Creates BubbleStashController & BubbleStashedHandleViewController

Adds two controllers to manage and animate the stash / unstash state
of the bubble bar. Adds them to BubbleControllers.

Bug: 253318833
Test: manual, with other CLs, see go/bubble-bar-tests
Flag: WM_BUBBLE_BAR
Change-Id: I1a67da888384b1ae0fe3f79a25ea6a2c1b7eef87
diff --git a/quickstep/src/com/android/launcher3/taskbar/StashedHandleView.java b/quickstep/src/com/android/launcher3/taskbar/StashedHandleView.java
index 5eec6a4..83e4571 100644
--- a/quickstep/src/com/android/launcher3/taskbar/StashedHandleView.java
+++ b/quickstep/src/com/android/launcher3/taskbar/StashedHandleView.java
@@ -30,6 +30,10 @@
 import com.android.launcher3.LauncherAnimUtils;
 import com.android.launcher3.R;
 
+/**
+ * View to render a handle that changes color based on the background to ensure contrast. Used for
+ * the taskbar when stashed as well as the bubble bar when stashed.
+ */
 public class StashedHandleView extends View {
 
     private static final long COLOR_CHANGE_DURATION = 120;
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java
index deac42f..4145ac6 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleBarViewController.java
@@ -47,10 +47,11 @@
     private final int mIconSize;
 
     // Initialized in init.
+    private BubbleStashController mBubbleStashController;
     private View.OnClickListener mBubbleClickListener;
     private View.OnClickListener mBubbleBarClickListener;
 
-    // These are exposed to BubbleStashController to animate for stashing/un-stashing
+    // These are exposed to {@link BubbleStashController} to animate for stashing/un-stashing
     private final MultiValueAlpha mBubbleBarAlpha;
     private final AnimatedFloat mBubbleBarScale = new AnimatedFloat(this::updateScale);
     private final AnimatedFloat mBubbleBarTranslationY = new AnimatedFloat(
@@ -73,6 +74,8 @@
     }
 
     public void init(TaskbarControllers controllers, BubbleControllers bubbleControllers) {
+        mBubbleStashController = bubbleControllers.bubbleStashController;
+
         mActivity.addOnDeviceProfileChangeListener(dp ->
                 mBarView.getLayoutParams().height = mActivity.getDeviceProfile().taskbarHeight
         );
@@ -171,8 +174,7 @@
 
     // TODO: (b/273592694) animate it
     private void updateVisibilityForStateChange() {
-        // TODO: check if it's stashed
-        if (!mHiddenForSysui && !mHiddenForNoBubbles) {
+        if (!mHiddenForSysui && !mBubbleStashController.isStashed() && !mHiddenForNoBubbles) {
             mBarView.setVisibility(VISIBLE);
         } else {
             mBarView.setVisibility(INVISIBLE);
@@ -271,6 +273,10 @@
      * from SystemUI.
      */
     public void setExpandedFromSysui(boolean isExpanded) {
-        // TODO: Tell bubble bar stash controller to stash or unstash the bubble bar
+        if (!isExpanded) {
+            mBubbleStashController.stashBubbleBar();
+        } else {
+            mBubbleStashController.showBubbleBar(true /* expand the bubbles */);
+        }
     }
 }
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleControllers.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleControllers.java
index e92d4fb..8b07062 100644
--- a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleControllers.java
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleControllers.java
@@ -24,6 +24,8 @@
 public class BubbleControllers {
 
     public final BubbleBarViewController bubbleBarViewController;
+    public final BubbleStashController bubbleStashController;
+    public final BubbleStashedHandleViewController bubbleStashedHandleViewController;
 
     private final RunnableList mPostInitRunnables = new RunnableList();
 
@@ -32,8 +34,12 @@
      *   * Call init
      *   * Call onDestroy
      */
-    public BubbleControllers(BubbleBarViewController bubbleBarViewController) {
+    public BubbleControllers(BubbleBarViewController bubbleBarViewController,
+            BubbleStashController bubbleStashController,
+            BubbleStashedHandleViewController bubbleStashedHandleViewController) {
         this.bubbleBarViewController = bubbleBarViewController;
+        this.bubbleStashController = bubbleStashController;
+        this.bubbleStashedHandleViewController = bubbleStashedHandleViewController;
     }
 
