content: /*
   * Copyright (C) 2012 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.lb.launcher;
  
  import android.animation.Animator;
  import android.animation.AnimatorListenerAdapter;
  import android.animation.AnimatorSet;
  import android.animation.ObjectAnimator;
  import android.animation.TimeInterpolator;
  import android.animation.ValueAnimator;
  import android.animation.ValueAnimator.AnimatorUpdateListener;
  import android.content.Context;
  import android.content.res.TypedArray;
  import android.graphics.Canvas;
  import android.graphics.Matrix;
  import android.graphics.PointF;
  import android.graphics.Rect;
  import android.os.Bundle;
  import android.os.Parcel;
  import android.os.Parcelable;
  import android.util.AttributeSet;
  import android.util.DisplayMetrics;
  import android.util.Log;
  import android.view.InputDevice;
  import android.view.KeyEvent;
  import android.view.MotionEvent;
  import android.view.VelocityTracker;
  import android.view.View;
  import android.view.ViewConfiguration;
  import android.view.ViewGroup;
  import android.view.ViewParent;
  import android.view.accessibility.AccessibilityEvent;
  import android.view.accessibility.AccessibilityManager;
  import android.view.accessibility.AccessibilityNodeInfo;
  import android.view.animation.AnimationUtils;
  import android.view.animation.DecelerateInterpolator;
  import android.view.animation.Interpolator;
  import android.view.animation.LinearInterpolator;
  import java.util.ArrayList;
  import com.lb.launcher.R;
  
  interface Page {
      public int getPageChildCount();
      public View getChildOnPageAt(int i);
      public void removeAllViewsOnPage();
      public void removeViewOnPageAt(int i);
      public int indexOfChildOnPage(View v);
  }
  
  /**
   * An abstraction of the original Workspace which supports browsing through a
   * sequential list of "pages"
   */
  public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarchyChangeListener {
      private static final String TAG = "PagedView";
      private static final boolean DEBUG = false;
      protected static final int INVALID_PAGE = -1;
  
      // the min drag distance for a fling to register, to prevent random page shifts
      private static final int MIN_LENGTH_FOR_FLING = 25;
  
      protected static final int PAGE_SNAP_ANIMATION_DURATION = 750;
      protected static final int OVER_SCROLL_PAGE_SNAP_ANIMATION_DURATION = 350;
      protected static final int SLOW_PAGE_SNAP_ANIMATION_DURATION = 950;
      protected static final float NANOTIME_DIV = 1000000000.0f;
  
      private static final float OVERSCROLL_ACCELERATE_FACTOR = 2;
      private static final float OVERSCROLL_DAMP_FACTOR = 0.07f;
  
      private static final float RETURN_TO_ORIGINAL_PAGE_THRESHOLD = 0.33f;
      // The page is moved more than halfway, automatically move to the next page on touch up.
      private static final float SIGNIFICANT_MOVE_THRESHOLD = 0.4f;
  
      // The following constants need to be scaled based on density. The scaled versions will be
      // assigned to the corresponding member variables below.
      private static final int FLING_THRESHOLD_VELOCITY = 500;
      private static final int MIN_SNAP_VELOCITY = 1500;
      private static final int MIN_FLING_VELOCITY = 250;
  
      // We are disabling touch interaction of the widget region for factory ROM.
      private static final boolean DISABLE_TOUCH_INTERACTION = false;
      private static final boolean DISABLE_TOUCH_SIDE_PAGES = true;
      private static final boolean DISABLE_FLING_TO_DELETE = true;
  
      public static final int INVALID_RESTORE_PAGE = -1001;
  
      private boolean mFreeScroll = false;
      private int mFreeScrollMinScrollX = -1;
      private int mFreeScrollMaxScrollX = -1;
  
      static final int AUTOMATIC_PAGE_SPACING = -1;
  
      protected int mFlingThresholdVelocity;
      protected int mMinFlingVelocity;
      protected int mMinSnapVelocity;
  
      protected float mDensity;
      protected float mSmoothingTime;
      protected float mTouchX;
  
      protected boolean mFirstLayout = true;
      private int mNormalChildHeight;
  
      protected int mCurrentPage;
      protected int mRestorePage = INVALID_RESTORE_PAGE;
      protected int mChildCountOnLastLayout;
  
      protected int mNextPage = INVALID_PAGE;
      protected int mMaxScrollX;
      protected LauncherScroller mScroller;
      private Interpolator mDefaultInterpolator;
      private VelocityTracker mVelocityTracker;
      private int mPageSpacing = 0;
  
      private float mParentDownMotionX;
      private float mParentDownMotionY;
      private float mDownMotionX;
      private float mDownMotionY;
      private float mDownScrollX;
      private float mDragViewBaselineLeft;
      protected float mLastMotionX;
      protected float mLastMotionXRemainder;
      protected float mLastMotionY;
      protected float mTotalMotionX;
      private int mLastScreenCenter = -1;
  
      private boolean mCancelTap;
  
      private int[] mPageScrolls;
  
      protected final static int TOUCH_STATE_REST = 0;
      protected final static int TOUCH_STATE_SCROLLING = 1;
      protected final static int TOUCH_STATE_PREV_PAGE = 2;
      protected final static int TOUCH_STATE_NEXT_PAGE = 3;
      protected final static int TOUCH_STATE_REORDERING = 4;
  
      protected final static float ALPHA_QUANTIZE_LEVEL = 0.0001f;
  
      protected int mTouchState = TOUCH_STATE_REST;
      protected boolean mForceScreenScrolled = false;
  
      protected OnLongClickListener mLongClickListener;
  
      protected int mTouchSlop;
      private int mPagingTouchSlop;
      private int mMaximumVelocity;
      protected int mPageLayoutWidthGap;
      protected int mPageLayoutHeightGap;
      protected int mCellCountX = 0;
      protected int mCellCountY = 0;
      protected boolean mCenterPagesVertically;
      protected boolean mAllowOverScroll = true;
      protected int mUnboundedScrollX;
      protected int[] mTempVisiblePagesRange = new int[2];
      protected boolean mForceDrawAllChildrenNextFrame;
      private boolean mSpacePagesAutomatically = false;
  
      // mOverScrollX is equal to getScrollX() when we're within the normal scroll range. Otherwise
      // it is equal to the scaled overscroll position. We use a separate value so as to prevent
      // the screens from continuing to translate beyond the normal bounds.
      protected int mOverScrollX;
  
      protected static final int INVALID_POINTER = -1;
  
      protected int mActivePointerId = INVALID_POINTER;
  
      private PageSwitchListener mPageSwitchListener;
  
      protected ArrayList<Boolean> mDirtyPageContent;
  
      // If true, syncPages and syncPageItems will be called to refresh pages
      protected boolean mContentIsRefreshable = true;
  
      // If true, modify alpha of neighboring pages as user scrolls left/right
      protected boolean mFadeInAdjacentScreens = false;
  
      // It true, use a different slop parameter (pagingTouchSlop = 2 * touchSlop) for deciding
      // to switch to a new page
      protected boolean mUsePagingTouchSlop = true;
  
      // If true, the subclass should directly update scrollX itself in its computeScroll method
      // (SmoothPagedView does this)
      protected boolean mDeferScrollUpdate = false;
      protected boolean mDeferLoadAssociatedPagesUntilScrollCompletes = false;
  
      protected boolean mIsPageMoving = false;
  
      // All syncs and layout passes are deferred until data is ready.
      protected boolean mIsDataReady = false;
  
      protected boolean mAllowLongPress = true;
  
      private boolean mWasInOverscroll = false;
  
      // Page Indicator
      private int mPageIndicatorViewId;
      private PageIndicator mPageIndicator;
      private boolean mAllowPagedViewAnimations = true;
  
      // The viewport whether the pages are to be contained (the actual view may be larger than the
      // viewport)
      private Rect mViewport = new Rect();
  
      // Reordering
      // We use the min scale to determine how much to expand the actually PagedView measured
      // dimensions such that when we are zoomed out, the view is not clipped
      private int REORDERING_DROP_REPOSITION_DURATION = 200;
      protected int REORDERING_REORDER_REPOSITION_DURATION = 300;
      protected int REORDERING_ZOOM_IN_OUT_DURATION = 250;
      private int REORDERING_SIDE_PAGE_HOVER_TIMEOUT = 80;
      private float mMinScale = 1f;
      private boolean mUseMinScale = false;
      protected View mDragView;
      protected AnimatorSet mZoomInOutAnim;
      private Runnable mSidePageHoverRunnable;
      private int mSidePageHoverIndex = -1;
      // This variable's scope is only for the duration of startReordering() and endReordering()
      private boolean mReorderingStarted = false;
      // This variable's scope is for the duration of startReordering() and after the zoomIn()
      // animation after endReordering()
      private boolean mIsReordering;
      // The runnable that settles the page after snapToPage and animateDragViewToOriginalPosition
      private int NUM_ANIMATIONS_RUNNING_BEFORE_ZOOM_OUT = 2;
      private int mPostReorderingPreZoomInRemainingAnimationCount;
      private Runnable mPostReorderingPreZoomInRunnable;
  
      // Convenience/caching
      private Matrix mTmpInvMatrix = new Matrix();
      private float[] mTmpPoint = new float[2];
      private int[] mTmpIntPoint = new int[2];
      private Rect mTmpRect = new Rect();
      private Rect mAltTmpRect = new Rect();
  
      // Fling to delete
      private int FLING_TO_DELETE_FADE_OUT_DURATION = 350;
      private float FLING_TO_DELETE_FRICTION = 0.035f;
      // The degrees specifies how much deviation from the up vector to still consider a fling "up"
      private float FLING_TO_DELETE_MAX_FLING_DEGREES = 65f;
      protected int mFlingToDeleteThresholdVelocity = -1400;
      // Drag to delete
      private boolean mDeferringForDelete = false;
      private int DELETE_SLIDE_IN_SIDE_PAGE_DURATION = 250;
      private int DRAG_TO_DELETE_FADE_OUT_DURATION = 350;
  
      // Drop to delete
      private View mDeleteDropTarget;
  
      // Bouncer
      private boolean mTopAlignPageWhenShrinkingForBouncer = false;
  
      protected final Rect mInsets = new Rect();
  
      public interface PageSwitchListener {
          void onPageSwitch(View newPage, int newPageIndex);
      }
  
      public PagedView(Context context) {
          this(context, null);
      }
  
      public PagedView(Context context, AttributeSet attrs) {
          this(context, attrs, 0);
      }
  
      public PagedView(Context context, AttributeSet attrs, int defStyle) {
          super(context, attrs, defStyle);
  
          TypedArray a = context.obtainStyledAttributes(attrs,
                  R.styleable.PagedView, defStyle, 0);
  
          mPageLayoutWidthGap = a.getDimensionPixelSize(
                  R.styleable.PagedView_pageLayoutWidthGap, 0);
          mPageLayoutHeightGap = a.getDimensionPixelSize(
                  R.styleable.PagedView_pageLayoutHeightGap, 0);
          mPageIndicatorViewId = a.getResourceId(R.styleable.PagedView_pageIndicator, -1);
          a.recycle();
  
          setHapticFeedbackEnabled(false);
          init();
      }
  
      /**
       * Initializes various states for this workspace.
       */
      protected void init() {
          mDirtyPageContent = new ArrayList<Boolean>();
          mDirtyPageContent.ensureCapacity(32);
          mScroller = new LauncherScroller(getContext());
          setDefaultInterpolator(new ScrollInterpolator());
          mCurrentPage = 0;
          mCenterPagesVertically = true;
  
          final ViewConfiguration configuration = ViewConfiguration.get(getContext());
          mTouchSlop = configuration.getScaledPagingTouchSlop();
          mPagingTouchSlop = configuration.getScaledPagingTouchSlop();
          mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
          mDensity = getResources().getDisplayMetrics().density;
  
