Merge "Introduces haptic feedback to launcher overview" into sc-v2-dev am: 8f0de5d711

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15177217

Change-Id: I8faf92aa56d0d4b663d7dd1cb8eca36344925ba9

quickstep/res/values/config.xml

@@ -30,6 +30,7 @@
          determines how many thumbnails will be fetched in the background. -->
     <integer name="recentsThumbnailCacheSize">3</integer>
     <integer name="recentsIconCacheSize">12</integer>
+    <integer name="recentsScrollHapticMinGapMillis">20</integer>
 
     <!-- Assistant Gesture -->
     <integer name="assistant_gesture_min_time_threshold">200</integer>

quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/NoButtonNavbarToOverviewTouchController.java

@@ -24,7 +24,7 @@ import static com.android.launcher3.LauncherState.OVERVIEW;
 import static com.android.launcher3.Utilities.EDGE_NAV_BAR;
 import static com.android.launcher3.anim.AnimatorListeners.forSuccessCallback;
 import static com.android.launcher3.anim.Interpolators.ACCEL_DEACCEL;
-import static com.android.launcher3.util.VibratorWrapper.OVERVIEW_HAPTIC;
+import static com.android.quickstep.util.VibratorWrapper.OVERVIEW_HAPTIC;
 import static com.android.systemui.shared.system.QuickStepContract.SYSUI_STATE_OVERVIEW_DISABLED;
 
 import android.animation.ObjectAnimator;
@@ -38,11 +38,11 @@ import com.android.launcher3.LauncherState;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.anim.AnimatorPlaybackController;
 import com.android.launcher3.states.StateAnimationConfig;
-import com.android.launcher3.util.VibratorWrapper;
 import com.android.quickstep.SystemUiProxy;
 import com.android.quickstep.util.AnimatorControllerWithResistance;
 import com.android.quickstep.util.MotionPauseDetector;
 import com.android.quickstep.util.OverviewToHomeAnim;
+import com.android.quickstep.util.VibratorWrapper;
 import com.android.quickstep.views.RecentsView;
 
 /**

quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/NoButtonQuickSwitchTouchController.java

@@ -41,7 +41,7 @@ import static com.android.launcher3.states.StateAnimationConfig.SKIP_SCRIM;
 import static com.android.launcher3.touch.BothAxesSwipeDetector.DIRECTION_RIGHT;
 import static com.android.launcher3.touch.BothAxesSwipeDetector.DIRECTION_UP;
 import static com.android.launcher3.util.DisplayController.getSingleFrameMs;
-import static com.android.launcher3.util.VibratorWrapper.OVERVIEW_HAPTIC;
+import static com.android.quickstep.util.VibratorWrapper.OVERVIEW_HAPTIC;
 import static com.android.quickstep.views.RecentsView.ADJACENT_PAGE_HORIZONTAL_OFFSET;
 import static com.android.quickstep.views.RecentsView.CONTENT_ALPHA;
 import static com.android.quickstep.views.RecentsView.FULLSCREEN_PROGRESS;
@@ -67,14 +67,15 @@ import com.android.launcher3.states.StateAnimationConfig;
 import com.android.launcher3.touch.BaseSwipeDetector;
 import com.android.launcher3.touch.BothAxesSwipeDetector;
 import com.android.launcher3.util.TouchController;
-import com.android.launcher3.util.VibratorWrapper;
 import com.android.quickstep.AnimatedFloat;
 import com.android.quickstep.SystemUiProxy;
 import com.android.quickstep.util.AnimatorControllerWithResistance;
 import com.android.quickstep.util.LayoutUtils;
 import com.android.quickstep.util.MotionPauseDetector;
+import com.android.quickstep.util.VibratorWrapper;
 import com.android.quickstep.util.WorkspaceRevealAnim;
 import com.android.quickstep.views.LauncherRecentsView;
+import com.android.quickstep.views.RecentsView;
 
 /**
  * Handles quick switching to a recent task from the home screen. To give as much flexibility to
@@ -398,6 +399,14 @@ public class NoButtonQuickSwitchTouchController implements TouchController,
             nonOverviewAnim.setFloatValues(startProgress, endProgress);
             mNonOverviewAnim.dispatchOnStart();
         }
+        if (targetState == QUICK_SWITCH) {
+            // Navigating to quick switch, add scroll feedback since the first time is not
+            // considered a scroll by the RecentsView.
+            VibratorWrapper.INSTANCE.get(mLauncher).vibrate(
+                    RecentsView.SCROLL_VIBRATION_PRIMITIVE,
+                    RecentsView.SCROLL_VIBRATION_PRIMITIVE_SCALE,
+                    RecentsView.SCROLL_VIBRATION_FALLBACK);
+        }
 
         nonOverviewAnim.setDuration(Math.max(xDuration, yDuration));
         mNonOverviewAnim.setEndAction(() -> onAnimationToStateCompleted(targetState));

quickstep/src/com/android/launcher3/uioverrides/touchcontrollers/TaskViewTouchController.java

@@ -22,6 +22,7 @@ import static com.android.launcher3.touch.SingleAxisSwipeDetector.DIRECTION_BOTH
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.os.SystemClock;
+import android.os.VibrationEffect;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.animation.Interpolator;
@@ -41,6 +42,7 @@ import com.android.launcher3.util.FlingBlockCheck;
 import com.android.launcher3.util.TouchController;
 import com.android.launcher3.views.BaseDragLayer;
 import com.android.quickstep.SysUINavigationMode;
+import com.android.quickstep.util.VibratorWrapper;
 import com.android.quickstep.views.RecentsView;
 import com.android.quickstep.views.TaskView;
 
@@ -55,6 +57,12 @@ public abstract class TaskViewTouchController<T extends BaseDraggingActivity>
     private static final long MIN_TASK_DISMISS_ANIMATION_DURATION = 300;
     private static final long MAX_TASK_DISMISS_ANIMATION_DURATION = 600;
 
+    public static final int TASK_DISMISS_VIBRATION_PRIMITIVE =
+            Utilities.ATLEAST_R ? VibrationEffect.Composition.PRIMITIVE_TICK : -1;
+    public static final float TASK_DISMISS_VIBRATION_PRIMITIVE_SCALE = 1f;
+    public static final VibrationEffect TASK_DISMISS_VIBRATION_FALLBACK =
+            VibratorWrapper.EFFECT_TEXTURE_TICK;
+
     protected final T mActivity;
     private final SingleAxisSwipeDetector mDetector;
     private final RecentsView mRecentsView;
@@ -334,10 +342,10 @@ public abstract class TaskViewTouchController<T extends BaseDraggingActivity>
             fling = false;
         }
         PagedOrientationHandler orientationHandler = mRecentsView.getPagedOrientationHandler();
+        boolean goingUp = orientationHandler.isGoingUp(velocity, mIsRtl);
         float progress = mCurrentAnimation.getProgressFraction();
         float interpolatedProgress = mCurrentAnimation.getInterpolatedProgress();
         if (fling) {
-            boolean goingUp = orientationHandler.isGoingUp(velocity, mIsRtl);
             goingToEnd = goingUp == mCurrentAnimationIsGoingUp;
         } else {
             goingToEnd = interpolatedProgress > SUCCESS_TRANSITION_PROGRESS;
@@ -357,6 +365,10 @@ public abstract class TaskViewTouchController<T extends BaseDraggingActivity>
         mCurrentAnimation.startWithVelocity(mActivity, goingToEnd,
                 velocity * orientationHandler.getSecondaryTranslationDirectionFactor(),
                 mEndDisplacement, animationDuration);
+        if (goingUp && goingToEnd) {
+            VibratorWrapper.INSTANCE.get(mActivity).vibrate(TASK_DISMISS_VIBRATION_PRIMITIVE,
+                    TASK_DISMISS_VIBRATION_PRIMITIVE_SCALE, TASK_DISMISS_VIBRATION_FALLBACK);
+        }
     }
 
     private void clearState() {

quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java

@@ -36,7 +36,6 @@ import static com.android.launcher3.util.DisplayController.getSingleFrameMs;
 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
 import static com.android.launcher3.util.SystemUiController.UI_STATE_FULLSCREEN_TASK;
-import static com.android.launcher3.util.VibratorWrapper.OVERVIEW_HAPTIC;
 import static com.android.quickstep.GestureState.GestureEndTarget.HOME;
 import static com.android.quickstep.GestureState.GestureEndTarget.LAST_TASK;
 import static com.android.quickstep.GestureState.GestureEndTarget.NEW_TASK;
@@ -46,6 +45,7 @@ import static com.android.quickstep.GestureState.STATE_END_TARGET_SET;
 import static com.android.quickstep.GestureState.STATE_RECENTS_ANIMATION_CANCELED;
 import static com.android.quickstep.GestureState.STATE_RECENTS_SCROLLING_FINISHED;
 import static com.android.quickstep.MultiStateCallback.DEBUG_STATES;
+import static com.android.quickstep.util.VibratorWrapper.OVERVIEW_HAPTIC;
 import static com.android.quickstep.views.RecentsView.UPDATE_SYSUI_FLAGS_THRESHOLD;
 import static com.android.systemui.shared.system.ActivityManagerWrapper.CLOSE_SYSTEM_WINDOWS_REASON_RECENTS;
 import static com.android.systemui.shared.system.RemoteAnimationTargetCompat.ACTIVITY_TYPE_HOME;
@@ -92,7 +92,6 @@ import com.android.launcher3.testing.TestProtocol;
 import com.android.launcher3.tracing.InputConsumerProto;
 import com.android.launcher3.tracing.SwipeHandlerProto;
 import com.android.launcher3.util.TraceHelper;
-import com.android.launcher3.util.VibratorWrapper;
 import com.android.launcher3.util.WindowBounds;
 import com.android.quickstep.BaseActivityInterface.AnimationFactory;
 import com.android.quickstep.GestureState.GestureEndTarget;
@@ -112,6 +111,7 @@ import com.android.quickstep.util.SurfaceTransactionApplier;
 import com.android.quickstep.util.SwipePipToHomeAnimator;
 import com.android.quickstep.util.TaskViewSimulator;
 import com.android.quickstep.util.TransformParams;
+import com.android.quickstep.util.VibratorWrapper;
 import com.android.quickstep.views.RecentsView;
 import com.android.quickstep.views.TaskView;
 import com.android.systemui.shared.recents.model.ThumbnailData;

quickstep/src/com/android/quickstep/interaction/EdgeBackGesturePanel.java

@@ -43,7 +43,7 @@ import androidx.dynamicanimation.animation.SpringForce;
 import com.android.launcher3.R;
 import com.android.launcher3.ResourceUtils;
 import com.android.launcher3.anim.Interpolators;
-import com.android.launcher3.util.VibratorWrapper;
+import com.android.quickstep.util.VibratorWrapper;
 
 /** Forked from platform/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarEdgePanel.java. */
 public class EdgeBackGesturePanel extends View {

quickstep/src/com/android/quickstep/interaction/NavBarGestureHandler.java

@@ -16,7 +16,6 @@
 package com.android.quickstep.interaction;
 
 import static com.android.launcher3.Utilities.squaredHypot;
-import static com.android.launcher3.util.VibratorWrapper.OVERVIEW_HAPTIC;
 import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestureResult.ASSISTANT_COMPLETED;
 import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestureResult.ASSISTANT_NOT_STARTED_BAD_ANGLE;
 import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestureResult.ASSISTANT_NOT_STARTED_SWIPE_TOO_SHORT;
@@ -26,6 +25,7 @@ import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestu
 import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestureResult.HOME_OR_OVERVIEW_NOT_STARTED_WRONG_SWIPE_DIRECTION;
 import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestureResult.OVERVIEW_GESTURE_COMPLETED;
 import static com.android.quickstep.interaction.NavBarGestureHandler.NavBarGestureResult.OVERVIEW_NOT_STARTED_TOO_FAR_FROM_EDGE;
+import static com.android.quickstep.util.VibratorWrapper.OVERVIEW_HAPTIC;
 
 import android.animation.ValueAnimator;
 import android.content.Context;
@@ -47,11 +47,11 @@ import androidx.annotation.Nullable;
 import com.android.launcher3.R;
 import com.android.launcher3.ResourceUtils;
 import com.android.launcher3.anim.Interpolators;
-import com.android.launcher3.util.VibratorWrapper;
 import com.android.quickstep.SysUINavigationMode.Mode;
 import com.android.quickstep.util.MotionPauseDetector;
 import com.android.quickstep.util.NavBarPosition;
 import com.android.quickstep.util.TriggerSwipeUpTouchTracker;
+import com.android.quickstep.util.VibratorWrapper;
 import com.android.systemui.shared.system.QuickStepContract;
 
 /** Utility class to handle Home and Assistant gestures. */

quickstep/src/com/android/quickstep/util/VibratorWrapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2019 The Android Open Source Project
+ * 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.
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.android.launcher3.util;
+package com.android.quickstep.util;
 
 import static android.os.VibrationEffect.createPredefined;
 import static android.provider.Settings.System.HAPTIC_FEEDBACK_ENABLED;
@@ -21,15 +21,20 @@ import static android.provider.Settings.System.HAPTIC_FEEDBACK_ENABLED;
 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
 
+import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.database.ContentObserver;
+import android.media.AudioAttributes;
 import android.os.Build;
 import android.os.VibrationEffect;
 import android.os.Vibrator;
 import android.provider.Settings;
 
+import com.android.launcher3.Utilities;
+import com.android.launcher3.util.MainThreadInitializedObject;
+
 /**
  * Wrapper around {@link Vibrator} to easily perform haptic feedback where necessary.
  */
@@ -39,8 +44,15 @@ public class VibratorWrapper {
     public static final MainThreadInitializedObject<VibratorWrapper> INSTANCE =
             new MainThreadInitializedObject<>(VibratorWrapper::new);
 
+    public static final AudioAttributes VIBRATION_ATTRS = new AudioAttributes.Builder()
+            .setUsage(AudioAttributes.USAGE_ASSISTANCE_SONIFICATION)
+            .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
+            .build();
+
     public static final VibrationEffect EFFECT_CLICK =
             createPredefined(VibrationEffect.EFFECT_CLICK);
+    public static final VibrationEffect EFFECT_TEXTURE_TICK =
+            VibrationEffect.createPredefined(VibrationEffect.EFFECT_TEXTURE_TICK);
 
     /**
      * Haptic when entering overview.
@@ -78,7 +90,27 @@ public class VibratorWrapper {
     /** Vibrates with the given effect if haptic feedback is available and enabled. */
     public void vibrate(VibrationEffect vibrationEffect) {
         if (mHasVibrator && mIsHapticFeedbackEnabled) {
-            UI_HELPER_EXECUTOR.execute(() -> mVibrator.vibrate(vibrationEffect));
+            UI_HELPER_EXECUTOR.execute(() -> mVibrator.vibrate(vibrationEffect, VIBRATION_ATTRS));
+        }
+    }
+
+    /**
+     * Vibrates with a single primitive, if supported, or use a fallback effect instead. This only
+     * vibrates if haptic feedback is available and enabled.
+     */
+    @SuppressLint("NewApi")
+    public void vibrate(int primitiveId, float primitiveScale, VibrationEffect fallbackEffect) {
+        if (mHasVibrator && mIsHapticFeedbackEnabled) {
+            UI_HELPER_EXECUTOR.execute(() -> {
+                if (Utilities.ATLEAST_R && primitiveId >= 0
+                        && mVibrator.areAllPrimitivesSupported(primitiveId)) {
+                    mVibrator.vibrate(VibrationEffect.startComposition()
+                            .addPrimitive(primitiveId, primitiveScale)
+                            .compose(), VIBRATION_ATTRS);
+                } else {
+                    mVibrator.vibrate(fallbackEffect, VIBRATION_ATTRS);
+                }
+            });
         }
     }
 }

