Don't create one-handed-background-panel after rotation

From code flow, when onConfigurationChanged() by rotating
OneHandedBackgroundPanelOrganizer#showBackgroundPanelLayer()
will be invoked and then create one-handed-background-panel
even though OHM is not activated.
Besides, this could introduce overhead on SF.

Test: manual rotate and dumpsys check HWC layers
Test: atest WMShellUnitTests
Bug: 196306312
Change-Id: Ia766078d5c76b08ab5b24e0ce965ad1d085e4686

libs/WindowManager/Shell/src/com/android/wm/shell/onehanded/OneHandedBackgroundPanelOrganizer.java

@@ -16,6 +16,8 @@
 
 package com.android.wm.shell.onehanded;
 
+import static com.android.wm.shell.onehanded.OneHandedState.STATE_ACTIVE;
+
 import android.animation.ValueAnimator;
 import android.content.Context;
 import android.graphics.Color;
@@ -46,7 +48,7 @@ import java.util.concurrent.Executor;
  * the screen has entered one handed mode.
  */
 public class OneHandedBackgroundPanelOrganizer extends DisplayAreaOrganizer
-        implements OneHandedAnimationCallback {
+        implements OneHandedAnimationCallback, OneHandedState.OnStateChangedListener {
     private static final String TAG = "OneHandedBackgroundPanelOrganizer";
     private static final int THEME_COLOR_OFFSET = 10;
     private static final int ALPHA_ANIMATION_DURATION = 200;
@@ -56,6 +58,7 @@ public class OneHandedBackgroundPanelOrganizer extends DisplayAreaOrganizer
     private final OneHandedSurfaceTransactionHelper.SurfaceControlTransactionFactory
             mTransactionFactory;
 
+    private @OneHandedState.State int mCurrentState;
     private ValueAnimator mAlphaAnimator;
 
     private float mTranslationFraction;
@@ -180,6 +183,9 @@ public class OneHandedBackgroundPanelOrganizer extends DisplayAreaOrganizer
      * Called when transition finished.
      */
     public void onStopFinished() {
+        if (mAlphaAnimator == null) {
+            return;
+        }
         mAlphaAnimator.start();
     }
 
@@ -224,6 +230,10 @@ public class OneHandedBackgroundPanelOrganizer extends DisplayAreaOrganizer
      */
     public void onConfigurationChanged() {
         updateThemeColors();
+
+        if (mCurrentState != STATE_ACTIVE) {
+            return;
+        }
         showBackgroundPanelLayer();
     }
 
@@ -242,6 +252,11 @@ public class OneHandedBackgroundPanelOrganizer extends DisplayAreaOrganizer
         return Math.max(origColor - THEME_COLOR_OFFSET, 0) / 255.0f;
     }
 
+    @Override
+    public void onStateChanged(int newState) {
+        mCurrentState = newState;
+    }
+
     void dump(@NonNull PrintWriter pw) {
         final String innerPrefix = "  ";
         pw.println(TAG);

libs/WindowManager/Shell/src/com/android/wm/shell/onehanded/OneHandedController.java

@@ -307,6 +307,7 @@ public class OneHandedController implements RemoteCallable<OneHandedController>
         mAccessibilityManager.addAccessibilityStateChangeListener(
                 mAccessibilityStateChangeListener);
 
+        mState.addSListeners(mBackgroundPanelOrganizer);
         mState.addSListeners(mTutorialHandler);
     }
 

libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/onehanded/OneHandedBackgroundPanelOrganizerTest.java

@@ -19,6 +19,9 @@ package com.android.wm.shell.onehanded;
 import static android.view.Display.DEFAULT_DISPLAY;
 import static android.window.DisplayAreaOrganizer.FEATURE_ONE_HANDED_BACKGROUND_PANEL;
 
+import static com.android.wm.shell.onehanded.OneHandedState.STATE_ACTIVE;
+import static com.android.wm.shell.onehanded.OneHandedState.STATE_NONE;
+
 import static com.google.common.truth.Truth.assertThat;
 
 import static org.mockito.ArgumentMatchers.anyInt;
@@ -109,4 +112,20 @@ public class OneHandedBackgroundPanelOrganizerTest extends OneHandedTestCase {
 
         assertThat(mSpiedBackgroundPanelOrganizer.mBackgroundSurface).isNull();
     }
+
+    @Test
+    public void testStateNone_onConfigurationChanged() {
+        mSpiedBackgroundPanelOrganizer.onStateChanged(STATE_NONE);
+        mSpiedBackgroundPanelOrganizer.onConfigurationChanged();
+
+        verify(mSpiedBackgroundPanelOrganizer, never()).showBackgroundPanelLayer();
+    }
+
+    @Test
+    public void testStateActivate_onConfigurationChanged() {
+        mSpiedBackgroundPanelOrganizer.onStateChanged(STATE_ACTIVE);
+        mSpiedBackgroundPanelOrganizer.onConfigurationChanged();
+
+        verify(mSpiedBackgroundPanelOrganizer).showBackgroundPanelLayer();
+    }
 }