A workaround for swipe-down-to-dismiss issue

Compatibility RecyclerView reports onNestedScroll `consumed` value as
true if scroll is enabled in any direction.
The SysUi RecyclerView reports ture only if can be scrolled in the
direction of the fling.
Add a workaround to ResolverDrawerLayout that restores the legacy
functionality.

Fix: 264005990
Test: manual testing
Change-Id: If379e43c57355489bf8b0265dbab14d796b3dff6

1 files changed, 23 insertions, 1 deletions

diff --git a/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java b/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java
index f5e20510..de76a1d2 100644
--- a/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java
+++ b/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java
@@ -841,7 +841,14 @@ public class ResolverDrawerLayout extends ViewGroup {
 
     @Override
     public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
-        if (!consumed && Math.abs(velocityY) > mMinFlingVelocity) {
+        // TODO: find a more suitable way to fix it.
+        //  RecyclerView started reporting `consumed` as true whenever a scrolling is enabled,
+        //  previously the value was based whether the fling can be performed in given direction
+        //  i.e. whether it is at the top or at the bottom. isRecyclerViewAtTheTop method is a
+        //  workaround that restores the legacy functionality.
+        boolean shouldConsume = (Math.abs(velocityY) > mMinFlingVelocity)
+                && (!consumed || (velocityY < 0 && isRecyclerViewAtTheTop(target)));
+        if (shouldConsume) {
             if (getShowAtTop()) {
                 if (isDismissable() && velocityY > 0) {
                     abortAnimation();
@@ -863,6 +870,21 @@ public class ResolverDrawerLayout extends ViewGroup {
         return false;
     }
 
+    private static boolean isRecyclerViewAtTheTop(View target) {
+        // TODO: there's a very similar functionality in #isNestedRecyclerChildScrolled(),
+        //  consolidate the two.
+        if (!(target instanceof RecyclerView)) {
+            return false;
+        }
+        RecyclerView recyclerView = (RecyclerView) target;
+        if (recyclerView.getChildCount() == 0) {
+            return true;
+        }
+        View firstChild = recyclerView.getChildAt(0);
+        return recyclerView.getChildAdapterPosition(firstChild) == 0
+                && firstChild.getTop() >= recyclerView.getPaddingTop();
+    }
+
     private boolean performAccessibilityActionCommon(int action) {
         switch (action) {
             case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: