Merge "Drag from appDrawer & pin onto secondary display homescreen" into tm-qpr-dev
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index a8d1367..75c28f9 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -299,6 +299,10 @@
     public static final BooleanFlag ENABLE_TRANSIENT_TASKBAR = getDebugFlag(
             "ENABLE_TRANSIENT_TASKBAR", false, "Enables transient taskbar.");
 
+    public static final BooleanFlag SECONDARY_DRAG_N_DROP_TO_PIN = getDebugFlag(
+            "SECONDARY_DRAG_N_DROP_TO_PIN", false,
+            "Enable dragging and dropping to pin apps within secondary display");
+
     public static void initialize(Context context) {
         synchronized (sDebugFlags) {
             for (DebugFlag flag : sDebugFlags) {
diff --git a/src/com/android/launcher3/secondarydisplay/PinnedAppsAdapter.java b/src/com/android/launcher3/secondarydisplay/PinnedAppsAdapter.java
index a0ed77e..f03c62a 100644
--- a/src/com/android/launcher3/secondarydisplay/PinnedAppsAdapter.java
+++ b/src/com/android/launcher3/secondarydisplay/PinnedAppsAdapter.java
@@ -168,15 +168,18 @@
         mPrefs.unregisterOnSharedPreferenceChangeListener(this);
     }
 
-    private void update(ItemInfo info, Function<ComponentKey, Boolean> op) {
+    /**
+     * Pins or unpins apps from home screen
+     */
+    public void update(ItemInfo info, Function<ComponentKey, Boolean> op) {
         ComponentKey key = new ComponentKey(info.getTargetComponent(), info.user);
         if (op.apply(key)) {
             createFilteredAppsList();
             Set<ComponentKey> copy = new HashSet<>(mPinnedApps);
             Executors.MODEL_EXECUTOR.submit(() ->
                     mPrefs.edit().putStringSet(PINNED_APPS_KEY,
-                        copy.stream().map(this::encode).collect(Collectors.toSet()))
-                        .apply());
+                                    copy.stream().map(this::encode).collect(Collectors.toSet()))
+                            .apply());
         }
     }
 
@@ -210,6 +213,13 @@
                 mPinnedApps.contains(new ComponentKey(info.getTargetComponent(), info.user)));
     }
 
+    /**
+     * Pins app to home screen
+     */
+    public void addPinnedApp(ItemInfo info) {
+        update(info, mPinnedApps::add);
+    }
+
     private class PinUnPinShortcut extends SystemShortcut<SecondaryDisplayLauncher> {
 
         private final boolean mIsPinned;
diff --git a/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java b/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java
index a55f7e3..1bea590 100644
--- a/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java
+++ b/src/com/android/launcher3/secondarydisplay/SecondaryDisplayLauncher.java
@@ -18,6 +18,9 @@
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.content.Intent;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
@@ -26,6 +29,9 @@
 
 import com.android.launcher3.AbstractFloatingView;
 import com.android.launcher3.BaseDraggingActivity;
+import com.android.launcher3.BubbleTextView;
+import com.android.launcher3.DragSource;
+import com.android.launcher3.DropTarget;
 import com.android.launcher3.InvariantDeviceProfile;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.LauncherModel;
@@ -33,6 +39,11 @@
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.allapps.ActivityAllAppsContainerView;
+import com.android.launcher3.dragndrop.DragController;
+import com.android.launcher3.dragndrop.DragOptions;
+import com.android.launcher3.dragndrop.DraggableView;
+import com.android.launcher3.graphics.DragPreviewProvider;
+import com.android.launcher3.icons.FastBitmapDrawable;
 import com.android.launcher3.model.BgDataModel;
 import com.android.launcher3.model.StringCache;
 import com.android.launcher3.model.data.AppInfo;
@@ -52,11 +63,11 @@
  * Launcher activity for secondary displays
  */
 public class SecondaryDisplayLauncher extends BaseDraggingActivity
-        implements BgDataModel.Callbacks {
+        implements BgDataModel.Callbacks, DragController.DragListener {
 
     private LauncherModel mModel;
-
     private BaseDragLayer mDragLayer;
+    private SecondaryDragController mDragController;
     private ActivityAllAppsContainerView<SecondaryDisplayLauncher> mAppsView;
     private View mAppsButton;
 
@@ -69,10 +80,13 @@
     private boolean mBindingItems = false;
     private SecondaryDisplayPredictions mSecondaryDisplayPredictions;
 
+    private final int[] mTempXY = new int[2];
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         mModel = LauncherAppState.getInstance(this).getModel();
+        mDragController = new SecondaryDragController(this);
         mOnboardingPrefs = new OnboardingPrefs<>(this, Utilities.getPrefs(this));
         mSecondaryDisplayPredictions = SecondaryDisplayPredictions.newInstance(this);
         if (getWindow().getDecorView().isAttachedToWindow()) {
@@ -86,6 +100,12 @@
         initUi();
     }
 
+    @Override
+    public void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        this.getDragController().removeDragListener(this);
+    }
+
     private void initUi() {
         if (mDragLayer != null) {
             return;
@@ -106,6 +126,7 @@
         mAppsView = findViewById(R.id.apps_view);
         mAppsButton = findViewById(R.id.all_apps_button);
 
+        mDragController.addDragListener(this);
         mPopupDataProvider = new PopupDataProvider(
                 mAppsView.getAppsStore()::updateNotificationDots);
 
@@ -113,6 +134,12 @@
     }
 
     @Override
+    protected void onPause() {
+        super.onPause();
+        mDragController.cancelDrag();
+    }
+
+    @Override
     public void onNewIntent(Intent intent) {
         super.onNewIntent(intent);
 
@@ -129,12 +156,21 @@
         showAppDrawer(false);
     }
 
+    public DragController getDragController() {
+        return mDragController;
+    }
+
     @Override
     public void onBackPressed() {
         if (finishAutoCancelActionMode()) {
             return;
         }
 
+        if (mDragController.isDragging()) {
+            mDragController.cancelDrag();
+            return;
+        }
+
         // Note: There should be at most one log per method call. This is enforced implicitly
         // by using if-else statements.
         AbstractFloatingView topView = AbstractFloatingView.getTopOpenView(this);
@@ -202,7 +238,7 @@
         float closeR = Themes.getDialogCornerRadius(this);
         float startR = mAppsButton.getWidth() / 2f;
 
-        float[] buttonPos = new float[] { startR, startR};
+        float[] buttonPos = new float[]{startR, startR};
         mDragLayer.getDescendantCoordRelativeToSelf(mAppsButton, buttonPos);
         mDragLayer.mapCoordInSelfToDescendant(mAppsView, buttonPos);
         final Animator animator = ViewAnimationUtils.createCircularReveal(mAppsView,
@@ -236,6 +272,7 @@
     @Override
     public void startBinding() {
         mBindingItems = true;
+        mDragController.cancelDrag();
     }
 
