Merge "Disable splash screen for launches from widget." into sc-dev am: 97aaa6e5ae

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15685202

Change-Id: Ie2fcf73aaa402706eb369f41c0326c3d641974d5
diff --git a/Android.bp b/Android.bp
index 1b6ffe4..45d022f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -112,6 +112,7 @@
         "androidx.preference_preference",
         "androidx.slice_slice-view",
         "androidx.cardview_cardview",
+        "com.google.android.material_material",
         "iconloader_base",
     ],
     manifest: "AndroidManifest-common.xml",
diff --git a/AndroidManifest-common.xml b/AndroidManifest-common.xml
index d725a16..4eecf29 100644
--- a/AndroidManifest-common.xml
+++ b/AndroidManifest-common.xml
@@ -144,7 +144,7 @@
         <activity
             android:name="com.android.launcher3.settings.SettingsActivity"
             android:label="@string/settings_button_text"
-            android:theme="@style/HomeSettingsTheme"
+            android:theme="@style/HomeSettings.Theme"
             android:exported="true"
             android:autoRemoveFromRecents="true">
             <intent-filter>
diff --git a/quickstep/res/interpolator/app_open_x.xml b/quickstep/res/interpolator/app_open_x.xml
new file mode 100644
index 0000000..5fa0bcb
--- /dev/null
+++ b/quickstep/res/interpolator/app_open_x.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/*
+** Copyright 2021, 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.
+*/
+-->
+
+<pathInterpolator xmlns:android="http://schemas.android.com/apk/res/android"
+    android:pathData="M 0, 0 C 0.1217, 0.0462, 0.15, 0.4686, 0.1667, 0.66 C 0.1834, 0.8878, 0.1667, 1, 1, 1"/>
diff --git a/quickstep/res/interpolator/three_point_fast_out_extra_slow_in.xml b/quickstep/res/interpolator/three_point_fast_out_extra_slow_in.xml
new file mode 100644
index 0000000..70c4231
--- /dev/null
+++ b/quickstep/res/interpolator/three_point_fast_out_extra_slow_in.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/*
+** Copyright 2021, 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.
+*/
+-->
+
+<pathInterpolator xmlns:android="http://schemas.android.com/apk/res/android"
+    android:pathData="M 0,0 C 0.05, 0, 0.133333, 0.06, 0.166666, 0.4 C 0.208333, 0.82, 0.25, 1, 1, 1"/>
diff --git a/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java b/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java
index a44de79..de0416b 100644
--- a/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java
+++ b/quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java
@@ -200,6 +200,17 @@
         }
     }
 
+    /**
+     * {@code LauncherOverlayCallbacks} scroll amount.
+     * Indicates transition progress to -1 screen.
+     * @param progress From 0 to 1.
+     */
+    @Override
+    public void onScrollChanged(float progress) {
+        super.onScrollChanged(progress);
+        mDepthController.onOverlayScrollChanged(progress);
+    }
+
     @Override
     public void startIntentSenderForResult(IntentSender intent, int requestCode,
             Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags, Bundle options) {
diff --git a/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java b/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java
index 5bb76d6..b557779 100644
--- a/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java
+++ b/quickstep/src/com/android/launcher3/QuickstepTransitionManager.java
@@ -32,7 +32,6 @@
 import static com.android.launcher3.anim.Interpolators.AGGRESSIVE_EASE;
 import static com.android.launcher3.anim.Interpolators.DEACCEL_1_5;
 import static com.android.launcher3.anim.Interpolators.DEACCEL_1_7;
-import static com.android.launcher3.anim.Interpolators.EXAGGERATED_EASE;
 import static com.android.launcher3.anim.Interpolators.LINEAR;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_SCRIM_FOR_APP_LAUNCH;
 import static com.android.launcher3.config.FeatureFlags.KEYGUARD_ANIMATION;
@@ -72,6 +71,7 @@
 import android.view.View;
 import android.view.ViewRootImpl;
 import android.view.ViewTreeObserver;
+import android.view.animation.AnimationUtils;
 import android.view.animation.Interpolator;
 import android.view.animation.PathInterpolator;
 
@@ -142,21 +142,11 @@
     private static final String CONTROL_REMOTE_APP_TRANSITION_PERMISSION =
             "android.permission.CONTROL_REMOTE_APP_TRANSITION_ANIMATIONS";
 
-    private static final long APP_LAUNCH_DURATION = 450;
-    // Use a shorter duration for x or y translation to create a curve effect
-    private static final long APP_LAUNCH_CURVED_DURATION = 250;
+    private static final long APP_LAUNCH_DURATION = 500;
+
     private static final long APP_LAUNCH_ALPHA_DURATION = 50;
     private static final long APP_LAUNCH_ALPHA_START_DELAY = 25;
 
