Add OverviewScrim to show below overview but above workspace

- Refactor some basic scrim logic to Scrim class and have
  WorkspaceAndHotseatScrim and OverviewScrim extend it
- Draw OverviewScrim under recents unless predictions are disabled, in
  which case draw it under hotseat (since that is in recents)
- Remove sysui scrim (behind status bar and nav bar) when overview is
  peeking

Bug: 132455160
Change-Id: Ia5d6f54582a4c5a70e3b2d4a98281567edd68519

13 files changed, 252 insertions, 79 deletions

diff --git a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewPeekState.java b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewPeekState.java
index c95476283..427206a65 100644
--- a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewPeekState.java
+++ b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewPeekState.java
@@ -15,7 +15,9 @@
  */
 package com.android.launcher3.uioverrides.states;
 import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_FADE;
+import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_SCRIM_FADE;
 import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_TRANSLATE_X;
+import static com.android.launcher3.anim.Interpolators.FAST_OUT_SLOW_IN;
 import static com.android.launcher3.anim.Interpolators.INSTANT;
 import static com.android.launcher3.anim.Interpolators.OVERSHOOT_1_7;
 
@@ -43,6 +45,7 @@ public class OverviewPeekState extends OverviewState {
         if (this == OVERVIEW_PEEK && fromState == NORMAL) {
             builder.setInterpolator(ANIM_OVERVIEW_FADE, INSTANT);
             builder.setInterpolator(ANIM_OVERVIEW_TRANSLATE_X, OVERSHOOT_1_7);
+            builder.setInterpolator(ANIM_OVERVIEW_SCRIM_FADE, FAST_OUT_SLOW_IN);
         }
     }
 }
diff --git a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewState.java b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewState.java
index 5543860ee..151ceb834 100644
--- a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewState.java
+++ b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/states/OverviewState.java
@@ -43,7 +43,6 @@ import com.android.launcher3.R;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.allapps.DiscoveryBounce;
 import com.android.launcher3.anim.AnimatorSetBuilder;
-import com.android.launcher3.uioverrides.UiFactory;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action;
 import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
 import com.android.quickstep.SysUINavigationMode;
@@ -128,14 +127,15 @@ public class OverviewState extends LauncherState {
         if (launcher.getDeviceProfile().isVerticalBarLayout()) {
             return VERTICAL_SWIPE_INDICATOR | RECENTS_CLEAR_ALL_BUTTON;
         } else {
+            boolean hasAllAppsHeaderExtra = launcher.getAppsView() != null
+                    && launcher.getAppsView().getFloatingHeaderView().hasVisibleContent();
             return HOTSEAT_SEARCH_BOX | VERTICAL_SWIPE_INDICATOR | RECENTS_CLEAR_ALL_BUTTON |
-                    (launcher.getAppsView().getFloatingHeaderView().hasVisibleContent()
-                            ? ALL_APPS_HEADER_EXTRA : HOTSEAT_ICONS);
+                    (hasAllAppsHeaderExtra ? ALL_APPS_HEADER_EXTRA : HOTSEAT_ICONS);
         }
     }
 
     @Override
-    public float getWorkspaceScrimAlpha(Launcher launcher) {
+    public float getOverviewScrimAlpha(Launcher launcher) {
         return 0.5f;
     }
 
diff --git a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/FlingAndHoldTouchController.java b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/FlingAndHoldTouchController.java
index f06b8a910..6142cdfc1 100644
--- a/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/FlingAndHoldTouchController.java
+++ b/quickstep/recents_ui_overrides/src/com/android/launcher3/uioverrides/touchcontrollers/FlingAndHoldTouchController.java
@@ -102,6 +102,9 @@ public class FlingAndHoldTouchController extends PortraitStatesTouchController {
                 mPeekAnim.start();
                 recentsView.performHapticFeedback(HapticFeedbackConstants.VIRTUAL_KEY,
                         HapticFeedbackConstants.FLAG_IGNORE_VIEW_SETTING);
+
+                mLauncher.getDragLayer().getScrim().animateToSysuiMultiplier(isPaused ? 0 : 1,
+                        peekDuration, 0);
             });
         }
     }
diff --git a/quickstep/recents_ui_overrides/src/com/android/quickstep/util/StaggeredWorkspaceAnim.java b/quickstep/recents_ui_overrides/src/com/android/quickstep/util/StaggeredWorkspaceAnim.java
index 1705c9712..1069bed59 100644
--- a/quickstep/recents_ui_overrides/src/com/android/quickstep/util/StaggeredWorkspaceAnim.java
+++ b/quickstep/recents_ui_overrides/src/com/android/quickstep/util/StaggeredWorkspaceAnim.java
@@ -15,6 +15,11 @@
  */
 package com.android.quickstep.util;
 