     @Override
@@ -308,4 +345,101 @@
             startActivitySafely(v, intent, item);
         }
     }
+
+    /**
+     * Core functionality for beginning a drag operation for an item that will be dropped within
+     * the secondary display grid home screen
+     */
+    public void beginDragShared(View child, DragSource source, DragOptions options) {
+        Object dragObject = child.getTag();
+        if (!(dragObject instanceof ItemInfo)) {
+            String msg = "Drag started with a view that has no tag set. This "
+                    + "will cause a crash (issue 11627249) down the line. "
+                    + "View: " + child + "  tag: " + child.getTag();
+            throw new IllegalStateException(msg);
+        }
+        beginDragShared(child, source, (ItemInfo) dragObject,
+                new DragPreviewProvider(child), options);
+    }
+
+    private void beginDragShared(View child, DragSource source,
+            ItemInfo dragObject, DragPreviewProvider previewProvider, DragOptions options) {
+
+        float iconScale = 1f;
+        if (child instanceof BubbleTextView) {
+            FastBitmapDrawable icon = ((BubbleTextView) child).getIcon();
+            if (icon != null) {
+                iconScale = icon.getAnimatedScale();
+            }
+        }
+
+        // clear pressed state if necessary
+        child.clearFocus();
+        child.setPressed(false);
+        if (child instanceof BubbleTextView) {
+            BubbleTextView icon = (BubbleTextView) child;
+            icon.clearPressedBackground();
+        }
+
+        DraggableView draggableView = null;
+        if (child instanceof DraggableView) {
+            draggableView = (DraggableView) child;
+        }
+
+        final View contentView = previewProvider.getContentView();
+        final float scale;
+        // The draggable drawable follows the touch point around on the screen
+        final Drawable drawable;
+        if (contentView == null) {
+            drawable = previewProvider.createDrawable();
+            scale = previewProvider.getScaleAndPosition(drawable, mTempXY);
+        } else {
+            drawable = null;
+            scale = previewProvider.getScaleAndPosition(contentView, mTempXY);
+        }
+        int halfPadding = previewProvider.previewPadding / 2;
+        int dragLayerX = mTempXY[0];
+        int dragLayerY = mTempXY[1];
+
+        Point dragVisualizeOffset = null;
+        Rect dragRect = new Rect();
+        if (draggableView != null) {
+            draggableView.getSourceVisualDragBounds(dragRect);
+            dragLayerY += dragRect.top;
+            dragVisualizeOffset = new Point(-halfPadding, halfPadding);
+        }
+        if (contentView != null) {
+            mDragController.startDrag(
+                    contentView,
+                    draggableView,
+                    dragLayerX,
+                    dragLayerY,
+                    source,
+                    dragObject,
+                    dragVisualizeOffset,
+                    dragRect,
+                    scale * iconScale,
+                    scale,
+                    options);
+        } else {
+            mDragController.startDrag(
+                    drawable,
+                    draggableView,
+                    dragLayerX,
+                    dragLayerY,
+                    source,
+                    dragObject,
+                    dragVisualizeOffset,
+                    dragRect,
+                    scale * iconScale,
+                    scale,
+                    options);
+        }
+    }
+
+    @Override
+    public void onDragStart(DropTarget.DragObject dragObject, DragOptions options) { }
+
+    @Override
+    public void onDragEnd() { }
 }
diff --git a/src/com/android/launcher3/secondarydisplay/SecondaryDragController.java b/src/com/android/launcher3/secondarydisplay/SecondaryDragController.java
new file mode 100644
index 0000000..9bf2764
--- /dev/null
+++ b/src/com/android/launcher3/secondarydisplay/SecondaryDragController.java
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2022 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.secondarydisplay;
+
+import android.content.res.Resources;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.util.Log;
+import android.view.HapticFeedbackConstants;
+import android.view.View;
+
+import androidx.annotation.Nullable;
+
+import com.android.launcher3.AbstractFloatingView;
+import com.android.launcher3.DragSource;
+import com.android.launcher3.DropTarget;
+import com.android.launcher3.R;
+import com.android.launcher3.accessibility.DragViewStateAnnouncer;
+import com.android.launcher3.dragndrop.DragController;
+import com.android.launcher3.dragndrop.DragDriver;
+import com.android.launcher3.dragndrop.DragOptions;
+import com.android.launcher3.dragndrop.DragView;
+import com.android.launcher3.dragndrop.DraggableView;
+import com.android.launcher3.model.data.ItemInfo;
+import com.android.launcher3.testing.shared.TestProtocol;
+
+/**
+ * Drag controller for Secondary Launcher activity
+ */
+public class SecondaryDragController extends DragController<SecondaryDisplayLauncher> {
+
+    private static final boolean PROFILE_DRAWING_DURING_DRAG = false;
+
+    public SecondaryDragController(SecondaryDisplayLauncher secondaryLauncher) {
+        super(secondaryLauncher);
+    }
+
+    @Override
+    protected DragView startDrag(@Nullable Drawable drawable, @Nullable View view,
+            DraggableView originalView, int dragLayerX, int dragLayerY, DragSource source,
+            ItemInfo dragInfo, Point dragOffset, Rect dragRegion, float initialDragViewScale,
+            float dragViewScaleOnDrop, DragOptions options) {
+
+        if (TestProtocol.sDebugTracing) {
+            Log.d(TestProtocol.NO_DROP_TARGET, "5");