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -79,7 +79,9 @@ import android.graphics.Typeface;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.SystemClock;
 import android.os.UserHandle;
+import android.os.VibrationEffect;
 import android.text.Layout;
 import android.text.StaticLayout;
 import android.text.TextPaint;
@@ -160,6 +162,7 @@ import com.android.quickstep.util.SplitSelectStateController;
 import com.android.quickstep.util.SurfaceTransactionApplier;
 import com.android.quickstep.util.TaskViewSimulator;
 import com.android.quickstep.util.TransformParams;
+import com.android.quickstep.util.VibratorWrapper;
 import com.android.systemui.plugins.ResourceProvider;
 import com.android.systemui.shared.recents.model.Task;
 import com.android.systemui.shared.recents.model.Task.TaskKey;
@@ -244,6 +247,12 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                 }
             };
 
+    public static final int SCROLL_VIBRATION_PRIMITIVE =
+            Utilities.ATLEAST_S ? VibrationEffect.Composition.PRIMITIVE_LOW_TICK : -1;
+    public static final float SCROLL_VIBRATION_PRIMITIVE_SCALE = 0.6f;
+    public static final VibrationEffect SCROLL_VIBRATION_FALLBACK =
+            VibratorWrapper.EFFECT_TEXTURE_TICK;
+
     /**
      * Can be used to tint the color of the RecentsView to simulate a scrim that can views
      * excluded from. Really should be a proper scrim.
@@ -397,6 +406,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
 
     protected final ACTIVITY_TYPE mActivity;
     private final float mFastFlingVelocity;
+    private final int mScrollHapticMinGapMillis;
     private final RecentsModel mModel;
     private final int mGridSideMargin;
     private final ClearAllButton mClearAllButton;
@@ -443,6 +453,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
     private ObjectAnimator mTintingAnimator;
 
     private int mOverScrollShift = 0;
+    private long mScrollLastHapticTimestamp;
 
     /**
      * TODO: Call reloadIdNeeded in onTaskStackChanged.
@@ -629,6 +640,8 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         final int rotation = mActivity.getDisplay().getRotation();
         mOrientationState.setRecentsRotation(rotation);
 
+        mScrollHapticMinGapMillis = getResources()
+                .getInteger(R.integer.recentsScrollHapticMinGapMillis);
         mFastFlingVelocity = getResources()
                 .getDimensionPixelSize(R.dimen.recents_fast_fling_velocity);
         mModel = RecentsModel.INSTANCE.get(context);
@@ -1228,6 +1241,25 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
         }
     }
 
+    @Override
+    protected void onEdgeAbsorbingScroll() {
+        vibrateForScroll();
+    }
+
+    @Override
+    protected void onScrollOverPageChanged() {
+        vibrateForScroll();
+    }
+
+    private void vibrateForScroll() {
+        long now = SystemClock.uptimeMillis();
+        if (now - mScrollLastHapticTimestamp > mScrollHapticMinGapMillis) {
+            mScrollLastHapticTimestamp = now;
+            VibratorWrapper.INSTANCE.get(mContext).vibrate(SCROLL_VIBRATION_PRIMITIVE,
+                    SCROLL_VIBRATION_PRIMITIVE_SCALE, SCROLL_VIBRATION_FALLBACK);
+        }
+    }
+
     @Override
     protected void determineScrollingStart(MotionEvent ev, float touchSlopScale) {
         // Enables swiping to the left or right only if the task overlay is not modal.

