Merge "Initial changes for handling overview button in Launcher" into ub-launcher3-master
diff --git a/quickstep/res/layout/overview_panel.xml b/quickstep/res/layout/overview_panel.xml
index 9f4f8a1..54190ec 100644
--- a/quickstep/res/layout/overview_panel.xml
+++ b/quickstep/res/layout/overview_panel.xml
@@ -24,8 +24,4 @@
     android:alpha="0.0"
     android:visibility="invisible" >
 
-    <com.android.launcher3.uioverrides.WorkspaceCard
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
 </com.android.quickstep.RecentsView>
\ No newline at end of file
diff --git a/quickstep/res/values/dimens.xml b/quickstep/res/values/dimens.xml
index cf86176..6a76b45 100644
--- a/quickstep/res/values/dimens.xml
+++ b/quickstep/res/values/dimens.xml
@@ -33,8 +33,6 @@
     <dimen name="quickstep_fling_threshold_velocity">500dp</dimen>
     <dimen name="quickstep_fling_min_velocity">250dp</dimen>
 
-    <dimen name="workspace_overview_offset_x">-24dp</dimen>
-
     <!-- Launcher app transition -->
     <dimen name="content_trans_y">25dp</dimen>
     <dimen name="workspace_trans_y">80dp</dimen>
diff --git a/quickstep/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java b/quickstep/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java
index b97669b..27b7f52 100644
--- a/quickstep/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java
+++ b/quickstep/src/com/android/launcher3/LauncherAppTransitionManagerImpl.java
@@ -295,7 +295,7 @@
         boolean launchingCenterTask = launchedTaskIndex == centerTaskIndex;
         boolean isRtl = recentsView.isRtl();
         if (launchingCenterTask) {
-            if (launchedTaskIndex - 1 >= recentsView.getFirstTaskIndex()) {
+            if (launchedTaskIndex - 1 >= 0) {
                 TaskView adjacentPage1 = (TaskView) recentsView.getPageAt(launchedTaskIndex - 1);
                 ObjectAnimator adjacentTask1ScaleAndTranslate =
                         LauncherAnimUtils.ofPropertyValuesHolder(adjacentPage1,
@@ -317,7 +317,7 @@
                                         .build());
                 launcherAnimator.play(adjacentTask2ScaleAndTranslate);
             }
-        } else if (centerTaskIndex >= recentsView.getFirstTaskIndex()) {
+        } else {
             // We are launching an adjacent task, so parallax the center and other adjacent task.
             TaskView centerTask = (TaskView) recentsView.getPageAt(centerTaskIndex);
             float translationX = Math.abs(v.getTranslationX());
@@ -329,7 +329,7 @@
                                     .build());
             launcherAnimator.play(centerTaskParallaxToRight);
             int otherAdjacentTaskIndex = centerTaskIndex + (centerTaskIndex - launchedTaskIndex);
-            if (otherAdjacentTaskIndex >= recentsView.getFirstTaskIndex()
+            if (otherAdjacentTaskIndex >= 0
                     && otherAdjacentTaskIndex < recentsView.getPageCount()) {
                 TaskView otherAdjacentTask = (TaskView) recentsView.getPageAt(
                         otherAdjacentTaskIndex);
diff --git a/quickstep/src/com/android/launcher3/uioverrides/FastOverviewState.java b/quickstep/src/com/android/launcher3/uioverrides/FastOverviewState.java
index acd4fc1..c86c5af 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/FastOverviewState.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/FastOverviewState.java
@@ -23,7 +23,7 @@
 public class FastOverviewState extends OverviewState {
 
     private static final int STATE_FLAGS = FLAG_SHOW_SCRIM | FLAG_DISABLE_RESTORE
-            | FLAG_PAGE_BACKGROUNDS | FLAG_DISABLE_INTERACTION | FLAG_OVERVIEW_UI;
+            | FLAG_DISABLE_INTERACTION | FLAG_OVERVIEW_UI;
 
     private static final boolean DEBUG_DIFFERENT_UI = false;
 
diff --git a/quickstep/src/com/android/launcher3/uioverrides/OverviewState.java b/quickstep/src/com/android/launcher3/uioverrides/OverviewState.java
index 854fb4f..4dfbf8d 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/OverviewState.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/OverviewState.java
@@ -16,7 +16,7 @@
 package com.android.launcher3.uioverrides;
 
 import static com.android.launcher3.LauncherAnimUtils.OVERVIEW_TRANSITION_MS;
-import static com.android.launcher3.anim.Interpolators.ACCEL_2;
+import static com.android.launcher3.anim.Interpolators.DEACCEL_2;
 import static com.android.launcher3.states.RotationHelper.REQUEST_ROTATE;
 
