Merge "Hinting RemoteViewsAdapter as to which views are visible"

5 files changed, 47 insertions, 10 deletions

diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java
index 38bb2e1bde81..0ba4541659a0 100644
--- a/core/java/android/widget/AbsListView.java
+++ b/core/java/android/widget/AbsListView.java
@@ -5572,6 +5572,16 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
     }
 
     /**
+     * Hints the RemoteViewsAdapter, if it exists, about which views are currently
+     * being displayed by the AbsListView.
+     */
+    void setVisibleRangeHint(int start, int end) {
+        if (mRemoteAdapter != null) {
+            mRemoteAdapter.setVisibleRangeHint(start, end);
+        }
+    }
+
+    /**
      * Sets the recycler listener to be notified whenever a View is set aside in
      * the recycler for later reuse. This listener can be used to free resources
      * associated to the View.
diff --git a/core/java/android/widget/AdapterViewAnimator.java b/core/java/android/widget/AdapterViewAnimator.java
index c83c78088617..9ea7b33401ba 100644
--- a/core/java/android/widget/AdapterViewAnimator.java
+++ b/core/java/android/widget/AdapterViewAnimator.java
@@ -555,6 +555,9 @@ public abstract class AdapterViewAnimator extends AdapterView<Adapter>
             mCurrentWindowStart = newWindowStart;
             mCurrentWindowEnd = newWindowEnd;
             mCurrentWindowStartUnbounded = newWindowStartUnbounded;
+            if (mRemoteViewsAdapter != null) {
+                mRemoteViewsAdapter.setVisibleRangeHint(mCurrentWindowStart, mCurrentWindowEnd);
+            }
         }
         requestLayout();
         invalidate();
diff --git a/core/java/android/widget/GridView.java b/core/java/android/widget/GridView.java
index 5d406de007dc..5c1eb94fd084 100644
--- a/core/java/android/widget/GridView.java
+++ b/core/java/android/widget/GridView.java
@@ -290,6 +290,7 @@ public class GridView extends AbsListView {
             pos += mNumColumns;
         }
 
+        setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1);
         return selectedView;
     }
 
@@ -382,6 +383,7 @@ public class GridView extends AbsListView {
             mFirstPosition = Math.max(0, pos + 1);
         }
 
+        setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1);
         return selectedView;
     }
 
diff --git a/core/java/android/widget/ListView.java b/core/java/android/widget/ListView.java
index 7f7a3a715a23..b6371a7073e9 100644
--- a/core/java/android/widget/ListView.java
+++ b/core/java/android/widget/ListView.java
@@ -678,6 +678,7 @@ public class ListView extends AbsListView {
             pos++;
         }
 
+        setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1);
         return selectedView;
     }
 
@@ -711,7 +712,7 @@ public class ListView extends AbsListView {
         }
 
         mFirstPosition = pos + 1;
-
+        setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1);
         return selectedView;
     }
 
diff --git a/core/java/android/widget/RemoteViewsAdapter.java b/core/java/android/widget/RemoteViewsAdapter.java
index 7b430328ef0f..586fdf4da501 100644
--- a/core/java/android/widget/RemoteViewsAdapter.java
+++ b/core/java/android/widget/RemoteViewsAdapter.java
@@ -68,6 +68,8 @@ public class RemoteViewsAdapter extends BaseAdapter implements Handler.Callback
     private RemoteViewsAdapterServiceConnection mServiceConnection;
     private WeakReference<RemoteAdapterConnectionCallback> mCallback;
     private FixedSizeRemoteViewsCache mCache;
+    private int mVisibleWindowLowerBound;
+    private int mVisibleWindowUpperBound;
 
     // A flag to determine whether we should notify data set changed after we connect
     private boolean mNotifyDataSetChangedAfterOnServiceConnected = false;
@@ -765,7 +767,7 @@ public class RemoteViewsAdapter extends BaseAdapter implements Handler.Callback
                     }
                     if (position > -1) {
                         // Load the item, and notify any existing RemoteViewsFrameLayouts
-                        updateRemoteViews(position, isRequested);
+                        updateRemoteViews(position, isRequested, true);
 
                         // Queue up for the next one to load
                         loadNextIndexInBackground();
@@ -827,8 +829,8 @@ public class RemoteViewsAdapter extends BaseAdapter implements Handler.Callback
         }
     }
 
-    private void updateRemoteViews(final int position, boolean isRequested) {
-        if (!mServiceConnection.isConnected()) return;
+    private void updateRemoteViews(final int position, boolean isRequested, boolean
+            notifyWhenLoaded) {
         IRemoteViewsFactory factory = mServiceConnection.getRemoteViewsFactory();
 
         // Load the item information from the remote service
@@ -864,12 +866,14 @@ public class RemoteViewsAdapter extends BaseAdapter implements Handler.Callback
             // there is new data for it.
             final RemoteViews rv = remoteViews;
             final int typeId = mCache.getMetaDataAt(position).typeId;
-            mMainQueue.post(new Runnable() {
-                @Override
-                public void run() {
-                    mRequestedViews.notifyOnRemoteViewsLoaded(position, rv, typeId);
-                }
-            });
+            if (notifyWhenLoaded) {
+                mMainQueue.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        mRequestedViews.notifyOnRemoteViewsLoaded(position, rv, typeId);
+                    }
+                });
+            }
         }
     }
 
@@ -929,6 +933,16 @@ public class RemoteViewsAdapter extends BaseAdapter implements Handler.Callback
         return typeId;
     }
 
+    /**
+     * This method allows an AdapterView using this Adapter to provide information about which
+     * views are currently being displayed. This allows for certain optimizations and preloading
+     * which  wouldn't otherwise be possible.
+     */
+    public void setVisibleRangeHint(int lowerBound, int upperBound) {
+        mVisibleWindowLowerBound = lowerBound;
+        mVisibleWindowUpperBound = upperBound;
+    }
+
     public View getView(int position, View convertView, ViewGroup parent) {
         // "Request" an index so that we can queue it for loading, initiate subsequent
         // preloading, etc.
@@ -1059,6 +1073,13 @@ public class RemoteViewsAdapter extends BaseAdapter implements Handler.Callback
         // Re-request the new metadata (only after the notification to the factory)
         updateTemporaryMetaData();
 
+        // Pre-load (our best guess of) the views which are currently visible in the AdapterView.
+        // This mitigates flashing and flickering of loading views when a widget notifies that
+        // its data has changed.
+        for (int i = mVisibleWindowLowerBound; i <= mVisibleWindowUpperBound; i++) {
+            updateRemoteViews(i, false, false);
+        }
+
         // Propagate the notification back to the base adapter
         mMainQueue.post(new Runnable() {
             @Override