+import static com.android.launcher3.LauncherAnimUtils.VIEW_TRANSLATE_Y;
+import static com.android.launcher3.LauncherState.BACKGROUND_APP;
+import static com.android.launcher3.LauncherState.NORMAL;
+import static com.android.launcher3.anim.Interpolators.LINEAR;
+
 import android.animation.Animator;
 import android.animation.Animator.AnimatorListener;
 import android.animation.AnimatorListenerAdapter;
@@ -35,15 +40,11 @@ import com.android.launcher3.Workspace;
 import com.android.launcher3.anim.AnimatorSetBuilder;
 import com.android.launcher3.anim.PropertySetter;
 import com.android.launcher3.anim.SpringObjectAnimator;
+import com.android.launcher3.graphics.OverviewScrim;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import static com.android.launcher3.LauncherAnimUtils.VIEW_TRANSLATE_Y;
-import static com.android.launcher3.LauncherState.BACKGROUND_APP;
-import static com.android.launcher3.LauncherState.NORMAL;
-import static com.android.launcher3.anim.Interpolators.LINEAR;
-
 /**
  * Creates an animation where all the workspace items are moved into their final location,
  * staggered row by row from the bottom up.
@@ -122,8 +123,8 @@ public class StaggeredWorkspaceAnim {
             addStaggeredAnimationForView(qsb, grid.inv.numRows + 2, totalRows);
         }
 
-        addWorkspaceScrimAnimationForState(launcher, BACKGROUND_APP, 0);
-        addWorkspaceScrimAnimationForState(launcher, NORMAL, ALPHA_DURATION_MS);
+        addScrimAnimationForState(launcher, BACKGROUND_APP, 0);
+        addScrimAnimationForState(launcher, NORMAL, ALPHA_DURATION_MS);
 
         AnimatorListener resetClipListener = new AnimatorListenerAdapter() {
             int numAnimations = mAnimators.size();
@@ -191,13 +192,17 @@ public class StaggeredWorkspaceAnim {
         mAnimators.add(alpha);
     }
 
-    private void addWorkspaceScrimAnimationForState(Launcher launcher, LauncherState state,
-            long duration) {
+    private void addScrimAnimationForState(Launcher launcher, LauncherState state, long duration) {
         AnimatorSetBuilder scrimAnimBuilder = new AnimatorSetBuilder();
         AnimationConfig scrimAnimConfig = new AnimationConfig();
         scrimAnimConfig.duration = duration;
         PropertySetter scrimPropertySetter = scrimAnimConfig.getPropertySetter(scrimAnimBuilder);
         launcher.getWorkspace().getStateTransitionAnimation().setScrim(scrimPropertySetter, state);
         mAnimators.add(scrimAnimBuilder.build());
+        Animator fadeOverviewScrim = ObjectAnimator.ofFloat(
+                launcher.getDragLayer().getOverviewScrim(), OverviewScrim.SCRIM_PROGRESS,
+                state.getOverviewScrimAlpha(launcher));
+        fadeOverviewScrim.setDuration(duration);
+        mAnimators.add(fadeOverviewScrim);
     }
 }
diff --git a/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java b/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
index f0204b9ba..174e49b8d 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/BaseRecentsViewStateController.java
@@ -19,16 +19,20 @@ package com.android.launcher3.uioverrides;
 import static com.android.launcher3.LauncherAnimUtils.SCALE_PROPERTY;
 import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_FADE;
 import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_SCALE;
+import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_SCRIM_FADE;
 import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_TRANSLATE_X;
 import static com.android.launcher3.anim.AnimatorSetBuilder.ANIM_OVERVIEW_TRANSLATE_Y;
 import static com.android.launcher3.anim.AnimatorSetBuilder.FLAG_DONT_ANIMATE_OVERVIEW;
 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.Scrim.SCRIM_PROGRESS;
 
 import android.util.FloatProperty;
 import android.view.View;
 import android.view.animation.Interpolator;
 