 import android.graphics.Rect;
@@ -24,7 +24,6 @@
 
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherState;
-import com.android.launcher3.R;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
 import com.android.quickstep.RecentsView;
@@ -35,7 +34,7 @@
 public class OverviewState extends LauncherState {
 
     private static final int STATE_FLAGS = FLAG_SHOW_SCRIM | FLAG_WORKSPACE_ICONS_CAN_BE_DRAGGED
-            | FLAG_DISABLE_RESTORE | FLAG_PAGE_BACKGROUNDS | FLAG_OVERVIEW_UI;
+            | FLAG_DISABLE_RESTORE | FLAG_OVERVIEW_UI;
 
     public OverviewState(int id) {
         this(id, STATE_FLAGS);
@@ -48,18 +47,13 @@
     @Override
     public float[] getWorkspaceScaleAndTranslation(Launcher launcher) {
         Rect pageRect = new Rect();
-        RecentsView.getScaledDownPageRect(launcher.getDeviceProfile(), launcher, pageRect);
-        RecentsView rv = launcher.getOverviewPanel();
+        RecentsView.getPageRect(launcher.getDeviceProfile(), launcher, pageRect);
 
         if (launcher.getWorkspace().getNormalChildWidth() <= 0 || pageRect.isEmpty()) {
             return super.getWorkspaceScaleAndTranslation(launcher);
         }
 
-        float overlap = 0;
-        if (rv.getCurrentPage() >= rv.getFirstTaskIndex()) {
-            overlap = launcher.getResources().getDimension(R.dimen.workspace_overview_offset_x);
-        }
-        return getScaleAndTranslationForPageRect(launcher, overlap, pageRect);
+        return getScaleAndTranslationForPageRect(launcher, pageRect);
     }
 
     @Override
@@ -85,40 +79,25 @@
     }
 
     public PageAlphaProvider getWorkspacePageAlphaProvider(Launcher launcher) {
-        final int centerPage = launcher.getWorkspace().getNextPage();
-        return new PageAlphaProvider(ACCEL_2) {
+        return new PageAlphaProvider(DEACCEL_2) {
             @Override
             public float getPageAlpha(int pageIndex) {
-                return  pageIndex != centerPage ? 0 : 1f;
+                return 0;
             }
         };
     }
 
-    public static float[] getScaleAndTranslationForPageRect(Launcher launcher, float offsetX,
-            Rect pageRect) {
+    public static float[] getScaleAndTranslationForPageRect(Launcher launcher, Rect pageRect) {
         Workspace ws = launcher.getWorkspace();
         float childWidth = ws.getNormalChildWidth();
-        float childHeight = ws.getNormalChildHeight();
 
-        float scale = pageRect.height() / childHeight;
+        float scale = pageRect.width() / childWidth;
         Rect insets = launcher.getDragLayer().getInsets();
 
         float halfHeight = ws.getExpectedHeight() / 2;
         float childTop = halfHeight - scale * (halfHeight - ws.getPaddingTop() - insets.top);
         float translationY = pageRect.top - childTop;
 
-        // Align the workspace horizontally centered with the task rect
-        float halfWidth = ws.getExpectedWidth() / 2;
-        float childCenter = halfWidth -
-                scale * (halfWidth - ws.getPaddingLeft() - insets.left - childWidth / 2);
-        float translationX = pageRect.centerX() - childCenter;
-
-        if (launcher.<RecentsView>getOverviewPanel().isRtl()) {
-            translationX -= offsetX / scale;
-        } else {
-            translationX += offsetX / scale;
-        }
-
-        return new float[] {scale, translationX, translationY};
+        return new float[] {scale, 0, translationY};
     }
 }
diff --git a/quickstep/src/com/android/launcher3/uioverrides/OverviewSwipeController.java b/quickstep/src/com/android/launcher3/uioverrides/OverviewSwipeController.java
index 468a561..958091b 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/OverviewSwipeController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/OverviewSwipeController.java
@@ -15,6 +15,13 @@
  */
 package com.android.launcher3.uioverrides;
 
+import static com.android.launcher3.LauncherState.ALL_APPS;
+import static com.android.launcher3.LauncherState.NORMAL;
+import static com.android.launcher3.LauncherState.OVERVIEW;
+import static com.android.launcher3.anim.Interpolators.DEACCEL_1_5;
+import static com.android.launcher3.anim.Interpolators.LINEAR;
+import static com.android.launcher3.anim.Interpolators.scrollInterpolatorForVelocity;
+
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
@@ -32,20 +39,13 @@
 import com.android.launcher3.dragndrop.DragLayer;
 import com.android.launcher3.touch.SwipeDetector;
 import com.android.launcher3.userevent.nano.LauncherLogProto;
-import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action.Direction;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action.Touch;
+import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
 import com.android.launcher3.util.TouchController;
 import com.android.quickstep.RecentsView;
 import com.android.quickstep.TaskView;
 