          // Scale the fling-to-delete threshold by the density
          mFlingToDeleteThresholdVelocity =
                  (int) (mFlingToDeleteThresholdVelocity * mDensity);
  
          mFlingThresholdVelocity = (int) (FLING_THRESHOLD_VELOCITY * mDensity);
          mMinFlingVelocity = (int) (MIN_FLING_VELOCITY * mDensity);
          mMinSnapVelocity = (int) (MIN_SNAP_VELOCITY * mDensity);
          setOnHierarchyChangeListener(this);
      }
  
      protected void setDefaultInterpolator(Interpolator interpolator) {
          mDefaultInterpolator = interpolator;
          mScroller.setInterpolator(mDefaultInterpolator);
      }
  
      protected void onAttachedToWindow() {
          super.onAttachedToWindow();
  
          // Hook up the page indicator
          ViewGroup parent = (ViewGroup) getParent();
          ViewGroup grandParent = (ViewGroup) parent.getParent();
          if (mPageIndicator == null && mPageIndicatorViewId > -1) {
              mPageIndicator = (PageIndicator) grandParent.findViewById(mPageIndicatorViewId);
              mPageIndicator.removeAllMarkers(mAllowPagedViewAnimations);
  
              ArrayList<PageIndicator.PageMarkerResources> markers =
                      new ArrayList<PageIndicator.PageMarkerResources>();
              for (int i = 0; i < getChildCount(); ++i) {
                  markers.add(getPageIndicatorMarker(i));
              }
  
              mPageIndicator.addMarkers(markers, mAllowPagedViewAnimations);
  
              OnClickListener listener = getPageIndicatorClickListener();
              if (listener != null) {
                  mPageIndicator.setOnClickListener(listener);
              }
              mPageIndicator.setContentDescription(getPageIndicatorDescription());
          }
      }
  
      protected String getPageIndicatorDescription() {
          return getCurrentPageDescription();
      }
  
      protected OnClickListener getPageIndicatorClickListener() {
          return null;
      }
  
      protected void onDetachedFromWindow() {
          // Unhook the page indicator
          mPageIndicator = null;
      }
  
      void setDeleteDropTarget(View v) {
          mDeleteDropTarget = v;
      }
  
      // Convenience methods to map points from self to parent and vice versa
      float[] mapPointFromViewToParent(View v, float x, float y) {
          mTmpPoint[0] = x;
          mTmpPoint[1] = y;
          v.getMatrix().mapPoints(mTmpPoint);
          mTmpPoint[0] += v.getLeft();
          mTmpPoint[1] += v.getTop();
          return mTmpPoint;
      }
      float[] mapPointFromParentToView(View v, float x, float y) {
          mTmpPoint[0] = x - v.getLeft();
          mTmpPoint[1] = y - v.getTop();
          v.getMatrix().invert(mTmpInvMatrix);
          mTmpInvMatrix.mapPoints(mTmpPoint);
          return mTmpPoint;
      }
  
      void updateDragViewTranslationDuringDrag() {
          if (mDragView != null) {
              float x = (mLastMotionX - mDownMotionX) + (getScrollX() - mDownScrollX) +
                      (mDragViewBaselineLeft - mDragView.getLeft());
              float y = mLastMotionY - mDownMotionY;
              mDragView.setTranslationX(x);
              mDragView.setTranslationY(y);
  
              if (DEBUG) Log.d(TAG, "PagedView.updateDragViewTranslationDuringDrag(): "
                      + x + ", " + y);
          }
      }
  
      public void setMinScale(float f) {
          mMinScale = f;
          mUseMinScale = true;
          requestLayout();
      }
  
      @Override
      public void setScaleX(float scaleX) {
          super.setScaleX(scaleX);
          if (isReordering(true)) {
              float[] p = mapPointFromParentToView(this, mParentDownMotionX, mParentDownMotionY);
              mLastMotionX = p[0];
              mLastMotionY = p[1];
              updateDragViewTranslationDuringDrag();
          }
      }
  
      // Convenience methods to get the actual width/height of the PagedView (since it is measured
      // to be larger to account for the minimum possible scale)
      int getViewportWidth() {
          return mViewport.width();
      }
      int getViewportHeight() {
          return mViewport.height();
      }
  
      // Convenience methods to get the offset ASSUMING that we are centering the pages in the
      // PagedView both horizontally and vertically
      int getViewportOffsetX() {
          return (getMeasuredWidth() - getViewportWidth()) / 2;
      }
  
      int getViewportOffsetY() {
          return (getMeasuredHeight() - getViewportHeight()) / 2;
      }
  
      PageIndicator getPageIndicator() {
          return mPageIndicator;
      }
      protected PageIndicator.PageMarkerResources getPageIndicatorMarker(int pageIndex) {
          return new PageIndicator.PageMarkerResources();
      }
  
      /**
       * Add a page change listener which will be called when a page is _finished_ listening.
       *
       */
      public void setPageSwitchListener(PageSwitchListener pageSwitchListener) {
          mPageSwitchListener = pageSwitchListener;
          if (mPageSwitchListener != null) {
              mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
          }
      }
  
      /**
       * Note: this is a reimplementation of View.isLayoutRtl() since that is currently hidden api.
       */
      public boolean isLayoutRtl() {
          return (getLayoutDirection() == LAYOUT_DIRECTION_RTL);
      }
  
      /**
       * Called by subclasses to mark that data is ready, and that we can begin loading and laying
       * out pages.
       */
      protected void setDataIsReady() {
          mIsDataReady = true;
      }
  
      protected boolean isDataReady() {
          return mIsDataReady;
      }
  
      /**
       * Returns the index of the currently displayed page.
       *
       * @return The index of the currently displayed page.
       */
      int getCurrentPage() {
          return mCurrentPage;
      }
  
      int getNextPage() {
          return (mNextPage != INVALID_PAGE) ? mNextPage : mCurrentPage;
      }
  
      int getPageCount() {
          return getChildCount();
      }
  
      View getPageAt(int index) {
          return getChildAt(index);
      }
  
      protected int indexToPage(int index) {
          return index;
      }
  
      /**
       * Updates the scroll of the current page immediately to its final scroll position.  We use this
       * in CustomizePagedView to allow tabs to share the same PagedView while resetting the scroll of
       * the previous tab page.
       */
      protected void updateCurrentPageScroll() {
          // If the current page is invalid, just reset the scroll position to zero
          int newX = 0;
          if (0 <= mCurrentPage && mCurrentPage < getPageCount()) {
              newX = getScrollForPage(mCurrentPage);
          }
          scrollTo(newX, 0);
          mScroller.setFinalX(newX);
          forceFinishScroller();
      }
  
      /**
       * Called during AllApps/Home transitions to avoid unnecessary work. When that other animation
       * {@link #updateCurrentPageScroll()} should be called, to correctly set the final state and
       * re-enable scrolling.
       */
      void stopScrolling() {
          mCurrentPage = getNextPage();
          notifyPageSwitchListener();
          forceFinishScroller();
      }
  
      private void abortScrollerAnimation(boolean resetNextPage) {
          mScroller.abortAnimation();
          // We need to clean up the next page here to avoid computeScrollHelper from
          // updating current page on the pass.
          if (resetNextPage) {
              mNextPage = INVALID_PAGE;
          }
      }
  
      private void forceFinishScroller() {
          mScroller.forceFinished(true);
          // We need to clean up the next page here to avoid computeScrollHelper from
          // updating current page on the pass.
          mNextPage = INVALID_PAGE;
      }
  
      private int validateNewPage(int newPage) {
          int validatedPage = newPage;
          // When in free scroll mode, we need to clamp to the free scroll page range.
          if (mFreeScroll) {
              getFreeScrollPageRange(mTempVisiblePagesRange);
              validatedPage = Math.max(mTempVisiblePagesRange[0],
                      Math.min(newPage, mTempVisiblePagesRange[1]));
          }
          // Ensure that it is clamped by the actual set of children in all cases
          validatedPage = Math.max(0, Math.min(validatedPage, getPageCount() - 1));
          return validatedPage;
      }
  
      /**
       * Sets the current page.
       */
      void setCurrentPage(int currentPage) {
          if (!mScroller.isFinished()) {
              abortScrollerAnimation(true);
          }
          // don't introduce any checks like mCurrentPage == currentPage here-- if we change the
          // the default
          if (getChildCount() == 0) {
              return;
          }
          mForceScreenScrolled = true;
          mCurrentPage = validateNewPage(currentPage);
          updateCurrentPageScroll();
          notifyPageSwitchListener();
          invalidate();
      }
  
      /**
       * The restore page will be set in place of the current page at the next (likely first)
       * layout.
       */
      void setRestorePage(int restorePage) {
          mRestorePage = restorePage;
      }
      int getRestorePage() {
          return mRestorePage;
      }
  
      /**
       * Should be called whenever the page changes. In the case of a scroll, we wait until the page
       * has settled.
       */
      protected void notifyPageSwitchListener() {
          if (mPageSwitchListener != null) {
              mPageSwitchListener.onPageSwitch(getPageAt(getNextPage()), getNextPage());
          }
  
          updatePageIndicator();
      }
  
      private void updatePageIndicator() {
          // Update the page indicator (when we aren't reordering)
          if (mPageIndicator != null) {
              mPageIndicator.setContentDescription(getPageIndicatorDescription());
              if (!isReordering(false)) {
                  mPageIndicator.setActiveMarker(getNextPage());
              }
          }
      }
      protected void pageBeginMoving() {
          if (!mIsPageMoving) {
              mIsPageMoving = true;
              onPageBeginMoving();
          }
      }
  
      protected void pageEndMoving() {
          if (mIsPageMoving) {
              mIsPageMoving = false;
              onPageEndMoving();
          }
      }
  
      protected boolean isPageMoving() {
          return mIsPageMoving;
      }
  
      // a method that subclasses can override to add behavior
      protected void onPageBeginMoving() {
      }
  
      // a method that subclasses can override to add behavior
      protected void onPageEndMoving() {
          mWasInOverscroll = false;
      }
  
      /**
       * Registers the specified listener on each page contained in this workspace.
       *
       * @param l The listener used to respond to long clicks.
       */
      @Override
      public void setOnLongClickListener(OnLongClickListener l) {
          mLongClickListener = l;
          final int count = getPageCount();
          for (int i = 0; i < count; i++) {
              getPageAt(i).setOnLongClickListener(l);
          }
          super.setOnLongClickListener(l);
      }
  
      @Override
      public void scrollBy(int x, int y) {
          scrollTo(mUnboundedScrollX + x, getScrollY() + y);
      }
  
      @Override
      public void scrollTo(int x, int y) {
          // In free scroll mode, we clamp the scrollX
          if (mFreeScroll) {
              x = Math.min(x, mFreeScrollMaxScrollX);
              x = Math.max(x, mFreeScrollMinScrollX);
          }
  
          final boolean isRtl = isLayoutRtl();
          mUnboundedScrollX = x;
  
          boolean isXBeforeFirstPage = isRtl ? (x > mMaxScrollX) : (x < 0);
          boolean isXAfterLastPage = isRtl ? (x < 0) : (x > mMaxScrollX);
          if (isXBeforeFirstPage) {
              super.scrollTo(0, y);
              if (mAllowOverScroll) {
                  mWasInOverscroll = true;
                  if (isRtl) {
                      overScroll(x - mMaxScrollX);
                  } else {
                      overScroll(x);
                  }
              }
          } else if (isXAfterLastPage) {
              super.scrollTo(mMaxScrollX, y);
              if (mAllowOverScroll) {
                  mWasInOverscroll = true;
                  if (isRtl) {
                      overScroll(x);
                  } else {
                      overScroll(x - mMaxScrollX);
                  }
              }
          } else {
              if (mWasInOverscroll) {
                  overScroll(0);
                  mWasInOverscroll = false;
              }
              mOverScrollX = x;
              super.scrollTo(x, y);
          }
  
          mTouchX = x;
          mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
  
          // Update the last motion events when scrolling
          if (isReordering(true)) {
              float[] p = mapPointFromParentToView(this, mParentDownMotionX, mParentDownMotionY);
              mLastMotionX = p[0];
              mLastMotionY = p[1];
              updateDragViewTranslationDuringDrag();
          }
      }
  
      private void sendScrollAccessibilityEvent() {
          AccessibilityManager am =
                  (AccessibilityManager) getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
          if (am.isEnabled()) {
              AccessibilityEvent ev =
                      AccessibilityEvent.obtain(AccessibilityEvent.TYPE_VIEW_SCROLLED);
              ev.setItemCount(getChildCount());
              ev.setFromIndex(mCurrentPage);
              ev.setToIndex(getNextPage());
  
              final int action;
              if (getNextPage() >= mCurrentPage) {
                  action = AccessibilityNodeInfo.ACTION_SCROLL_FORWARD;
              } else {
                  action = AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD;
              }
  
              ev.setAction(action);
              sendAccessibilityEventUnchecked(ev);
          }
      }
  