     /**
@@ -43,6 +49,8 @@
      */
     public void init(TaskbarControllers taskbarControllers) {
         bubbleBarViewController.init(taskbarControllers, this);
+        bubbleStashedHandleViewController.init(taskbarControllers, this);
+        bubbleStashController.init(taskbarControllers, this);
 
         mPostInitRunnables.executeAllAndDestroy();
     }
@@ -61,6 +69,6 @@
      * Cleans up all controllers.
      */
     public void onDestroy() {
-        // TODO
+        bubbleStashedHandleViewController.onDestroy();
     }
 }
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleStashController.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleStashController.java
new file mode 100644
index 0000000..0ab53b0
--- /dev/null
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleStashController.java
@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) 2023 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.taskbar.bubbles;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.AnimatorSet;
+import android.annotation.Nullable;
+import android.view.InsetsController;
+
+import com.android.launcher3.anim.AnimatedFloat;
+import com.android.launcher3.taskbar.StashedHandleViewController;
+import com.android.launcher3.taskbar.TaskbarActivityContext;
+import com.android.launcher3.taskbar.TaskbarControllers;
+import com.android.launcher3.taskbar.TaskbarStashController;
+import com.android.launcher3.util.MultiPropertyFactory;
+
+/**
+ * Coordinates between controllers such as BubbleBarView and BubbleHandleViewController to
+ * create a cohesive animation between stashed/unstashed states.
+ */
+public class BubbleStashController {
+
+    private static final String TAG = BubbleStashController.class.getSimpleName();
+
+    /**
+     * How long to stash/unstash.
+     */
+    public static final long BAR_STASH_DURATION = InsetsController.ANIMATION_DURATION_RESIZE;
+
+    /**
+     * The scale bubble bar animates to when being stashed.
+     */
+    private static final float STASHED_BAR_SCALE = 0.5f;
+
+    protected final TaskbarActivityContext mActivity;
+
+    // Initialized in init.
+    private TaskbarControllers mControllers;
+    private BubbleBarViewController mBarViewController;
+    private BubbleStashedHandleViewController mHandleViewController;
+    private TaskbarStashController mTaskbarStashController;
+
+    private MultiPropertyFactory.MultiProperty mIconAlphaForStash;
+    private AnimatedFloat mIconScaleForStash;
+    private AnimatedFloat mIconTranslationYForStash;
+    private MultiPropertyFactory.MultiProperty mBubbleStashedHandleAlpha;
+
+    private boolean mRequestedStashState;
+    private boolean mRequestedExpandedState;
+
+    private boolean mIsStashed;
+    private int mStashedHeight;
+    private int mUnstashedHeight;
+    private boolean mBubblesShowingOnHome;
+    private boolean mBubblesShowingOnOverview;
+
+    @Nullable
+    private AnimatorSet mAnimator;
+
+    public BubbleStashController(TaskbarActivityContext activity) {
+        mActivity = activity;
+    }
+
+    public void init(TaskbarControllers controllers, BubbleControllers bubbleControllers) {
+        mControllers = controllers;
+        mBarViewController = bubbleControllers.bubbleBarViewController;
+        mHandleViewController = bubbleControllers.bubbleStashedHandleViewController;
+        mTaskbarStashController = controllers.taskbarStashController;
+
+        mIconAlphaForStash = mBarViewController.getBubbleBarAlpha().get(0);
+        mIconScaleForStash = mBarViewController.getBubbleBarScale();
+        mIconTranslationYForStash = mBarViewController.getBubbleBarTranslationY();
+
+        mBubbleStashedHandleAlpha = mHandleViewController.getStashedHandleAlpha().get(
+                StashedHandleViewController.ALPHA_INDEX_STASHED);
+
+        mStashedHeight = mHandleViewController.getStashedHeight();
+        mUnstashedHeight = mHandleViewController.getUnstashedHeight();
+
+        bubbleControllers.runAfterInit(() -> {
+            if (mTaskbarStashController.isStashed()) {
+                stashBubbleBar();
+            } else {
+                showBubbleBar(false /* expandBubbles */);
+            }
+        });
+    }
+
+    /**
+     * Returns the touchable height of the bubble bar based on it's stashed state.
+     */