+        }
+
+        if (PROFILE_DRAWING_DURING_DRAG) {
+            android.os.Debug.startMethodTracing("Launcher");
+        }
+        mActivity.hideKeyboard();
+
+        mOptions = options;
+        if (mOptions.simulatedDndStartPoint != null) {
+            mLastTouch.x = mMotionDown.x = mOptions.simulatedDndStartPoint.x;
+            mLastTouch.y = mMotionDown.y = mOptions.simulatedDndStartPoint.y;
+        }
+
+        final int registrationX = mMotionDown.x - dragLayerX;
+        final int registrationY = mMotionDown.y - dragLayerY;
+
+        final int dragRegionLeft = dragRegion == null ? 0 : dragRegion.left;
+        final int dragRegionTop = dragRegion == null ? 0 : dragRegion.top;
+
+        mLastDropTarget = null;
+
+        mDragObject = new DropTarget.DragObject(mActivity.getApplicationContext());
+        mDragObject.originalView = originalView;
+
+        mIsInPreDrag = mOptions.preDragCondition != null
+                && !mOptions.preDragCondition.shouldStartDrag(0);
+
+        final Resources res = mActivity.getResources();
+        final float scaleDps = mIsInPreDrag
+                ? res.getDimensionPixelSize(R.dimen.pre_drag_view_scale) : 0f;
+
+        final DragView dragView = mDragObject.dragView = drawable != null
+                ? new SecondaryDragView(
+                mActivity,
+                drawable,
+                registrationX,
+                registrationY,
+                initialDragViewScale,
+                dragViewScaleOnDrop,
+                scaleDps)
+                : new SecondaryDragView(
+                        mActivity,
+                        view,
+                        view.getMeasuredWidth(),
+                        view.getMeasuredHeight(),
+                        registrationX,
+                        registrationY,
+                        initialDragViewScale,
+                        dragViewScaleOnDrop,
+                        scaleDps);
+        dragView.setItemInfo(dragInfo);
+        mDragObject.dragComplete = false;
+
+        mDragObject.xOffset = mMotionDown.x - (dragLayerX + dragRegionLeft);
+        mDragObject.yOffset = mMotionDown.y - (dragLayerY + dragRegionTop);
+
+        mDragDriver = DragDriver.create(this, mOptions, ev -> {
+        });
+        if (!mOptions.isAccessibleDrag) {
+            mDragObject.stateAnnouncer = DragViewStateAnnouncer.createFor(dragView);
+        }
+
+        mDragObject.dragSource = source;
+        mDragObject.dragInfo = dragInfo;
+        mDragObject.originalDragInfo = mDragObject.dragInfo.makeShallowCopy();
+
+        if (dragOffset != null) {
+            dragView.setDragVisualizeOffset(new Point(dragOffset));
+        }
+        if (dragRegion != null) {
+            dragView.setDragRegion(new Rect(dragRegion));
+        }
+
+        mActivity.getDragLayer().performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
+        dragView.show(mLastTouch.x, mLastTouch.y);
+        mDistanceSinceScroll = 0;
+
+        if (!mIsInPreDrag) {
+            callOnDragStart();
+        } else if (mOptions.preDragCondition != null) {
+            mOptions.preDragCondition.onPreDragStart(mDragObject);
+        }
+
+        handleMoveEvent(mLastTouch.x, mLastTouch.y);
+        return dragView;
+    }
+
+    @Override
+    protected void exitDrag() { }
+
+    @Override
+    protected DropTarget getDefaultDropTarget(int[] dropCoordinates) {
+        DropTarget target = new DropTarget() {
+            @Override
+            public boolean isDropEnabled() {
+                return true;
+            }
+
+            @Override
+            public void onDrop(DragObject dragObject, DragOptions options) {
+                ((SecondaryDragLayer) mActivity.getDragLayer()).getPinnedAppsAdapter().addPinnedApp(
+                        dragObject.dragInfo);
+                dragObject.dragView.remove();
+            }
+
+            @Override
+            public void onDragEnter(DragObject dragObject) {
+                if (getDistanceDragged() > mActivity.getResources().getDimensionPixelSize(
+                        R.dimen.drag_distanceThreshold)) {
+                    mActivity.showAppDrawer(false);
+                    AbstractFloatingView.closeAllOpenViews(mActivity);
+                }
+            }
+
+            @Override
+            public void onDragOver(DragObject dragObject) { }
+
+            @Override
+            public void onDragExit(DragObject dragObject) { }
+
+            @Override
+            public boolean acceptDrop(DragObject dragObject) {
+                return true;
+            }
+
+            @Override
+            public void prepareAccessibilityDrop() { }
+
+            @Override
+            public void getHitRectRelativeToDragLayer(Rect outRect) { }
+        };
+        return target;
+    }
+}
diff --git a/src/com/android/launcher3/secondarydisplay/SecondaryDragLayer.java b/src/com/android/launcher3/secondarydisplay/SecondaryDragLayer.java
index c79d70d..42d5970 100644
--- a/src/com/android/launcher3/secondarydisplay/SecondaryDragLayer.java
+++ b/src/com/android/launcher3/secondarydisplay/SecondaryDragLayer.java
@@ -29,8 +29,12 @@
 import com.android.launcher3.AbstractFloatingView;
 import com.android.launcher3.BubbleTextView;
 import com.android.launcher3.DeviceProfile;
+import com.android.launcher3.DropTarget;
 import com.android.launcher3.R;
 import com.android.launcher3.allapps.ActivityAllAppsContainerView;
+import com.android.launcher3.config.FeatureFlags;
+import com.android.launcher3.dragndrop.DragOptions;
+import com.android.launcher3.dragndrop.DragView;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.popup.PopupContainerWithArrow;
 import com.android.launcher3.popup.PopupDataProvider;
@@ -59,7 +63,8 @@
 