-    // We scale the durations for the downward app launch animations (minus the scale animation).
-    private static final float APP_LAUNCH_DOWN_DUR_SCALE_FACTOR = 0.8f;
-    private static final long APP_LAUNCH_DOWN_DURATION =
-            (long) (APP_LAUNCH_DURATION * APP_LAUNCH_DOWN_DUR_SCALE_FACTOR);
-    private static final long APP_LAUNCH_DOWN_CURVED_DURATION =
-            (long) (APP_LAUNCH_CURVED_DURATION * APP_LAUNCH_DOWN_DUR_SCALE_FACTOR);
-    private static final long APP_LAUNCH_ALPHA_DOWN_DURATION =
-            (long) (APP_LAUNCH_ALPHA_DURATION * APP_LAUNCH_DOWN_DUR_SCALE_FACTOR);
-
     public static final int ANIMATION_NAV_FADE_IN_DURATION = 266;
     public static final int ANIMATION_NAV_FADE_OUT_DURATION = 133;
     public static final long ANIMATION_DELAY_NAV_FADE_IN =
@@ -166,9 +156,6 @@
     public static final Interpolator NAV_FADE_OUT_INTERPOLATOR =
             new PathInterpolator(0.2f, 0f, 1f, 1f);
 
-    private static final long CROP_DURATION = 375;
-    private static final long RADIUS_DURATION = 375;
-
     public static final int RECENTS_LAUNCH_DURATION = 336;
     private static final int LAUNCHER_RESUME_START_DELAY = 100;
     private static final int CLOSING_TRANSITION_DURATION_MS = 250;
@@ -222,6 +209,9 @@
     // Will never be larger than MAX_NUM_TASKS
     private LinkedHashMap<Integer, Pair<Integer, Integer>> mTaskStartParams;
 
+    private final Interpolator mOpeningXInterpolator;
+    private final Interpolator mOpeningInterpolator;
+
     public QuickstepTransitionManager(Context context) {
         mLauncher = Launcher.cast(Launcher.getLauncher(context));
         mDragLayer = mLauncher.getDragLayer();
@@ -248,6 +238,10 @@
             SystemUiProxy.INSTANCE.get(mLauncher).setStartingWindowListener(
                     mStartingWindowListener);
         }
+
+        mOpeningXInterpolator = AnimationUtils.loadInterpolator(context, R.interpolator.app_open_x);
+        mOpeningInterpolator = AnimationUtils.loadInterpolator(context,
+                R.interpolator.three_point_fast_out_extra_slow_in);
     }
 
     @Override
@@ -651,27 +645,29 @@
         final float finalShadowRadius = appTargetsAreTranslucent ? 0 : mMaxShadowRadius;
 
         MultiValueUpdateListener listener = new MultiValueUpdateListener() {
-            FloatProp mDx = new FloatProp(0, prop.dX, 0, prop.xDuration, AGGRESSIVE_EASE);
-            FloatProp mDy = new FloatProp(0, prop.dY, 0, prop.yDuration, AGGRESSIVE_EASE);
+            FloatProp mDx = new FloatProp(0, prop.dX, 0, APP_LAUNCH_DURATION,
+                    mOpeningXInterpolator);
+            FloatProp mDy = new FloatProp(0, prop.dY, 0, APP_LAUNCH_DURATION,
+                    mOpeningInterpolator);
 
             FloatProp mIconScaleToFitScreen = new FloatProp(prop.initialAppIconScale,
-                    prop.finalAppIconScale, 0, APP_LAUNCH_DURATION, EXAGGERATED_EASE);
+                    prop.finalAppIconScale, 0, APP_LAUNCH_DURATION, mOpeningInterpolator);
             FloatProp mIconAlpha = new FloatProp(prop.iconAlphaStart, 0f,
-                    APP_LAUNCH_ALPHA_START_DELAY, prop.alphaDuration, LINEAR);
+                    APP_LAUNCH_ALPHA_START_DELAY, APP_LAUNCH_ALPHA_DURATION, LINEAR);
 
             FloatProp mWindowRadius = new FloatProp(initialWindowRadius, finalWindowRadius, 0,
-                    RADIUS_DURATION, EXAGGERATED_EASE);
+                    APP_LAUNCH_DURATION, mOpeningInterpolator);
             FloatProp mShadowRadius = new FloatProp(0, finalShadowRadius, 0,
-                    APP_LAUNCH_DURATION, EXAGGERATED_EASE);
+                    APP_LAUNCH_DURATION, mOpeningInterpolator);
 
             FloatProp mCropRectCenterX = new FloatProp(prop.cropCenterXStart, prop.cropCenterXEnd,
-                    0, CROP_DURATION, EXAGGERATED_EASE);
+                    0, APP_LAUNCH_DURATION, mOpeningInterpolator);
             FloatProp mCropRectCenterY = new FloatProp(prop.cropCenterYStart, prop.cropCenterYEnd,
-                    0, CROP_DURATION, EXAGGERATED_EASE);
+                    0, APP_LAUNCH_DURATION, mOpeningInterpolator);
             FloatProp mCropRectWidth = new FloatProp(prop.cropWidthStart, prop.cropWidthEnd, 0,
-                    CROP_DURATION, EXAGGERATED_EASE);
+                    APP_LAUNCH_DURATION, mOpeningInterpolator);
             FloatProp mCropRectHeight = new FloatProp(prop.cropHeightStart, prop.cropHeightEnd, 0,
-                    CROP_DURATION, EXAGGERATED_EASE);
+                    APP_LAUNCH_DURATION, mOpeningInterpolator);
 
