From 99c4becf246726dcfeea16bd65c134f4fc875293 Mon Sep 17 00:00:00 2001
From: vadimt <vadimt@google.com>
Date: Tue, 16 May 2023 14:21:31 -0700
Subject: [PATCH] Switch ScrimView to use view alpha
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Using view alpha instead of background paint’s color alpha component
will make ScrimView alpha and visibility available to View Capture and
any analysis tool that’s based on it.

The change makes ScimView background completely opaque, and makes Scrim
View use variable alpha instead of always-1.0 alpha.

Changes some code that depends on the old way of representing ScrimView
opacity.

Also moves “updateSysUiColors()” call in ScrimView#setBackgroundColor
below updating alpha and background color so the new values are used in
the calculations.

Bug: 282991128
Test: local, presubmit
Change-Id: I6ca089bae55adfb9c3140d06da4fbb3b08f2bf8b
---
 .../NoButtonQuickSwitchTouchController.java   |  3 +-
 .../FallbackRecentsStateController.java       |  2 +-
 .../android/launcher3/LauncherAnimUtils.java  |  5 ++++
 .../WorkspaceStateTransitionAnimation.java    |  2 +-
 .../anim/AnimatedPropertySetter.java          |  9 +++---
 .../launcher3/anim/PropertySetter.java        |  5 +++-
 .../android/launcher3/views/ScrimView.java    | 30 +++++++------------
 7 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/NoButtonQuickSwitchTouchController.java b/quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/NoButtonQuickSwitchTouchController.java
index d3ef58936e..9f9cb00c07 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/NoButtonQuickSwitchTouchController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/NoButtonQuickSwitchTouchController.java
@@ -16,7 +16,6 @@
 package com.android.launcher3.uioverrides.touchcontrollers;
 
 import static android.view.MotionEvent.ACTION_DOWN;
-import static android.view.MotionEvent.ACTION_MOVE;
 
 import static com.android.app.animation.Interpolators.ACCELERATE_0_75;
 import static com.android.app.animation.Interpolators.DECELERATE_3;
@@ -262,7 +261,7 @@ public class NoButtonQuickSwitchTouchController implements TouchController,
         xAnim.setFloat(mRecentsView, ADJACENT_PAGE_HORIZONTAL_OFFSET, scaleAndOffset[1], LINEAR);
         // Use QuickSwitchState instead of OverviewState to determine scrim color,
         // since we need to take potential taskbar into account.
-        xAnim.setViewBackgroundColor(mLauncher.getScrimView(),
+        xAnim.setScrimViewBackgroundColor(mLauncher.getScrimView(),
                 QUICK_SWITCH_FROM_HOME.getWorkspaceScrimColor(mLauncher), LINEAR);
         if (mRecentsView.getTaskViewCount() == 0) {
             xAnim.addFloat(mRecentsView, CONTENT_ALPHA, 0f, 1f, LINEAR);
diff --git a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java
index 8a9e04e488..ca8381b4bf 100644
--- a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java
+++ b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsStateController.java
@@ -114,7 +114,7 @@ public class FallbackRecentsStateController implements StateHandler<RecentsState
         setter.setFloat(mRecentsView, TASK_THUMBNAIL_SPLASH_ALPHA,
                 state.showTaskThumbnailSplash() ? 1f : 0f, INSTANT);
 
-        setter.setViewBackgroundColor(mActivity.getScrimView(), state.getScrimColor(mActivity),
+        setter.setScrimViewBackgroundColor(mActivity.getScrimView(), state.getScrimColor(mActivity),
                 config.getInterpolator(ANIM_SCRIM_FADE, LINEAR));
 
         RecentsState currentState = mActivity.getStateManager().getState();
diff --git a/src/com/android/launcher3/LauncherAnimUtils.java b/src/com/android/launcher3/LauncherAnimUtils.java
index c20f323055..51abfd36ee 100644
--- a/src/com/android/launcher3/LauncherAnimUtils.java
+++ b/src/com/android/launcher3/LauncherAnimUtils.java
@@ -30,6 +30,7 @@ import android.widget.ImageView;
 import android.widget.TextView;
 
 import com.android.launcher3.util.MultiScalePropertyFactory;
+import com.android.launcher3.views.ScrimView;
 
 public class LauncherAnimUtils {
     /**
@@ -194,6 +195,10 @@ public class LauncherAnimUtils {
 
                 @Override
                 public Integer get(View view) {
+                    if (view instanceof ScrimView) {
+                        return ((ScrimView) view).getBackgroundColor();
+                    }
+
                     if (!(view.getBackground() instanceof ColorDrawable)) {
                         return Color.TRANSPARENT;
                     }
diff --git a/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java b/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
index c04cdfdb0f..68c4ba0dda 100644
--- a/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
+++ b/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
@@ -199,7 +199,7 @@ public class WorkspaceStateTransitionAnimation {
         propertySetter.setFloat(sysUiScrim, SYSUI_PROGRESS,
                 state.hasFlag(FLAG_HAS_SYS_UI_SCRIM) ? 1 : 0, LINEAR);
 