      // we moved this functionality to a helper function so SmoothPagedView can reuse it
      protected boolean computeScrollHelper() {
          if (mScroller.computeScrollOffset()) {
              // Don't bother scrolling if the page does not need to be moved
              if (getScrollX() != mScroller.getCurrX()
                  || getScrollY() != mScroller.getCurrY()
                  || mOverScrollX != mScroller.getCurrX()) {
                  float scaleX = mFreeScroll ? getScaleX() : 1f;
                  int scrollX = (int) (mScroller.getCurrX() * (1 / scaleX));
                  scrollTo(scrollX, mScroller.getCurrY());
              }
              invalidate();
              return true;
          } else if (mNextPage != INVALID_PAGE) {
              sendScrollAccessibilityEvent();
  
              mCurrentPage = validateNewPage(mNextPage);
              mNextPage = INVALID_PAGE;
              notifyPageSwitchListener();
  
              // Load the associated pages if necessary
              if (mDeferLoadAssociatedPagesUntilScrollCompletes) {
                  loadAssociatedPages(mCurrentPage);
                  mDeferLoadAssociatedPagesUntilScrollCompletes = false;
              }
  
              // We don't want to trigger a page end moving unless the page has settled
              // and the user has stopped scrolling
              if (mTouchState == TOUCH_STATE_REST) {
                  pageEndMoving();
              }
  
              onPostReorderingAnimationCompleted();
              AccessibilityManager am = (AccessibilityManager)
                      getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
              if (am.isEnabled()) {
                  // Notify the user when the page changes
                  announceForAccessibility(getCurrentPageDescription());
              }
              return true;
          }
          return false;
      }
  
      @Override
      public void computeScroll() {
          computeScrollHelper();
      }
  
      protected boolean shouldSetTopAlignedPivotForWidget(int childIndex) {
          return mTopAlignPageWhenShrinkingForBouncer;
      }
  
      public static class LayoutParams extends ViewGroup.LayoutParams {
          public boolean isFullScreenPage = false;
  
          /**
           * {@inheritDoc}
           */
          public LayoutParams(int width, int height) {
              super(width, height);
          }
  
          public LayoutParams(ViewGroup.LayoutParams source) {
              super(source);
          }
      }
  
      protected LayoutParams generateDefaultLayoutParams() {
          return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
      }
  
      public void addFullScreenPage(View page) {
          LayoutParams lp = generateDefaultLayoutParams();
          lp.isFullScreenPage = true;
          super.addView(page, 0, lp);
      }
  
      public int getNormalChildHeight() {
          return mNormalChildHeight;
      }
  
      @Override
      protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
          if (!mIsDataReady || getChildCount() == 0) {
              super.onMeasure(widthMeasureSpec, heightMeasureSpec);
              return;
          }
  
          // We measure the dimensions of the PagedView to be larger than the pages so that when we
          // zoom out (and scale down), the view is still contained in the parent
          int widthMode = MeasureSpec.getMode(widthMeasureSpec);
          int widthSize = MeasureSpec.getSize(widthMeasureSpec);
          int heightMode = MeasureSpec.getMode(heightMeasureSpec);
          int heightSize = MeasureSpec.getSize(heightMeasureSpec);
          // NOTE: We multiply by 2f to account for the fact that depending on the offset of the
          // viewport, we can be at most one and a half screens offset once we scale down
          DisplayMetrics dm = getResources().getDisplayMetrics();
          int maxSize = Math.max(dm.widthPixels + mInsets.left + mInsets.right,
                  dm.heightPixels + mInsets.top + mInsets.bottom);
  
          int parentWidthSize = (int) (2f * maxSize);
          int parentHeightSize = (int) (2f * maxSize);
          int scaledWidthSize, scaledHeightSize;
          if (mUseMinScale) {
              scaledWidthSize = (int) (parentWidthSize / mMinScale);
              scaledHeightSize = (int) (parentHeightSize / mMinScale);
          } else {
              scaledWidthSize = widthSize;
              scaledHeightSize = heightSize;
          }
          mViewport.set(0, 0, widthSize, heightSize);
  
          if (widthMode == MeasureSpec.UNSPECIFIED || heightMode == MeasureSpec.UNSPECIFIED) {
              super.onMeasure(widthMeasureSpec, heightMeasureSpec);
              return;
          }
  
          // Return early if we aren't given a proper dimension
          if (widthSize <= 0 || heightSize <= 0) {
              super.onMeasure(widthMeasureSpec, heightMeasureSpec);
              return;
          }
  
          /* Allow the height to be set as WRAP_CONTENT. This allows the particular case
           * of the All apps view on XLarge displays to not take up more space then it needs. Width
           * is still not allowed to be set as WRAP_CONTENT since many parts of the code expect
           * each page to have the same width.
           */
          final int verticalPadding = getPaddingTop() + getPaddingBottom();
          final int horizontalPadding = getPaddingLeft() + getPaddingRight();
  
          int referenceChildWidth = 0;
          // The children are given the same width and height as the workspace
          // unless they were set to WRAP_CONTENT
          if (DEBUG) Log.d(TAG, "PagedView.onMeasure(): " + widthSize + ", " + heightSize);
          if (DEBUG) Log.d(TAG, "PagedView.scaledSize: " + scaledWidthSize + ", " + scaledHeightSize);
          if (DEBUG) Log.d(TAG, "PagedView.parentSize: " + parentWidthSize + ", " + parentHeightSize);
          if (DEBUG) Log.d(TAG, "PagedView.horizontalPadding: " + horizontalPadding);
          if (DEBUG) Log.d(TAG, "PagedView.verticalPadding: " + verticalPadding);
          final int childCount = getChildCount();
          for (int i = 0; i < childCount; i++) {
              // disallowing padding in paged view (just pass 0)
              final View child = getPageAt(i);
              if (child.getVisibility() != GONE) {
                  final LayoutParams lp = (LayoutParams) child.getLayoutParams();
  
                  int childWidthMode;
                  int childHeightMode;
                  int childWidth;
                  int childHeight;
  
                  if (!lp.isFullScreenPage) {
                      if (lp.width == LayoutParams.WRAP_CONTENT) {
                          childWidthMode = MeasureSpec.AT_MOST;
                      } else {
                          childWidthMode = MeasureSpec.EXACTLY;
                      }
  
                      if (lp.height == LayoutParams.WRAP_CONTENT) {
                          childHeightMode = MeasureSpec.AT_MOST;
                      } else {
                          childHeightMode = MeasureSpec.EXACTLY;
                      }
  
                      childWidth = getViewportWidth() - horizontalPadding
                              - mInsets.left - mInsets.right;
                      childHeight = getViewportHeight() - verticalPadding
                              - mInsets.top - mInsets.bottom;
                      mNormalChildHeight = childHeight;
                  } else {
                      childWidthMode = MeasureSpec.EXACTLY;
                      childHeightMode = MeasureSpec.EXACTLY;
  
                      childWidth = getViewportWidth() - mInsets.left - mInsets.right;
                      childHeight = getViewportHeight();
                  }
                  if (referenceChildWidth == 0) {
                      referenceChildWidth = childWidth;
                  }
  
                  final int childWidthMeasureSpec =
                          MeasureSpec.makeMeasureSpec(childWidth, childWidthMode);
                      final int childHeightMeasureSpec =
                          MeasureSpec.makeMeasureSpec(childHeight, childHeightMode);
                  child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
              }
          }
          if (mSpacePagesAutomatically) {
              int spacing = (getViewportWidth() - mInsets.left - mInsets.right
                      - referenceChildWidth) / 2;
              if (spacing >= 0) {
                  setPageSpacing(spacing);
              }
              mSpacePagesAutomatically = false;
          }
          setMeasuredDimension(scaledWidthSize, scaledHeightSize);
      }
  
      /**
       * This method should be called once before first layout / measure pass.
       */
      protected void setSinglePageInViewport() {
          mSpacePagesAutomatically = true;
      }
  
      @Override
      protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
          if (!mIsDataReady || getChildCount() == 0) {
              return;
          }
  
          if (DEBUG) Log.d(TAG, "PagedView.onLayout()");
          final int childCount = getChildCount();
  
          int offsetX = getViewportOffsetX();
          int offsetY = getViewportOffsetY();
  
          // Update the viewport offsets
          mViewport.offset(offsetX,  offsetY);
  
          final boolean isRtl = isLayoutRtl();
  
          final int startIndex = isRtl ? childCount - 1 : 0;
          final int endIndex = isRtl ? -1 : childCount;
          final int delta = isRtl ? -1 : 1;
  
          int verticalPadding = getPaddingTop() + getPaddingBottom();
  
          LayoutParams lp = (LayoutParams) getChildAt(startIndex).getLayoutParams();
          LayoutParams nextLp;
  
          int childLeft = offsetX + (lp.isFullScreenPage ? 0 : getPaddingLeft());
          if (mPageScrolls == null || getChildCount() != mChildCountOnLastLayout) {
              mPageScrolls = new int[getChildCount()];
          }
  
          for (int i = startIndex; i != endIndex; i += delta) {
              final View child = getPageAt(i);
              if (child.getVisibility() != View.GONE) {
                  lp = (LayoutParams) child.getLayoutParams();
                  int childTop;
                  if (lp.isFullScreenPage) {
                      childTop = offsetY;
                  } else {
                      childTop = offsetY + getPaddingTop() + mInsets.top;
                      if (mCenterPagesVertically) {
                          childTop += (getViewportHeight() - mInsets.top - mInsets.bottom - verticalPadding - child.getMeasuredHeight()) / 2;
                      }
                  }
  
                  final int childWidth = child.getMeasuredWidth();
                  final int childHeight = child.getMeasuredHeight();
  
                  if (DEBUG) Log.d(TAG, "\tlayout-child" + i + ": " + childLeft + ", " + childTop);
                  child.layout(childLeft, childTop,
                          childLeft + child.getMeasuredWidth(), childTop + childHeight);
  
                  int scrollOffsetLeft = lp.isFullScreenPage ? 0 : getPaddingLeft();
                  mPageScrolls[i] = childLeft - scrollOffsetLeft - offsetX;
  
                  int pageGap = mPageSpacing;
                  int next = i + delta;
                  if (next != endIndex) {
                      nextLp = (LayoutParams) getPageAt(next).getLayoutParams();
                  } else {
                      nextLp = null;
                  }
  
                  // Prevent full screen pages from showing in the viewport
                  // when they are not the current page.
                  if (lp.isFullScreenPage) {
                      pageGap = getPaddingLeft();
                  } else if (nextLp != null && nextLp.isFullScreenPage) {
                      pageGap = getPaddingRight();
                  }
  
                  childLeft += childWidth + pageGap;
              }
          }
  
          if (mFirstLayout && mCurrentPage >= 0 && mCurrentPage < getChildCount()) {
              updateCurrentPageScroll();
              mFirstLayout = false;
          }
  
          if (childCount > 0) {
              final int index = isLayoutRtl() ? 0 : childCount - 1;
              mMaxScrollX = getScrollForPage(index);
          } else {
              mMaxScrollX = 0;
          }
  
          if (mScroller.isFinished() && mChildCountOnLastLayout != getChildCount() &&
                  !mDeferringForDelete) {
              if (mRestorePage != INVALID_RESTORE_PAGE) {
                  setCurrentPage(mRestorePage);
                  mRestorePage = INVALID_RESTORE_PAGE;
              } else {
                  setCurrentPage(getNextPage());
              }
          }
          mChildCountOnLastLayout = getChildCount();
  
          if (isReordering(true)) {
              updateDragViewTranslationDuringDrag();
          }
      }
  
      public void setPageSpacing(int pageSpacing) {
          mPageSpacing = pageSpacing;
          requestLayout();
      }
  
      protected void screenScrolled(int screenCenter) {
          boolean isInOverscroll = mOverScrollX < 0 || mOverScrollX > mMaxScrollX;
  
          if (mFadeInAdjacentScreens && !isInOverscroll) {
              for (int i = 0; i < getChildCount(); i++) {
                  View child = getChildAt(i);
                  if (child != null) {
                      float scrollProgress = getScrollProgress(screenCenter, child, i);
                      float alpha = 1 - Math.abs(scrollProgress);
                      child.setAlpha(alpha);
                  }
              }
              invalidate();
          }
      }
  
      protected void enablePagedViewAnimations() {
          mAllowPagedViewAnimations = true;
  