             FloatProp mNavFadeOut = new FloatProp(1f, 0f, 0, ANIMATION_NAV_FADE_OUT_DURATION,
                     NAV_FADE_OUT_INTERPOLATOR);
@@ -873,22 +869,23 @@
                     WIDGET_CROSSFADE_DURATION_MILLIS / 2 /* delay */,
                     WIDGET_CROSSFADE_DURATION_MILLIS / 2 /* duration */, LINEAR);
             final FloatProp mWindowRadius = new FloatProp(initialWindowRadius, finalWindowRadius,
-                    0 /* start */, RADIUS_DURATION, LINEAR);
-            final FloatProp mCornerRadiusProgress = new FloatProp(0, 1, 0, RADIUS_DURATION, LINEAR);
+                    0 /* start */, APP_LAUNCH_DURATION, mOpeningInterpolator);
+            final FloatProp mCornerRadiusProgress = new FloatProp(0, 1, 0, APP_LAUNCH_DURATION,
+                    mOpeningInterpolator);
 
             // Window & widget background positioning bounds
             final FloatProp mDx = new FloatProp(widgetBackgroundBounds.centerX(),
-                    windowTargetBounds.centerX(), 0 /* delay */, APP_LAUNCH_CURVED_DURATION,
-                    EXAGGERATED_EASE);
+                    windowTargetBounds.centerX(), 0 /* delay */, APP_LAUNCH_DURATION,
+                    mOpeningXInterpolator);
             final FloatProp mDy = new FloatProp(widgetBackgroundBounds.centerY(),
                     windowTargetBounds.centerY(), 0 /* delay */, APP_LAUNCH_DURATION,
-                    EXAGGERATED_EASE);
+                    mOpeningInterpolator);
             final FloatProp mWidth = new FloatProp(widgetBackgroundBounds.width(),
                     windowTargetBounds.width(), 0 /* delay */, APP_LAUNCH_DURATION,
-                    EXAGGERATED_EASE);
+                    mOpeningInterpolator);
             final FloatProp mHeight = new FloatProp(widgetBackgroundBounds.height(),
                     windowTargetBounds.height(), 0 /* delay */, APP_LAUNCH_DURATION,
-                    EXAGGERATED_EASE);
+                    mOpeningInterpolator);
 
             final FloatProp mNavFadeOut = new FloatProp(1f, 0f, 0, ANIMATION_NAV_FADE_OUT_DURATION,
                     NAV_FADE_OUT_INTERPOLATOR);
@@ -1424,10 +1421,6 @@
         public final float dX;
         public final float dY;
 
-        public final long xDuration;
-        public final long yDuration;
-        public final long alphaDuration;
-
         public final float initialAppIconScale;
         public final float finalAppIconScale;
 
@@ -1459,14 +1452,6 @@
             dX = centerX - launcherIconBounds.centerX();
             dY = centerY - launcherIconBounds.centerY();
 
-            boolean useUpwardAnimation = launcherIconBounds.top > centerY
-                    || Math.abs(dY) < dp.cellHeightPx;
-            xDuration = useUpwardAnimation ? APP_LAUNCH_CURVED_DURATION
-                    : APP_LAUNCH_DOWN_DURATION;
-            yDuration = useUpwardAnimation ? APP_LAUNCH_DURATION
-                    : APP_LAUNCH_DOWN_CURVED_DURATION;
-            alphaDuration = useUpwardAnimation ? APP_LAUNCH_ALPHA_DURATION
-                    : APP_LAUNCH_ALPHA_DOWN_DURATION;
             iconAlphaStart = hasSplashScreen && !hasDifferentAppIcon ? 0 : 1f;
 
             final int windowIconSize = ResourceUtils.getDimenByName("starting_surface_icon_size",
diff --git a/quickstep/src/com/android/launcher3/statehandlers/DepthController.java b/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
index 8c9ac12..bb58f45 100644
--- a/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
+++ b/quickstep/src/com/android/launcher3/statehandlers/DepthController.java
@@ -125,6 +125,10 @@
     private WallpaperManagerCompat mWallpaperManager;
     private SurfaceControl mSurface;
     /**
+     * How visible the -1 overlay is, from 0 to 1.
+     */
+    private float mOverlayScrollProgress;
+    /**
      * Ratio from 0 to 1, where 0 is fully zoomed out, and 1 is zoomed in.
      * @see android.service.wallpaper.WallpaperService.Engine#onZoomChanged(float)
      */
@@ -264,12 +268,24 @@
         }
     }
 
