Add new fade in/out feature for drawable containers.

This is used to allow list view's pressed and activated indicators
to fade in an out, though of course it can be used elsewhere as well.

There is a lot of complexity in supporting this in list view.  The
two main things that are being dealt with:

- When recycling views, we need to make sure that the view's drawable
  state doesn't get animated from an old row's state.  The recycler
  now keeps track of which position a view was last in, and if it is
  reused at a new position there is a new View/Drawable API to tell
  it to jump to its current state instead of animating.

- For the pressed indicator to fade out, we need to keep displaying it
  after it is hidden.  There are new variables and code to keep track
  of this state, and tweaks in various places to be able to remember
  the last selected position and continue updating the drawable bounds
  as needed.

Change-Id: Ic96aa1a3c05e519665abf3098892ff2cc4f0ef2f

6 files changed, 128 insertions, 49 deletions

diff --git a/core/java/android/util/StateSet.java b/core/java/android/util/StateSet.java
index f3d8159..21d8e45 100644
--- a/core/java/android/util/StateSet.java
+++ b/core/java/android/util/StateSet.java
@@ -38,6 +38,7 @@ import com.android.internal.R;
 public class StateSet {
 
     public static final int[] WILD_CARD = new int[0];
+    public static final int[] NOTHING = new int[] { 0 };
 
     /**
      * Return whether the stateSetOrSpec is matched by all StateSets.
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index fd7f4a4..340678d 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -8620,6 +8620,16 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
     }
 
     /**
+     * Call {@link Drawable#jumpToCurrentState() Drawable.jumpToCurrentState()}
+     * on all Drawable objects associated with this view.
+     */
+    public void jumpDrawablesToCurrentState() {
+        if (mBGDrawable != null) {
+            mBGDrawable.jumpToCurrentState();
+        }
+    }
+
+    /**
      * Sets the background color for this view.
      * @param color the color of the background
      */
diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java
index 4e90ecd..7629673 100644
--- a/core/java/android/widget/AbsListView.java
+++ b/core/java/android/widget/AbsListView.java
@@ -36,6 +36,7 @@ import android.util.AttributeSet;
 import android.util.Log;
 import android.util.LongSparseArray;
 import android.util.SparseBooleanArray;
+import android.util.StateSet;
 import android.view.ActionMode;
 import android.view.Gravity;
 import android.view.HapticFeedbackConstants;
@@ -254,6 +255,17 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
     Drawable mSelector;
 
     /**
+     * Set to true if we would like to have the selector showing itself.
+     * We still need to draw and position it even if this is false.
+     */
+    boolean mSelectorShowing;
+
+    /**
+     * The current position of the selector in the list.
+     */
+    int mSelectorPosition = INVALID_POSITION;
+
+    /**
      * Defines the selector's location and dimension at drawing time
      */
     Rect mSelectorRect = new Rect();
@@ -1324,6 +1336,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             setSelectedPositionInt(INVALID_POSITION);
             // Do this before setting mNeedSync since setNextSelectedPosition looks at mNeedSync
             setNextSelectedPositionInt(INVALID_POSITION);
+            mSelectorPosition = INVALID_POSITION;
             mNeedSync = true;
             mSyncRowId = ss.firstId;
             mSyncPosition = ss.position;
@@ -1416,6 +1429,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         setSelectedPositionInt(INVALID_POSITION);
         setNextSelectedPositionInt(INVALID_POSITION);
         mSelectedTop = 0;
+        mSelectorShowing = false;
+        mSelectorPosition = INVALID_POSITION;
         mSelectorRect.setEmpty();
         invalidate();
     }
@@ -1708,7 +1723,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             }
 
             if (child != scrapView) {
-                mRecycler.addScrapView(scrapView);
+                mRecycler.addScrapView(scrapView, position);
                 if (mCacheColorHint != 0) {
                     child.setDrawingCacheBackgroundColor(mCacheColorHint);
                 }
@@ -1734,7 +1749,11 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         return child;
     }
 
