Fixed header elevation shadow on rotate

Change-Id: I1a4b55cf9af67d93e56d84378036c0061b6e8104

src/com/android/launcher3/BaseRecyclerView.java

@@ -273,7 +273,7 @@ public abstract class BaseRecyclerView extends RecyclerView
      *
      * @return the scroll top of this recycler view.
      */
-    protected abstract int getCurrentScrollY();
+    public abstract int getCurrentScrollY();
 
     /**
      * Maps the touch (from 0..1) to the adapter position that should be visible.

src/com/android/launcher3/allapps/AllAppsRecyclerView.java

@@ -375,7 +375,7 @@ public class AllAppsRecyclerView extends BaseRecyclerView
     }
 
     @Override
-    protected int getCurrentScrollY() {
+    public int getCurrentScrollY() {
         // Return early if there are no items or we haven't been measured
         List<AlphabeticalAppsList.AdapterItem> items = mApps.getAdapterItems();
         if (items.isEmpty() || mNumAppsPerRow == 0 || getChildCount() == 0) {

src/com/android/launcher3/allapps/HeaderElevationController.java

@@ -12,6 +12,7 @@ import android.view.ViewGroup;
 import android.view.ViewOutlineProvider;
 import android.widget.FrameLayout;
 
+import com.android.launcher3.BaseRecyclerView;
 import com.android.launcher3.R;
 
 /**
@@ -28,7 +29,7 @@ public abstract class HeaderElevationController extends RecyclerView.OnScrollLis
 
     @Override
     public final void onScrolled(RecyclerView recyclerView, int dx, int dy) {
-        mCurrentY += dy;
+        mCurrentY = ((BaseRecyclerView) recyclerView).getCurrentScrollY();
         onScroll(mCurrentY);
     }
 

src/com/android/launcher3/widget/WidgetsRecyclerView.java

@@ -129,7 +129,7 @@ public class WidgetsRecyclerView extends BaseRecyclerView {
     }
 
     @Override
-    protected int getCurrentScrollY() {
+    public int getCurrentScrollY() {
         // Skip early if widgets are not bound.
         if (isModelNotReady() || getChildCount() == 0) {
             return -1;