+import androidx.annotation.NonNull;
+
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherState;
 import com.android.launcher3.LauncherState.ScaleAndTranslation;
@@ -36,8 +40,7 @@ import com.android.launcher3.LauncherStateManager.AnimationConfig;
 import com.android.launcher3.LauncherStateManager.StateHandler;
 import com.android.launcher3.anim.AnimatorSetBuilder;
 import com.android.launcher3.anim.PropertySetter;
-
-import androidx.annotation.NonNull;
+import com.android.launcher3.graphics.OverviewScrim;
 
 /**
  * State handler for recents view. Manages UI changes and animations for recents view based off the
@@ -67,6 +70,8 @@ public abstract class BaseRecentsViewStateController<T extends View>
         mRecentsView.setTranslationX(translationX);
         mRecentsView.setTranslationY(scaleAndTranslation.translationY);
         getContentAlphaProperty().set(mRecentsView, state.overviewUi ? 1f : 0);
+        OverviewScrim scrim = mLauncher.getDragLayer().getOverviewScrim();
+        SCRIM_PROGRESS.set(scrim, state.getOverviewScrimAlpha(mLauncher));
     }
 
     @Override
@@ -110,6 +115,9 @@ public abstract class BaseRecentsViewStateController<T extends View>
                 translateYInterpolator);
         setter.setFloat(mRecentsView, getContentAlphaProperty(), toState.overviewUi ? 1 : 0,
                 builder.getInterpolator(ANIM_OVERVIEW_FADE, AGGRESSIVE_EASE_IN_OUT));
+        OverviewScrim scrim = mLauncher.getDragLayer().getOverviewScrim();
+        setter.setFloat(scrim, SCRIM_PROGRESS, toState.getOverviewScrimAlpha(mLauncher),
+                builder.getInterpolator(ANIM_OVERVIEW_SCRIM_FADE, LINEAR));
     }
 
     /**
diff --git a/quickstep/src/com/android/quickstep/views/ShelfScrimView.java b/quickstep/src/com/android/quickstep/views/ShelfScrimView.java
index 5a2f5c162..3747f9a8b 100644
--- a/quickstep/src/com/android/quickstep/views/ShelfScrimView.java
+++ b/quickstep/src/com/android/quickstep/views/ShelfScrimView.java
@@ -98,7 +98,7 @@ public class ShelfScrimView extends ScrimView implements NavigationModeChangeLis
 
     public ShelfScrimView(Context context, AttributeSet attrs) {
         super(context, attrs);
-        mMaxScrimAlpha = Math.round(OVERVIEW.getWorkspaceScrimAlpha(mLauncher) * 255);
+        mMaxScrimAlpha = Math.round(OVERVIEW.getOverviewScrimAlpha(mLauncher) * 255);
 
         mEndAlpha = Color.alpha(mEndScrim);
         mRadius = BOTTOM_CORNER_RADIUS_RATIO * Themes.getDialogCornerRadius(context);
diff --git a/src/com/android/launcher3/LauncherState.java b/src/com/android/launcher3/LauncherState.java
index dcfd272b4..6e2626b61 100644
--- a/src/com/android/launcher3/LauncherState.java
+++ b/src/com/android/launcher3/LauncherState.java
@@ -243,6 +243,10 @@ public class LauncherState {
         return 0;
     }
 
+    public float getOverviewScrimAlpha(Launcher launcher) {
+        return 0;
+    }
+
     public String getDescription(Launcher launcher) {
         return launcher.getWorkspace().getCurrentPageDescription();
     }
diff --git a/src/com/android/launcher3/anim/AnimatorSetBuilder.java b/src/com/android/launcher3/anim/AnimatorSetBuilder.java
index 52a896eda..11db25be4 100644
--- a/src/com/android/launcher3/anim/AnimatorSetBuilder.java
+++ b/src/com/android/launcher3/anim/AnimatorSetBuilder.java
@@ -39,6 +39,7 @@ public class AnimatorSetBuilder {
     public static final int ANIM_OVERVIEW_TRANSLATE_Y = 8;
     public static final int ANIM_OVERVIEW_FADE = 9;
     public static final int ANIM_ALL_APPS_FADE = 10;
+    public static final int ANIM_OVERVIEW_SCRIM_FADE = 11;
 
