Synchronize selected item data on-demand after data set invalidation

Previously, the selected item data could become inconsistent between a
call to Adapter.notifyDataSetChanged()/Invalidated() and the subsequent
layout pass.

Bug: 21614294
Change-Id: I45c9c98b2f6a8d8b8fb17de2065efa505cbf3c92

1 files changed, 49 insertions, 10 deletions

diff --git a/core/java/android/widget/AdapterView.java b/core/java/android/widget/AdapterView.java
index 696271105639..cfe02bdd12f9 100644
--- a/core/java/android/widget/AdapterView.java
+++ b/core/java/android/widget/AdapterView.java
@@ -551,37 +551,67 @@ public abstract class AdapterView<T extends Adapter> extends ViewGroup {
     }
 
     /**
-     * Return the position of the currently selected item within the adapter's data set
+     * Returns the position of the currently selected item within the adapter's
+     * data set, or {@link #INVALID_POSITION} if there is nothing selected.
+     * <p>
+     * <strong>Note:</strong> Prior to {@link android.os.Build.VERSION_CODES#MNC},
+     * calling this method between an adapter data set change and a subsequent
+     * layout pass could return invalid data.
      *
-     * @return int Position (starting at 0), or {@link #INVALID_POSITION} if there is nothing selected.
+     * @return the selected item's position (starting at 0), or
+     *         {@link #INVALID_POSITION} if there is nothing selected
      */
     @ViewDebug.CapturedViewProperty
     public int getSelectedItemPosition() {
+        syncSelectedItem();
         return mNextSelectedPosition;
     }
 
     /**
-     * @return The id corresponding to the currently selected item, or {@link #INVALID_ROW_ID}
-     * if nothing is selected.
+     * Returns the row ID corresponding to the currently selected item, or
+     * {@link #INVALID_ROW_ID} if nothing is selected.
+     * <p>
+     * <strong>Note:</strong> Prior to {@link android.os.Build.VERSION_CODES#MNC},
+     * calling this method between an adapter data set change and a subsequent
+     * layout pass could return invalid data.
+     *
+     * @return the selected item's row ID, or {@link #INVALID_ROW_ID} if
+     *         nothing is selected
      */
     @ViewDebug.CapturedViewProperty
     public long getSelectedItemId() {
+        syncSelectedItem();
         return mNextSelectedRowId;
     }
 
     /**
-     * @return The view corresponding to the currently selected item, or null
-     * if nothing is selected
+     * Returns the view corresponding to the currently selected item, or
+     * {@code null} if nothing is selected.
+     * <p>
+     * <strong>Note:</strong> Prior to {@link android.os.Build.VERSION_CODES#MNC},
+     * calling this method between an adapter data set change and a subsequent
+     * layout pass could return inconsistent data.
+     *
+     * @return the selected item's view, or {@code null} if nothing is selected
      */
+    @Nullable
     public abstract View getSelectedView();
 
     /**
-     * @return The data corresponding to the currently selected item, or
-     * null if there is nothing selected.
+     * Returns the data corresponding to the currently selected item, or
+     * {@code null} if nothing is selected.
+     * <p>
+     * <strong>Note:</strong> Prior to {@link android.os.Build.VERSION_CODES#MNC},
+     * calling this method between an adapter data set change and a subsequent
+     * layout pass could return inconsistent data.
+     *
+     * @return the data corresponding to the currently selected item, or
+     *         {@code null} if there is nothing selected.
      */
+    @Nullable
     public Object getSelectedItem() {
-        T adapter = getAdapter();
-        int selection = getSelectedItemPosition();
+        final T adapter = getAdapter();
+        final int selection = getSelectedItemPosition();
         if (adapter != null && adapter.getCount() > 0 && selection >= 0) {
             return adapter.getItem(selection);
         } else {
@@ -590,6 +620,15 @@ public abstract class AdapterView<T extends Adapter> extends ViewGroup {
     }
 
     /**
+     * Synchronizes the selected item's position and ID, if necessary.
+     */
+    void syncSelectedItem() {
+        if (mDataChanged) {
+            onLayout(false, mLeft, mTop, mRight, mBottom);
+        }
+    }
+
+    /**
      * @return The number of items owned by the Adapter associated with this
      *         AdapterView. (This is the number of data items, which may be
      *         larger than the number of visible views.)