+    public void onOverlayScrollChanged(float progress) {
+        // Round out the progress to dedupe frequent, non-perceptable updates
+        int progressI = (int) (progress * 256);
+        float progressF = Utilities.boundToRange(progressI / 256f, 0f, 1f);
+        if (Float.compare(mOverlayScrollProgress, progressF) == 0) {
+            return;
+        }
+        mOverlayScrollProgress = progressF;
+        dispatchTransactionSurface(mDepth);
+    }
+
     private boolean dispatchTransactionSurface(float depth) {
         boolean supportsBlur = BlurUtils.supportsBlursOnWindows();
         if (supportsBlur && (mSurface == null || !mSurface.isValid())) {
             return false;
         }
         ensureDependencies();
+        depth = Math.max(depth, mOverlayScrollProgress);
         IBinder windowToken = mLauncher.getRootView().getWindowToken();
         if (windowToken != null) {
             mWallpaperManager.setWallpaperZoomOut(windowToken, depth);
diff --git a/quickstep/src/com/android/quickstep/FallbackSwipeHandler.java b/quickstep/src/com/android/quickstep/FallbackSwipeHandler.java
index fd44e02..e2f198c 100644
--- a/quickstep/src/com/android/quickstep/FallbackSwipeHandler.java
+++ b/quickstep/src/com/android/quickstep/FallbackSwipeHandler.java
@@ -173,7 +173,9 @@
     @Override
     protected void notifyGestureAnimationStartToRecents() {
         if (mRunningOverHome) {
-            mRecentsView.onGestureAnimationStartOnHome(mGestureState.getRunningTask());
+            if (SysUINavigationMode.getMode(mContext).hasGestures) {
+                mRecentsView.onGestureAnimationStartOnHome(mGestureState.getRunningTask());
+            }
         } else {
             super.notifyGestureAnimationStartToRecents();
         }
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index ce79125..11a4884 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -1764,8 +1764,6 @@
             // When switching to tasks in quick switch, ensures the snapped page's scroll maintain
             // invariant between quick switch and overview, to ensure a smooth animation transition.
             updateGridProperties();
-        } else if (endTarget == GestureState.GestureEndTarget.RECENTS) {
-            setEnableFreeScroll(true);
         }
     }
 
@@ -1775,7 +1773,7 @@
     public void onGestureAnimationEnd() {
         mGestureActive = false;
         if (mOrientationState.setGestureActive(false)) {
-            updateOrientationHandler();
+            updateOrientationHandler(/* forceRecreateDragLayerControllers = */ false);
         }
 
         setEnableFreeScroll(true);
@@ -2906,8 +2904,11 @@
         boolean isStartShift;
         if (midpointIndex > -1) {
             // When there is a midpoint reference task, adjacent tasks have less distance to travel
-            // to reach offscreen. Offset the task position to the task's starting point.
-            int midpointScroll = getScrollForPage(midpointIndex);
+            // to reach offscreen. Offset the task position to the task's starting point, and offset
+            // by current page's scroll diff.
+            int midpointScroll = getScrollForPage(midpointIndex)
+                    + mOrientationHandler.getPrimaryScroll(this) - getScrollForPage(mCurrentPage);
+
             getPersistentChildPosition(midpointIndex, midpointScroll, taskPosition);
             float midpointStart = mOrientationHandler.getStart(taskPosition);
 