src/com/android/launcher3/PagedView.java

@@ -108,6 +108,8 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
     // relative scroll position unchanged in updateCurrentPageScroll. Cleared when snapping to a
     // page.
     protected int mCurrentPageScrollDiff;
+    // The current page the PagedView is scrolling over on it's way to the destination page.
+    protected int mCurrentScrollOverPage;
 
     @ViewDebug.ExportedProperty(category = "launcher")
     protected int mNextPage = INVALID_PAGE;
@@ -180,6 +182,7 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
         mScroller = new OverScroller(context, SCROLL);
         mCurrentPage = 0;
+        mCurrentScrollOverPage = 0;
 
         final ViewConfiguration configuration = ViewConfiguration.get(context);
         mTouchSlop = configuration.getScaledTouchSlop();
@@ -437,6 +440,7 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
         }
         int prevPage = overridePrevPage != INVALID_PAGE ? overridePrevPage : mCurrentPage;
         mCurrentPage = validateNewPage(currentPage);
+        mCurrentScrollOverPage = mCurrentPage;
         updateCurrentPageScroll();
         notifyPageSwitchListener(prevPage);
         invalidate();
@@ -557,9 +561,11 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
                 if (newPos < mMinScroll && oldPos >= mMinScroll) {
                     mEdgeGlowLeft.onAbsorb((int) mScroller.getCurrVelocity());
                     mScroller.abortAnimation();
+                    onEdgeAbsorbingScroll();
                 } else if (newPos > mMaxScroll && oldPos <= mMaxScroll) {
                     mEdgeGlowRight.onAbsorb((int) mScroller.getCurrVelocity());
                     mScroller.abortAnimation();
+                    onEdgeAbsorbingScroll();
                 }
             }
 
@@ -577,6 +583,7 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
             sendScrollAccessibilityEvent();
             int prevPage = mCurrentPage;
             mCurrentPage = validateNewPage(mNextPage);
+            mCurrentScrollOverPage = mCurrentPage;
             mNextPage = INVALID_PAGE;
             notifyPageSwitchListener(prevPage);
 
@@ -837,6 +844,7 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
     public void onViewRemoved(View child) {
         super.onViewRemoved(child);
         mCurrentPage = validateNewPage(mCurrentPage);
+        mCurrentScrollOverPage = mCurrentPage;
         dispatchPageCountChanged();
     }
 
@@ -1408,6 +1416,20 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
     protected void onNotSnappingToPageInFreeScroll() { }
 
+    /**
+     * Called when the view edges absorb part of the scroll. Subclasses can override this
+     * to provide custom behavior during animation.
+     */
+    protected void onEdgeAbsorbingScroll() {
+    }
+
+    /**
+     * Called when the current page closest to the center of the screen changes as part of the
+     * scroll. Subclasses can override this to provide custom behavior during scroll.
+     */
+    protected void onScrollOverPageChanged() {
+    }
+
     protected boolean shouldFlingForVelocity(int velocity) {
         float threshold = mAllowEasyFling ? mEasyFlingThresholdVelocity : mFlingThresholdVelocity;
         return Math.abs(velocity) > threshold;
@@ -1691,6 +1713,15 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
         return mAllowOverScroll;
     }
 
+    @Override
+    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
+        int newDestinationPage = getDestinationPage();
+        if (newDestinationPage >= 0 && newDestinationPage != mCurrentScrollOverPage) {
+            mCurrentScrollOverPage = newDestinationPage;
+            onScrollOverPageChanged();
+        }
+    }
+
     @Override
     public CharSequence getAccessibilityClassName() {
         // Some accessibility services have special logic for ScrollView. Since we provide same