+    public int getTouchableHeight() {
+        return mIsStashed ? mStashedHeight : mUnstashedHeight;
+    }
+
+    /**
+     * Returns whether the bubble bar is currently stashed.
+     */
+    public boolean isStashed() {
+        return mIsStashed;
+    }
+
+    /**
+     * Called when launcher enters or exits the home page. Bubbles are unstashed on home.
+     */
+    public void setBubblesShowingOnHome(boolean onHome) {
+        if (mBubblesShowingOnHome != onHome) {
+            mBubblesShowingOnHome = onHome;
+            if (mBubblesShowingOnHome) {
+                showBubbleBar(/* expanded= */ false);
+            } else if (!mBarViewController.isExpanded()) {
+                stashBubbleBar();
+            }
+        }
+    }
+
+    /** Whether bubbles are showing on the launcher home page. */
+    public boolean isBubblesShowingOnHome() {
+        return mBubblesShowingOnHome;
+    }
+
+    // TODO: when tapping on an app in overview, this is a bit delayed compared to taskbar stashing
+    /** Called when launcher enters or exits overview. Bubbles are unstashed on overview. */
+    public void setBubblesShowingOnOverview(boolean onOverview) {
+        if (mBubblesShowingOnOverview != onOverview) {
+            mBubblesShowingOnOverview = onOverview;
+            if (!mBubblesShowingOnOverview && !mBarViewController.isExpanded()) {
+                stashBubbleBar();
+            }
+        }
+    }
+
+    /** Called when sysui locked state changes, when locked, bubble bar is stashed. */
+    public void onSysuiLockedStateChange(boolean isSysuiLocked) {
+        if (isSysuiLocked) {
+            // TODO: should the normal path flip mBubblesOnHome / check if this is needed
+            // If we're locked, we're no longer showing on home.
+            mBubblesShowingOnHome = false;
+            mBubblesShowingOnOverview = false;
+            stashBubbleBar();
+        }
+    }
+
+    /**
+     * Stashes the bubble bar if allowed based on other state (e.g. on home and overview the
+     * bar does not stash).
+     */
+    public void stashBubbleBar() {
+        mRequestedStashState = true;
+        mRequestedExpandedState = false;
+        updateStashedAndExpandedState();
+    }
+
+    /**
+     * Shows the bubble bar, and expands bubbles depending on {@param expandBubbles}.
+     */
+    public void showBubbleBar(boolean expandBubbles) {
+        mRequestedStashState = false;
+        mRequestedExpandedState = expandBubbles;
+        updateStashedAndExpandedState();
+    }
+
+    private void updateStashedAndExpandedState() {
+        if (mBarViewController.isHiddenForNoBubbles()) {
+            // If there are no bubbles the bar and handle are invisible, nothing to do here.
+            return;
+        }
+        boolean isStashed = mRequestedStashState
+                && !mBubblesShowingOnHome
+                && !mBubblesShowingOnOverview;
+        if (mIsStashed != isStashed) {
+            mIsStashed = isStashed;
+            if (mAnimator != null) {
+                mAnimator.cancel();
+            }
+            mAnimator = createStashAnimator(mIsStashed, BAR_STASH_DURATION);
+            mAnimator.start();
+            onIsStashedChanged();
+        }
+        if (mBarViewController.isExpanded() != mRequestedExpandedState) {
+            mBarViewController.setExpanded(mRequestedExpandedState);
+        }
+    }
+
+    /**
+     * Create a stash animation.
+     *
+     * @param isStashed whether it's a stash animation or an unstash animation
+     * @param duration duration of the animation
+     * @return the animation
+     */
+    private AnimatorSet createStashAnimator(boolean isStashed, long duration) {
+        AnimatorSet animatorSet = new AnimatorSet();
+        final float stashTranslation = (mUnstashedHeight - mStashedHeight) / 2f;
+
+        AnimatorSet fullLengthAnimatorSet = new AnimatorSet();
+        // Not exactly half and may overlap. See [first|second]HalfDurationScale below.
+        AnimatorSet firstHalfAnimatorSet = new AnimatorSet();
+        AnimatorSet secondHalfAnimatorSet = new AnimatorSet();
+
+        final float firstHalfDurationScale;
+        final float secondHalfDurationScale;
+
+        if (isStashed) {
+            firstHalfDurationScale = 0.75f;