diff --git a/res/color-v31/home_settings_switch_thumb_color.xml b/res/color-v31/home_settings_switch_thumb_color.xml
new file mode 100644
index 0000000..91d3d9b
--- /dev/null
+++ b/res/color-v31/home_settings_switch_thumb_color.xml
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2021 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.
+-->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Disabled status of thumb -->
+    <item android:state_enabled="false"
+        android:color="@color/home_settings_thumb_off_color" />
+    <!-- Toggle off status of thumb -->
+    <item android:state_checked="false"
+        android:color="@color/home_settings_thumb_off_color" />
+    <!-- Enabled or toggle on status of thumb -->
+    <item android:color="@color/home_settings_state_on_color" />
+</selector>
diff --git a/res/color-v31/home_settings_switch_track_color.xml b/res/color-v31/home_settings_switch_track_color.xml
new file mode 100644
index 0000000..50784f5
--- /dev/null
+++ b/res/color-v31/home_settings_switch_track_color.xml
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2021 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.
+-->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Disabled status of thumb -->
+    <item android:state_enabled="false"
+        android:color="@color/home_settings_track_off_color"
+        android:alpha="?android:attr/disabledAlpha" />
+    <!-- Toggle off status of thumb -->
+    <item android:state_checked="false"
+        android:color="@color/home_settings_track_off_color" />
+    <!-- Enabled or toggle on status of thumb -->
+    <item android:color="@color/home_settings_track_on_color" />
+</selector>
diff --git a/res/drawable-v31/home_settings_switch_thumb.xml b/res/drawable-v31/home_settings_switch_thumb.xml
new file mode 100644
index 0000000..260d5ea
--- /dev/null
+++ b/res/drawable-v31/home_settings_switch_thumb.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2021 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.
+-->
+
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:top="4dp"
+        android:left="4dp"
+        android:right="4dp"
+        android:bottom="4dp">
+        <shape android:shape="oval" >
+            <size android:height="20dp" android:width="20dp" />
+            <solid android:color="@color/home_settings_switch_thumb_color" />
+        </shape>
+    </item>
+</layer-list>
\ No newline at end of file
diff --git a/res/drawable-v31/home_settings_switch_track.xml b/res/drawable-v31/home_settings_switch_track.xml
new file mode 100644
index 0000000..502a300
--- /dev/null
+++ b/res/drawable-v31/home_settings_switch_track.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2021 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.
+-->
+
+<shape
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle"
+    android:width="52dp"
+    android:height="28dp">
+
+    <solid android:color="@color/home_settings_switch_track_color" />
+    <corners android:radius="35dp" />
+</shape>
\ No newline at end of file
diff --git a/res/layout-v31/settings_activity.xml b/res/layout-v31/settings_activity.xml
new file mode 100644
index 0000000..59e14f2
--- /dev/null
+++ b/res/layout-v31/settings_activity.xml
@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2021 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.
+-->
+<androidx.coordinatorlayout.widget.CoordinatorLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/content_parent"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:fitsSystemWindows="true">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/app_bar"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:background="?android:attr/colorPrimary"
+        android:fitsSystemWindows="true"
+        android:outlineAmbientShadowColor="@android:color/transparent"
+        android:outlineSpotShadowColor="@android:color/transparent"
+        android:theme="@style/HomeSettings.CollapsingToolbar">
+
+        <com.google.android.material.appbar.CollapsingToolbarLayout
+            android:id="@+id/collapsing_toolbar"
+            android:layout_width="match_parent"
+            android:layout_height="226dp"
+            android:clipToPadding="false"
+            app:collapsedTitleTextAppearance="@style/HomeSettings.CollapsedToolbarTitle"
+            app:contentScrim="@color/home_settings_header_collapsed"
+            app:expandedTitleMarginEnd="24dp"
+            app:expandedTitleMarginStart="24dp"
+            app:expandedTitleTextAppearance="@style/HomeSettings.ExpandedToolbarTitle"
+            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap"
+            app:maxLines="3"
+            app:scrimAnimationDuration="50"
+            app:scrimVisibleHeightTrigger="174dp"
+            app:statusBarScrim="@null"
+            app:titleCollapseMode="fade"
+            app:toolbarId="@id/action_bar">
+
+            <Toolbar
+                android:id="@+id/action_bar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                android:theme="?android:attr/actionBarTheme"
+                android:transitionName="shared_element_view"
+                app:layout_collapseMode="pin" />
+
+        </com.google.android.material.appbar.CollapsingToolbarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <FrameLayout
+        android:id="@+id/content_frame"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior" />
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/res/values-night-v31/colors.xml b/res/values-night-v31/colors.xml
new file mode 100644
index 0000000..2c1bc90
--- /dev/null
+++ b/res/values-night-v31/colors.xml
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+/*
+* Copyright (C) 2021 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.
+*/
+-->
+
+<resources>
+    <color name="home_settings_header_accent">@android:color/system_accent1_100</color>
+    <color name="home_settings_header_collapsed">@android:color/system_neutral1_700</color>
+    <color name="home_settings_header_expanded">@android:color/system_neutral1_900</color>
+
+    <color name="home_settings_thumb_off_color">@android:color/system_neutral2_300</color>
+    <color name="home_settings_track_on_color">@android:color/system_accent2_700</color>
+    <color name="home_settings_track_off_color">@android:color/system_neutral1_700</color>
+</resources>
\ No newline at end of file
diff --git a/res/values-v31/colors.xml b/res/values-v31/colors.xml
index d73ee57..c2ebeff 100644
--- a/res/values-v31/colors.xml
+++ b/res/values-v31/colors.xml
@@ -42,6 +42,16 @@
 