     public static final int FLAG_DONT_ANIMATE_OVERVIEW = 1 << 0;
 
diff --git a/src/com/android/launcher3/dragndrop/DragLayer.java b/src/com/android/launcher3/dragndrop/DragLayer.java
index 6ba015b2e..b59164ae0 100644
--- a/src/com/android/launcher3/dragndrop/DragLayer.java
+++ b/src/com/android/launcher3/dragndrop/DragLayer.java
@@ -48,12 +48,13 @@ import com.android.launcher3.CellLayout;
 import com.android.launcher3.DropTargetBar;
 import com.android.launcher3.Launcher;
 import com.android.launcher3.R;
-import com.android.launcher3.graphics.RotationMode;
 import com.android.launcher3.ShortcutAndWidgetContainer;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.anim.Interpolators;
 import com.android.launcher3.folder.Folder;
 import com.android.launcher3.folder.FolderIcon;
+import com.android.launcher3.graphics.OverviewScrim;
+import com.android.launcher3.graphics.RotationMode;
 import com.android.launcher3.graphics.WorkspaceAndHotseatScrim;
 import com.android.launcher3.keyboard.ViewGroupFocusHelper;
 import com.android.launcher3.uioverrides.UiFactory;
@@ -92,7 +93,8 @@ public class DragLayer extends BaseDragLayer<Launcher> {
 
     // Related to adjacent page hints
     private final ViewGroupFocusHelper mFocusIndicatorHelper;
-    private final WorkspaceAndHotseatScrim mScrim;
+    private final WorkspaceAndHotseatScrim mWorkspaceScrim;
+    private final OverviewScrim mOverviewScrim;
 
     /**
      * Used to create a new DragLayer from XML.
@@ -108,12 +110,13 @@ public class DragLayer extends BaseDragLayer<Launcher> {
         setChildrenDrawingOrderEnabled(true);
 
         mFocusIndicatorHelper = new ViewGroupFocusHelper(this);
-        mScrim = new WorkspaceAndHotseatScrim(this);
+        mWorkspaceScrim = new WorkspaceAndHotseatScrim(this);
+        mOverviewScrim = new OverviewScrim(this);
     }
 
     public void setup(DragController dragController, Workspace workspace) {
         mDragController = dragController;
-        mScrim.setWorkspace(workspace);
+        mWorkspaceScrim.setWorkspace(workspace);
         recreateControllers();
     }
 
@@ -529,25 +532,39 @@ public class DragLayer extends BaseDragLayer<Launcher> {
     @Override
     protected void dispatchDraw(Canvas canvas) {
         // Draw the background below children.
-        mScrim.draw(canvas);
+        mWorkspaceScrim.draw(canvas);
+        mOverviewScrim.updateCurrentScrimmedView(this);
         mFocusIndicatorHelper.draw(canvas);
         super.dispatchDraw(canvas);
     }
 
     @Override
+    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
+        if (child == mOverviewScrim.getScrimmedView()) {
+            mOverviewScrim.draw(canvas);
+        }
+        return super.drawChild(canvas, child, drawingTime);
+    }
+
+    @Override
     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
         super.onSizeChanged(w, h, oldw, oldh);
-        mScrim.setSize(w, h);
+        mWorkspaceScrim.setSize(w, h);
     }
 
     @Override
     public void setInsets(Rect insets) {
         super.setInsets(insets);
-        mScrim.onInsetsChanged(insets);
+        mWorkspaceScrim.onInsetsChanged(insets);
+        mOverviewScrim.onInsetsChanged(insets);
     }
 
     public WorkspaceAndHotseatScrim getScrim() {
-        return mScrim;
+        return mWorkspaceScrim;
+    }
+
+    public OverviewScrim getOverviewScrim() {
+        return mOverviewScrim;
     }
 