-    void positionSelector(View sel) {
+    void positionSelector(int position, View sel) {
+        if (position != INVALID_POSITION) {
+            mSelectorPosition = position;
+        }
+
         final Rect selectorRect = mSelectorRect;
         selectorRect.set(sel.getLeft(), sel.getTop(), sel.getRight(), sel.getBottom());
         positionSelector(selectorRect.left, selectorRect.top, selectorRect.right,
@@ -1743,7 +1762,9 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         final boolean isChildViewEnabled = mIsChildViewEnabled;
         if (sel.isEnabled() != isChildViewEnabled) {
             mIsChildViewEnabled = !isChildViewEnabled;
-            refreshDrawableState();
+            if (mSelectorShowing) {
+                refreshDrawableState();
+            }
         }
     }
 
@@ -1822,7 +1843,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
     }
 
     private void drawSelector(Canvas canvas) {
-        if (shouldShowSelector() && mSelectorRect != null && !mSelectorRect.isEmpty()) {
+        if (!mSelectorRect.isEmpty()) {
             final Drawable selector = mSelector;
             selector.setBounds(mSelectorRect);
             selector.draw(canvas);
@@ -1866,7 +1887,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         mSelectionRightPadding = padding.right;
         mSelectionBottomPadding = padding.bottom;
         sel.setCallback(this);
-        sel.setState(getDrawableState());
+        updateSelectorState();
     }
 
     /**
@@ -1891,7 +1912,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         Drawable selector = mSelector;
         Rect selectorRect = mSelectorRect;
         if (selector != null && (isFocused() || touchModeDrawsInPressedState())
-                && selectorRect != null && !selectorRect.isEmpty()) {
+                && !selectorRect.isEmpty()) {
 
             final View v = getChildAt(mSelectedPosition - mFirstPosition);
 
@@ -1926,12 +1947,20 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         mScrollDown = down;
     }
 
+    void updateSelectorState() {
+        if (mSelector != null) {
+            if (shouldShowSelector()) {
+                mSelector.setState(getDrawableState());
+            } else {
+                mSelector.setState(StateSet.NOTHING);
+            }
+        }
+    }
+
     @Override
     protected void drawableStateChanged() {
         super.drawableStateChanged();
-        if (mSelector != null) {
-            mSelector.setState(getDrawableState());
-        }
+        updateSelectorState();
     }
 
     @Override
@@ -2141,7 +2170,6 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                 } else {
                     mTouchMode = TOUCH_MODE_DONE_WAITING;
                 }
-
             }
         }
     }
@@ -2316,10 +2344,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                     mLayoutMode = LAYOUT_NORMAL;
 
                     if (!mDataChanged) {
-                        layoutChildren();
                         child.setPressed(true);
-                        positionSelector(child);
                         setPressed(true);
+                        layoutChildren();
+                        positionSelector(mMotionPosition, child);
 
                         final int longPressTimeout = ViewConfiguration.getLongPressTimeout();
                         final boolean longClickable = isLongClickable();
@@ -2566,7 +2594,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                             setSelectedPositionInt(mMotionPosition);
                             layoutChildren();
                             child.setPressed(true);
-                            positionSelector(child);
+                            positionSelector(mMotionPosition, child);
                             setPressed(true);
                             if (mSelector != null) {
                                 Drawable d = mSelector.getCurrent();
@@ -2576,16 +2604,17 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                             }
                             postDelayed(new Runnable() {
                                 public void run() {
+                                    mTouchMode = TOUCH_MODE_REST;
                                     child.setPressed(false);
                                     setPressed(false);
                                     if (!mDataChanged) {
                                         post(performClick);
                                     }
-                                    mTouchMode = TOUCH_MODE_REST;
                                 }
                             }, ViewConfiguration.getPressedStateDuration());
                         } else {
                             mTouchMode = TOUCH_MODE_REST;
+                            updateSelectorState();
                         }
                         return true;
                     } else if (!mDataChanged && mAdapter.isEnabled(motionPosition)) {
@@ -2593,6 +2622,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                     }
                 }
                 mTouchMode = TOUCH_MODE_REST;
+                updateSelectorState();
                 break;
             case TOUCH_MODE_SCROLL:
                 final int childCount = getChildCount();
@@ -3507,7 +3537,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                     count++;
                     int position = firstPosition + i;
                     if (position >= headerViewsCount && position < footerViewsStart) {
-                        mRecycler.addScrapView(child);
+                        mRecycler.addScrapView(child, position);
 