-import static com.android.launcher3.LauncherState.ALL_APPS;
-import static com.android.launcher3.LauncherState.NORMAL;
-import static com.android.launcher3.LauncherState.OVERVIEW;
-import static com.android.launcher3.anim.Interpolators.DEACCEL_1_5;
-import static com.android.launcher3.anim.Interpolators.LINEAR;
-import static com.android.launcher3.anim.Interpolators.scrollInterpolatorForVelocity;
-
 /**
  * Touch controller for swipe interaction in Overview state
  */
@@ -132,28 +132,22 @@
                 mTaskBeingDragged = null;
                 mSwipeDownEnabled = true;
 
-                int currentPage = mRecentsView.getCurrentPage();
-                if (currentPage == 0) {
-                    // User is on home tile
+                View view = mRecentsView.getChildAt(mRecentsView.getCurrentPage());
+                if (mLauncher.getDragLayer().isEventOverView(view, ev) &&
+                        view instanceof TaskView) {
+                    // The tile can be dragged down to open the task.
+                    mTaskBeingDragged = (TaskView) view;
                     directionsToDetectScroll = SwipeDetector.DIRECTION_BOTH;
+                    mStartingTarget = LauncherLogProto.ItemType.TASK;
+                } else if (isEventOverHotseat(ev)) {
+                    // The hotseat is being dragged
+                    directionsToDetectScroll = SwipeDetector.DIRECTION_POSITIVE;
+                    mSwipeDownEnabled = false;
+                    mStartingTarget = ContainerType.HOTSEAT;
                 } else {
-                    View view = mRecentsView.getChildAt(currentPage);
-                    if (mLauncher.getDragLayer().isEventOverView(view, ev) &&
-                            view instanceof TaskView) {
-                        // The tile can be dragged down to open the task.
-                        mTaskBeingDragged = (TaskView) view;
-                        directionsToDetectScroll = SwipeDetector.DIRECTION_BOTH;
-                        mStartingTarget = LauncherLogProto.ItemType.TASK;
-                    } else if (isEventOverHotseat(ev)) {
-                        // The hotseat is being dragged
-                        directionsToDetectScroll = SwipeDetector.DIRECTION_POSITIVE;
-                        mSwipeDownEnabled = false;
-                        mStartingTarget = ContainerType.HOTSEAT;
-                    } else {
-                        mNoIntercept = true;
-                        mStartingTarget = ContainerType.WORKSPACE;
-                        return false;
-                    }
+                    mNoIntercept = true;
+                    mStartingTarget = ContainerType.WORKSPACE;
+                    return false;
                 }
             }
 
diff --git a/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java b/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java
index 92d071a..2a2e9c5 100644
--- a/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java
+++ b/quickstep/src/com/android/launcher3/uioverrides/RecentsViewStateController.java
@@ -16,7 +16,7 @@
 package com.android.launcher3.uioverrides;
 
 import static com.android.launcher3.LauncherState.NORMAL;
-import static com.android.launcher3.LauncherState.OVERVIEW;
+import static com.android.launcher3.anim.Interpolators.ACCEL;
 
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
@@ -28,7 +28,6 @@
 import com.android.launcher3.LauncherStateManager.AnimationConfig;
 import com.android.launcher3.LauncherStateManager.StateHandler;
 import com.android.launcher3.PagedView;
-import com.android.launcher3.Utilities;
 import com.android.launcher3.anim.AnimationSuccessListener;
 import com.android.launcher3.anim.AnimatorSetBuilder;
 import com.android.launcher3.anim.Interpolators;
@@ -40,31 +39,26 @@
 
     private final Launcher mLauncher;
     private final RecentsView mRecentsView;
-    private final WorkspaceCard mWorkspaceCard;
 
     private final AnimatedFloat mTransitionProgress = new AnimatedFloat(this::onTransitionProgress);
     // The fraction representing the visibility of the RecentsView. This allows delaying the
     // overall transition while the RecentsView is being shown or hidden.
     private final AnimatedFloat mVisibilityMultiplier = new AnimatedFloat(this::onVisibilityProgress);
 