     @Override
diff --git a/src/com/android/launcher3/graphics/OverviewScrim.java b/src/com/android/launcher3/graphics/OverviewScrim.java
new file mode 100644
index 000000000..d707403ed
--- /dev/null
+++ b/src/com/android/launcher3/graphics/OverviewScrim.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.graphics;
+
+import static android.view.View.VISIBLE;
+
+import static com.android.launcher3.LauncherState.HOTSEAT_ICONS;
+import static com.android.launcher3.LauncherState.OVERVIEW;
+
+import android.graphics.Rect;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+/**
+ * View scrim which draws behind overview (recent apps).
+ */
+public class OverviewScrim extends Scrim {
+
+    private @NonNull View mStableScrimmedView;
+    // Might be higher up if mStableScrimmedView is invisible.
+    private @Nullable View mCurrentScrimmedView;
+
+    public OverviewScrim(View view) {
+        super(view);
+        mStableScrimmedView = mCurrentScrimmedView = mLauncher.getOverviewPanel();
+
+        onExtractedColorsChanged(mWallpaperColorInfo);
+    }
+
+    public void onInsetsChanged(Rect insets) {
+        mStableScrimmedView = (OVERVIEW.getVisibleElements(mLauncher) & HOTSEAT_ICONS) != 0
+                ? mLauncher.getHotseat()
+                : mLauncher.getOverviewPanel();
+    }
+
+    public void updateCurrentScrimmedView(ViewGroup root) {
+        // Find the lowest view that is at or above the view we want to show the scrim behind.
+        mCurrentScrimmedView = mStableScrimmedView;
+        int currentIndex = root.indexOfChild(mCurrentScrimmedView);
+        final int childCount = root.getChildCount();
+        while (mCurrentScrimmedView.getVisibility() != VISIBLE && currentIndex < childCount) {
+            currentIndex++;
+            mCurrentScrimmedView = root.getChildAt(currentIndex);
+        }
+    }
+
+    /**
+     * @return The view to draw the scrim behind.
+     */
+    public View getScrimmedView() {
+        return mCurrentScrimmedView;
+    }
+}
diff --git a/src/com/android/launcher3/graphics/Scrim.java b/src/com/android/launcher3/graphics/Scrim.java
new file mode 100644
index 000000000..5c14f8d20
--- /dev/null
+++ b/src/com/android/launcher3/graphics/Scrim.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.graphics;
+
+import static com.android.launcher3.icons.GraphicsUtils.setColorAlphaBound;
+
+import android.graphics.Canvas;
+import android.util.Property;
+import android.view.View;
+
+import com.android.launcher3.Launcher;
+import com.android.launcher3.uioverrides.WallpaperColorInfo;
+
+/**
+ * Contains general scrim properties such as wallpaper-extracted color that subclasses can use.
+ */
+public class Scrim implements View.OnAttachStateChangeListener,
+        WallpaperColorInfo.OnChangeListener {
+
+    public static Property<Scrim, Float> SCRIM_PROGRESS =
+            new Property<Scrim, Float>(Float.TYPE, "scrimProgress") {
+                @Override
+                public Float get(Scrim scrim) {
+                    return scrim.mScrimProgress;
+                }
+
+                @Override
+                public void set(Scrim scrim, Float value) {
+                    scrim.setScrimProgress(value);
+                }
+            };
+
+    protected final Launcher mLauncher;
+    protected final WallpaperColorInfo mWallpaperColorInfo;
+    protected final View mRoot;
+
+    protected float mScrimProgress;
+    protected int mScrimColor;
+    protected int mScrimAlpha = 0;
+
+    public Scrim(View view) {
+        mRoot = view;
+        mLauncher = Launcher.getLauncher(view.getContext());
+        mWallpaperColorInfo = WallpaperColorInfo.getInstance(mLauncher);
+
+        view.addOnAttachStateChangeListener(this);
+    }
+
+    public void draw(Canvas canvas) {
+        canvas.drawColor(setColorAlphaBound(mScrimColor, mScrimAlpha));
+    }
+
+    private void setScrimProgress(float progress) {
+        if (mScrimProgress != progress) {
+            mScrimProgress = progress;
+            mScrimAlpha = Math.round(255 * mScrimProgress);
+            invalidate();
+        }
+    }
+
+    @Override
+    public void onViewAttachedToWindow(View view) {
+        mWallpaperColorInfo.addOnChangeListener(this);
+        onExtractedColorsChanged(mWallpaperColorInfo);
+    }
+
+    @Override
+    public void onViewDetachedFromWindow(View view) {
+        mWallpaperColorInfo.removeOnChangeListener(this);
+    }
+
+    @Override
+    public void onExtractedColorsChanged(WallpaperColorInfo wallpaperColorInfo) {
+        mScrimColor = wallpaperColorInfo.getMainColor();
+        if (mScrimAlpha > 0) {
+            invalidate();
+        }
+    }
+
+    public void invalidate() {
+        mRoot.invalidate();
+    }
+}
diff --git a/src/com/android/launcher3/graphics/WorkspaceAndHotseatScrim.java b/src/com/android/launcher3/graphics/WorkspaceAndHotseatScrim.java
index c0aa75f28..6740fa16e 100644
--- a/src/com/android/launcher3/graphics/WorkspaceAndHotseatScrim.java
+++ b/src/com/android/launcher3/graphics/WorkspaceAndHotseatScrim.java
@@ -40,34 +40,19 @@ import android.util.DisplayMetrics;
 import android.util.Property;
 import android.view.View;
 