     <color name="folder_dot_color">@android:color/system_accent2_50</color>
 
+    <color name="home_settings_header_accent">@android:color/system_accent1_600</color>
+    <color name="home_settings_header_collapsed">@android:color/system_neutral1_100</color>
+    <color name="home_settings_header_expanded">@android:color/system_neutral1_50</color>
+
+    <color name="home_settings_state_on_color">@android:color/system_accent1_100</color>
+    <color name="home_settings_state_off_color">@android:color/system_accent2_100</color>
+    <color name="home_settings_thumb_off_color">@android:color/system_neutral2_100</color>
+    <color name="home_settings_track_on_color">@android:color/system_accent1_600</color>
+    <color name="home_settings_track_off_color">@android:color/system_neutral2_600</color>
+
     <color name="workspace_accent_color_light">@android:color/system_accent1_100</color>
     <color name="workspace_accent_color_dark">@android:color/system_accent2_600</color>
 </resources>
diff --git a/res/values-v31/config.xml b/res/values-v31/config.xml
new file mode 100644
index 0000000..afb9e6d
--- /dev/null
+++ b/res/values-v31/config.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright (C) 2021 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.
+  -->
+<resources>
+    <bool name="home_settings_icon_space_reserved">false</bool>
+    <bool name="home_settings_allow_divider">false</bool>
+</resources>
\ No newline at end of file
diff --git a/res/values-v31/styles.xml b/res/values-v31/styles.xml
new file mode 100644
index 0000000..0d2fce0
--- /dev/null
+++ b/res/values-v31/styles.xml
@@ -0,0 +1,95 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/*
+* Copyright (C) 2021 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.
+*/
+-->
+
+<resources>
+
+    <style name="HomeSettings.Theme" parent="@android:style/Theme.DeviceDefault.Settings">
+        <item name="android:listPreferredItemPaddingEnd">16dp</item>
+        <item name="android:listPreferredItemPaddingStart">24dp</item>
+        <item name="android:navigationBarColor">@android:color/transparent</item>
+        <item name="android:statusBarColor">@android:color/transparent</item>
+        <item name="android:switchStyle">@style/HomeSettings.SwitchStyle</item>
+        <item name="android:textAppearanceListItem">@style/HomeSettings.PreferenceTitle</item>
+        <item name="android:windowActionBar">false</item>
+        <item name="android:windowNoTitle">true</item>
+        <item name="preferenceTheme">@style/HomeSettings.PreferenceTheme</item>
+    </style>
+
+    <style name="HomeSettings.PreferenceTheme" parent="@style/PreferenceThemeOverlay">
+        <item name="preferenceCategoryStyle">@style/HomeSettings.CategoryStyle</item>
+        <item name="preferenceCategoryTitleTextAppearance">@style/HomeSettings.CategoryTitle</item>
+        <item name="preferenceFragmentCompatStyle">@style/HomeSettings.FragmentCompatStyle</item>
+        <item name="preferenceScreenStyle">@style/HomeSettings.PreferenceScreenStyle</item>
+        <item name="preferenceStyle">@style/HomeSettings.PreferenceStyle</item>
+        <item name="switchPreferenceStyle">@style/HomeSettings.SwitchPreferenceStyle</item>
+    </style>
+
+    <style name="HomeSettings.CategoryStyle" parent="@style/Preference.Category.Material">
+        <item name="allowDividerAbove">@bool/home_settings_allow_divider</item>
+        <item name="allowDividerBelow">@bool/home_settings_allow_divider</item>
+        <item name="iconSpaceReserved">@bool/home_settings_icon_space_reserved</item>
+    </style>
+
+    <style name="HomeSettings.PreferenceStyle" parent="@style/Preference.Material">
+        <item name="iconSpaceReserved">@bool/home_settings_icon_space_reserved</item>
+    </style>
+
+    <style name="HomeSettings.PreferenceScreenStyle"
+            parent="@style/Preference.PreferenceScreen.Material">
+        <item name="iconSpaceReserved">@bool/home_settings_icon_space_reserved</item>
+    </style>
+
+    <style name="HomeSettings.SwitchPreferenceStyle"
+            parent="@style/Preference.SwitchPreference.Material">
+        <item name="iconSpaceReserved">@bool/home_settings_icon_space_reserved</item>
+    </style>
+
+    <style name="HomeSettings.SwitchStyle"
+            parent="@android:style/Widget.Material.CompoundButton.Switch">
+        <item name="android:switchMinWidth">52dp</item>
+        <item name="android:thumb">@drawable/home_settings_switch_thumb</item>
+        <item name="android:track">@drawable/home_settings_switch_track</item>
+    </style>
+
+    <style name="HomeSettings.PreferenceTitle"
+            parent="@android:style/TextAppearance.Material.Subhead">
+        <item name="android:fontFamily">google-sans</item>
+        <item name="android:textSize">20sp</item>
+    </style>
+
+    <style name="HomeSettings.CategoryTitle" parent="@android:style/TextAppearance.Material.Body2">
+        <item name="android:fontFamily">google-sans-text-medium</item>
+    </style>
+
+    <style name="HomeSettings.CollapsingToolbar" parent="@style/Theme.MaterialComponents.DayNight">
+        <item name="colorAccent">@color/home_settings_header_accent</item>
+        <item name="colorPrimary">@color/home_settings_header_expanded</item>
+        <item name="elevationOverlayColor">?attr/colorPrimary</item>
+        <item name="elevationOverlayEnabled">true</item>
+    </style>
+
+    <style name="HomeSettings.CollapsedToolbarTitle"
+            parent="@android:style/TextAppearance.DeviceDefault.Widget.ActionBar.Title">
+        <item name="android:fontFamily">google-sans</item>
+    </style>
+
+    <style name="HomeSettings.ExpandedToolbarTitle" parent="HomeSettings.CollapsedToolbarTitle">
+        <item name="android:textSize">36sp</item>
+    </style>
+</resources>
\ No newline at end of file
diff --git a/res/values/styles.xml b/res/values/styles.xml
index d30b80c..e4a245a 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -147,18 +147,18 @@
     <style name="AppTheme.Dark.DarkMainColor" parent="@style/LauncherTheme.Dark.DarkMainColor" />
     <style name="AppTheme.Dark.DarkText" parent="@style/LauncherTheme.Dark.DarkText" />
 