+            secondHalfDurationScale = 0.5f;
+
+            fullLengthAnimatorSet.play(mIconTranslationYForStash.animateToValue(stashTranslation));
+
+            firstHalfAnimatorSet.playTogether(
+                    mIconAlphaForStash.animateToValue(0),
+                    mIconScaleForStash.animateToValue(STASHED_BAR_SCALE));
+            secondHalfAnimatorSet.playTogether(
+                    mBubbleStashedHandleAlpha.animateToValue(1));
+        } else  {
+            firstHalfDurationScale = 0.5f;
+            secondHalfDurationScale = 0.75f;
+
+            // If we're on home, adjust the translation so the bubble bar aligns with hotseat.
+            final float hotseatTransY = mActivity.getDeviceProfile().getTaskbarOffsetY();
+            final float translationY = mBubblesShowingOnHome ? hotseatTransY : 0;
+            fullLengthAnimatorSet.playTogether(
+                    mIconScaleForStash.animateToValue(1),
+                    mIconTranslationYForStash.animateToValue(translationY));
+
+            firstHalfAnimatorSet.playTogether(
+                    mBubbleStashedHandleAlpha.animateToValue(0)
+            );
+            secondHalfAnimatorSet.playTogether(
+                    mIconAlphaForStash.animateToValue(1)
+            );
+        }
+
+        fullLengthAnimatorSet.play(mHandleViewController.createRevealAnimToIsStashed(isStashed));
+
+        fullLengthAnimatorSet.setDuration(duration);
+        firstHalfAnimatorSet.setDuration((long) (duration * firstHalfDurationScale));
+        secondHalfAnimatorSet.setDuration((long) (duration * secondHalfDurationScale));
+        secondHalfAnimatorSet.setStartDelay((long) (duration * (1 - secondHalfDurationScale)));
+
+        animatorSet.playTogether(fullLengthAnimatorSet, firstHalfAnimatorSet,
+                secondHalfAnimatorSet);
+        animatorSet.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mAnimator = null;
+                mControllers.runAfterInit(() -> {
+                    if (isStashed) {
+                        mBarViewController.setExpanded(false);
+                    }
+                });
+            }
+        });
+        return animatorSet;
+    }
+
+    private void onIsStashedChanged() {
+        mControllers.runAfterInit(() -> {
+            mHandleViewController.onIsStashedChanged();
+            // TODO: when stash changes tell taskbarInsetsController the insets have changed.
+        });
+    }
+}
diff --git a/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleStashedHandleViewController.java b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleStashedHandleViewController.java
new file mode 100644
index 0000000..2170a5d
--- /dev/null
+++ b/quickstep/src/com/android/launcher3/taskbar/bubbles/BubbleStashedHandleViewController.java
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2023 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.taskbar.bubbles;
+
+import static android.view.View.INVISIBLE;
+import static android.view.View.VISIBLE;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ValueAnimator;
+import android.content.res.Resources;
+import android.graphics.Outline;
+import android.graphics.Rect;
+import android.view.View;
+import android.view.ViewOutlineProvider;
+
+import com.android.launcher3.R;
+import com.android.launcher3.anim.RevealOutlineAnimation;
+import com.android.launcher3.anim.RoundedRectRevealOutlineProvider;
+import com.android.launcher3.taskbar.StashedHandleView;
+import com.android.launcher3.taskbar.TaskbarActivityContext;
+import com.android.launcher3.taskbar.TaskbarControllers;
+import com.android.launcher3.util.Executors;
+import com.android.launcher3.util.MultiPropertyFactory;
+import com.android.launcher3.util.MultiValueAlpha;
+import com.android.systemui.shared.navigationbar.RegionSamplingHelper;
+
+/**
+ * Handles properties/data collection, then passes the results to our stashed handle View to render.
+ */
+public class BubbleStashedHandleViewController {
+
+    private final TaskbarActivityContext mActivity;
+    private final StashedHandleView mStashedHandleView;
+    private final MultiValueAlpha mTaskbarStashedHandleAlpha;
+
+    // Initialized in init.
+    private BubbleBarViewController mBarViewController;
+    private BubbleStashController mBubbleStashController;