      }
      protected void disablePagedViewAnimations() {
          mAllowPagedViewAnimations = false;
      }
  
      @Override
      public void onChildViewAdded(View parent, View child) {
          // Update the page indicator, we don't update the page indicator as we
          // add/remove pages
          if (mPageIndicator != null && !isReordering(false)) {
              int pageIndex = indexOfChild(child);
              mPageIndicator.addMarker(pageIndex,
                      getPageIndicatorMarker(pageIndex),
                      mAllowPagedViewAnimations);
          }
  
          // This ensures that when children are added, they get the correct transforms / alphas
          // in accordance with any scroll effects.
          mForceScreenScrolled = true;
          updateFreescrollBounds();
          invalidate();
      }
  
      @Override
      public void onChildViewRemoved(View parent, View child) {
          mForceScreenScrolled = true;
          updateFreescrollBounds();
          invalidate();
      }
  
      private void removeMarkerForView(int index) {
          // Update the page indicator, we don't update the page indicator as we
          // add/remove pages
          if (mPageIndicator != null && !isReordering(false)) {
              mPageIndicator.removeMarker(index, mAllowPagedViewAnimations);
          }
      }
  
      @Override
      public void removeView(View v) {
          // XXX: We should find a better way to hook into this before the view
          // gets removed form its parent...
          removeMarkerForView(indexOfChild(v));
          super.removeView(v);
      }
      @Override
      public void removeViewInLayout(View v) {
          // XXX: We should find a better way to hook into this before the view
          // gets removed form its parent...
          removeMarkerForView(indexOfChild(v));
          super.removeViewInLayout(v);
      }
      @Override
      public void removeViewAt(int index) {
          // XXX: We should find a better way to hook into this before the view
          // gets removed form its parent...
          removeViewAt(index);
          super.removeViewAt(index);
      }
      @Override
      public void removeAllViewsInLayout() {
          // Update the page indicator, we don't update the page indicator as we
          // add/remove pages
          if (mPageIndicator != null) {
              mPageIndicator.removeAllMarkers(mAllowPagedViewAnimations);
          }
  
          super.removeAllViewsInLayout();
      }
  
      protected int getChildOffset(int index) {
          if (index < 0 || index > getChildCount() - 1) return 0;
  
          int offset = getPageAt(index).getLeft() - getViewportOffsetX();
  
          return offset;
      }
  
      protected void getFreeScrollPageRange(int[] range) {
          range[0] = 0;
          range[1] = Math.max(0, getChildCount() - 1);
      }
  
      protected void getVisiblePages(int[] range) {
          final int pageCount = getChildCount();
          mTmpIntPoint[0] = mTmpIntPoint[1] = 0;
  
          range[0] = -1;
          range[1] = -1;
  
          if (pageCount > 0) {
              int viewportWidth = getViewportWidth();
              int curScreen = 0;
  
              int count = getChildCount();
              for (int i = 0; i < count; i++) {
                  View currPage = getPageAt(i);
  
                  mTmpIntPoint[0] = 0;
                  Utilities.getDescendantCoordRelativeToParent(currPage, this, mTmpIntPoint, false);
                  if (mTmpIntPoint[0] > viewportWidth) {
                      if (range[0] == -1) {
                          continue;
                      } else {
                          break;
                      }
                  }
  
                  mTmpIntPoint[0] = currPage.getMeasuredWidth();
                  Utilities.getDescendantCoordRelativeToParent(currPage, this, mTmpIntPoint, false);
                  if (mTmpIntPoint[0] < 0) {
                      if (range[0] == -1) {
                          continue;
                      } else {
                          break;
                      }
                  }
                  curScreen = i;
                  if (range[0] < 0) {
                      range[0] = curScreen;
                  }
              }
  
              range[1] = curScreen;
          } else {
              range[0] = -1;
              range[1] = -1;
          }
      }
  
      protected boolean shouldDrawChild(View child) {
          return child.getVisibility() == VISIBLE;
      }
  
      @Override
      protected void dispatchDraw(Canvas canvas) {
          // Find out which screens are visible; as an optimization we only call draw on them
          final int pageCount = getChildCount();
          if (pageCount > 0) {
              int halfScreenSize = getViewportWidth() / 2;
              // mOverScrollX is equal to getScrollX() when we're within the normal scroll range.
              // Otherwise it is equal to the scaled overscroll position.
              int screenCenter = mOverScrollX + halfScreenSize;
  
              if (screenCenter != mLastScreenCenter || mForceScreenScrolled) {
                  // set mForceScreenScrolled before calling screenScrolled so that screenScrolled can
                  // set it for the next frame
                  mForceScreenScrolled = false;
                  screenScrolled(screenCenter);
                  mLastScreenCenter = screenCenter;
              }
  
              getVisiblePages(mTempVisiblePagesRange);
              final int leftScreen = mTempVisiblePagesRange[0];
              final int rightScreen = mTempVisiblePagesRange[1];
              if (leftScreen != -1 && rightScreen != -1) {
                  final long drawingTime = getDrawingTime();
                  // Clip to the bounds
                  canvas.save();
                  canvas.clipRect(getScrollX(), getScrollY(), getScrollX() + getRight() - getLeft(),
                          getScrollY() + getBottom() - getTop());
  
                  // Draw all the children, leaving the drag view for last
                  for (int i = pageCount - 1; i >= 0; i--) {
                      final View v = getPageAt(i);
                      if (v == mDragView) continue;
                      if (mForceDrawAllChildrenNextFrame ||
                                 (leftScreen <= i && i <= rightScreen && shouldDrawChild(v))) {
                          drawChild(canvas, v, drawingTime);
                      }
                  }
                  // Draw the drag view on top (if there is one)
                  if (mDragView != null) {
                      drawChild(canvas, mDragView, drawingTime);
                  }
  
                  mForceDrawAllChildrenNextFrame = false;
                  canvas.restore();
              }
          }
      }
  
      @Override
      public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
          int page = indexToPage(indexOfChild(child));
          if (page != mCurrentPage || !mScroller.isFinished()) {
              snapToPage(page);
              return true;
          }
          return false;
      }
  
      @Override
      protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
          int focusablePage;
          if (mNextPage != INVALID_PAGE) {
              focusablePage = mNextPage;
          } else {
              focusablePage = mCurrentPage;
          }
          View v = getPageAt(focusablePage);
          if (v != null) {
              return v.requestFocus(direction, previouslyFocusedRect);
          }
          return false;
      }
  
      @Override
      public boolean dispatchUnhandledMove(View focused, int direction) {
          // XXX-RTL: This will be fixed in a future CL
          if (direction == View.FOCUS_LEFT) {
              if (getCurrentPage() > 0) {
                  snapToPage(getCurrentPage() - 1);
                  return true;
              }
          } else if (direction == View.FOCUS_RIGHT) {
              if (getCurrentPage() < getPageCount() - 1) {
                  snapToPage(getCurrentPage() + 1);
                  return true;
              }
          }
          return super.dispatchUnhandledMove(focused, direction);
      }
  
      @Override
      public void addFocusables(ArrayList<View> views, int direction, int focusableMode) {
          // XXX-RTL: This will be fixed in a future CL
          if (mCurrentPage >= 0 && mCurrentPage < getPageCount()) {
              getPageAt(mCurrentPage).addFocusables(views, direction, focusableMode);
          }
          if (direction == View.FOCUS_LEFT) {
              if (mCurrentPage > 0) {
                  getPageAt(mCurrentPage - 1).addFocusables(views, direction, focusableMode);
              }
          } else if (direction == View.FOCUS_RIGHT){
              if (mCurrentPage < getPageCount() - 1) {
                  getPageAt(mCurrentPage + 1).addFocusables(views, direction, focusableMode);
              }
          }
      }
  
      /**
       * If one of our descendant views decides that it could be focused now, only
       * pass that along if it's on the current page.
       *
       * This happens when live folders requery, and if they're off page, they
       * end up calling requestFocus, which pulls it on page.
       */
      @Override
      public void focusableViewAvailable(View focused) {
          View current = getPageAt(mCurrentPage);
          View v = focused;
          while (true) {
              if (v == current) {
                  super.focusableViewAvailable(focused);
                  return;
              }
              if (v == this) {
                  return;
              }
              ViewParent parent = v.getParent();
              if (parent instanceof View) {
                  v = (View)v.getParent();
              } else {
                  return;
              }
          }
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
          if (disallowIntercept) {
              // We need to make sure to cancel our long press if
              // a scrollable widget takes over touch events
              final View currentPage = getPageAt(mCurrentPage);
              currentPage.cancelLongPress();
          }
          super.requestDisallowInterceptTouchEvent(disallowIntercept);
      }
  
      /**
       * Return true if a tap at (x, y) should trigger a flip to the previous page.
       */
      protected boolean hitsPreviousPage(float x, float y) {
          if (isLayoutRtl()) {
              return (x > (getViewportOffsetX() + getViewportWidth() -
                      getPaddingRight() - mPageSpacing));
          }
          return (x < getViewportOffsetX() + getPaddingLeft() + mPageSpacing);
      }
  
      /**
       * Return true if a tap at (x, y) should trigger a flip to the next page.
       */
      protected boolean hitsNextPage(float x, float y) {
          if (isLayoutRtl()) {
              return (x < getViewportOffsetX() + getPaddingLeft() + mPageSpacing);
          }
          return  (x > (getViewportOffsetX() + getViewportWidth() -
                  getPaddingRight() - mPageSpacing));
      }
  
      /** Returns whether x and y originated within the buffered viewport */
      private boolean isTouchPointInViewportWithBuffer(int x, int y) {
          mTmpRect.set(mViewport.left - mViewport.width() / 2, mViewport.top,
                  mViewport.right + mViewport.width() / 2, mViewport.bottom);
          return mTmpRect.contains(x, y);
      }
  
      @Override
      public boolean onInterceptTouchEvent(MotionEvent ev) {
          if (DISABLE_TOUCH_INTERACTION) {
              return false;
          }
  
          /*
           * This method JUST determines whether we want to intercept the motion.
           * If we return true, onTouchEvent will be called and we do the actual
           * scrolling there.
           */
          acquireVelocityTrackerAndAddMovement(ev);
  
          // Skip touch handling if there are no pages to swipe
          if (getChildCount() <= 0) return super.onInterceptTouchEvent(ev);
  
          /*
           * Shortcut the most recurring case: the user is in the dragging
           * state and he is moving his finger.  We want to intercept this
           * motion.
           */
          final int action = ev.getAction();
          if ((action == MotionEvent.ACTION_MOVE) &&
                  (mTouchState == TOUCH_STATE_SCROLLING)) {
              return true;
          }
  
          switch (action & MotionEvent.ACTION_MASK) {
              case MotionEvent.ACTION_MOVE: {
                  /*
                   * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
                   * whether the user has moved far enough from his original down touch.
                   */
                  if (mActivePointerId != INVALID_POINTER) {
                      determineScrollingStart(ev);
                  }
                  // if mActivePointerId is INVALID_POINTER, then we must have missed an ACTION_DOWN
                  // event. in that case, treat the first occurence of a move event as a ACTION_DOWN
                  // i.e. fall through to the next case (don't break)
                  // (We sometimes miss ACTION_DOWN events in Workspace because it ignores all events
                  // while it's small- this was causing a crash before we checked for INVALID_POINTER)
                  break;
              }
  
              case MotionEvent.ACTION_DOWN: {
                  final float x = ev.getX();
                  final float y = ev.getY();
                  // Remember location of down touch
                  mDownMotionX = x;
                  mDownMotionY = y;
                  mDownScrollX = getScrollX();
                  mLastMotionX = x;
                  mLastMotionY = y;
                  float[] p = mapPointFromViewToParent(this, x, y);
                  mParentDownMotionX = p[0];
                  mParentDownMotionY = p[1];
                  mLastMotionXRemainder = 0;
                  mTotalMotionX = 0;
                  mActivePointerId = ev.getPointerId(0);
  
