Added mechanisms for updating the UI on rotation & on configuration change.

Bug: 261252772
Test: adb install the APK, then enable the menu from the Settings Accessibility page
Change-Id: Id76094ccabecab28072d6131e853bddb747a4ef7

packages/SystemUI/accessibility/accessibilitymenu/src/com/android/systemui/accessibility/accessibilitymenu/AccessibilityMenuService.java

@@ -17,6 +17,10 @@
 package com.android.systemui.accessibility.accessibilitymenu;
 
 import android.accessibilityservice.AccessibilityService;
+import android.content.res.Configuration;
+import android.hardware.display.DisplayManager;
+import android.os.Handler;
+import android.view.Display;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.accessibility.AccessibilityEvent;
@@ -27,23 +31,99 @@ import com.android.systemui.accessibility.accessibilitymenu.view.A11yMenuOverlay
 public class AccessibilityMenuService extends AccessibilityService implements View.OnTouchListener {
     private static final String TAG = "A11yMenuService";
 
+    private static final long BUFFER_MILLISECONDS_TO_PREVENT_UPDATE_FAILURE = 100L;
+
     private A11yMenuOverlayLayout mA11yMenuLayout;
 
+    private static boolean sInitialized = false;
+
+    // TODO(b/136716947): Support multi-display once a11y framework side is ready.
+    private DisplayManager mDisplayManager;
+    final DisplayManager.DisplayListener mDisplayListener = new DisplayManager.DisplayListener() {
+        int mRotation;
+
+        @Override
+        public void onDisplayAdded(int displayId) {}
+
+        @Override
+        public void onDisplayRemoved(int displayId) {
+            // TODO(b/136716947): Need to reset A11yMenuOverlayLayout by display id.
+        }
+
+        @Override
+        public void onDisplayChanged(int displayId) {
+            Display display = mDisplayManager.getDisplay(Display.DEFAULT_DISPLAY);
+            if (mRotation != display.getRotation()) {
+                mRotation = display.getRotation();
+                mA11yMenuLayout.updateViewLayout();
+            }
+        }
+    };
+
+    // Update layout.
+    private final Handler mHandler = new Handler(getMainLooper());
+    private final Runnable mOnConfigChangedRunnable = new Runnable() {
+        @Override
+        public void run() {
+            if (!sInitialized) {
+                return;
+            }
+            // Re-assign theme to service after onConfigurationChanged
+            getTheme().applyStyle(R.style.ServiceTheme, true);
+            // Caches & updates the page index to ViewPager when a11y menu is refreshed.
+            // Otherwise, the menu page would reset on a UI update.
+            int cachedPageIndex = mA11yMenuLayout.getPageIndex();
+            mA11yMenuLayout.configureLayout(cachedPageIndex);
+        }
+    };
+
     @Override
     public void onCreate() {
         super.onCreate();
     }
 
+    @Override
+    public void onDestroy() {
+        if (mHandler.hasCallbacks(mOnConfigChangedRunnable)) {
+            mHandler.removeCallbacks(mOnConfigChangedRunnable);
+        }
+
+        super.onDestroy();
+    }
+
     @Override
     protected void onServiceConnected() {
         mA11yMenuLayout = new A11yMenuOverlayLayout(this);
-        super.onServiceConnected();
+
+        // Temporary measure to force visibility
         mA11yMenuLayout.toggleVisibility();
+
+        mDisplayManager = getSystemService(DisplayManager.class);
+        mDisplayManager.registerDisplayListener(mDisplayListener, null);
+
+        sInitialized = true;
     }
 
     @Override
     public void onAccessibilityEvent(AccessibilityEvent event) {}
 
+    /**
+     * This method would notify service when device configuration, such as display size,
+     * localization, orientation or theme, is changed.
+     *
+     * @param newConfig the new device configuration.
+     */
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        // Prevent update layout failure
+        // if multiple onConfigurationChanged are called at the same time.
+        if (mHandler.hasCallbacks(mOnConfigChangedRunnable)) {
+            mHandler.removeCallbacks(mOnConfigChangedRunnable);
+        }
+        mHandler.postDelayed(
+                mOnConfigChangedRunnable, BUFFER_MILLISECONDS_TO_PREVENT_UPDATE_FAILURE);
+    }
+
     @Override
     public void onInterrupt() {
     }