-    private boolean mIsRecentsScrollingToFirstTask;
+    private boolean mIsRecentsSlidingInOrOut;
 
     public RecentsViewStateController(Launcher launcher) {
         mLauncher = launcher;
         mRecentsView = launcher.getOverviewPanel();
         mRecentsView.setStateController(this);
-
-        mWorkspaceCard = (WorkspaceCard) mRecentsView.getChildAt(0);
-        mWorkspaceCard.setup(launcher);
     }
 
     @Override
     public void setState(LauncherState state) {
-        mWorkspaceCard.setWorkspaceScrollingEnabled(state.overviewUi);
         setVisibility(state.overviewUi);
         setTransitionProgress(state.overviewUi ? 1 : 0);
         if (state.overviewUi) {
-            for (int i = mRecentsView.getFirstTaskIndex(); i < mRecentsView.getPageCount(); i++) {
+            for (int i = 0; i < mRecentsView.getPageCount(); i++) {
                 ((TaskView) mRecentsView.getPageAt(i)).resetVisualProperties();
             }
             mRecentsView.updateCurveProperties();
@@ -74,22 +68,19 @@
     @Override
     public void setStateWithAnimation(final LauncherState toState,
             AnimatorSetBuilder builder, AnimationConfig config) {
-        boolean settingEnabled = Utilities.getPrefs(mLauncher)
-            .getBoolean("pref_scroll_to_first_task_default_true", true);
-        mIsRecentsScrollingToFirstTask = mLauncher.isInState(NORMAL) && toState == OVERVIEW
-                && settingEnabled;
-        // TODO: Instead of animating the workspace translationX, move the contents
-        mWorkspaceCard.setWorkspaceScrollingEnabled(mIsRecentsScrollingToFirstTask);
+        LauncherState fromState = mLauncher.getStateManager().getState();
+        mIsRecentsSlidingInOrOut = fromState == NORMAL && toState.overviewUi
+                || fromState.overviewUi && toState == NORMAL;
 
         // Scroll to the workspace card before changing to the NORMAL state.
         int currPage = mRecentsView.getCurrentPage();
-        LauncherState fromState = mLauncher.getStateManager().getState();
         if (fromState.overviewUi && toState == NORMAL && currPage != 0 && !config.userControlled) {
             int maxSnapDuration = PagedView.SLOW_PAGE_SNAP_ANIMATION_DURATION;
             int durationPerPage = maxSnapDuration / 10;
             int snapDuration = Math.min(maxSnapDuration, durationPerPage * currPage);
             mRecentsView.snapToPage(0, snapDuration);
-            builder.setStartDelay(snapDuration);
+            // Let the snapping animation play for a bit before we translate off screen.
+            builder.setStartDelay(snapDuration / 4);
         }
 
         ObjectAnimator progressAnim =
@@ -100,7 +91,6 @@
 
             @Override
             public void onAnimationSuccess(Animator animator) {
-                mWorkspaceCard.setWorkspaceScrollingEnabled(toState.overviewUi);
                 mRecentsView.setCurrentPage(mRecentsView.getPageNearestToCenterOfScreen());
             }
         });
@@ -145,11 +135,14 @@
 
     private void onTransitionProgress() {
         applyProgress();
-        if (mIsRecentsScrollingToFirstTask) {
-            int scrollForFirstTask = mRecentsView.getScrollForPage(mRecentsView.getFirstTaskIndex());
-            int scrollForPage0 = mRecentsView.getScrollForPage(0);
-            mRecentsView.setScrollX((int) (mTransitionProgress.value * scrollForFirstTask
-                    + (1 - mTransitionProgress.value) * scrollForPage0));
+        if (mIsRecentsSlidingInOrOut) {
+            float interpolatedProgress = ACCEL.getInterpolation(mTransitionProgress.value);
+            // Slide in from the side as we swipe.
+            int translation = mRecentsView.getWidth();
+            if (mRecentsView.isRtl()) {
+                translation = -translation;
+            }
+            mRecentsView.setTranslationX(translation * (1 - interpolatedProgress));
         }
     }
 
