Merge changes I6e3f4da2,I8acfbd1a into nyc-dev

* changes:
  Fully detach unused scrap views
  Remove detached headers

core/java/android/widget/AbsListView.java

@@ -2322,7 +2322,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
      *
      * @param position The position to display
      * @param isScrap Array of at least 1 boolean, the first entry will become true if
-     *                the returned view was taken from the scrap heap, false if otherwise.
+     *                the returned view was taken from the "temporary detached" scrap heap, false if
+     *                otherwise.
      *
      * @return A view displaying the data associated with the specified position
      */
@@ -2362,10 +2363,18 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                 // Failed to re-bind the data, return scrap to the heap.
                 mRecycler.addScrapView(scrapView, position);
             } else {
-                isScrap[0] = true;
+                if (child.isTemporarilyDetached()) {
+                    isScrap[0] = true;
+
+                    // Finish the temporary detach started in addScrapView().
+                    child.dispatchFinishTemporaryDetach();
+                } else {
+                    // we set isScrap to "true" only if the view is temporarily detached.
+                    // if the view is fully detached, it is as good as a view created by the
+                    // adapter
+                    isScrap[0] = false;
+                }
 
-                // Finish the temporary detach started in addScrapView().
-                child.dispatchFinishTemporaryDetach();
             }
         }
 
@@ -5152,6 +5161,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             fillGap(down);
         }
 
+        mRecycler.fullyDetachScrapViews();
         if (!inTouchMode && mSelectedPosition != INVALID_POSITION) {
             final int childIndex = mSelectedPosition - mFirstPosition;
             if (childIndex >= 0 && childIndex < getChildCount()) {
@@ -6861,8 +6871,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                             scrapViews = mScrapViews[whichScrap];
                         }
 
-                        victim.dispatchStartTemporaryDetach();
                         lp.scrappedFromPosition = mFirstActivePosition + i;
+                        removeDetachedView(victim, false);
                         scrapViews.add(victim);
 
                         if (hasListener) {
@@ -6871,10 +6881,28 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
                     }
                 }
             }
-
             pruneScrapViews();
         }
 
+        /**
+         * At the end of a layout pass, all temp detached views should either be re-attached or
+         * completely detached. This method ensures that any remaining view in the scrap list is
+         * fully detached.
+         */
+        void fullyDetachScrapViews() {
+            final int viewTypeCount = mViewTypeCount;
+            final ArrayList<View>[] scrapViews = mScrapViews;
+            for (int i = 0; i < viewTypeCount; ++i) {
+                final ArrayList<View> scrapPile = scrapViews[i];
+                for (int j = scrapPile.size() - 1; j >= 0; j--) {
+                    final View view = scrapPile.get(j);
+                    if (view.isTemporarilyDetached()) {
+                        removeDetachedView(view, false);
+                    }
+                }
+            }
+        }
+
         /**
          * Makes sure that the size of mScrapViews does not exceed the size of
          * mActiveViews, which can happen if an adapter does not recycle its
@@ -6888,10 +6916,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
             for (int i = 0; i < viewTypeCount; ++i) {
                 final ArrayList<View> scrapPile = scrapViews[i];
                 int size = scrapPile.size();
-                final int extras = size - maxViews;
-                size--;
-                for (int j = 0; j < extras; j++) {
-                    removeDetachedView(scrapPile.remove(size--), false);
+                while (size > maxViews) {
+                    scrapPile.remove(--size);
                 }
             }
 

core/java/android/widget/ListView.java

@@ -54,6 +54,7 @@ import android.view.accessibility.AccessibilityNodeProvider;
 import android.widget.RemoteViews.RemoteView;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /*
  * Implementation Notes:
@@ -1763,6 +1764,10 @@ public class ListView extends AbsListView {
             // Flush any cached views that did not get reused above
             recycleBin.scrapActiveViews();
 
+            // remove any header/footer that has been temp detached and not re-attached
+            removeUnusedFixedViews(mHeaderViewInfos);
+            removeUnusedFixedViews(mFooterViewInfos);
+
             if (sel != null) {
                 // The current selected item should get focus if items are
                 // focusable.
@@ -1879,6 +1884,36 @@ public class ListView extends AbsListView {
         }
     }
 
+    @Override
+    boolean trackMotionScroll(int deltaY, int incrementalDeltaY) {
+        final boolean result = super.trackMotionScroll(deltaY, incrementalDeltaY);
+        removeUnusedFixedViews(mHeaderViewInfos);
+        removeUnusedFixedViews(mFooterViewInfos);
+        return result;
+    }
+
+    /**
+     * Header and Footer views are not scrapped / recycled like other views but they are still
+     * detached from the ViewGroup. After a layout operation, call this method to remove such views.
+     *
+     * @param infoList The info list to be traversed
+     */
+    private void removeUnusedFixedViews(@Nullable List<FixedViewInfo> infoList) {
+        if (infoList == null) {
+            return;
+        }
+        for (int i = infoList.size() - 1; i >= 0; i--) {
+            final FixedViewInfo fixedViewInfo = infoList.get(i);
+            final View view = fixedViewInfo.view;
+            final LayoutParams lp = (LayoutParams) view.getLayoutParams();
+            if (view.getParent() == null && lp != null && lp.recycledHeaderFooter) {
+                removeDetachedView(view, false);
+                lp.recycledHeaderFooter = false;
+            }
+
+        }
+    }
+
     /**
      * @param child a direct child of this list.
      * @return Whether child is a header or footer view.
@@ -3179,6 +3214,9 @@ public class ListView extends AbsListView {
                 last = getChildAt(--lastIndex);
             }
         }
+        recycleBin.fullyDetachScrapViews();
+        removeUnusedFixedViews(mHeaderViewInfos);
+        removeUnusedFixedViews(mFooterViewInfos);
     }
 
     private View addViewAbove(View theView, int position) {