                         if (ViewDebug.TRACE_RECYCLER) {
                             ViewDebug.trace(child,
@@ -3528,7 +3558,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                     count++;
                     int position = firstPosition + i;
                     if (position >= headerViewsCount && position < footerViewsStart) {
-                        mRecycler.addScrapView(child);
+                        mRecycler.addScrapView(child, position);
 
                         if (ViewDebug.TRACE_RECYCLER) {
                             ViewDebug.trace(child,
@@ -3563,8 +3593,15 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         if (!inTouchMode && mSelectedPosition != INVALID_POSITION) {
             final int childIndex = mSelectedPosition - mFirstPosition;
             if (childIndex >= 0 && childIndex < getChildCount()) {
-                positionSelector(getChildAt(childIndex));
+                positionSelector(mSelectedPosition, getChildAt(childIndex));
+            }
+        } else if (mSelectorPosition != INVALID_POSITION) {
+            final int childIndex = mSelectorPosition - mFirstPosition;
+            if (childIndex >= 0 && childIndex < getChildCount()) {
+                positionSelector(INVALID_POSITION, getChildAt(childIndex));
             }
+        } else {
+            mSelectorRect.setEmpty();
         }
 
         mBlockLayoutRequests = false;
@@ -3616,7 +3653,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             setSelectedPositionInt(INVALID_POSITION);
             setNextSelectedPositionInt(INVALID_POSITION);
             mSelectedTop = 0;
-            mSelectorRect.setEmpty();
+            mSelectorShowing = false;
         }
     }
 
@@ -3876,6 +3913,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         mNextSelectedPosition = INVALID_POSITION;
         mNextSelectedRowId = INVALID_ROW_ID;
         mNeedSync = false;
+        mSelectorPosition = INVALID_POSITION;
         checkSelectionChanged();
     }
 
@@ -4562,6 +4600,13 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         @ViewDebug.ExportedProperty(category = "list")
         boolean forceAdd;
 
+        /**
+         * The position the view was removed from when pulled out of the
+         * scrap heap.
+         * @hide
+         */
+        int scrappedFromPosition;
+
         public LayoutParams(Context c, AttributeSet attrs) {
             super(c, attrs);
         }
@@ -4741,23 +4786,12 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
          * @return A view from the ScrapViews collection. These are unordered.
          */
         View getScrapView(int position) {
-            ArrayList<View> scrapViews;
             if (mViewTypeCount == 1) {
-                scrapViews = mCurrentScrap;
-                int size = scrapViews.size();
-                if (size > 0) {
-                    return scrapViews.remove(size - 1);
-                } else {
-                    return null;
-                }
+                return retrieveFromScrap(mCurrentScrap, position);
             } else {
                 int whichScrap = mAdapter.getItemViewType(position);
                 if (whichScrap >= 0 && whichScrap < mScrapViews.length) {
-                    scrapViews = mScrapViews[whichScrap];
-                    int size = scrapViews.size();
-                    if (size > 0) {
-                        return scrapViews.remove(size - 1);
-                    }
+                    return retrieveFromScrap(mScrapViews[whichScrap], position);
                 }
             }
             return null;
@@ -4768,7 +4802,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
          *
          * @param scrap The view to add
          */
-        void addScrapView(View scrap) {
+        void addScrapView(View scrap, int position) {
             AbsListView.LayoutParams lp = (AbsListView.LayoutParams) scrap.getLayoutParams();
             if (lp == null) {
                 return;
@@ -4784,6 +4818,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                 return;
             }
 
+            lp.scrappedFromPosition = position;
+
             if (mViewTypeCount == 1) {
                 scrap.dispatchStartTemporaryDetach();
                 mCurrentScrap.add(scrap);
@@ -4810,7 +4846,9 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             for (int i = count - 1; i >= 0; i--) {
                 final View victim = activeViews[i];
                 if (victim != null) {
-                    int whichScrap = ((AbsListView.LayoutParams) victim.getLayoutParams()).viewType;
+                    final AbsListView.LayoutParams lp
+                            = (AbsListView.LayoutParams) victim.getLayoutParams();
+                    int whichScrap = lp.viewType;
 
                     activeViews[i] = null;
 