-        propertySetter.setViewBackgroundColor(mLauncher.getScrimView(),
+        propertySetter.setScrimViewBackgroundColor(mLauncher.getScrimView(),
                 state.getWorkspaceScrimColor(mLauncher),
                 config.getInterpolator(ANIM_SCRIM_FADE, ACCELERATE_2));
     }
diff --git a/src/com/android/launcher3/anim/AnimatedPropertySetter.java b/src/com/android/launcher3/anim/AnimatedPropertySetter.java
index 82e645a7a0..ff6bdec091 100644
--- a/src/com/android/launcher3/anim/AnimatedPropertySetter.java
+++ b/src/com/android/launcher3/anim/AnimatedPropertySetter.java
@@ -24,13 +24,14 @@ import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.animation.TimeInterpolator;
 import android.animation.ValueAnimator;
-import android.graphics.drawable.ColorDrawable;
 import android.util.FloatProperty;
 import android.util.IntProperty;
 import android.view.View;
 
 import androidx.annotation.NonNull;
 
+import com.android.launcher3.views.ScrimView;
+
 import java.util.function.Consumer;
 
 /**
@@ -62,9 +63,9 @@ public class AnimatedPropertySetter extends PropertySetter {
     }
 
     @Override
-    public Animator setViewBackgroundColor(View view, int color, TimeInterpolator interpolator) {
-        if (view == null || (view.getBackground() instanceof ColorDrawable
-                && ((ColorDrawable) view.getBackground()).getColor() == color)) {
+    public Animator setScrimViewBackgroundColor(ScrimView view, int color,
+            TimeInterpolator interpolator) {
+        if (view == null || view.getBackgroundColor() == color) {
             return NO_OP;
         }
         ObjectAnimator anim = ObjectAnimator.ofArgb(view, VIEW_BACKGROUND_COLOR, color);
diff --git a/src/com/android/launcher3/anim/PropertySetter.java b/src/com/android/launcher3/anim/PropertySetter.java
index 6ba58b6a98..0b2858d5ad 100644
--- a/src/com/android/launcher3/anim/PropertySetter.java
+++ b/src/com/android/launcher3/anim/PropertySetter.java
@@ -25,6 +25,8 @@ import android.view.View;
 
 import androidx.annotation.NonNull;
 
+import com.android.launcher3.views.ScrimView;
+
 import java.util.function.Consumer;
 
 /**
@@ -62,7 +64,8 @@ public abstract class PropertySetter {
      * Sets the background color of the provided view using the provided interpolator.
      */
     @NonNull
-    public Animator setViewBackgroundColor(View view, int color, TimeInterpolator interpolator) {
+    public Animator setScrimViewBackgroundColor(ScrimView view, int color,
+            TimeInterpolator interpolator) {
         if (view != null) {
             view.setBackgroundColor(color);
         }
diff --git a/src/com/android/launcher3/views/ScrimView.java b/src/com/android/launcher3/views/ScrimView.java
index ca80c516f0..6a9aedfc25 100644
--- a/src/com/android/launcher3/views/ScrimView.java
+++ b/src/com/android/launcher3/views/ScrimView.java
@@ -21,7 +21,6 @@ import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Rect;
-import android.graphics.drawable.ColorDrawable;
 import android.util.AttributeSet;
 import android.view.View;
 
@@ -62,19 +61,17 @@ public class ScrimView extends View implements Insettable {
         return false;
     }
 
-    @Override
-    protected boolean onSetAlpha(int alpha) {
-        updateSysUiColors();
-        dispatchVisibilityListenersIfNeeded();
-        return super.onSetAlpha(alpha);
-    }
-
     @Override
     public void setBackgroundColor(int color) {
         mBackgroundColor = color;
-        updateSysUiColors();
         dispatchVisibilityListenersIfNeeded();
-        super.setBackgroundColor(color);
+        if (Color.alpha(color) == 0) {
+            setAlpha(0);
+        } else {
+            setAlpha(1);
+            super.setBackgroundColor(color);
+        }
+        updateSysUiColors();
     }
 
     public int getBackgroundColor() {
@@ -89,7 +86,7 @@ public class ScrimView extends View implements Insettable {
     }
 
     public boolean isFullyOpaque() {
-        return mIsVisible && getAlpha() == 1 && Color.alpha(mBackgroundColor) == 255;
+        return mIsVisible && getAlpha() == 1;
     }
 
     @Override
@@ -120,8 +117,7 @@ public class ScrimView extends View implements Insettable {
         // status bar.
         final float threshold = STATUS_BAR_COLOR_FORCE_UPDATE_THRESHOLD;
         boolean forceChange = getVisibility() == VISIBLE
-                && getAlpha() > threshold
-                && (Color.alpha(mBackgroundColor) / 255f) > threshold;
+                && getAlpha() > threshold;
         if (forceChange) {
             getSystemUiController().updateUiState(UI_STATE_SCRIM_VIEW, !isScrimDark());
         } else {
@@ -148,13 +144,7 @@ public class ScrimView extends View implements Insettable {
     }
 
     private boolean isScrimDark() {
-        if (!(getBackground() instanceof ColorDrawable)) {
-            throw new IllegalStateException(
-                    "ScrimView must have a ColorDrawable background, this one has: "
-                            + getBackground());
-        }
-        return ColorUtils.calculateLuminance(
-                ((ColorDrawable) getBackground()).getColor()) < 0.5f;
+        return ColorUtils.calculateLuminance(mBackgroundColor) < 0.5f;
     }
 
     /**