diff --git a/quickstep/src/com/android/launcher3/uioverrides/WorkspaceCard.java b/quickstep/src/com/android/launcher3/uioverrides/WorkspaceCard.java
deleted file mode 100644
index 8533502..0000000
--- a/quickstep/src/com/android/launcher3/uioverrides/WorkspaceCard.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright (C) 2017 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.uioverrides;
-
-import static com.android.launcher3.LauncherState.NORMAL;
-import static com.android.quickstep.RecentsView.SCROLL_TYPE_WORKSPACE;
-
-import android.content.Context;
-import android.graphics.Canvas;
-import android.graphics.Rect;
-import android.util.AttributeSet;
-import android.view.View;
-import android.view.View.OnClickListener;
-
-import com.android.launcher3.Launcher;
-import com.android.launcher3.R;
-import com.android.launcher3.Workspace;
-import com.android.quickstep.RecentsView;
-import com.android.quickstep.RecentsView.PageCallbacks;
-import com.android.quickstep.RecentsView.ScrollState;
-
-public class WorkspaceCard extends View implements PageCallbacks, OnClickListener {
-
-    private final Rect mTempRect = new Rect();
-
-    private Launcher mLauncher;
-    private Workspace mWorkspace;
-
-    private float mLinearInterpolationForPage2 = 1;
-    private float mTranslateXPage0, mTranslateXPage1;
-    private float mExtraScrollShift;
-
-    private boolean mIsWorkspaceScrollingEnabled;
-
-    public WorkspaceCard(Context context) {
-        this(context, null);
-    }
-
-    public WorkspaceCard(Context context, AttributeSet attrs) {
-        this(context, attrs, 0);
-    }
-
-    public WorkspaceCard(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-        setOnClickListener(this);
-    }
-
-    /**
-     * Draw nothing.
-     */
-    @Override
-    public void draw(Canvas canvas) { }
-
-    @Override
-    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
-        super.onLayout(changed, left, top, right, bottom);
-
-        // Initiate data
-        mLinearInterpolationForPage2 = RecentsView.getScaledDownPageRect(
-                mLauncher.getDeviceProfile(), mLauncher, mTempRect);
-
-        float[] scale = OverviewState.getScaleAndTranslationForPageRect(mLauncher, 0, mTempRect);
-        mTranslateXPage0 = scale[1];
-        mTranslateXPage1 = OverviewState
-                .getScaleAndTranslationForPageRect(mLauncher,
-                        getResources().getDimension(R.dimen.workspace_overview_offset_x) / scale[0],
-                        mTempRect)[1];
-
-        mExtraScrollShift = 0;
-        if (mWorkspace != null && getWidth() > 0) {
-            float workspaceWidth = mWorkspace.getNormalChildWidth() * scale[0];
-            mExtraScrollShift = (workspaceWidth - getWidth()) / 2;
-            setScaleX(workspaceWidth / getWidth());
-        }
-    }
-
-    @Override
-    public void onClick(View view) {
-        mLauncher.getStateManager().goToState(NORMAL);
-    }
-
-    public void setup(Launcher launcher) {
-        mLauncher = launcher;
-        mWorkspace = mLauncher.getWorkspace();
-    }
-
-    public void setWorkspaceScrollingEnabled(boolean isEnabled) {
-        mIsWorkspaceScrollingEnabled = isEnabled;
-    }
-
-    @Override
-    public int onPageScroll(ScrollState scrollState) {
-        float factor = scrollState.linearInterpolation;
-        float translateX = scrollState.distanceFromScreenCenter;
-        if (mIsWorkspaceScrollingEnabled) {
-            float shift = factor * (mTranslateXPage1 - mTranslateXPage0);
-            mWorkspace.setTranslationX(shift + mTranslateXPage0);
-            translateX += shift;
-        }
-
-        setTranslationX(translateX);
-
-        // If the workspace card is still the first page, shift all the other pages.
-        if (scrollState.linearInterpolation > mLinearInterpolationForPage2) {
-            scrollState.prevPageExtraWidth = 0;
-        } else if (mLinearInterpolationForPage2 > 0) {
-            scrollState.prevPageExtraWidth = mExtraScrollShift *
-                    (1 - scrollState.linearInterpolation / mLinearInterpolationForPage2);
-        } else {
-            scrollState.prevPageExtraWidth = mExtraScrollShift;
-        }
-        return SCROLL_TYPE_WORKSPACE;
-    }
-}
diff --git a/quickstep/src/com/android/quickstep/QuickScrubController.java b/quickstep/src/com/android/quickstep/QuickScrubController.java
index f28d51c..dc1c0d2 100644
--- a/quickstep/src/com/android/quickstep/QuickScrubController.java
+++ b/quickstep/src/com/android/quickstep/QuickScrubController.java
@@ -22,10 +22,9 @@
 import com.android.launcher3.Launcher;
 import com.android.launcher3.OnAlarmListener;
 import com.android.launcher3.Utilities;
-import com.android.launcher3.userevent.nano.LauncherLogProto;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action.Touch;
-import com.android.launcher3.userevent.nano.LauncherLogProto.ControlType;
 import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
+import com.android.launcher3.userevent.nano.LauncherLogProto.ControlType;
 