@@ -4826,6 +4864,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                         scrapViews = mScrapViews[whichScrap];
                     }
                     victim.dispatchStartTemporaryDetach();
+                    lp.scrappedFromPosition = mFirstActivePosition + i;
                     scrapViews.add(victim);
 
                     if (hasListener) {
@@ -4911,4 +4950,22 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             }
         }
     }
+
+    static View retrieveFromScrap(ArrayList<View> scrapViews, int position) {
+        int size = scrapViews.size();
+        if (size > 0) {
+            // See if we still have a view for this position.
+            for (int i=0; i<size; i++) {
+                View view = scrapViews.get(i);
+                if (((AbsListView.LayoutParams)view.getLayoutParams())
+                        .scrappedFromPosition == position) {
+                    scrapViews.remove(i);
+                    return view;
+                }
+            }
+            return scrapViews.remove(size - 1);
+        } else {
+            return null;
+        }
+    }
 }
diff --git a/core/java/android/widget/AdapterView.java b/core/java/android/widget/AdapterView.java
index f5afb94..f16efbd 100644
--- a/core/java/android/widget/AdapterView.java
+++ b/core/java/android/widget/AdapterView.java
@@ -18,7 +18,6 @@ package android.widget;
 
 import android.content.Context;
 import android.database.DataSetObserver;
-import android.os.Handler;
 import android.os.Parcelable;
 import android.os.SystemClock;
 import android.util.AttributeSet;
diff --git a/core/java/android/widget/GridView.java b/core/java/android/widget/GridView.java
index 46c7d33..936a97d 100644
--- a/core/java/android/widget/GridView.java
+++ b/core/java/android/widget/GridView.java
@@ -1009,7 +1009,7 @@ public class GridView extends AbsListView {
             childHeight = child.getMeasuredHeight();
 
             if (mRecycler.shouldRecycleViewType(p.viewType)) {
-                mRecycler.addScrapView(child);
+                mRecycler.addScrapView(child, -1);
             }
         }
         
@@ -1148,7 +1148,7 @@ public class GridView extends AbsListView {
 
             if (dataChanged) {
                 for (int i = 0; i < childCount; i++) {
-                    recycleBin.addScrapView(getChildAt(i));
+                    recycleBin.addScrapView(getChildAt(i), firstPosition+i);
                 }
             } else {
                 recycleBin.fillActiveViews(childCount, firstPosition);
@@ -1215,11 +1215,11 @@ public class GridView extends AbsListView {
             recycleBin.scrapActiveViews();
 
             if (sel != null) {
-               positionSelector(sel);
+               positionSelector(INVALID_POSITION, sel);
                mSelectedTop = sel.getTop();
             } else if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) {
                 View child = getChildAt(mMotionPosition - mFirstPosition);
-                if (child != null) positionSelector(child);                
+                if (child != null) positionSelector(mMotionPosition, child);
             } else {
                 mSelectedTop = 0;
                 mSelectorRect.setEmpty();
@@ -1391,6 +1391,11 @@ public class GridView extends AbsListView {
         if (mCachingStarted) {
             child.setDrawingCacheEnabled(true);
         }
+
+        if (recycled && (((AbsListView.LayoutParams)child.getLayoutParams()).scrappedFromPosition)
+                != position) {
+            child.jumpDrawablesToCurrentState();
+        }
     }
 
     /**
diff --git a/core/java/android/widget/ListView.java b/core/java/android/widget/ListView.java
index b5e103f..e0119e9 100644
--- a/core/java/android/widget/ListView.java
+++ b/core/java/android/widget/ListView.java
@@ -581,7 +581,7 @@ public class ListView extends AbsListView {
         final boolean scroll = scrollYDelta != 0;
         if (scroll) {
             scrollListItemsBy(-scrollYDelta);
-            positionSelector(child);
+            positionSelector(INVALID_POSITION, child);
             mSelectedTop = child.getTop();
             invalidate();
         }
@@ -1086,7 +1086,7 @@ public class ListView extends AbsListView {
 
             if (recycleOnMeasure() && mRecycler.shouldRecycleViewType(
                     ((LayoutParams) child.getLayoutParams()).viewType)) {
-                mRecycler.addScrapView(child);
+                mRecycler.addScrapView(child, -1);
             }
         }
 
