Set communal view alpha.

This changelist alters the communal view's alpha during
transitions such as the shade expansion to be consistent
with the rest of the keyguard content, which dims out
during these events.

Bug: 197035411
Test: CommunalHostViewControllerTest#testAlphaPropagation
Test: NotificationPanelViewTest#testCommunalAlphaUpdate
Change-Id: I8c499d7c8746efe3b560935af09ff9da12c0e849

packages/SystemUI/src/com/android/systemui/communal/CommunalHostViewController.java

@@ -160,6 +160,21 @@ public class CommunalHostViewController extends ViewController<CommunalHostView>
                 statusBarState, keyguardFadingAway, goingToFullShade, oldStatusBarState);
     }
 
+    /**
+     * Set keyguard status view alpha.
+     */
+    public void setAlpha(float alpha) {
+        if (!mKeyguardVisibilityHelper.isVisibilityAnimating()) {
+            mView.setAlpha(alpha);
+
+            // Some communal view implementations, such as SurfaceViews, do not behave correctly
+            // inheriting the alpha of their parent. Directly set child alpha here to work around
+            // this.
+            for (int i = mView.getChildCount() - 1; i >= 0; --i) {
+                mView.getChildAt(i).setAlpha(alpha);
+            }
+        }
+    }
     @Override
     public void init() {
         super.init();

packages/SystemUI/src/com/android/systemui/communal/service/CommunalSurfaceViewController.java

@@ -209,6 +209,7 @@ public class CommunalSurfaceViewController extends ViewController<SurfaceView> {
                     if (surfacePackage != null) {
                         mView.setChildSurfacePackage(surfacePackage);
                         mView.setZOrderOnTop(true);
+                        mView.setUseAlpha();
                         mView.postInvalidate();
                         mCommunalStateController.setCommunalViewShowing(true);
                     } else {

packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java

@@ -1574,6 +1574,12 @@ public class NotificationPanelViewController extends PanelViewController {
         return true;
     }
 
+    private void updateCommunal() {
+        if (mCommunalViewController != null) {
+            mCommunalViewController.setAlpha(mKeyguardOnlyContentAlpha);
+        }
+    }
+
     private void updateClock() {
         float alpha = mClockPositionResult.clockAlpha * mKeyguardOnlyContentAlpha;
         mKeyguardStatusViewController.setAlpha(alpha);
@@ -2675,6 +2681,7 @@ public class NotificationPanelViewController extends PanelViewController {
             updateKeyguardBottomAreaAlpha();
         }
         updateClock();
+        updateCommunal();
     }
 
     private void trackMovement(MotionEvent event) {

packages/SystemUI/tests/src/com/android/systemui/communal/CommunalHostViewControllerTest.java

@@ -77,6 +77,9 @@ public class CommunalHostViewControllerTest extends SysuiTestCase {
     @Mock
     private CommunalSource mCommunalSource;
 
+    @Mock
+    private View mChildView;
+
     @Before
     public void setup() {
         MockitoAnnotations.initMocks(this);
@@ -211,4 +214,16 @@ public class CommunalHostViewControllerTest extends SysuiTestCase {
         // Verify state controller is notified communal view is hidden.
         verify(mCommunalStateController).setCommunalViewShowing(false);
     }
+
+    @Test
+    public void testAlphaPropagation() {
+        final float alpha = 0.8f;
+
+        // Ensure alpha setting is propagated to children.
+        when(mCommunalView.getChildCount()).thenReturn(1);
+        when(mCommunalView.getChildAt(0)).thenReturn(mChildView);
+        mController.setAlpha(alpha);
+        verify(mChildView).setAlpha(alpha);
+        verify(mCommunalView).setAlpha(alpha);
+    }
 }

packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewTest.java

@@ -29,6 +29,7 @@ import static com.google.common.truth.Truth.assertThat;
 
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.ArgumentMatchers.anyFloat;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.atLeast;
@@ -901,6 +902,14 @@ public class NotificationPanelViewTest extends SysuiTestCase {
                 anyBoolean(), anyBoolean(), anyInt());
     }
 
+    @Test
+    public void testCommunalAlphaUpdate() {
+        // Verify keyguard content alpha changes are propagate. Note the actual value set is not
+        // checked since an interpolation is applied to the incoming value.
+        mNotificationPanelViewController.setKeyguardOnlyContentAlpha(0.8f);
+        verify(mCommunalHostViewController).setAlpha(anyFloat());
+    }
+
     private void triggerPositionClockAndNotifications() {
         mNotificationPanelViewController.closeQs();
     }