                  /*
                   * If being flinged and user touches the screen, initiate drag;
                   * otherwise don't.  mScroller.isFinished should be false when
                   * being flinged.
                   */
                  final int xDist = Math.abs(mScroller.getFinalX() - mScroller.getCurrX());
                  final boolean finishedScrolling = (mScroller.isFinished() || xDist < mTouchSlop / 3);
  
                  if (finishedScrolling) {
                      mTouchState = TOUCH_STATE_REST;
                      if (!mScroller.isFinished() && !mFreeScroll) {
                          setCurrentPage(getNextPage());
                          pageEndMoving();
                      }
                  } else {
                      if (isTouchPointInViewportWithBuffer((int) mDownMotionX, (int) mDownMotionY)) {
                          mTouchState = TOUCH_STATE_SCROLLING;
                      } else {
                          mTouchState = TOUCH_STATE_REST;
                      }
                  }
  
                  // check if this can be the beginning of a tap on the side of the pages
                  // to scroll the current page
                  if (!DISABLE_TOUCH_SIDE_PAGES) {
                      if (mTouchState != TOUCH_STATE_PREV_PAGE && mTouchState != TOUCH_STATE_NEXT_PAGE) {
                          if (getChildCount() > 0) {
                              if (hitsPreviousPage(x, y)) {
                                  mTouchState = TOUCH_STATE_PREV_PAGE;
                              } else if (hitsNextPage(x, y)) {
                                  mTouchState = TOUCH_STATE_NEXT_PAGE;
                              }
                          }
                      }
                  }
                  break;
              }
  
              case MotionEvent.ACTION_UP:
              case MotionEvent.ACTION_CANCEL:
                  resetTouchState();
                  break;
  
              case MotionEvent.ACTION_POINTER_UP:
                  onSecondaryPointerUp(ev);
                  releaseVelocityTracker();
                  break;
          }
  
          /*
           * The only time we want to intercept motion events is if we are in the
           * drag mode.
           */
          return mTouchState != TOUCH_STATE_REST;
      }
  
      protected void determineScrollingStart(MotionEvent ev) {
          determineScrollingStart(ev, 1.0f);
      }
  
      /*
       * Determines if we should change the touch state to start scrolling after the
       * user moves their touch point too far.
       */
      protected void determineScrollingStart(MotionEvent ev, float touchSlopScale) {
          // Disallow scrolling if we don't have a valid pointer index
          final int pointerIndex = ev.findPointerIndex(mActivePointerId);
          if (pointerIndex == -1) return;
  
          // Disallow scrolling if we started the gesture from outside the viewport
          final float x = ev.getX(pointerIndex);
          final float y = ev.getY(pointerIndex);
          if (!isTouchPointInViewportWithBuffer((int) x, (int) y)) return;
  
          final int xDiff = (int) Math.abs(x - mLastMotionX);
          final int yDiff = (int) Math.abs(y - mLastMotionY);
  
          final int touchSlop = Math.round(touchSlopScale * mTouchSlop);
          boolean xPaged = xDiff > mPagingTouchSlop;
          boolean xMoved = xDiff > touchSlop;
          boolean yMoved = yDiff > touchSlop;
  
          if (xMoved || xPaged || yMoved) {
              if (mUsePagingTouchSlop ? xPaged : xMoved) {
                  // Scroll if the user moved far enough along the X axis
                  mTouchState = TOUCH_STATE_SCROLLING;
                  mTotalMotionX += Math.abs(mLastMotionX - x);
                  mLastMotionX = x;
                  mLastMotionXRemainder = 0;
                  mTouchX = getViewportOffsetX() + getScrollX();
                  mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                  onScrollInteractionBegin();
                  pageBeginMoving();
              }
          }
      }
  
      protected float getMaxScrollProgress() {
          return 1.0f;
      }
  
      protected void cancelCurrentPageLongPress() {
          if (mAllowLongPress) {
              //mAllowLongPress = false;
              // Try canceling the long press. It could also have been scheduled
              // by a distant descendant, so use the mAllowLongPress flag to block
              // everything
              final View currentPage = getPageAt(mCurrentPage);
              if (currentPage != null) {
                  currentPage.cancelLongPress();
              }
          }
      }
  
      protected float getBoundedScrollProgress(int screenCenter, View v, int page) {
          final int halfScreenSize = getViewportWidth() / 2;
  
          screenCenter = Math.min(getScrollX() + halfScreenSize, screenCenter);
          screenCenter = Math.max(halfScreenSize,  screenCenter);
  
          return getScrollProgress(screenCenter, v, page);
      }
  
      protected float getScrollProgress(int screenCenter, View v, int page) {
          final int halfScreenSize = getViewportWidth() / 2;
  
          int delta = screenCenter - (getScrollForPage(page) + halfScreenSize);
          int count = getChildCount();
  
          final int totalDistance;
  
          int adjacentPage = page + 1;
          if ((delta < 0 && !isLayoutRtl()) || (delta > 0 && isLayoutRtl())) {
              adjacentPage = page - 1;
          }
  
          if (adjacentPage < 0 || adjacentPage > count - 1) {
              totalDistance = v.getMeasuredWidth() + mPageSpacing;
          } else {
              totalDistance = Math.abs(getScrollForPage(adjacentPage) - getScrollForPage(page));
          }
  
          float scrollProgress = delta / (totalDistance * 1.0f);
          scrollProgress = Math.min(scrollProgress, getMaxScrollProgress());
          scrollProgress = Math.max(scrollProgress, - getMaxScrollProgress());
          return scrollProgress;
      }
  
      public int getScrollForPage(int index) {
          if (mPageScrolls == null || index >= mPageScrolls.length || index < 0) {
              return 0;
          } else {
              return mPageScrolls[index];
          }
      }
  
      // While layout transitions are occurring, a child's position may stray from its baseline
      // position. This method returns the magnitude of this stray at any given time.
      public int getLayoutTransitionOffsetForPage(int index) {
          if (mPageScrolls == null || index >= mPageScrolls.length || index < 0) {
              return 0;
          } else {
              View child = getChildAt(index);
  
              int scrollOffset = 0;
              LayoutParams lp = (LayoutParams) child.getLayoutParams();
              if (!lp.isFullScreenPage) {
                  scrollOffset = isLayoutRtl() ? getPaddingRight() : getPaddingLeft();
              }
  
              int baselineX = mPageScrolls[index] + scrollOffset + getViewportOffsetX();
              return (int) (child.getX() - baselineX);
          }
      }
  
      // This curve determines how the effect of scrolling over the limits of the page dimishes
      // as the user pulls further and further from the bounds
      private float overScrollInfluenceCurve(float f) {
          f -= 1.0f;
          return f * f * f + 1.0f;
      }
  
      protected float acceleratedOverFactor(float amount) {
          int screenSize = getViewportWidth();
  
          // We want to reach the max over scroll effect when the user has
          // over scrolled half the size of the screen
          float f = OVERSCROLL_ACCELERATE_FACTOR * (amount / screenSize);
  
          if (f == 0) return 0;
  
          // Clamp this factor, f, to -1 < f < 1
          if (Math.abs(f) >= 1) {
              f /= Math.abs(f);
          }
          return f;
      }
  
      protected void dampedOverScroll(float amount) {
          int screenSize = getViewportWidth();
  
          float f = (amount / screenSize);
  
          if (f == 0) return;
          f = f / (Math.abs(f)) * (overScrollInfluenceCurve(Math.abs(f)));
  
          // Clamp this factor, f, to -1 < f < 1
          if (Math.abs(f) >= 1) {
              f /= Math.abs(f);
          }
  
          int overScrollAmount = (int) Math.round(OVERSCROLL_DAMP_FACTOR * f * screenSize);
          if (amount < 0) {
              mOverScrollX = overScrollAmount;
              super.scrollTo(mOverScrollX, getScrollY());
          } else {
              mOverScrollX = mMaxScrollX + overScrollAmount;
              super.scrollTo(mOverScrollX, getScrollY());
          }
          invalidate();
      }
  
      protected void overScroll(float amount) {
          dampedOverScroll(amount);
      }
  
      protected float maxOverScroll() {
          // Using the formula in overScroll, assuming that f = 1.0 (which it should generally not
          // exceed). Used to find out how much extra wallpaper we need for the over scroll effect
          float f = 1.0f;
          f = f / (Math.abs(f)) * (overScrollInfluenceCurve(Math.abs(f)));
          return OVERSCROLL_DAMP_FACTOR * f;
      }
  
      protected void enableFreeScroll() {
          setEnableFreeScroll(true);
      }
  
      protected void disableFreeScroll() {
          setEnableFreeScroll(false);
      }
  
      void updateFreescrollBounds() {
          getFreeScrollPageRange(mTempVisiblePagesRange);
          if (isLayoutRtl()) {
              mFreeScrollMinScrollX = getScrollForPage(mTempVisiblePagesRange[1]);
              mFreeScrollMaxScrollX = getScrollForPage(mTempVisiblePagesRange[0]);
          } else {
              mFreeScrollMinScrollX = getScrollForPage(mTempVisiblePagesRange[0]);
              mFreeScrollMaxScrollX = getScrollForPage(mTempVisiblePagesRange[1]);
          }
      }
  
      private void setEnableFreeScroll(boolean freeScroll) {
          mFreeScroll = freeScroll;
  
          if (mFreeScroll) {
              updateFreescrollBounds();
              getFreeScrollPageRange(mTempVisiblePagesRange);
              if (getCurrentPage() < mTempVisiblePagesRange[0]) {
                  setCurrentPage(mTempVisiblePagesRange[0]);
              } else if (getCurrentPage() > mTempVisiblePagesRange[1]) {
                  setCurrentPage(mTempVisiblePagesRange[1]);
              }
          }
  
          setEnableOverscroll(!freeScroll);
      }
  
      private void setEnableOverscroll(boolean enable) {
          mAllowOverScroll = enable;
      }
  
      int getNearestHoverOverPageIndex() {
          if (mDragView != null) {
              int dragX = (int) (mDragView.getLeft() + (mDragView.getMeasuredWidth() / 2)
                      + mDragView.getTranslationX());
              getFreeScrollPageRange(mTempVisiblePagesRange);
              int minDistance = Integer.MAX_VALUE;
              int minIndex = indexOfChild(mDragView);
              for (int i = mTempVisiblePagesRange[0]; i <= mTempVisiblePagesRange[1]; i++) {
                  View page = getPageAt(i);
                  int pageX = (int) (page.getLeft() + page.getMeasuredWidth() / 2);
                  int d = Math.abs(dragX - pageX);
                  if (d < minDistance) {
                      minIndex = i;
                      minDistance = d;
                  }
              }
              return minIndex;
          }
          return -1;
      }
  
      @Override
      public boolean onTouchEvent(MotionEvent ev) {
          if (DISABLE_TOUCH_INTERACTION) {
              return false;
          }
  
          super.onTouchEvent(ev);
  
          // Skip touch handling if there are no pages to swipe
          if (getChildCount() <= 0) return super.onTouchEvent(ev);
  
          acquireVelocityTrackerAndAddMovement(ev);
  
          final int action = ev.getAction();
  
          switch (action & MotionEvent.ACTION_MASK) {
          case MotionEvent.ACTION_DOWN:
              /*
               * If being flinged and user touches, stop the fling. isFinished
               * will be false if being flinged.
               */
              if (!mScroller.isFinished()) {
                  abortScrollerAnimation(false);
              }
  