-    <style name="HomeSettingsTheme" parent="@android:style/Theme.DeviceDefault.Settings">
+    <style name="HomeSettings.Theme" parent="@android:style/Theme.DeviceDefault.Settings">
         <item name="android:navigationBarColor">?android:colorPrimaryDark</item>
         <item name="android:windowActionBar">false</item>
         <item name="android:windowNoTitle">true</item>
-        <item name="preferenceTheme">@style/HomeSettingsPreferenceTheme</item>
+        <item name="preferenceTheme">@style/HomeSettings.PreferenceTheme</item>
     </style>
 
-    <style name="HomeSettingsPreferenceTheme" parent="@style/PreferenceThemeOverlay.v14.Material">
-        <item name="preferenceFragmentCompatStyle">@style/HomeSettingsFragmentCompatStyle</item>
+    <style name="HomeSettings.PreferenceTheme" parent="@style/PreferenceThemeOverlay.v14.Material">
+        <item name="preferenceFragmentCompatStyle">@style/HomeSettings.FragmentCompatStyle</item>
     </style>
 
-    <style name="HomeSettingsFragmentCompatStyle" parent="@style/PreferenceFragment.Material">
+    <style name="HomeSettings.FragmentCompatStyle" parent="@style/PreferenceFragment.Material">
         <item name="android:layout">@layout/home_settings</item>
     </style>
 
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 099f256..5fb862e 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -218,7 +218,8 @@
  * Default launcher application.
  */
 public class Launcher extends StatefulActivity<LauncherState> implements LauncherExterns,
-        Callbacks, InvariantDeviceProfile.OnIDPChangeListener, PluginListener<OverlayPlugin> {
+        Callbacks, InvariantDeviceProfile.OnIDPChangeListener, PluginListener<OverlayPlugin>,
+        LauncherOverlayCallbacks {
     public static final String TAG = "Launcher";
 
     public static final ActivityTracker<Launcher> ACTIVITY_TRACKER = new ActivityTracker<>();
@@ -619,7 +620,7 @@
     @Override
     public void setLauncherOverlay(LauncherOverlay overlay) {
         if (overlay != null) {
-            overlay.setOverlayCallbacks(new LauncherOverlayCallbacksImpl());
+            overlay.setOverlayCallbacks(this);
         }
         mWorkspace.setLauncherOverlay(overlay);
     }
@@ -1123,12 +1124,15 @@
         mAppWidgetHost.setActivityResumed(false);
     }
 
-    class LauncherOverlayCallbacksImpl implements LauncherOverlayCallbacks {
-
-        public void onScrollChanged(float progress) {
-            if (mWorkspace != null) {
-                mWorkspace.onOverlayScrollChanged(progress);
-            }
+    /**
+     * {@code LauncherOverlayCallbacks} scroll amount.
+     * Indicates transition progress to -1 screen.
+     * @param progress From 0 to 1.
+     */
+    @Override
+    public void onScrollChanged(float progress) {
+        if (mWorkspace != null) {
+            mWorkspace.onOverlayScrollChanged(progress);
         }
     }
 
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index eef3980..545f4c3 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -72,6 +72,7 @@
 import java.util.List;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.Executor;
+import java.util.function.Consumer;
 import java.util.function.Supplier;
 
 /**
@@ -376,7 +377,13 @@
                     loaderResults.bindWidgets();
                     return true;
                 } else {
-                    startLoaderForResults(loaderResults);
+                    stopLoader();
+                    mLoaderTask = new LoaderTask(
+                            mApp, mBgAllAppsList, mBgDataModel, mModelDelegate, loaderResults);
+
+                    // Always post the loader task, instead of running directly
+                    // (even on same thread) so that we exit any nested synchronized blocks
+                    MODEL_EXECUTOR.post(mLoaderTask);
                 }
             }
         }
@@ -399,25 +406,17 @@
         }
     }
 
-    public void startLoaderForResults(LoaderResults results) {
+    /**
+     * Loads the model if not loaded
+     * @param callback called with the data model upon successful load or null on model thread.
+     */
+    public void loadAsync(Consumer<BgDataModel> callback) {
         synchronized (mLock) {
-            stopLoader();
-            mLoaderTask = new LoaderTask(
-                    mApp, mBgAllAppsList, mBgDataModel, mModelDelegate, results);
-
-            // Always post the loader task, instead of running directly (even on same thread) so
-            // that we exit any nested synchronized blocks
-            MODEL_EXECUTOR.post(mLoaderTask);
-        }
-    }
-
-    public void startLoaderForResultsIfNotLoaded(LoaderResults results) {
-        synchronized (mLock) {
-            if (!isModelLoaded()) {
-                Log.d(TAG, "Workspace not loaded, loading now");
-                startLoaderForResults(results);
+            if (!mModelLoaded && !mIsLoaderTaskRunning) {
+                startLoader();
             }
         }
+        MODEL_EXECUTOR.post(() -> callback.accept(isModelLoaded() ? mBgDataModel : null));
     }
 