+import androidx.core.graphics.ColorUtils;
+
 import com.android.launcher3.CellLayout;
-import com.android.launcher3.Launcher;
 import com.android.launcher3.R;
 import com.android.launcher3.ResourceUtils;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.uioverrides.WallpaperColorInfo;
 import com.android.launcher3.util.Themes;
 
-import androidx.core.graphics.ColorUtils;
-
 /**
  * View scrim which draws behind hotseat and workspace
  */
-public class WorkspaceAndHotseatScrim implements
-        View.OnAttachStateChangeListener, WallpaperColorInfo.OnChangeListener {
-
-    public static Property<WorkspaceAndHotseatScrim, Float> SCRIM_PROGRESS =
-            new Property<WorkspaceAndHotseatScrim, Float>(Float.TYPE, "scrimProgress") {
-                @Override
-                public Float get(WorkspaceAndHotseatScrim scrim) {
-                    return scrim.mScrimProgress;
-                }
-
-                @Override
-                public void set(WorkspaceAndHotseatScrim scrim, Float value) {
-                    scrim.setScrimProgress(value);
-                }
-            };
+public class WorkspaceAndHotseatScrim extends Scrim {
 
     public static Property<WorkspaceAndHotseatScrim, Float> SYSUI_PROGRESS =
             new Property<WorkspaceAndHotseatScrim, Float>(Float.TYPE, "sysUiProgress") {
@@ -117,9 +102,6 @@ public class WorkspaceAndHotseatScrim implements
     private static final int ALPHA_MASK_WIDTH_DP = 2;
 
     private final Rect mHighlightRect = new Rect();
-    private final Launcher mLauncher;
-    private final WallpaperColorInfo mWallpaperColorInfo;
-    private final View mRoot;
 
     private Workspace mWorkspace;
 
@@ -132,11 +114,6 @@ public class WorkspaceAndHotseatScrim implements
 
     private final Drawable mTopScrim;
 
-    private int mFullScrimColor;
-
-    private float mScrimProgress;
-    private int mScrimAlpha = 0;
-
     private float mSysUiProgress = 1;
     private boolean mHideSysUiScrim;
 
@@ -144,9 +121,7 @@ public class WorkspaceAndHotseatScrim implements
     private float mSysUiAnimMultiplier = 1;
 
     public WorkspaceAndHotseatScrim(View view) {
-        mRoot = view;
-        mLauncher = Launcher.getLauncher(view.getContext());
-        mWallpaperColorInfo = WallpaperColorInfo.getInstance(mLauncher);
+        super(view);
 
         mMaskHeight = ResourceUtils.pxFromDp(ALPHA_MASK_BITMAP_DP,
                 view.getResources().getDisplayMetrics());
@@ -154,7 +129,6 @@ public class WorkspaceAndHotseatScrim implements
         mBottomMask = mTopScrim == null ? null : createDitheredAlphaMask();
         mHideSysUiScrim = mTopScrim == null;
 
-        view.addOnAttachStateChangeListener(this);
         onExtractedColorsChanged(mWallpaperColorInfo);
     }
 
@@ -176,7 +150,7 @@ public class WorkspaceAndHotseatScrim implements
                 canvas.clipRect(mHighlightRect, Region.Op.DIFFERENCE);
             }
 
