From dff14cadd78af3992dfd7c8c989314d11758554d Mon Sep 17 00:00:00 2001
From: Material Design Team <noreply@google.com>
Date: Thu, 12 May 2022 17:11:48 -0400
Subject: [PATCH] [AppBarLayout] Loosen check for scrollable child when adding
 a11y actions

Adding the a11y delegate and a11y actions was dependent on there being a CoordinatorLayout child that both inherits from certain scrolling classes (NestedScrollingChild, ListView, ScrollView) and has an AppBarLayout scrolling behavior. This was too restrictive and so we only check for a behavior.

Any scrolling child may add an a11y delegate or scroll action to the parent CoordinatorLayout.

PiperOrigin-RevId: 448335380
(cherry picked from commit 4b81bb1d1a467d03b6f323639f5358ec14445c67)
---
 .../android/material/appbar/AppBarLayout.java | 30 +++++++++++++------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/lib/java/com/google/android/material/appbar/AppBarLayout.java b/lib/java/com/google/android/material/appbar/AppBarLayout.java
index 3b60de07e17..778a8e29317 100644
--- a/lib/java/com/google/android/material/appbar/AppBarLayout.java
+++ b/lib/java/com/google/android/material/appbar/AppBarLayout.java
@@ -1732,17 +1732,14 @@ private void updateAccessibilityActions(
         CoordinatorLayout coordinatorLayout, @NonNull T appBarLayout) {
       ViewCompat.removeAccessibilityAction(coordinatorLayout, ACTION_SCROLL_FORWARD.getId());
       ViewCompat.removeAccessibilityAction(coordinatorLayout, ACTION_SCROLL_BACKWARD.getId());
-      View scrollingView = findFirstScrollingChild(coordinatorLayout);
-      // Don't add a11y actions if there is no scrolling view that the abl depends on for scrolling
-      // or the abl has no scroll range.
-      if (scrollingView == null || appBarLayout.getTotalScrollRange() == 0) {
+      // Don't add a11y actions if the abl has no scroll range.
+      if (appBarLayout.getTotalScrollRange() == 0) {
         return;
       }
-      // Don't add actions if the scrolling view doesn't have the behavior that will cause the abl
-      // to scroll.
-      CoordinatorLayout.LayoutParams lp =
-          (CoordinatorLayout.LayoutParams) scrollingView.getLayoutParams();
-      if (!(lp.getBehavior() instanceof ScrollingViewBehavior)) {
+      // Don't add actions if a child view doesn't have the behavior that will cause the abl to
+      // scroll.
+      View scrollingView = getChildWithScrollingBehavior(coordinatorLayout);
+      if (scrollingView == null) {
         return;
       }
 
@@ -1769,6 +1766,21 @@ public void onInitializeAccessibilityNodeInfo(
           addAccessibilityScrollActions(coordinatorLayout, appBarLayout, scrollingView);
     }
 
+    @Nullable
+    private View getChildWithScrollingBehavior(CoordinatorLayout coordinatorLayout) {
+      final int childCount = coordinatorLayout.getChildCount();
+      for (int i = 0; i < childCount; i++) {
+        final View child = coordinatorLayout.getChildAt(i);
+
+        CoordinatorLayout.LayoutParams lp =
+            (CoordinatorLayout.LayoutParams) child.getLayoutParams();
+        if (lp.getBehavior() instanceof ScrollingViewBehavior) {
+          return child;
+        }
+      }
+      return null;
+    }
+
     private boolean childrenHaveScrollFlags(AppBarLayout appBarLayout) {
       final int childCount = appBarLayout.getChildCount();
       for (int i = 0; i < childCount; i++) {