHandler();
	}
	}

	/**
	* @return True if the drag is started.
	*/
	private boolean handleDragStarted(int x, int y) {
	final View child = getViewAtPosition(x, y);
	if (!(child instanceof ContactTileRow)) {
	// Bail early.
	return false;
	}

	final ContactTileRow tile = (ContactTileRow) child;

	if (tile.getTileAdapter().hasPotentialRemoveEntryIndex()) {
	return false;
	}

	final int itemIndex = tile.getItemIndex(x, y);
	if (itemIndex != -1 && mOnDragDropListener != null) {
	final PhoneFavoriteTileView tileView =
	(PhoneFavoriteTileView) tile.getViewAtPosition(x, y);
	if (mDragShadowOverlay == null) {
	return false;
	}

	mDragShadowOverlay.clearAnimation();
	mDragShadowBitmap = createDraggedChildBitmap(tileView);
	if (mDragShadowBitmap == null) {
	return false;
	}

	if (tileView instanceof PhoneFavoriteRegularRowView) {
	mDragShadowLeft = tile.getLeft();
	mDragShadowTop = tile.getTop();
	} else {
	// Square tile is relative to the contact tile,
	// and contact tile is relative to this list view.
	mDragShadowLeft = tileView.getLeft() + tileView.getParentRow().getLeft();
	mDragShadowTop = tileView.getTop() + tileView.getParentRow().getTop();
	}

	mDragShadowOverlay.setImageBitmap(mDragShadowBitmap);
	mDragShadowOverlay.setVisibility(VISIBLE);
	mDragShadowOverlay.setAlpha(DRAG_SHADOW_ALPHA);

	mDragShadowOverlay.setX(mDragShadowLeft);
	mDragShadowOverlay.setY(mDragShadowTop);

	// x and y passed in are the coordinates of where the user has touched down, calculate
	// the offset to the top left coordinate of the dragged child. This will be used for
	// drawing the drag shadow.
	mTouchOffsetToChildLeft = x - mDragShadowLeft;
	mTouchOffsetToChildTop = y - mDragShadowTop;

	// invalidate to trigger a redraw of the drag shadow.
	invalidate();

	mOnDragDropListener.onDragStarted(itemIndex);
	}

	return true;
	}

	private void handleDragHovered(int x, int y) {
	// Update the drag shadow location.
	mDragShadowLeft = x - mTouchOffsetToChildLeft;
	mDragShadowTop = y - mTouchOffsetToChildTop;
	// Draw the drag shadow at its last known location if the drag shadow exists.
	if (mDragShadowOverlay != null) {
	mDragShadowOverlay.setX(mDragShadowLeft);
	mDragShadowOverlay.setY(mDragShadowTop);
	}

	final View child = getViewAtPosition(x, y);
	if (!(child instanceof ContactTileRow)) {
	// Bail early.
	return;
	}

	final ContactTileRow tile = (ContactTileRow) child;
	final int itemIndex = tile.getItemIndex(x, y);
	if (itemIndex != -1 && mOnDragDropListener != null) {
	mOnDragDropListener.onDragHovered(itemIndex);
	}
	}

	private void handleDragFinished(int x, int y) {
	// Update the drag shadow location.
	mDragShadowLeft = x - mTouchOffsetToChildLeft;
	mDragShadowTop = y - mTouchOffsetToChildTop;

	if (mDragShadowOverlay != null) {
	mDragShadowOverlay.clearAnimation();
	mDragShadowOverlay.animate().alpha(0.0f)
	.setDuration(mAnimationDuration)
	.setListener(mDragShadowOverAnimatorListener)
	.start();
	}

	if (mOnDragDropListener != null) {
	mOnDragDropListener.onDragFinished();
	}
	}

	private Bitmap createDraggedChildBitmap(View view) {
	view.setDrawingCacheEnabled(true);
	final Bitmap cache = view.getDrawingCache();

	Bitmap bitmap = null;
	if (cache != null) {
	try {
	bitmap = cache.copy(Bitmap.Config.ARGB_8888, false);
	} catch (final OutOfMemoryError e) {
	Log.w(LOG_TAG, "Failed to copy bitmap from Drawing cache", e);
	bitmap = null;
	}
	}

	view.destroyDrawingCache();
	view.setDrawingCacheEnabled(false);

	return bitmap;
	}

	public interface OnDragDropListener {
	public void onDragStarted(int itemIndex);
	public void onDragHovered(int itemIndex);
	public void onDragFinished();
	}
	}