-            canvas.drawColor(setColorAlphaBound(mFullScrimColor, mScrimAlpha));
+            super.draw(canvas);
             canvas.restore();
         }
 
@@ -190,11 +164,8 @@ public class WorkspaceAndHotseatScrim implements
                 mSysUiAnimMultiplier = 0;
                 reapplySysUiAlphaNoInvalidate();
 
-                ObjectAnimator anim = ObjectAnimator.ofFloat(this, SYSUI_ANIM_MULTIPLIER, 1);
-                anim.setAutoCancel(true);
-                anim.setDuration(600);
-                anim.setStartDelay(mLauncher.getWindow().getTransitionBackgroundFadeDuration());
-                anim.start();
+                animateToSysuiMultiplier(1, 600,
+                        mLauncher.getWindow().getTransitionBackgroundFadeDuration());
                 mAnimateScrimOnNextDraw = false;
             }
 
@@ -207,24 +178,24 @@ public class WorkspaceAndHotseatScrim implements
         }
     }
 
+    public void animateToSysuiMultiplier(float toMultiplier, long duration,
+            long startDelay) {
+        ObjectAnimator anim = ObjectAnimator.ofFloat(this, SYSUI_ANIM_MULTIPLIER, toMultiplier);
+        anim.setAutoCancel(true);
+        anim.setDuration(duration);
+        anim.setStartDelay(startDelay);
+        anim.start();
+    }
+
     public void onInsetsChanged(Rect insets) {
         mDrawTopScrim = mTopScrim != null && insets.top > 0;
         mDrawBottomScrim = mBottomMask != null &&
                 !mLauncher.getDeviceProfile().isVerticalBarLayout();
     }
 
-    private void setScrimProgress(float progress) {
-        if (mScrimProgress != progress) {
-            mScrimProgress = progress;
-            mScrimAlpha = Math.round(255 * mScrimProgress);
-            invalidate();
-        }
-    }
-
     @Override
     public void onViewAttachedToWindow(View view) {
-        mWallpaperColorInfo.addOnChangeListener(this);
-        onExtractedColorsChanged(mWallpaperColorInfo);
+        super.onViewAttachedToWindow(view);
 
         if (mTopScrim != null) {
             IntentFilter filter = new IntentFilter(ACTION_SCREEN_OFF);
@@ -235,7 +206,7 @@ public class WorkspaceAndHotseatScrim implements
 
     @Override
     public void onViewDetachedFromWindow(View view) {
-        mWallpaperColorInfo.removeOnChangeListener(this);
+        super.onViewDetachedFromWindow(view);
         if (mTopScrim != null) {
             mRoot.getContext().unregisterReceiver(mReceiver);
         }
@@ -248,10 +219,7 @@ public class WorkspaceAndHotseatScrim implements
         mBottomMaskPaint.setColor(ColorUtils.compositeColors(DARK_SCRIM_COLOR,
                 wallpaperColorInfo.getMainColor()));
         reapplySysUiAlpha();
-        mFullScrimColor = wallpaperColorInfo.getMainColor();
-        if (mScrimAlpha > 0) {
-            invalidate();
-        }
+        super.onExtractedColorsChanged(wallpaperColorInfo);
     }
 
     public void setSize(int w, int h) {
@@ -291,10 +259,6 @@ public class WorkspaceAndHotseatScrim implements
         }
     }
 
-    public void invalidate() {
-        mRoot.invalidate();
-    }
-
     public Bitmap createDitheredAlphaMask() {
         DisplayMetrics dm = mLauncher.getResources().getDisplayMetrics();
         int width = ResourceUtils.pxFromDp(ALPHA_MASK_WIDTH_DP, dm);
diff --git a/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java b/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
index 49f515ad4..054534417 100644
--- a/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
+++ b/src/com/android/launcher3/touch/AbstractStateChangeTouchController.java
@@ -518,6 +518,7 @@ public abstract class AbstractStateChangeTouchController
             logReachedState(logAction, targetState);
         }
         mLauncher.getStateManager().goToState(targetState, false /* animated */);
+        mLauncher.getDragLayer().getScrim().animateToSysuiMultiplier(1, 0, 0);
     }
 
     private void logReachedState(int logAction, LauncherState targetState) {