 /**
  * Responds to quick scrub callbacks to page through and launch recent tasks.
@@ -52,6 +51,7 @@
     private boolean mInQuickScrub;
     private int mQuickScrubSection;
     private int mStartPage;
+    private boolean mStartedFromHome;
     private boolean mHasAlarmRun;
 
     public QuickScrubController(Launcher launcher, RecentsView recentsView) {
@@ -65,7 +65,8 @@
 
     public void onQuickScrubStart(boolean startingFromHome) {
         mInQuickScrub = true;
-        mStartPage = startingFromHome ? 0 : mRecentsView.getFirstTaskIndex();
+        mStartPage = 0;
+        mStartedFromHome = startingFromHome;
         mQuickScrubSection = 0;
         mHasAlarmRun = false;
         mLauncher.getUserEventDispatcher().resetActionDurationMillis();
@@ -78,11 +79,7 @@
         }
         int page = mRecentsView.getNextPage();
         Runnable launchTaskRunnable = () -> {
-            if (page < mRecentsView.getFirstTaskIndex()) {
-                mRecentsView.getPageAt(page).performClick();
-            } else {
-                ((TaskView) mRecentsView.getPageAt(page)).launchTask(true);
-            }
+            ((TaskView) mRecentsView.getPageAt(page)).launchTask(true);
         };
         int snapDuration = Math.abs(page - mRecentsView.getPageNearestToCenterOfScreen())
                 * QUICKSCRUB_END_SNAP_DURATION_PER_PAGE;
@@ -94,7 +91,7 @@
             launchTaskRunnable.run();
         }
         mLauncher.getUserEventDispatcher().logActionOnControl(Touch.DRAGDROP,
-                ControlType.QUICK_SCRUB_BUTTON, null, mStartPage == 0 ?
+                ControlType.QUICK_SCRUB_BUTTON, null, mStartedFromHome ?
                         ContainerType.WORKSPACE : ContainerType.APP);
     }
 
@@ -116,7 +113,7 @@
     }
 
     public void onQuickSwitch() {
-        for (int i = mRecentsView.getFirstTaskIndex(); i < mRecentsView.getPageCount(); i++) {
+        for (int i = 0; i < mRecentsView.getPageCount(); i++) {
             TaskView taskView = (TaskView) mRecentsView.getPageAt(i);
             if (taskView.getTask().key.id != mRecentsView.getRunningTaskId()) {
                 Runnable launchTaskRunnable = () -> taskView.launchTask(true);
@@ -131,13 +128,13 @@
             }
         }
         mLauncher.getUserEventDispatcher().logActionOnControl(Touch.FLING,
-                ControlType.QUICK_SCRUB_BUTTON, null, mStartPage == 0 ?
+                ControlType.QUICK_SCRUB_BUTTON, null, mStartedFromHome ?
                         ContainerType.WORKSPACE : ContainerType.APP);
     }
 
     public void snapToPageForCurrentQuickScrubSection() {
         if (mInQuickScrub) {
-            goToPageWithHaptic(mRecentsView.getFirstTaskIndex() + mQuickScrubSection);
+            goToPageWithHaptic(mQuickScrubSection);
         }
     }
 
diff --git a/quickstep/src/com/android/quickstep/RecentsView.java b/quickstep/src/com/android/quickstep/RecentsView.java
index 9ae41eb..fdfca84 100644
--- a/quickstep/src/com/android/quickstep/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/RecentsView.java
@@ -17,9 +17,6 @@
 package com.android.quickstep;
 
 import static com.android.launcher3.LauncherState.NORMAL;
-import static com.android.launcher3.LauncherState.OVERVIEW;
-import static com.android.quickstep.TaskView.CURVE_FACTOR;
-import static com.android.quickstep.TaskView.CURVE_INTERPOLATOR;
 
 import android.animation.LayoutTransition;
 import android.animation.LayoutTransition.TransitionListener;
@@ -52,7 +49,6 @@
 import com.android.launcher3.PagedView;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
-import com.android.launcher3.uioverrides.OverviewState;
 import com.android.launcher3.uioverrides.RecentsViewStateController;
 import com.android.systemui.shared.recents.model.RecentsTaskLoadPlan;
 import com.android.systemui.shared.recents.model.RecentsTaskLoader;
@@ -72,10 +68,6 @@
 
     private static final Rect sTempStableInsets = new Rect();
 