              // Remember where the motion event started
              mDownMotionX = mLastMotionX = ev.getX();
              mDownMotionY = mLastMotionY = ev.getY();
              mDownScrollX = getScrollX();
              float[] p = mapPointFromViewToParent(this, mLastMotionX, mLastMotionY);
              mParentDownMotionX = p[0];
              mParentDownMotionY = p[1];
              mLastMotionXRemainder = 0;
              mTotalMotionX = 0;
              mActivePointerId = ev.getPointerId(0);
  
              if (mTouchState == TOUCH_STATE_SCROLLING) {
                  onScrollInteractionBegin();
                  pageBeginMoving();
              }
              break;
  
          case MotionEvent.ACTION_MOVE:
              if (mTouchState == TOUCH_STATE_SCROLLING) {
                  // Scroll to follow the motion event
                  final int pointerIndex = ev.findPointerIndex(mActivePointerId);
  
                  if (pointerIndex == -1) return true;
  
                  final float x = ev.getX(pointerIndex);
                  final float deltaX = mLastMotionX + mLastMotionXRemainder - x;
  
                  mTotalMotionX += Math.abs(deltaX);
  
                  // Only scroll and update mLastMotionX if we have moved some discrete amount.  We
                  // keep the remainder because we are actually testing if we've moved from the last
                  // scrolled position (which is discrete).
                  if (Math.abs(deltaX) >= 1.0f) {
                      mTouchX += deltaX;
                      mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                      if (!mDeferScrollUpdate) {
                          scrollBy((int) deltaX, 0);
                          if (DEBUG) Log.d(TAG, "onTouchEvent().Scrolling: " + deltaX);
                      } else {
                          invalidate();
                      }
                      mLastMotionX = x;
                      mLastMotionXRemainder = deltaX - (int) deltaX;
                  } else {
                      awakenScrollBars();
                  }
              } else if (mTouchState == TOUCH_STATE_REORDERING) {
                  // Update the last motion position
                  mLastMotionX = ev.getX();
                  mLastMotionY = ev.getY();
  
                  // Update the parent down so that our zoom animations take this new movement into
                  // account
                  float[] pt = mapPointFromViewToParent(this, mLastMotionX, mLastMotionY);
                  mParentDownMotionX = pt[0];
                  mParentDownMotionY = pt[1];
                  updateDragViewTranslationDuringDrag();
  
                  // Find the closest page to the touch point
                  final int dragViewIndex = indexOfChild(mDragView);
  
                  // Change the drag view if we are hovering over the drop target
                  boolean isHoveringOverDelete = isHoveringOverDeleteDropTarget(
                          (int) mParentDownMotionX, (int) mParentDownMotionY);
                  setPageHoveringOverDeleteDropTarget(dragViewIndex, isHoveringOverDelete);
  
                  if (DEBUG) Log.d(TAG, "mLastMotionX: " + mLastMotionX);
                  if (DEBUG) Log.d(TAG, "mLastMotionY: " + mLastMotionY);
                  if (DEBUG) Log.d(TAG, "mParentDownMotionX: " + mParentDownMotionX);
                  if (DEBUG) Log.d(TAG, "mParentDownMotionY: " + mParentDownMotionY);
  
                  final int pageUnderPointIndex = getNearestHoverOverPageIndex();
                  if (pageUnderPointIndex > -1 && pageUnderPointIndex != indexOfChild(mDragView) &&
                          !isHoveringOverDelete) {
                      mTempVisiblePagesRange[0] = 0;
                      mTempVisiblePagesRange[1] = getPageCount() - 1;
                      getFreeScrollPageRange(mTempVisiblePagesRange);
                      if (mTempVisiblePagesRange[0] <= pageUnderPointIndex &&
                              pageUnderPointIndex <= mTempVisiblePagesRange[1] &&
                              pageUnderPointIndex != mSidePageHoverIndex && mScroller.isFinished()) {
                          mSidePageHoverIndex = pageUnderPointIndex;
                          mSidePageHoverRunnable = new Runnable() {
                              @Override
                              public void run() {
                                  // Setup the scroll to the correct page before we swap the views
                                  snapToPage(pageUnderPointIndex);
  
                                  // For each of the pages between the paged view and the drag view,
                                  // animate them from the previous position to the new position in
                                  // the layout (as a result of the drag view moving in the layout)
                                  int shiftDelta = (dragViewIndex < pageUnderPointIndex) ? -1 : 1;
                                  int lowerIndex = (dragViewIndex < pageUnderPointIndex) ?
                                          dragViewIndex + 1 : pageUnderPointIndex;
                                  int upperIndex = (dragViewIndex > pageUnderPointIndex) ?
                                          dragViewIndex - 1 : pageUnderPointIndex;
                                  for (int i = lowerIndex; i <= upperIndex; ++i) {
                                      View v = getChildAt(i);
                                      // dragViewIndex < pageUnderPointIndex, so after we remove the
                                      // drag view all subsequent views to pageUnderPointIndex will
                                      // shift down.
                                      int oldX = getViewportOffsetX() + getChildOffset(i);
                                      int newX = getViewportOffsetX() + getChildOffset(i + shiftDelta);
  
                                      // Animate the view translation from its old position to its new
                                      // position
                                      AnimatorSet anim = (AnimatorSet) v.getTag(ANIM_TAG_KEY);
                                      if (anim != null) {
                                          anim.cancel();
                                      }
  
                                      v.setTranslationX(oldX - newX);
                                      anim = new AnimatorSet();
                                      anim.setDuration(REORDERING_REORDER_REPOSITION_DURATION);
                                      anim.playTogether(
                                              ObjectAnimator.ofFloat(v, "translationX", 0f));
                                      anim.start();
                                      v.setTag(anim);
                                  }
  
                                  removeView(mDragView);
                                  onRemoveView(mDragView, false);
                                  addView(mDragView, pageUnderPointIndex);
                                  onAddView(mDragView, pageUnderPointIndex);
                                  mSidePageHoverIndex = -1;
                                  if (mPageIndicator != null) {
                                      mPageIndicator.setActiveMarker(getNextPage());
                                  }
                              }
                          };
                          postDelayed(mSidePageHoverRunnable, REORDERING_SIDE_PAGE_HOVER_TIMEOUT);
                      }
                  } else {
                      removeCallbacks(mSidePageHoverRunnable);
                      mSidePageHoverIndex = -1;
                  }
              } else {
                  determineScrollingStart(ev);
              }
              break;
  
          case MotionEvent.ACTION_UP:
              if (mTouchState == TOUCH_STATE_SCROLLING) {
                  final int activePointerId = mActivePointerId;
                  final int pointerIndex = ev.findPointerIndex(activePointerId);
                  final float x = ev.getX(pointerIndex);
                  final VelocityTracker velocityTracker = mVelocityTracker;
                  velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                  int velocityX = (int) velocityTracker.getXVelocity(activePointerId);
                  final int deltaX = (int) (x - mDownMotionX);
                  final int pageWidth = getPageAt(mCurrentPage).getMeasuredWidth();
                  boolean isSignificantMove = Math.abs(deltaX) > pageWidth *
                          SIGNIFICANT_MOVE_THRESHOLD;
  
                  mTotalMotionX += Math.abs(mLastMotionX + mLastMotionXRemainder - x);
  
                  boolean isFling = mTotalMotionX > MIN_LENGTH_FOR_FLING &&
                          Math.abs(velocityX) > mFlingThresholdVelocity;
  
                  if (!mFreeScroll) {
                      // In the case that the page is moved far to one direction and then is flung
                      // in the opposite direction, we use a threshold to determine whether we should
                      // just return to the starting page, or if we should skip one further.
                      boolean returnToOriginalPage = false;
                      if (Math.abs(deltaX) > pageWidth * RETURN_TO_ORIGINAL_PAGE_THRESHOLD &&
                              Math.signum(velocityX) != Math.signum(deltaX) && isFling) {
                          returnToOriginalPage = true;
                      }
  
                      int finalPage;
                      // We give flings precedence over large moves, which is why we short-circuit our
                      // test for a large move if a fling has been registered. That is, a large
                      // move to the left and fling to the right will register as a fling to the right.
                      final boolean isRtl = isLayoutRtl();
                      boolean isDeltaXLeft = isRtl ? deltaX > 0 : deltaX < 0;
                      boolean isVelocityXLeft = isRtl ? velocityX > 0 : velocityX < 0;
                      if (((isSignificantMove && !isDeltaXLeft && !isFling) ||
                              (isFling && !isVelocityXLeft)) && mCurrentPage > 0) {
                          finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage - 1;
                          snapToPageWithVelocity(finalPage, velocityX);
                      } else if (((isSignificantMove && isDeltaXLeft && !isFling) ||
                              (isFling && isVelocityXLeft)) &&
                              mCurrentPage < getChildCount() - 1) {
                          finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage + 1;
                          snapToPageWithVelocity(finalPage, velocityX);
                      } else {
                          snapToDestination();
                      }
                  } else {
                      if (!mScroller.isFinished()) {
                          abortScrollerAnimation(true);
                      }
  
                      float scaleX = getScaleX();
                      int vX = (int) (-velocityX * scaleX);
                      int initialScrollX = (int) (getScrollX() * scaleX);
  
                      mScroller.setInterpolator(mDefaultInterpolator);
                      mScroller.fling(initialScrollX,
                              getScrollY(), vX, 0, Integer.MIN_VALUE, Integer.MAX_VALUE, 0, 0);
                      invalidate();
                  }
                  onScrollInteractionEnd();
              } else if (mTouchState == TOUCH_STATE_PREV_PAGE) {
                  // at this point we have not moved beyond the touch slop
                  // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                  // we can just page
                  int nextPage = Math.max(0, mCurrentPage - 1);
                  if (nextPage != mCurrentPage) {
                      snapToPage(nextPage);
                  } else {
                      snapToDestination();
                  }
              } else if (mTouchState == TOUCH_STATE_NEXT_PAGE) {
                  // at this point we have not moved beyond the touch slop
                  // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                  // we can just page
                  int nextPage = Math.min(getChildCount() - 1, mCurrentPage + 1);
                  if (nextPage != mCurrentPage) {
                      snapToPage(nextPage);
                  } else {
                      snapToDestination();
                  }
              } else if (mTouchState == TOUCH_STATE_REORDERING) {
                  // Update the last motion position
                  mLastMotionX = ev.getX();
                  mLastMotionY = ev.getY();
  
                  // Update the parent down so that our zoom animations take this new movement into
                  // account
                  float[] pt = mapPointFromViewToParent(this, mLastMotionX, mLastMotionY);
                  mParentDownMotionX = pt[0];
                  mParentDownMotionY = pt[1];
                  updateDragViewTranslationDuringDrag();
                  boolean handledFling = false;
                  if (!DISABLE_FLING_TO_DELETE) {
                      // Check the velocity and see if we are flinging-to-delete
                      PointF flingToDeleteVector = isFlingingToDelete();
                      if (flingToDeleteVector != null) {
                          onFlingToDelete(flingToDeleteVector);
                          handledFling = true;
                      }
                  }
                  if (!handledFling && isHoveringOverDeleteDropTarget((int) mParentDownMotionX,
                          (int) mParentDownMotionY)) {
                      onDropToDelete();
                  }
              } else {
                  if (!mCancelTap) {
                      onUnhandledTap(ev);
                  }
              }
  
              // Remove the callback to wait for the side page hover timeout
              removeCallbacks(mSidePageHoverRunnable);
              // End any intermediate reordering states
              resetTouchState();
              break;
  
          case MotionEvent.ACTION_CANCEL:
              if (mTouchState == TOUCH_STATE_SCROLLING) {
                  snapToDestination();
              }
              resetTouchState();
              break;
  
          case MotionEvent.ACTION_POINTER_UP:
              onSecondaryPointerUp(ev);
              releaseVelocityTracker();
              break;
          }
  
          return true;
      }
  
      public void onFlingToDelete(View v) {}
      public void onRemoveView(View v, boolean deletePermanently) {}
      public void onRemoveViewAnimationCompleted() {}
      public void onAddView(View v, int index) {}
  
      private void resetTouchState() {
          releaseVelocityTracker();
          endReordering();
          mCancelTap = false;
          mTouchState = TOUCH_STATE_REST;
          mActivePointerId = INVALID_POINTER;
      }
  
