From 0fb7f056de2d3991151147b3e1c8640be08493c8 Mon Sep 17 00:00:00 2001
From: Lucas Dupin <dupin@google.com>
Date: Wed, 2 Jun 2021 12:28:26 -0700
Subject: [PATCH] Avoid overlap when fading notifications in

This CL reduces the number of awkward overlaping frames, where the scrim
is partially visible on top of the app while notifications are also
semi-transparent.

One great benefit of this CL, as well, is that it avoids overdraw,
drawing notifications after the shade window becomes opaque.

Test: using jank scripts
Test: manual
Fixes: 189964129
Change-Id: Ie2fe23aba101bc4c4a5692f999d672e79ddf8e0a
---
 .../com/android/systemui/animation/Interpolators.java  |  6 ++++--
 .../systemui/statusbar/phone/ScrimControllerTest.java  | 10 +++++-----
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/packages/SystemUI/animation/src/com/android/systemui/animation/Interpolators.java b/packages/SystemUI/animation/src/com/android/systemui/animation/Interpolators.java
index e1f72c1937849..457e8e6e9a5fa 100644
--- a/packages/SystemUI/animation/src/com/android/systemui/animation/Interpolators.java
+++ b/packages/SystemUI/animation/src/com/android/systemui/animation/Interpolators.java
@@ -99,8 +99,10 @@ public class Interpolators {
      * @param forNotification If we want the alpha of the notification shade or the scrim.
      */
     public static float getNotificationScrimAlpha(float fraction, boolean forNotification) {
-        if (!forNotification) {
-            fraction = MathUtils.saturate(1.7f * fraction);
+        if (forNotification) {
+            fraction = MathUtils.constrainedMap(0f, 1f, 0.3f, 1f, fraction);
+        } else {
+            fraction = MathUtils.constrainedMap(0f, 1f, 0f, 0.5f, fraction);
         }
         fraction = fraction * 1.2f - 0.2f;
         if (fraction <= 0) {
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 8b0b579bea548..7876bae0d2664 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
@@ -584,7 +584,7 @@ public class ScrimControllerTest extends SysuiTestCase {
         ));
 
         // Back scrim should be visible after start dragging
-        mScrimController.setPanelExpansion(0.5f);
+        mScrimController.setPanelExpansion(0.3f);
         assertScrimAlpha(Map.of(
                 mScrimInFront, TRANSPARENT,
                 mNotificationsScrim, SEMI_TRANSPARENT,
@@ -1046,7 +1046,7 @@ public class ScrimControllerTest extends SysuiTestCase {
     @Test
     public void testScrimsVisible_whenShadeVisible() {
         mScrimController.transitionTo(ScrimState.UNLOCKED);
-        mScrimController.setPanelExpansion(0.5f);
+        mScrimController.setPanelExpansion(0.3f);
         // notifications scrim alpha change require calling setQsPosition
         mScrimController.setQsPosition(0, 300);
         finishAnimationsImmediately();
@@ -1061,7 +1061,7 @@ public class ScrimControllerTest extends SysuiTestCase {
     public void testScrimsVisible_whenShadeVisible_clippingQs() {
         mScrimController.setClipsQsScrim(true);
         mScrimController.transitionTo(ScrimState.UNLOCKED);
-        mScrimController.setPanelExpansion(0.5f);
+        mScrimController.setPanelExpansion(0.3f);
         // notifications scrim alpha change require calling setQsPosition
         mScrimController.setQsPosition(0.5f, 300);
         finishAnimationsImmediately();
@@ -1111,7 +1111,7 @@ public class ScrimControllerTest extends SysuiTestCase {
         mScrimController.transitionTo(ScrimState.SHADE_LOCKED);
 
         assertAlphaAfterExpansion(mNotificationsScrim, /* alpha */ 0.8f, /* expansion */ 0.8f);
-        assertAlphaAfterExpansion(mNotificationsScrim, /* alpha */ 0.2f, /* expansion */ 0.2f);
+        assertAlphaAfterExpansion(mNotificationsScrim, /* alpha */ 0.47f, /* expansion */ 0.2f);
     }
 
     @Test
@@ -1119,7 +1119,7 @@ public class ScrimControllerTest extends SysuiTestCase {
         mScrimController.transitionTo(ScrimState.KEYGUARD);
 
         assertAlphaAfterExpansion(mNotificationsScrim, /* alpha */ 0.2f, /* expansion */ 0.4f);
-        assertAlphaAfterExpansion(mNotificationsScrim, /* alpha */ 0.8f, /* expansion */ 0.2f);
+        assertAlphaAfterExpansion(mNotificationsScrim, /* alpha */ 0.52f, /* expansion */ 0.2f);
     }
 
     @Test