     @Override
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index 5bdc402..2bb4e5c 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -687,8 +687,9 @@
         CellLayout finalScreen = mWorkspaceScreens.get(finalScreenId);
 
         // If the final screen is empty, convert it to the extra empty screen
-        if (finalScreen.getShortcutsAndWidgets().getChildCount() == 0 &&
-                !finalScreen.isDropPending()) {
+        if (finalScreen != null
+                && finalScreen.getShortcutsAndWidgets().getChildCount() == 0
+                && !finalScreen.isDropPending()) {
             mWorkspaceScreens.remove(finalScreenId);
             mScreenOrder.removeValue(finalScreenId);
 
diff --git a/src/com/android/launcher3/graphics/PreviewSurfaceRenderer.java b/src/com/android/launcher3/graphics/PreviewSurfaceRenderer.java
index df49359..3b140a0 100644
--- a/src/com/android/launcher3/graphics/PreviewSurfaceRenderer.java
+++ b/src/com/android/launcher3/graphics/PreviewSurfaceRenderer.java
@@ -49,7 +49,6 @@
 import com.android.launcher3.model.GridSizeMigrationTaskV2;
 import com.android.launcher3.model.LoaderTask;
 import com.android.launcher3.model.ModelDelegate;
-import com.android.launcher3.model.ModelPreload;
 import com.android.launcher3.util.ComponentKey;
 import com.android.launcher3.util.RunnableList;
 import com.android.launcher3.util.Themes;
@@ -174,18 +173,13 @@
                 }
             }.run();
         } else {
-            new ModelPreload() {
-
-                @Override
-                public void onComplete(boolean isSuccess) {
-                    if (isSuccess) {
-                        MAIN_EXECUTOR.execute(() ->
-                                renderView(inflationContext, getBgDataModel(), null));
-                    } else {
-                        Log.e(TAG, "Model loading failed");
-                    }
+            LauncherAppState.getInstance(inflationContext).getModel().loadAsync(dataModel -> {
+                if (dataModel != null) {
+                    MAIN_EXECUTOR.execute(() -> renderView(inflationContext, dataModel, null));
+                } else {
+                    Log.e(TAG, "Model loading failed");
                 }
-            }.start(inflationContext);
+            });
         }
     }
 
diff --git a/src/com/android/launcher3/model/ModelPreload.java b/src/com/android/launcher3/model/ModelPreload.java
deleted file mode 100644
index 756b7da..0000000
--- a/src/com/android/launcher3/model/ModelPreload.java
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Copyright (C) 2018 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.model;
-
-import static com.android.launcher3.util.Executors.MODEL_EXECUTOR;
-
-import android.content.Context;
-import android.util.Log;
-
-import androidx.annotation.WorkerThread;
-
-import com.android.launcher3.LauncherAppState;
-import com.android.launcher3.LauncherModel;
-import com.android.launcher3.LauncherModel.ModelUpdateTask;
-import com.android.launcher3.model.BgDataModel.Callbacks;
-
-import java.util.concurrent.Executor;
-
-/**
- * Utility class to preload LauncherModel
- */
-public class ModelPreload implements ModelUpdateTask {
-
-    private static final String TAG = "ModelPreload";
-
-    private LauncherAppState mApp;
-    private LauncherModel mModel;
-    private BgDataModel mBgDataModel;
-    private AllAppsList mAllAppsList;
-
-    @Override
-    public final void init(LauncherAppState app, LauncherModel model, BgDataModel dataModel,
-            AllAppsList allAppsList, Executor uiExecutor) {
-        mApp = app;
-        mModel = model;
-        mBgDataModel = dataModel;
-        mAllAppsList = allAppsList;
-    }
-
-    @Override
-    public final void run() {
-        mModel.startLoaderForResultsIfNotLoaded(
-                new LoaderResults(mApp, mBgDataModel, mAllAppsList, new Callbacks[0]));
-        MODEL_EXECUTOR.post(() -> {
-            Log.d(TAG, "Preload completed : " + mModel.isModelLoaded());
-            onComplete(mModel.isModelLoaded());
-        });
-    }
-
-    public BgDataModel getBgDataModel() {
-        return mBgDataModel;
-    }
-
-    /**
-     * Called when the task is complete
-     */
-    @WorkerThread
-    public void onComplete(boolean isSuccess) { }
-
-    public void start(Context context) {
-        LauncherAppState.getInstance(context).getModel().enqueueModelUpdateTask(this);
-    }
-}
\ No newline at end of file