      /**
       * Triggered by scrolling via touch
       */
      protected void onScrollInteractionBegin() {
      }
  
      protected void onScrollInteractionEnd() {
      }
  
      protected void onUnhandledTap(MotionEvent ev) {
          ((Launcher) getContext()).onClick(this);
      }
  
      @Override
      public boolean onGenericMotionEvent(MotionEvent event) {
          if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
              switch (event.getAction()) {
                  case MotionEvent.ACTION_SCROLL: {
                      // Handle mouse (or ext. device) by shifting the page depending on the scroll
                      final float vscroll;
                      final float hscroll;
                      if ((event.getMetaState() & KeyEvent.META_SHIFT_ON) != 0) {
                          vscroll = 0;
                          hscroll = event.getAxisValue(MotionEvent.AXIS_VSCROLL);
                      } else {
                          vscroll = -event.getAxisValue(MotionEvent.AXIS_VSCROLL);
                          hscroll = event.getAxisValue(MotionEvent.AXIS_HSCROLL);
                      }
                      if (hscroll != 0 || vscroll != 0) {
                          boolean isForwardScroll = isLayoutRtl() ? (hscroll < 0 || vscroll < 0)
                                                           : (hscroll > 0 || vscroll > 0);
                          if (isForwardScroll) {
                              scrollRight();
                          } else {
                              scrollLeft();
                          }
                          return true;
                      }
                  }
              }
          }
          return super.onGenericMotionEvent(event);
      }
  
      private void acquireVelocityTrackerAndAddMovement(MotionEvent ev) {
          if (mVelocityTracker == null) {
              mVelocityTracker = VelocityTracker.obtain();
          }
          mVelocityTracker.addMovement(ev);
      }
  
      private void releaseVelocityTracker() {
          if (mVelocityTracker != null) {
              mVelocityTracker.clear();
              mVelocityTracker.recycle();
              mVelocityTracker = null;
          }
      }
  
      private void onSecondaryPointerUp(MotionEvent ev) {
          final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >>
                  MotionEvent.ACTION_POINTER_INDEX_SHIFT;
          final int pointerId = ev.getPointerId(pointerIndex);
          if (pointerId == mActivePointerId) {
              // This was our active pointer going up. Choose a new
              // active pointer and adjust accordingly.
              // TODO: Make this decision more intelligent.
              final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
              mLastMotionX = mDownMotionX = ev.getX(newPointerIndex);
              mLastMotionY = ev.getY(newPointerIndex);
              mLastMotionXRemainder = 0;
              mActivePointerId = ev.getPointerId(newPointerIndex);
              if (mVelocityTracker != null) {
                  mVelocityTracker.clear();
              }
          }
      }
  
      @Override
      public void requestChildFocus(View child, View focused) {
          super.requestChildFocus(child, focused);
          int page = indexToPage(indexOfChild(child));
          if (page >= 0 && page != getCurrentPage() && !isInTouchMode()) {
              snapToPage(page);
          }
      }
  
      protected int getChildWidth(int index) {
          return getPageAt(index).getMeasuredWidth();
      }
  
      int getPageNearestToPoint(float x) {
          int index = 0;
          for (int i = 0; i < getChildCount(); ++i) {
              if (x < getChildAt(i).getRight() - getScrollX()) {
                  return index;
              } else {
                  index++;
              }
          }
          return Math.min(index, getChildCount() - 1);
      }
  
      int getPageNearestToCenterOfScreen() {
          int minDistanceFromScreenCenter = Integer.MAX_VALUE;
          int minDistanceFromScreenCenterIndex = -1;
          int screenCenter = getViewportOffsetX() + getScrollX() + (getViewportWidth() / 2);
          final int childCount = getChildCount();
          for (int i = 0; i < childCount; ++i) {
              View layout = (View) getPageAt(i);
              int childWidth = layout.getMeasuredWidth();
              int halfChildWidth = (childWidth / 2);
              int childCenter = getViewportOffsetX() + getChildOffset(i) + halfChildWidth;
              int distanceFromScreenCenter = Math.abs(childCenter - screenCenter);
              if (distanceFromScreenCenter < minDistanceFromScreenCenter) {
                  minDistanceFromScreenCenter = distanceFromScreenCenter;
                  minDistanceFromScreenCenterIndex = i;
              }
          }
          return minDistanceFromScreenCenterIndex;
      }
  
      protected boolean isInOverScroll() {
          return (mOverScrollX > mMaxScrollX || mOverScrollX < 0);
      }
  
      protected int getPageSnapDuration() {
          if (isInOverScroll()) {
              return OVER_SCROLL_PAGE_SNAP_ANIMATION_DURATION;
          }
          return PAGE_SNAP_ANIMATION_DURATION;
  
      }
  
      protected void snapToDestination() {
          snapToPage(getPageNearestToCenterOfScreen(), getPageSnapDuration());
      }
  
      private static class ScrollInterpolator implements Interpolator {
          public ScrollInterpolator() {
          }
  
          public float getInterpolation(float t) {
              t -= 1.0f;
              return t*t*t*t*t + 1;
          }
      }
  
      // We want the duration of the page snap animation to be influenced by the distance that
      // the screen has to travel, however, we don't want this duration to be effected in a
      // purely linear fashion. Instead, we use this method to moderate the effect that the distance
      // of travel has on the overall snap duration.
      float distanceInfluenceForSnapDuration(float f) {
          f -= 0.5f; // center the values about 0.
          f *= 0.3f * Math.PI / 2.0f;
          return (float) Math.sin(f);
      }
  
      protected void snapToPageWithVelocity(int whichPage, int velocity) {
          whichPage = validateNewPage(whichPage);
          int halfScreenSize = getViewportWidth() / 2;
  
          final int newX = getScrollForPage(whichPage);
          int delta = newX - mUnboundedScrollX;
          int duration = 0;
  
          if (Math.abs(velocity) < mMinFlingVelocity || isInOverScroll()) {
              // If the velocity is low enough, then treat this more as an automatic page advance
              // as opposed to an apparent physical response to flinging
              snapToPage(whichPage, getPageSnapDuration());
              return;
          }
  
          // Here we compute a "distance" that will be used in the computation of the overall
          // snap duration. This is a function of the actual distance that needs to be traveled;
          // we keep this value close to half screen size in order to reduce the variance in snap
          // duration as a function of the distance the page needs to travel.
          float distanceRatio = Math.min(1f, 1.0f * Math.abs(delta) / (2 * halfScreenSize));
          float distance = halfScreenSize + halfScreenSize *
                  distanceInfluenceForSnapDuration(distanceRatio);
  
          velocity = Math.abs(velocity);
          velocity = Math.max(mMinSnapVelocity, velocity);
  
          // we want the page's snap velocity to approximately match the velocity at which the
          // user flings, so we scale the duration by a value near to the derivative of the scroll
          // interpolator at zero, ie. 5. We use 4 to make it a little slower.
          duration = 4 * Math.round(1000 * Math.abs(distance / velocity));
  
          snapToPage(whichPage, delta, duration);
      }
  
      protected void snapToPage(int whichPage) {
          snapToPage(whichPage, getPageSnapDuration());
      }
  
      protected void snapToPageImmediately(int whichPage) {
          snapToPage(whichPage, getPageSnapDuration(), true, null);
      }
  
      protected void snapToPage(int whichPage, int duration) {
          snapToPage(whichPage, duration, false, null);
      }
  
      protected void snapToPage(int whichPage, int duration, TimeInterpolator interpolator) {
          snapToPage(whichPage, duration, false, interpolator);
      }
  
      protected void snapToPage(int whichPage, int duration, boolean immediate,
              TimeInterpolator interpolator) {
          whichPage = validateNewPage(whichPage);
  
          int newX = getScrollForPage(whichPage);
          final int sX = mUnboundedScrollX;
          final int delta = newX - sX;
          snapToPage(whichPage, delta, duration, immediate, interpolator);
      }
  
      protected void snapToPage(int whichPage, int delta, int duration) {
          snapToPage(whichPage, delta, duration, false, null);
      }
  
      protected void snapToPage(int whichPage, int delta, int duration, boolean immediate,
              TimeInterpolator interpolator) {
          whichPage = validateNewPage(whichPage);
  
          mNextPage = whichPage;
          View focusedChild = getFocusedChild();
          if (focusedChild != null && whichPage != mCurrentPage &&
                  focusedChild == getPageAt(mCurrentPage)) {
              focusedChild.clearFocus();
          }
  
          sendScrollAccessibilityEvent();
  
          pageBeginMoving();
          awakenScrollBars(duration);
          if (immediate) {
              duration = 0;
          } else if (duration == 0) {
              duration = Math.abs(delta);
          }
  
          if (!mScroller.isFinished()) {
              abortScrollerAnimation(false);
          }
  
          if (interpolator != null) {
              mScroller.setInterpolator(interpolator);
          } else {
              mScroller.setInterpolator(mDefaultInterpolator);
          }
  
          mScroller.startScroll(mUnboundedScrollX, 0, delta, 0, duration);
  
          updatePageIndicator();
  
          // Trigger a compute() to finish switching pages if necessary
          if (immediate) {
              computeScroll();
          }
  
          // Defer loading associated pages until the scroll settles
          mDeferLoadAssociatedPagesUntilScrollCompletes = true;
  
          mForceScreenScrolled = true;
          invalidate();
      }
  
      public void scrollLeft() {
          if (getNextPage() > 0) snapToPage(getNextPage() - 1);
      }
  
      public void scrollRight() {
          if (getNextPage() < getChildCount() -1) snapToPage(getNextPage() + 1);
      }
  
      public int getPageForView(View v) {
          int result = -1;
          if (v != null) {
              ViewParent vp = v.getParent();
              int count = getChildCount();
              for (int i = 0; i < count; i++) {
                  if (vp == getPageAt(i)) {
                      return i;
                  }
              }
          }
          return result;
      }
  
      /**
       * @return True is long presses are still allowed for the current touch
       */
      public boolean allowLongPress() {
          return mAllowLongPress;
      }
  
      @Override
      public boolean performLongClick() {
          mCancelTap = true;
          return super.performLongClick();
      }
  
      /**
       * Set true to allow long-press events to be triggered, usually checked by
       * {@link Launcher} to accept or block dpad-initiated long-presses.
       */
      public void setAllowLongPress(boolean allowLongPress) {
          mAllowLongPress = allowLongPress;
      }
  
      public static class SavedState extends BaseSavedState {
          int currentPage = -1;
  
          SavedState(Parcelable superState) {
              super(superState);
          }
  
          private SavedState(Parcel in) {
              super(in);
              currentPage = in.readInt();
          }
  
          @Override
          public void writeToParcel(Parcel out, int flags) {
              super.writeToParcel(out, flags);
              out.writeInt(currentPage);
          }
  
          public static final Parcelable.Creator<SavedState> CREATOR =
                  new Parcelable.Creator<SavedState>() {
              public SavedState createFromParcel(Parcel in) {
                  return new SavedState(in);
              }
  
              public SavedState[] newArray(int size) {
                  return new SavedState[size];
              }
          };
      }
  
      protected void loadAssociatedPages(int page) {
          loadAssociatedPages(page, false);
      }
      protected void loadAssociatedPages(int page, boolean immediateAndOnly) {
          if (mContentIsRefreshable) {
              final int count = getChildCount();
              if (page < count) {
                  int lowerPageBound = getAssociatedLowerPageBound(page);
                  int upperPageBound = getAssociatedUpperPageBound(page);
                  if (DEBUG) Log.d(TAG, "loadAssociatedPages: " + lowerPageBound + "/"
                          + upperPageBound);
                  // First, clear any pages that should no longer be loaded
                  for (int i = 0; i < count; ++i) {
                      Page layout = (Page) getPageAt(i);
                      if ((i < lowerPageBound) || (i > upperPageBound)) {
                          if (layout.getPageChildCount() > 0) {
                              layout.removeAllViewsOnPage();
                          }
                          mDirtyPageContent.set(i, true);
                      }
                  }
                  // Next, load any new pages
                  for (int i = 0; i < count; ++i) {
                      if ((i != page) && immediateAndOnly) {
                          continue;
                      }
                      if (lowerPageBound <= i && i <= upperPageBound) {
                          if (mDirtyPageContent.get(i)) {
                              syncPageItems(i, (i == page) && immediateAndOnly);
                              mDirtyPageContent.set(i, false);
                          }
                      }
                  }
              }
          }
      }
  
      protected int getAssociatedLowerPageBound(int page) {
          return Math.max(0, page - 1);
      }
      protected int getAssociatedUpperPageBound(int page) {
          final int count = getChildCount();
          return Math.min(page + 1, count - 1);
      }
  