@@ -1203,7 +1203,7 @@ public class ListView extends AbsListView {
             // Recycle the view before we possibly return from the method
             if (recyle && recycleBin.shouldRecycleViewType(
                     ((LayoutParams) child.getLayoutParams()).viewType)) {
-                recycleBin.addScrapView(child);
+                recycleBin.addScrapView(child, -1);
             }
 
             returnedHeight += child.getMeasuredHeight();
@@ -1507,7 +1507,7 @@ public class ListView extends AbsListView {
             // already cached in mHeaderViews;
             if (dataChanged) {
                 for (int i = 0; i < childCount; i++) {
-                    recycleBin.addScrapView(getChildAt(i));
+                    recycleBin.addScrapView(getChildAt(i), firstPosition+i);
                     if (ViewDebug.TRACE_RECYCLER) {
                         ViewDebug.trace(getChildAt(i),
                                 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i);
@@ -1610,19 +1610,19 @@ public class ListView extends AbsListView {
                         if (focused != null) {
                             focused.clearFocus();
                         }
-                        positionSelector(sel);
+                        positionSelector(INVALID_POSITION, sel);
                     } else {
                         sel.setSelected(false);
                         mSelectorRect.setEmpty();
                     }
                 } else {
-                    positionSelector(sel);
+                    positionSelector(INVALID_POSITION, sel);
                 }
                 mSelectedTop = sel.getTop();
             } else {
                 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) {
                     View child = getChildAt(mMotionPosition - mFirstPosition);
-                    if (child != null) positionSelector(child);
+                    if (child != null) positionSelector(mMotionPosition, child);
                 } else {
                     mSelectedTop = 0;
                     mSelectorRect.setEmpty();
@@ -1703,7 +1703,7 @@ public class ListView extends AbsListView {
 
 
         if (!mDataChanged) {
-            // Try to use an exsiting view for this position
+            // Try to use an existing view for this position
             child = mRecycler.getActiveView(position);
             if (child != null) {
                 if (ViewDebug.TRACE_RECYCLER) {
@@ -1820,6 +1820,11 @@ public class ListView extends AbsListView {
         if (mCachingStarted && !child.isDrawingCacheEnabled()) {
             child.setDrawingCacheEnabled(true);
         }
+
+        if (recycled && (((AbsListView.LayoutParams)child.getLayoutParams()).scrappedFromPosition)
+                != position) {
+            child.jumpDrawablesToCurrentState();
+        }
     }
 
     @Override
@@ -2288,6 +2293,7 @@ public class ListView extends AbsListView {
         }
 
         View selectedView = getSelectedView();
+        int selectedPos = mSelectedPosition;
 
         int nextSelectedPosition = lookForSelectablePositionOnScreen(direction);
         int amountToScroll = amountToScroll(direction, nextSelectedPosition);
@@ -2305,6 +2311,7 @@ public class ListView extends AbsListView {
             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
@@ -2345,7 +2352,7 @@ public class ListView extends AbsListView {
 
         if (needToRedraw) {
             if (selectedView != null) {
-                positionSelector(selectedView);
+                positionSelector(selectedPos, selectedView);
                 mSelectedTop = selectedView.getTop();
             }
             if (!awakenScrollBars()) {
@@ -2841,7 +2848,7 @@ public class ListView extends AbsListView {
                 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams();
                 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
                     detachViewFromParent(first);
-                    recycleBin.addScrapView(first);
+                    recycleBin.addScrapView(first, mFirstPosition);
                 } else {
                     removeViewInLayout(first);
                 }
@@ -2872,7 +2879,7 @@ public class ListView extends AbsListView {
                 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams();
                 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) {
                     detachViewFromParent(last);
-                    recycleBin.addScrapView(last);
+                    recycleBin.addScrapView(last, mFirstPosition+lastIndex);
                 } else {
                     removeViewInLayout(last);
                 }