     @Override
     public void recreateControllers() {
-        mControllers = new TouchController[] {new CloseAllAppsTouchController()};
+        mControllers = new TouchController[]{new CloseAllAppsTouchController(),
+                mActivity.getDragController()};
     }
 
     /**
@@ -166,6 +171,10 @@
         }
     }
 
+    public PinnedAppsAdapter getPinnedAppsAdapter() {
+        return mPinnedAppsAdapter;
+    }
+
     private boolean onIconLongClicked(View v) {
         if (!(v instanceof BubbleTextView)) {
             return false;
@@ -183,6 +192,7 @@
         if (popupDataProvider == null) {
             return false;
         }
+
         final PopupContainerWithArrow container =
                 (PopupContainerWithArrow) mActivity.getLayoutInflater().inflate(
                         R.layout.popup_container, mActivity.getDragLayer(), false);
@@ -192,7 +202,42 @@
                 Collections.emptyList(),
                 Arrays.asList(mPinnedAppsAdapter.getSystemShortcut(item, v),
                         APP_INFO.getShortcut(mActivity, item, v)));
-        v.getParent().requestDisallowInterceptTouchEvent(true);
+        container.requestFocus();
+
+        if (!FeatureFlags.SECONDARY_DRAG_N_DROP_TO_PIN.get() || !mActivity.isAppDrawerShown()) {
+            return true;
+        }
+
+        DragOptions options = new DragOptions();
+        DeviceProfile grid = mActivity.getDeviceProfile();
+        options.intrinsicIconScaleFactor = (float) grid.allAppsIconSizePx / grid.iconSizePx;
+        options.preDragCondition = container.createPreDragCondition(false);
+        if (options.preDragCondition == null) {
+            options.preDragCondition = new DragOptions.PreDragCondition() {
+                private DragView<SecondaryDisplayLauncher> mDragView;
+
+                @Override
+                public boolean shouldStartDrag(double distanceDragged) {
+                    return mDragView != null && mDragView.isAnimationFinished();
+                }
+
+                @Override
+                public void onPreDragStart(DropTarget.DragObject dragObject) {
+                    mDragView = dragObject.dragView;
+                    if (!shouldStartDrag(0)) {
+                        mDragView.setOnAnimationEndCallback(() -> {
+                            mActivity.beginDragShared(v, mActivity.getAppsView(), options);
+                        });
+                    }
+                }
+
+                @Override
+                public void onPreDragEnd(DropTarget.DragObject dragObject, boolean dragStarted) {
+                    mDragView = null;
+                }
+            };
+        }
+        mActivity.beginDragShared(v, mActivity.getAppsView(), options);
         return true;
     }
 }
diff --git a/src/com/android/launcher3/secondarydisplay/SecondaryDragView.java b/src/com/android/launcher3/secondarydisplay/SecondaryDragView.java
new file mode 100644
index 0000000..0168b8f
--- /dev/null
+++ b/src/com/android/launcher3/secondarydisplay/SecondaryDragView.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2022 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.secondarydisplay;
+
+import android.graphics.drawable.Drawable;
+import android.view.View;
+
+import com.android.launcher3.R;
+import com.android.launcher3.dragndrop.DragView;
+
+/**
+ * A DragView drawn/used by the Secondary Launcher activity.
+ */
+public class SecondaryDragView extends DragView<SecondaryDisplayLauncher> {
+
+    public SecondaryDragView(SecondaryDisplayLauncher launcher,
+            Drawable drawable,
+            int registrationX, int registrationY, float initialScale, float scaleOnDrop,
+            float finalScaleDps) {
+        super(launcher, drawable, registrationX, registrationY, initialScale, scaleOnDrop,
+                finalScaleDps);
+    }
+
+    public SecondaryDragView(SecondaryDisplayLauncher launcher, View content, int width, int height,
+            int registrationX, int registrationY, float initialScale, float scaleOnDrop,
+            float finalScaleDps) {
+        super(launcher, content, width, height, registrationX, registrationY, initialScale,
+                scaleOnDrop, finalScaleDps);
+    }
+
+    @Override
+    public void animateTo(int toTouchX, int toTouchY, Runnable onCompleteRunnable, int duration) {
+        Runnable onAnimationEnd = () -> {
+            if (onCompleteRunnable != null) {
+                onCompleteRunnable.run();
+            }
+            mActivity.getDragLayer().removeView(this);
+        };
+
+        duration = Math.max(duration,
+                getResources().getInteger(R.integer.config_dropAnimMinDuration));
+
+        animate()
+                .translationX(toTouchX - mRegistrationX)
+                .translationY(toTouchY - mRegistrationY)
+                .scaleX(mScaleOnDrop)
+                .scaleY(mScaleOnDrop)
+                .withEndAction(onAnimationEnd)
+                .setDuration(duration)
+                .start();
+    }
+}