Android A11Y: handle LocationChanged event only for focused element

LocationChanged event unconditionally triggered invalidateVirtualViewId
call. That call results in TYPE_WINDOW_CONTENT_CHANGED Android event,
which causes a lot of background processing.
That is not correct, because LocationChanged event is generated by
every accessible element, not only the one that has A11Y focus.

This patch checks event->uniqueId(), and processes only events that
come from the focused accessible element.

Done-with: Mike Achtelik <mike.achtelik@gmail.com>
Task-number: QTBUG-102594
Pick-to: 6.3 6.2 5.15
Change-Id: I6b941733c9d215fed5ee5a7aeeb5be234add9ebe
Reviewed-by: Mike Achtelik <mike.achtelik@gmail.com>
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java

@@ -949,11 +949,11 @@ public class QtActivityDelegate
         m_splashScreen.startAnimation(fadeOut);
     }
 
-    public void notifyAccessibilityLocationChange()
+    public void notifyAccessibilityLocationChange(int viewId)
     {
         if (m_accessibilityDelegate == null)
             return;
-        m_accessibilityDelegate.notifyLocationChange();
+        m_accessibilityDelegate.notifyLocationChange(viewId);
     }
 
     public void notifyObjectHide(int viewId, int parentId)

src/android/jar/src/org/qtproject/qt/android/QtNative.java

@@ -973,13 +973,13 @@ public class QtNative
         return m_activityDelegate.isKeyboardVisible() && !m_isKeyboardHiding;
     }
 
-    private static void notifyAccessibilityLocationChange()
+    private static void notifyAccessibilityLocationChange(final int viewId)
     {
         runAction(new Runnable() {
             @Override
             public void run() {
                 if (m_activityDelegate != null) {
-                    m_activityDelegate.notifyAccessibilityLocationChange();
+                    m_activityDelegate.notifyAccessibilityLocationChange(viewId);
                 }
             }
         });

src/android/jar/src/org/qtproject/qt/android/accessibility/QtAccessibilityDelegate.java

@@ -193,8 +193,9 @@ public class QtAccessibilityDelegate extends View.AccessibilityDelegate
         return true;
     }
 
-    public void notifyLocationChange()
+    public void notifyLocationChange(int viewId)
     {
+        if (m_focusedVirtualViewId == viewId)
             invalidateVirtualViewId(m_focusedVirtualViewId);
     }
 

src/android/java/src/org/qtproject/qt/android/bindings/QtActivity.java

@@ -1133,9 +1133,9 @@ public class QtActivity extends Activity
         QtNative.activityDelegate().updateSelection(selStart, selEnd, candidatesStart, candidatesEnd);
     }
 
-    public void notifyAccessibilityLocationChange()
+    public void notifyAccessibilityLocationChange(int viewId)
     {
-        QtNative.activityDelegate().notifyAccessibilityLocationChange();
+        QtNative.activityDelegate().notifyAccessibilityLocationChange(viewId);
     }
 
     public void notifyObjectHide(int viewId, int parentId)

src/plugins/platforms/android/androidjniaccessibility.cpp

@@ -135,9 +135,9 @@ namespace QtAndroidAccessibility
         return iface;
     }
 
-    void notifyLocationChange()
+    void notifyLocationChange(uint accessibilityObjectId)
     {
-        QtAndroid::notifyAccessibilityLocationChange();
+        QtAndroid::notifyAccessibilityLocationChange(accessibilityObjectId);
     }
 
     static int parentId_helper(int objectId); // forward declaration

src/plugins/platforms/android/androidjniaccessibility.h

@@ -51,7 +51,7 @@ namespace QtAndroidAccessibility
     void initialize();
     bool isActive();
     bool registerNatives(JNIEnv *env);
-    void notifyLocationChange();
+    void notifyLocationChange(uint accessibilityObjectId);
     void notifyObjectHide(uint accessibilityObjectId);
     void notifyObjectFocus(uint accessibilityObjectId);
     void notifyValueChanged(uint accessibilityObjectId);

src/plugins/platforms/android/androidjnimain.cpp

@@ -210,9 +210,10 @@ namespace QtAndroid
         QJniObject::callStaticMethod<void>(m_applicationClass, "setSystemUiVisibility", "(I)V", jint(uiVisibility));
     }
 
-    void notifyAccessibilityLocationChange()
+    void notifyAccessibilityLocationChange(uint accessibilityObjectId)
     {
-        QJniObject::callStaticMethod<void>(m_applicationClass, "notifyAccessibilityLocationChange");
+        QJniObject::callStaticMethod<void>(m_applicationClass, "notifyAccessibilityLocationChange",
+                                           "(I)V", accessibilityObjectId);
     }
 
     void notifyObjectHide(uint accessibilityObjectId, uint parentObjectId)

src/plugins/platforms/android/androidjnimain.h

@@ -100,7 +100,7 @@ namespace QtAndroid
     jobject createBitmap(int width, int height, QImage::Format format, JNIEnv *env);
     jobject createBitmapDrawable(jobject bitmap, JNIEnv *env = nullptr);
 
-    void notifyAccessibilityLocationChange();
+    void notifyAccessibilityLocationChange(uint accessibilityObjectId);
     void notifyObjectHide(uint accessibilityObjectId, uint parentObjectId);
     void notifyObjectFocus(uint accessibilityObjectId);
     void notifyValueChanged(uint accessibilityObjectId, jstring value);

src/plugins/platforms/android/qandroidplatformaccessibility.cpp

@@ -61,7 +61,7 @@ void QAndroidPlatformAccessibility::notifyAccessibilityUpdate(QAccessibleEvent *
     // so that the element can be moved on the screen if it's focused.
 
     if (event->type() == QAccessible::LocationChanged) {
-        QtAndroidAccessibility::notifyLocationChange();
+        QtAndroidAccessibility::notifyLocationChange(event->uniqueId());
     } else if (event->type() == QAccessible::ObjectHide) {
         QtAndroidAccessibility::notifyObjectHide(event->uniqueId());
     } else if (event->type() == QAccessible::Focus) {