Fix for potential race condition in Spinners

Added measure to try & ensure popups have time to collapse before trying to send TYPE_VIEW_SELECTED

Bug: 256048559
Test: Test in topic
Change-Id: I8ef5ff37ca08a4adb8c7ffda53a7ac810ba2763d

core/api/test-current.txt

@@ -3252,6 +3252,7 @@ package android.widget {
 
   public class Spinner extends android.widget.AbsSpinner implements android.content.DialogInterface.OnClickListener {
     method public boolean isPopupShowing();
+    method public void onClick(int);
   }
 
   @android.widget.RemoteViews.RemoteView public class TextClock extends android.widget.TextView {

core/java/android/widget/AdapterView.java

@@ -968,7 +968,8 @@ public abstract class AdapterView<T extends Adapter> extends ViewGroup {
         final int position = getSelectedItemPosition();
         if (position >= 0) {
             // we fire selection events here not in View
-            sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED);
+            // posting the event should delay it long enough for UI changes to take effect.
+            post(() -> sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED));
         }
     }
 

core/java/android/widget/Spinner.java

@@ -802,6 +802,21 @@ public class Spinner extends AbsSpinner implements OnClickListener {
         dialog.dismiss();
     }
 
+    /**
+     * Sets selection and dismisses the spinner's popup if it can be dismissed.
+     * For ease of use in tests, where publicly obtaining the spinner's popup is difficult.
+     *
+     * @param which index of the item to be selected.
+     * @hide
+     */
+    @TestApi
+    public void onClick(int which) {
+        setSelection(which);
+        if (mPopup != null && mPopup.isShowing()) {
+            mPopup.dismiss();
+        }
+    }
+
     @Override
     public CharSequence getAccessibilityClassName() {
         return Spinner.class.getName();