-    public static final int SCROLL_TYPE_NONE = 0;
-    public static final int SCROLL_TYPE_TASK = 1;
-    public static final int SCROLL_TYPE_WORKSPACE = 2;
-
     private static final String PREF_FLIP_RECENTS = "pref_flip_recents";
 
     private final Launcher mLauncher;
@@ -152,7 +144,6 @@
                 mIsRtl = !mIsRtl;
             }
             setLayoutDirection(mIsRtl ? View.LAYOUT_DIRECTION_RTL : View.LAYOUT_DIRECTION_LTR);
-            mScrollState.isRtl = mIsRtl;
         }
     }
 
@@ -274,7 +265,7 @@
     }
 
     public TaskView getTaskView(int taskId) {
-        for (int i = getFirstTaskIndex(); i < getChildCount(); i++) {
+        for (int i = 0; i < getChildCount(); i++) {
             TaskView tv = (TaskView) getChildAt(i);
             if (tv.getTask().key.id == taskId) {
                 return tv;
@@ -407,33 +398,6 @@
         return padding;
     }
 
-    /**
-     * Sets the {@param outRect} to match the position of the first tile such that it is scaled
-     * down to match the 2nd taskView.
-     * @return returns the factor which determines the scaling factor for the second task.
-     */
-    public static float getScaledDownPageRect(DeviceProfile dp, Context context, Rect outRect) {
-        getPageRect(dp, context, outRect);
-
-        int pageSpacing = context.getResources()
-                .getDimensionPixelSize(R.dimen.recents_page_spacing);
-        float halfScreenWidth = dp.widthPx * 0.5f;
-        float halfPageWidth = outRect.width() * 0.5f;
-        float pageCenter = outRect.right + pageSpacing + halfPageWidth;
-        float distanceFromCenter = Math.abs(halfScreenWidth - pageCenter);
-        float distanceToReachEdge = halfScreenWidth + halfPageWidth + pageSpacing;
-        float linearInterpolation = Math.min(1, distanceFromCenter / distanceToReachEdge);
-
-        float scale = 1 - CURVE_INTERPOLATOR.getInterpolation(linearInterpolation) * CURVE_FACTOR;
-
-        int topMargin = context.getResources()
-                .getDimensionPixelSize(R.dimen.task_thumbnail_top_margin);
-        outRect.top -= topMargin;
-        Utilities.scaleRectAboutCenter(outRect, scale);
-        outRect.top += (int) (scale * topMargin);
-        return linearInterpolation;
-    }
-
     public static void getPageRect(DeviceProfile grid, Context context, Rect outRect) {
         Rect targetPadding = getPadding(grid, context);
         Rect insets = grid.getInsets();
@@ -474,8 +438,7 @@
         if (getPageCount() == 0 || getPageAt(0).getMeasuredWidth() == 0) {
             return;
         }
-        final int halfPageWidth = mScrollState.halfPageWidth = getNormalChildWidth() / 2;
-        mScrollState.lastScrollType = SCROLL_TYPE_NONE;
+        final int halfPageWidth = getNormalChildWidth() / 2;
         final int screenCenter = mInsets.left + getPaddingLeft() + getScrollX() + halfPageWidth;
         final int halfScreenWidth = getMeasuredWidth() / 2;
         final int pageSpacing = mPageSpacing;
@@ -484,11 +447,11 @@
         for (int i = 0; i < pageCount; i++) {
             View page = getPageAt(i);
             int pageCenter = page.getLeft() + halfPageWidth;
-            mScrollState.distanceFromScreenCenter = screenCenter - pageCenter;
+            float distanceFromScreenCenter = screenCenter - pageCenter;
             float distanceToReachEdge = halfScreenWidth + halfPageWidth + pageSpacing;
             mScrollState.linearInterpolation = Math.min(1,
-                    Math.abs(mScrollState.distanceFromScreenCenter) / distanceToReachEdge);
-            mScrollState.lastScrollType = ((PageCallbacks) page).onPageScroll(mScrollState);
+                    Math.abs(distanceFromScreenCenter) / distanceToReachEdge);
+            ((PageCallbacks) page).onPageScroll(mScrollState);
         }
     }
 
@@ -640,25 +603,17 @@
     public interface PageCallbacks {
 
         /**
-         * Updates the page UI based on scroll params and returns the type of scroll
-         * effect performed.
-         *
-         * @see #SCROLL_TYPE_NONE
-         * @see #SCROLL_TYPE_TASK
-         * @see #SCROLL_TYPE_WORKSPACE
+         * Updates the page UI based on scroll params.
          */
-        int onPageScroll(ScrollState scrollState);
+        default void onPageScroll(ScrollState scrollState) {};
     }
 
     public static class ScrollState {
 
-        public boolean isRtl;
-        public int lastScrollType;
-
-        public int halfPageWidth;
-        public float distanceFromScreenCenter;
+        /**
+         * The progress from 0 to 1, where 0 is the center
+         * of the screen and 1 is the edge of the screen.
+         */
         public float linearInterpolation;
-
-        public float prevPageExtraWidth;
     }
 }
diff --git a/quickstep/src/com/android/quickstep/TaskView.java b/quickstep/src/com/android/quickstep/TaskView.java
index b407f75..e0b03b8 100644
--- a/quickstep/src/com/android/quickstep/TaskView.java
+++ b/quickstep/src/com/android/quickstep/TaskView.java
@@ -16,9 +16,6 @@
 
 package com.android.quickstep;
 
