Set new scrimMultiplier instead of scrimProgress for overview -> home

Animating this new property allows us to adjust the scrim without
competing with other state animations that could be setting the
scrim progress. Also reset scrimMultipler = 1 for state transitions.

Test: Swipe from home to overview, then during that transition swipe
from overview to home; when the former transition ends while the
second is still in progress, ensure scrim value doesn't jump

Bug: 144170434
Change-Id: I44b57ced1c6902e558fe1818bcbf11ceb4ff2f6f
Merged-In: I44b57ced1c6902e558fe1818bcbf11ceb4ff2f6f
diff --git a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/NavBarToHomeTouchController.java b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/NavBarToHomeTouchController.java
index 61f6702..9cc3e1a 100644
--- a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/NavBarToHomeTouchController.java
+++ b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/NavBarToHomeTouchController.java
@@ -66,8 +66,8 @@
         SingleAxisSwipeDetector.Listener {
 
     private static final Interpolator PULLBACK_INTERPOLATOR = DEACCEL_3;
-    // How much of the overview scrim we can remove during the transition.
-    private static final float OVERVIEW_TO_HOME_SCRIM_PROGRESS = 0.5f;
+    // The min amount of overview scrim we keep during the transition.
+    private static final float OVERVIEW_TO_HOME_SCRIM_MULTIPLIER = 0.5f;
 
     private final Launcher mLauncher;
     private final SingleAxisSwipeDetector mSwipeDetector;
@@ -163,11 +163,11 @@
             RecentsView recentsView = mLauncher.getOverviewPanel();
             AnimatorControllerWithResistance.createRecentsResistanceFromOverviewAnim(mLauncher,
                     builder);
-            float endScrimAlpha = Utilities.mapRange(OVERVIEW_TO_HOME_SCRIM_PROGRESS,
-                    mStartState.getOverviewScrimAlpha(mLauncher),
-                    mEndState.getOverviewScrimAlpha(mLauncher));
+
             builder.setFloat(mLauncher.getDragLayer().getOverviewScrim(),
-                    OverviewScrim.SCRIM_PROGRESS, endScrimAlpha, PULLBACK_INTERPOLATOR);
+                    OverviewScrim.SCRIM_MULTIPLIER, OVERVIEW_TO_HOME_SCRIM_MULTIPLIER,
+                    PULLBACK_INTERPOLATOR);
+
             if (ENABLE_QUICKSTEP_LIVE_TILE.get()) {
                 builder.addOnFrameCallback(
                         () -> recentsView.redrawLiveTile(false /* mightNeedToRefill */));
diff --git a/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java b/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
index 1b8e244..aad7e17 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
@@ -18,6 +18,7 @@
 
 import static com.android.launcher3.anim.Interpolators.AGGRESSIVE_EASE_IN_OUT;
 import static com.android.launcher3.anim.Interpolators.LINEAR;
+import static com.android.launcher3.graphics.OverviewScrim.SCRIM_MULTIPLIER;
 import static com.android.launcher3.graphics.Scrim.SCRIM_PROGRESS;
 import static com.android.launcher3.states.StateAnimationConfig.ANIM_OVERVIEW_FADE;
 import static com.android.launcher3.states.StateAnimationConfig.ANIM_OVERVIEW_MODAL;
@@ -70,6 +71,7 @@
         getContentAlphaProperty().set(mRecentsView, state.overviewUi ? 1f : 0);
         OverviewScrim scrim = mLauncher.getDragLayer().getOverviewScrim();
         SCRIM_PROGRESS.set(scrim, state.getOverviewScrimAlpha(mLauncher));
+        SCRIM_MULTIPLIER.set(scrim, 1f);
         getTaskModalnessProperty().set(mRecentsView, state.getOverviewModalness());
     }
 
@@ -108,6 +110,8 @@
         OverviewScrim scrim = mLauncher.getDragLayer().getOverviewScrim();
         setter.setFloat(scrim, SCRIM_PROGRESS, toState.getOverviewScrimAlpha(mLauncher),
                 config.getInterpolator(ANIM_OVERVIEW_SCRIM_FADE, LINEAR));
+        setter.setFloat(scrim, SCRIM_MULTIPLIER, 1f,
+                config.getInterpolator(ANIM_OVERVIEW_SCRIM_FADE, LINEAR));
 
         setter.setFloat(
                 mRecentsView, getTaskModalnessProperty(),
diff --git a/src/com/android/launcher3/graphics/OverviewScrim.java b/src/com/android/launcher3/graphics/OverviewScrim.java
index 94acbfd..c0c3e5e 100644
--- a/src/com/android/launcher3/graphics/OverviewScrim.java
+++ b/src/com/android/launcher3/graphics/OverviewScrim.java
@@ -22,6 +22,7 @@
 import static com.android.launcher3.LauncherState.OVERVIEW;
 
 import android.graphics.Rect;
+import android.util.FloatProperty;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -33,10 +34,25 @@
  */
 public class OverviewScrim extends Scrim {
 
+    public static final FloatProperty<OverviewScrim> SCRIM_MULTIPLIER =
+            new FloatProperty<OverviewScrim>("scrimMultiplier") {
+                @Override
+                public Float get(OverviewScrim scrim) {
+                    return scrim.mScrimMultiplier;
+                }
+
+                @Override
+                public void setValue(OverviewScrim scrim, float v) {
+                    scrim.setScrimMultiplier(v);
+                }
+            };
+
     private @NonNull View mStableScrimmedView;
     // Might be higher up if mStableScrimmedView is invisible.
     private @Nullable View mCurrentScrimmedView;
 
+    private float mScrimMultiplier = 1f;
+
     public OverviewScrim(View view) {
         super(view);
         mStableScrimmedView = mCurrentScrimmedView = mLauncher.getOverviewPanel();
@@ -68,4 +84,16 @@
     public @Nullable View getScrimmedView() {
         return mCurrentScrimmedView;
     }
+
+    private void setScrimMultiplier(float scrimMultiplier) {
+        if (Float.compare(mScrimMultiplier, scrimMultiplier) != 0) {
+            mScrimMultiplier = scrimMultiplier;
+            invalidate();
+        }
+    }
+
+    @Override
+    protected int getScrimAlpha() {
+        return Math.round(super.getScrimAlpha() * mScrimMultiplier);
+    }
 }
diff --git a/src/com/android/launcher3/graphics/Scrim.java b/src/com/android/launcher3/graphics/Scrim.java
index f90962d..a151cba 100644
--- a/src/com/android/launcher3/graphics/Scrim.java
+++ b/src/com/android/launcher3/graphics/Scrim.java
@@ -61,7 +61,11 @@
     }
 
     public void draw(Canvas canvas) {
-        canvas.drawColor(setColorAlphaBound(mScrimColor, mScrimAlpha));
+        canvas.drawColor(setColorAlphaBound(mScrimColor, getScrimAlpha()));
+    }
+
+    protected int getScrimAlpha() {
+        return mScrimAlpha;
     }
 
     private void setScrimProgress(float progress) {