Add accessibility scroll support to some widgets.

1. Added support for accessibility scroll action to
   some widgets that are scrollable.

2. Making the super call when handling an accessibility
   action in the views to call super first to allow
   an accessibility delegate to intercept the call.

bug:5932640

Change-Id: I5eb37d64bf9fba1d5c596981132e0df717e2a18a

1 files changed, 30 insertions, 0 deletions

diff --git a/core/java/android/widget/StackView.java b/core/java/android/widget/StackView.java
index 22df3bc23883..dd0915ba47e3 100644
--- a/core/java/android/widget/StackView.java
+++ b/core/java/android/widget/StackView.java
@@ -32,6 +32,7 @@ import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.Region;
 import android.graphics.TableMaskFilter;
+import android.os.Bundle;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.InputDevice;
@@ -1228,6 +1229,35 @@ public class StackView extends AdapterViewAnimator {
     public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
         super.onInitializeAccessibilityNodeInfo(info);
         info.setClassName(StackView.class.getName());
+        info.setScrollable(getChildCount() > 1);
+        if (getDisplayedChild() < getChildCount() - 1) {
+            info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
+        }
+        if (getDisplayedChild() > 0) {
+            info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
+        }
+    }
+
+    @Override
+    public boolean performAccessibilityAction(int action, Bundle arguments) {
+        if (super.performAccessibilityAction(action, arguments)) {
+            return true;
+        }
+        switch (action) {
+            case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: {
+                if (getDisplayedChild() < getChildCount() - 1) {
+                    showNext();
+                    return true;
+                }
+            } return false;
+            case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: {
+                if (getDisplayedChild() > 0) {
+                    showPrevious();
+                    return true;
+                }
+            } return false;
+        }
+        return false;
     }
 
     class LayoutParams extends ViewGroup.LayoutParams {