+    private RegionSamplingHelper mRegionSamplingHelper;
+    private int mBarSize;
+    private int mStashedHandleWidth;
+    private int mStashedHandleHeight;
+
+    // The bounds we want to clip to in the settled state when showing the stashed handle.
+    private final Rect mStashedHandleBounds = new Rect();
+
+    // When the reveal animation is cancelled, we can assume it's about to create a new animation,
+    // which should start off at the same point the cancelled one left off.
+    private float mStartProgressForNextRevealAnim;
+    private boolean mWasLastRevealAnimReversed;
+
+    // XXX: if there are more of these maybe do state flags instead
+    private boolean mHiddenForSysui;
+    private boolean mHiddenForNoBubbles;
+    private boolean mHiddenForHomeButtonDisabled;
+
+    public BubbleStashedHandleViewController(TaskbarActivityContext activity,
+            StashedHandleView stashedHandleView) {
+        mActivity = activity;
+        mStashedHandleView = stashedHandleView;
+        mTaskbarStashedHandleAlpha = new MultiValueAlpha(mStashedHandleView, 1);
+    }
+
+    public void init(TaskbarControllers controllers, BubbleControllers bubbleControllers) {
+        mBarViewController = bubbleControllers.bubbleBarViewController;
+        mBubbleStashController = bubbleControllers.bubbleStashController;
+
+        Resources resources = mActivity.getResources();
+        mStashedHandleHeight = resources.getDimensionPixelSize(
+                R.dimen.bubblebar_stashed_handle_height);
+        mStashedHandleWidth = resources.getDimensionPixelSize(
+                R.dimen.bubblebar_stashed_handle_width);
+        mBarSize = resources.getDimensionPixelSize(R.dimen.bubblebar_size);
+
+        final int bottomMargin = resources.getDimensionPixelSize(
+                R.dimen.transient_taskbar_bottom_margin);
+        mStashedHandleView.getLayoutParams().height = mBarSize + bottomMargin;
+
+        mTaskbarStashedHandleAlpha.get(0).setValue(0);
+
+        final int stashedTaskbarHeight = resources.getDimensionPixelSize(
+                R.dimen.bubblebar_stashed_size);
+        mStashedHandleView.setOutlineProvider(new ViewOutlineProvider() {
+            @Override
+            public void getOutline(View view, Outline outline) {
+                float stashedHandleRadius = view.getHeight() / 2f;
+                outline.setRoundRect(mStashedHandleBounds, stashedHandleRadius);
+            }
+        });
+
+        mRegionSamplingHelper = new RegionSamplingHelper(mStashedHandleView,
+                new RegionSamplingHelper.SamplingCallback() {
+                    @Override
+                    public void onRegionDarknessChanged(boolean isRegionDark) {
+                        mStashedHandleView.updateHandleColor(isRegionDark, true /* animate */);
+                    }
+
+                    @Override
+                    public Rect getSampledRegion(View sampledView) {
+                        return mStashedHandleView.getSampledRegion();
+                    }
+                }, Executors.UI_HELPER_EXECUTOR);
+
+        mStashedHandleView.addOnLayoutChangeListener((view, i, i1, i2, i3, i4, i5, i6, i7) -> {
+            // As more bubbles get added, the icon bounds become larger. To ensure a consistent
+            // handle bar position, we pin it to the edge of the screen.
+            Rect bubblebarRect = mBarViewController.getBubbleBarBounds();
+            final int stashedCenterY = view.getHeight() - stashedTaskbarHeight / 2;
+
+            mStashedHandleBounds.set(
+                    bubblebarRect.right - mStashedHandleWidth,
+                    stashedCenterY - mStashedHandleHeight / 2,
+                    bubblebarRect.right,
+                    stashedCenterY + mStashedHandleHeight / 2);
+            mStashedHandleView.updateSampledRegion(mStashedHandleBounds);
+
+            view.setPivotX(view.getWidth());
+            view.setPivotY(view.getHeight() - stashedTaskbarHeight / 2f);
+        });
+    }
+
+    public void onDestroy() {
+        mRegionSamplingHelper.stopAndDestroy();
+        mRegionSamplingHelper = null;
+    }
+
+    /**
+     * Returns the height of the stashed handle.
+     */
+    public int getStashedHeight() {
+        return mStashedHandleHeight;
+    }
+
+    /**