-import static com.android.quickstep.RecentsView.SCROLL_TYPE_TASK;
-import static com.android.quickstep.RecentsView.SCROLL_TYPE_WORKSPACE;
-
 import android.animation.TimeInterpolator;
 import android.app.ActivityOptions;
 import android.content.Context;
@@ -47,17 +44,15 @@
  */
 public class TaskView extends FrameLayout implements TaskCallbacks, PageCallbacks {
 
-    /** Designates how "curvy" the carousel is from 0 to 1, where 0 is a straight line. */
-    public static final float CURVE_FACTOR = 0.25f;
-    /** A circular curve of x from 0 to 1, where 0 is the center of the screen and 1 is the edge. */
-    public static final TimeInterpolator CURVE_INTERPOLATOR
-            = x -> (float) (1 - Math.sqrt(1 - Math.pow(x, 2)));
+    /** A curve of x from 0 to 1, where 0 is the center of the screen and 1 is the edge. */
+    private static final TimeInterpolator CURVE_INTERPOLATOR
+            = x -> (float) -Math.cos(x * Math.PI) / 2f + .5f;
 
     /**
      * The alpha of a black scrim on a page in the carousel as it leaves the screen.
      * In the resting position of the carousel, the adjacent pages have about half this scrim.
      */
-    private static final float MAX_PAGE_SCRIM_ALPHA = 0.8f;
+    private static final float MAX_PAGE_SCRIM_ALPHA = 0.4f;
 
     private static final long SCALE_ICON_DURATION = 120;
 
@@ -163,34 +158,11 @@
     }
 
     @Override
-    public int onPageScroll(ScrollState scrollState) {
+    public void onPageScroll(ScrollState scrollState) {
         float curveInterpolation =
                 CURVE_INTERPOLATOR.getInterpolation(scrollState.linearInterpolation);
-        float scale = 1 - curveInterpolation * CURVE_FACTOR;
-        setScaleX(scale);
-        setScaleY(scale);
-
-        // Make sure the biggest card (i.e. the one in front) shows on top of the adjacent ones.
-        setTranslationZ(scale);
 
         mSnapshotView.setDimAlpha(1 - curveInterpolation * MAX_PAGE_SCRIM_ALPHA);
-
-        float translation =
-                scrollState.distanceFromScreenCenter * curveInterpolation * CURVE_FACTOR;
-
-        if (scrollState.lastScrollType == SCROLL_TYPE_WORKSPACE) {
-            // Make sure that the task cards do not overlap with the workspace card
-            float min = scrollState.halfPageWidth * (1 - scale);
-            if (scrollState.isRtl) {
-                setTranslationX(Math.min(translation, min) - scrollState.prevPageExtraWidth);
-            } else {
-                setTranslationX(Math.max(translation, -min) + scrollState.prevPageExtraWidth);
-            }
-        } else {
-            setTranslationX(translation);
-        }
-        scrollState.prevPageExtraWidth = 0;
-        return SCROLL_TYPE_TASK;
     }
 
     private static final class TaskOutlineProvider extends ViewOutlineProvider {
diff --git a/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java b/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java
index ede0ad2..bab8ef1 100644
--- a/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java
+++ b/quickstep/src/com/android/quickstep/WindowTransformSwipeHandler.java
@@ -588,9 +588,8 @@
                 mLauncherTransitionController.setPlayFraction(shift);
 
                 // Make sure the window follows the first task if it moves, e.g. during quick scrub.
-                int firstTaskIndex = mRecentsView.getFirstTaskIndex();
-                View firstTask = mRecentsView.getPageAt(firstTaskIndex);
-                int scrollForFirstTask = mRecentsView.getScrollForPage(firstTaskIndex);
+                View firstTask = mRecentsView.getPageAt(0);
+                int scrollForFirstTask = mRecentsView.getScrollForPage(0);
                 int offsetFromFirstTask = (scrollForFirstTask - mRecentsView.getScrollX());
                 if (offsetFromFirstTask != 0) {
                     synchronized (mTargetRect) {