Don't blend front scrim on AOD

The scrim tint is always blended with the main color, as determined by
color extraction and the theme. For AOD, it should always fade to dark
and never be blended with a light color. This is most noticeable in
low light environments when the front scrim is animated and then
blended with white.

Fixes: 223592183
Test: atest ScrimControllerTest + manual (phone in low light,
transition to AOD)

Change-Id: I6b7b78b26bcbf63989580d2f46981d79bcc9a99b

4 files changed, 41 insertions, 3 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/scrim/ScrimView.java b/packages/SystemUI/src/com/android/systemui/scrim/ScrimView.java
index 7530681c82b2..f68e0429ef7c 100644
--- a/packages/SystemUI/src/com/android/systemui/scrim/ScrimView.java
+++ b/packages/SystemUI/src/com/android/systemui/scrim/ScrimView.java
@@ -58,6 +58,7 @@ public class ScrimView extends View {
     private Drawable mDrawable;
     private PorterDuffColorFilter mColorFilter;
     private int mTintColor;
+    private boolean mBlendWithMainColor = true;
     private Runnable mChangeRunnable;
     private Executor mChangeRunnableExecutor;
     private Executor mExecutor;
@@ -192,6 +193,19 @@ public class ScrimView extends View {
     }
 
     /**
+     * The call to {@link #setTint} will blend with the main color, with the amount
+     * determined by the alpha of the tint. Set to false to avoid this blend.
+     */
+    public void setBlendWithMainColor(boolean blend) {
+        mBlendWithMainColor = blend;
+    }
+
+    /** @return true if blending tint color with main color */
+    public boolean shouldBlendWithMainColor() {
+        return mBlendWithMainColor;
+    }
+
+    /**
      * Tints this view, optionally animating it.
      * @param color The color.
      * @param animated If we should animate.
@@ -211,8 +225,11 @@ public class ScrimView extends View {
             // Optimization to blend colors and avoid a color filter
             ScrimDrawable drawable = (ScrimDrawable) mDrawable;
             float tintAmount = Color.alpha(mTintColor) / 255f;
-            int mainTinted = ColorUtils.blendARGB(mColors.getMainColor(), mTintColor,
-                    tintAmount);
+
+            int mainTinted = mTintColor;
+            if (mBlendWithMainColor) {
+                mainTinted = ColorUtils.blendARGB(mColors.getMainColor(), mTintColor, tintAmount);
+            }
             drawable.setColor(mainTinted, animated);
         } else {
             boolean hasAlpha = Color.alpha(mTintColor) != 0;
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java
index f9e17da9773f..0e77866bef1d 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimController.java
@@ -402,6 +402,8 @@ public class ScrimController implements ViewTreeObserver.OnPreDrawListener, Dump
         mScrimBehind.setFocusable(!state.isLowPowerState());
         mNotificationsScrim.setFocusable(!state.isLowPowerState());
 
+        mScrimInFront.setBlendWithMainColor(state.shouldBlendWithMainColor());
+
         // Cancel blanking transitions that were pending before we requested a new state
         if (mPendingFrameCallback != null) {
             mScrimBehind.removeCallbacks(mPendingFrameCallback);
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimState.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimState.java
index 47b705845fce..4a5f712d587c 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimState.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/ScrimState.java
@@ -203,6 +203,11 @@ public enum ScrimState {
         public boolean isLowPowerState() {
             return true;
         }
+
+        @Override
+        public boolean shouldBlendWithMainColor() {
+            return false;
+        }
     },
 
     /**
@@ -325,6 +330,13 @@ public enum ScrimState {
     public void prepare(ScrimState previousState) {
     }
 
+    /**
+     * Whether a particular state should enable blending with extracted theme colors.
+     */
+    public boolean shouldBlendWithMainColor() {
+        return true;
+    }
+
     public float getFrontAlpha() {
         return mFrontAlpha;
     }
@@ -422,4 +434,4 @@ public enum ScrimState {
     public void setClipQsScrim(boolean clipsQsScrim) {
         mClipQsScrim = clipsQsScrim;
     }
-}
\ No newline at end of file
+}
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
index dce520c0973d..5f8dda359563 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/ScrimControllerTest.java
@@ -1490,6 +1490,13 @@ public class ScrimControllerTest extends SysuiTestCase {
         assertAlphaAfterExpansion(mNotificationsScrim, 0f, expansion);
     }
 
+    @Test
+    public void aodStateSetsFrontScrimToNotBlend() {
+        mScrimController.transitionTo(ScrimState.AOD);
+        Assert.assertFalse("Front scrim should not blend with main color",
+                mScrimInFront.shouldBlendWithMainColor());
+    }
+
     private void assertAlphaAfterExpansion(ScrimView scrim, float expectedAlpha, float expansion) {
         mScrimController.setRawPanelExpansionFraction(expansion);
         finishAnimationsImmediately();