+     * Returns the height when the bubble bar is unstashed (so the height of the bubble bar).
+     */
+    public int getUnstashedHeight() {
+        return mBarSize;
+    }
+
+    /**
+     * Called when system ui state changes. Bubbles don't show when the device is locked.
+     */
+    public void setHiddenForSysui(boolean hidden) {
+        if (mHiddenForSysui != hidden) {
+            mHiddenForSysui = hidden;
+            updateVisibilityForStateChange();
+        }
+    }
+
+    /**
+     * Called when the handle should be hidden (or shown) because there are no bubbles
+     * (or 1+ bubbles).
+     */
+    public void setHiddenForBubbles(boolean hidden) {
+        if (mHiddenForNoBubbles != hidden) {
+            mHiddenForNoBubbles = hidden;
+            updateVisibilityForStateChange();
+        }
+    }
+
+    /**
+     * Called when the home button is enabled / disabled. Bubbles don't show if home is disabled.
+     */
+    // TODO: is this needed for bubbles?
+    public void setIsHomeButtonDisabled(boolean homeDisabled) {
+        mHiddenForHomeButtonDisabled = homeDisabled;
+        updateVisibilityForStateChange();
+    }
+
+    // TODO: (b/273592694) animate it?
+    private void updateVisibilityForStateChange() {
+        if (!mHiddenForSysui && !mHiddenForHomeButtonDisabled && !mHiddenForNoBubbles) {
+            mStashedHandleView.setVisibility(VISIBLE);
+        } else {
+            mStashedHandleView.setVisibility(INVISIBLE);
+        }
+        updateRegionSampling();
+    }
+
+    /**
+     * Called when bubble bar is stash state changes so that updates to the stashed handle color
+     * can be started or stopped.
+     */
+    public void onIsStashedChanged() {
+        updateRegionSampling();
+    }
+
+    private void updateRegionSampling() {
+        boolean handleVisible = mStashedHandleView.getVisibility() == VISIBLE
+                && mBubbleStashController.isStashed();
+        mRegionSamplingHelper.setWindowVisible(handleVisible);
+        if (handleVisible) {
+            mStashedHandleView.updateSampledRegion(mStashedHandleBounds);
+            mRegionSamplingHelper.start(mStashedHandleView.getSampledRegion());
+        } else {
+            mRegionSamplingHelper.stop();
+        }
+    }
+
+    /**
+     * Sets the translation of the stashed handle during the swipe up gesture.
+     */
+    public void setTranslationYForSwipe(float transY) {
+        mStashedHandleView.setTranslationY(transY);
+    }
+
+    /**
+     * Used by {@link BubbleStashController} to animate the handle when stashing or un stashing.
+     */
+    public MultiPropertyFactory<View> getStashedHandleAlpha() {
+        return mTaskbarStashedHandleAlpha;
+    }
+
+    /**
+     * Creates and returns an Animator that updates the stashed handle  shape and size.
+     * When stashed, the shape is a thin rounded pill. When unstashed, the shape morphs into
+     * the size of where the bubble bar icons will be.
+     */
+    public Animator createRevealAnimToIsStashed(boolean isStashed) {
+        Rect bubbleBarBounds = new Rect(mBarViewController.getBubbleBarBounds());
+
+        // Account for the full visual height of the bubble bar
+        int heightDiff = (mBarSize - bubbleBarBounds.height()) / 2;
+        bubbleBarBounds.top -= heightDiff;
+        bubbleBarBounds.bottom += heightDiff;
+        float stashedHandleRadius = mStashedHandleView.getHeight() / 2f;
+        final RevealOutlineAnimation handleRevealProvider = new RoundedRectRevealOutlineProvider(
+                stashedHandleRadius, stashedHandleRadius, bubbleBarBounds, mStashedHandleBounds);
+
+        boolean isReversed = !isStashed;
+        boolean changingDirection = mWasLastRevealAnimReversed != isReversed;
+        mWasLastRevealAnimReversed = isReversed;
+        if (changingDirection) {
+            mStartProgressForNextRevealAnim = 1f - mStartProgressForNextRevealAnim;
+        }
+
+        ValueAnimator revealAnim = handleRevealProvider.createRevealAnimator(mStashedHandleView,
+                isReversed, mStartProgressForNextRevealAnim);
+        revealAnim.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                mStartProgressForNextRevealAnim = ((ValueAnimator) animation).getAnimatedFraction();
+            }
+        });
+        return revealAnim;
+    }
+}