      /**
       * This method is called ONLY to synchronize the number of pages that the paged view has.
       * To actually fill the pages with information, implement syncPageItems() below.  It is
       * guaranteed that syncPageItems() will be called for a particular page before it is shown,
       * and therefore, individual page items do not need to be updated in this method.
       */
      public abstract void syncPages();
  
      /**
       * This method is called to synchronize the items that are on a particular page.  If views on
       * the page can be reused, then they should be updated within this method.
       */
      public abstract void syncPageItems(int page, boolean immediate);
  
      protected void invalidatePageData() {
          invalidatePageData(-1, false);
      }
      protected void invalidatePageData(int currentPage) {
          invalidatePageData(currentPage, false);
      }
      protected void invalidatePageData(int currentPage, boolean immediateAndOnly) {
          if (!mIsDataReady) {
              return;
          }
  
          if (mContentIsRefreshable) {
              // Force all scrolling-related behavior to end
              forceFinishScroller();
  
              // Update all the pages
              syncPages();
  
              // We must force a measure after we've loaded the pages to update the content width and
              // to determine the full scroll width
              measure(MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY),
                      MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY));
  
              // Set a new page as the current page if necessary
              if (currentPage > -1) {
                  setCurrentPage(Math.min(getPageCount() - 1, currentPage));
              }
  
              // Mark each of the pages as dirty
              final int count = getChildCount();
              mDirtyPageContent.clear();
              for (int i = 0; i < count; ++i) {
                  mDirtyPageContent.add(true);
              }
  
              // Load any pages that are necessary for the current window of views
              loadAssociatedPages(mCurrentPage, immediateAndOnly);
              requestLayout();
          }
          if (isPageMoving()) {
              // If the page is moving, then snap it to the final position to ensure we don't get
              // stuck between pages
              snapToDestination();
          }
      }
  
      // Animate the drag view back to the original position
      void animateDragViewToOriginalPosition() {
          if (mDragView != null) {
              AnimatorSet anim = new AnimatorSet();
              anim.setDuration(REORDERING_DROP_REPOSITION_DURATION);
              anim.playTogether(
                      ObjectAnimator.ofFloat(mDragView, "translationX", 0f),
                      ObjectAnimator.ofFloat(mDragView, "translationY", 0f),
                      ObjectAnimator.ofFloat(mDragView, "scaleX", 1f),
                      ObjectAnimator.ofFloat(mDragView, "scaleY", 1f));
              anim.addListener(new AnimatorListenerAdapter() {
                  @Override
                  public void onAnimationEnd(Animator animation) {
                      onPostReorderingAnimationCompleted();
                  }
              });
              anim.start();
          }
      }
  
      protected void onStartReordering() {
          // Set the touch state to reordering (allows snapping to pages, dragging a child, etc.)
          mTouchState = TOUCH_STATE_REORDERING;
          mIsReordering = true;
  
          // We must invalidate to trigger a redraw to update the layers such that the drag view
          // is always drawn on top
          invalidate();
      }
  
      private void onPostReorderingAnimationCompleted() {
          // Trigger the callback when reordering has settled
          --mPostReorderingPreZoomInRemainingAnimationCount;
          if (mPostReorderingPreZoomInRunnable != null &&
                  mPostReorderingPreZoomInRemainingAnimationCount == 0) {
              mPostReorderingPreZoomInRunnable.run();
              mPostReorderingPreZoomInRunnable = null;
          }
      }
  
      protected void onEndReordering() {
          mIsReordering = false;
      }
  
      public boolean startReordering(View v) {
          int dragViewIndex = indexOfChild(v);
  
          if (mTouchState != TOUCH_STATE_REST || dragViewIndex == -1) return false;
  
          mTempVisiblePagesRange[0] = 0;
          mTempVisiblePagesRange[1] = getPageCount() - 1;
          getFreeScrollPageRange(mTempVisiblePagesRange);
          mReorderingStarted = true;
  
          // Check if we are within the reordering range
          if (mTempVisiblePagesRange[0] <= dragViewIndex &&
              dragViewIndex <= mTempVisiblePagesRange[1]) {
              // Find the drag view under the pointer
              mDragView = getChildAt(dragViewIndex);
              mDragView.animate().scaleX(1.15f).scaleY(1.15f).setDuration(100).start();
              mDragViewBaselineLeft = mDragView.getLeft();
              snapToPage(getPageNearestToCenterOfScreen());
              disableFreeScroll();
              onStartReordering();
              return true;
          }
          return false;
      }
  
      boolean isReordering(boolean testTouchState) {
          boolean state = mIsReordering;
          if (testTouchState) {
              state &= (mTouchState == TOUCH_STATE_REORDERING);
          }
          return state;
      }
      void endReordering() {
          // For simplicity, we call endReordering sometimes even if reordering was never started.
          // In that case, we don't want to do anything.
          if (!mReorderingStarted) return;
          mReorderingStarted = false;
  
          // If we haven't flung-to-delete the current child, then we just animate the drag view
          // back into position
          final Runnable onCompleteRunnable = new Runnable() {
              @Override
              public void run() {
                  onEndReordering();
              }
          };
          if (!mDeferringForDelete) {
              mPostReorderingPreZoomInRunnable = new Runnable() {
                  public void run() {
                      onCompleteRunnable.run();
                      enableFreeScroll();
                  };
              };
  
              mPostReorderingPreZoomInRemainingAnimationCount =
                      NUM_ANIMATIONS_RUNNING_BEFORE_ZOOM_OUT;
              // Snap to the current page
              snapToPage(indexOfChild(mDragView), 0);
              // Animate the drag view back to the front position
              animateDragViewToOriginalPosition();
          } else {
              // Handled in post-delete-animation-callbacks
          }
      }
  
      /*
       * Flinging to delete - IN PROGRESS
       */
      private PointF isFlingingToDelete() {
          ViewConfiguration config = ViewConfiguration.get(getContext());
          mVelocityTracker.computeCurrentVelocity(1000, config.getScaledMaximumFlingVelocity());
  
          if (mVelocityTracker.getYVelocity() < mFlingToDeleteThresholdVelocity) {
              // Do a quick dot product test to ensure that we are flinging upwards
              PointF vel = new PointF(mVelocityTracker.getXVelocity(),
                      mVelocityTracker.getYVelocity());
              PointF upVec = new PointF(0f, -1f);
              float theta = (float) Math.acos(((vel.x * upVec.x) + (vel.y * upVec.y)) /
                      (vel.length() * upVec.length()));
              if (theta <= Math.toRadians(FLING_TO_DELETE_MAX_FLING_DEGREES)) {
                  return vel;
              }
          }
          return null;
      }
  
      /**
       * Creates an animation from the current drag view along its current velocity vector.
       * For this animation, the alpha runs for a fixed duration and we update the position
       * progressively.
       */
      private static class FlingAlongVectorAnimatorUpdateListener implements AnimatorUpdateListener {
          private View mDragView;
          private PointF mVelocity;
          private Rect mFrom;
          private long mPrevTime;
          private float mFriction;
  
          private final TimeInterpolator mAlphaInterpolator = new DecelerateInterpolator(0.75f);
  
          public FlingAlongVectorAnimatorUpdateListener(View dragView, PointF vel, Rect from,
                  long startTime, float friction) {
              mDragView = dragView;
              mVelocity = vel;
              mFrom = from;
              mPrevTime = startTime;
              mFriction = 1f - (mDragView.getResources().getDisplayMetrics().density * friction);
          }
  
          @Override
          public void onAnimationUpdate(ValueAnimator animation) {
              float t = ((Float) animation.getAnimatedValue()).floatValue();
              long curTime = AnimationUtils.currentAnimationTimeMillis();
  
              mFrom.left += (mVelocity.x * (curTime - mPrevTime) / 1000f);
              mFrom.top += (mVelocity.y * (curTime - mPrevTime) / 1000f);
  
              mDragView.setTranslationX(mFrom.left);
              mDragView.setTranslationY(mFrom.top);
              mDragView.setAlpha(1f - mAlphaInterpolator.getInterpolation(t));
  
              mVelocity.x *= mFriction;
              mVelocity.y *= mFriction;
              mPrevTime = curTime;
          }
      };
  
      private static final int ANIM_TAG_KEY = 100;
  
      private Runnable createPostDeleteAnimationRunnable(final View dragView) {
          return new Runnable() {
              @Override
              public void run() {
                  int dragViewIndex = indexOfChild(dragView);
  
                  // For each of the pages around the drag view, animate them from the previous
                  // position to the new position in the layout (as a result of the drag view moving
                  // in the layout)
                  // NOTE: We can make an assumption here because we have side-bound pages that we
                  //       will always have pages to animate in from the left
                  getFreeScrollPageRange(mTempVisiblePagesRange);
                  boolean isLastWidgetPage = (mTempVisiblePagesRange[0] == mTempVisiblePagesRange[1]);
                  boolean slideFromLeft = (isLastWidgetPage ||
                          dragViewIndex > mTempVisiblePagesRange[0]);
  
                  // Setup the scroll to the correct page before we swap the views
                  if (slideFromLeft) {
                      snapToPageImmediately(dragViewIndex - 1);
                  }
  
                  int firstIndex = (isLastWidgetPage ? 0 : mTempVisiblePagesRange[0]);
                  int lastIndex = Math.min(mTempVisiblePagesRange[1], getPageCount() - 1);
                  int lowerIndex = (slideFromLeft ? firstIndex : dragViewIndex + 1 );
                  int upperIndex = (slideFromLeft ? dragViewIndex - 1 : lastIndex);
                  ArrayList<Animator> animations = new ArrayList<Animator>();
                  for (int i = lowerIndex; i <= upperIndex; ++i) {
                      View v = getChildAt(i);
                      // dragViewIndex < pageUnderPointIndex, so after we remove the
                      // drag view all subsequent views to pageUnderPointIndex will
                      // shift down.
                      int oldX = 0;
                      int newX = 0;
                      if (slideFromLeft) {
                          if (i == 0) {
                              // Simulate the page being offscreen with the page spacing
                              oldX = getViewportOffsetX() + getChildOffset(i) - getChildWidth(i)
                                      - mPageSpacing;
                          } else {
                              oldX = getViewportOffsetX() + getChildOffset(i - 1);
                          }
                          newX = getViewportOffsetX() + getChildOffset(i);
                      } else {
                          oldX = getChildOffset(i) - getChildOffset(i - 1);
                          newX = 0;
                      }
  
                      // Animate the view translation from its old position to its new
                      // position
                      AnimatorSet anim = (AnimatorSet) v.getTag();
                      if (anim != null) {
                          anim.cancel();
                      }
  
                      // Note: Hacky, but we want to skip any optimizations to not draw completely
                      // hidden views
                      v.setAlpha(Math.max(v.getAlpha(), 0.01f));
                      v.setTranslationX(oldX - newX);
                      anim = new AnimatorSet();
                      anim.playTogether(
                              ObjectAnimator.ofFloat(v, "translationX", 0f),
                              ObjectAnimator.ofFloat(v, "alpha", 1f));
                      animations.add(anim);
                      v.setTag(ANIM_TAG_KEY, anim);
                  }
  
                  AnimatorSet slideAnimations = new AnimatorSet();
                  slideAnimations.playTogether(animations);
                  slideAnimations.setDuration(DELETE_SLIDE_IN_SIDE_PAGE_DURATION);
                  slideAnimations.addListener(new AnimatorListenerAdapter() {
                      @Override
                      public void onAnimationEnd(Animator animation) {
                          mDeferringForDelete = false;
                          onEndReordering();
                          onRemoveViewAnimationCompleted();
                      }
                  });
                  slideAnimations.start();
  
                  removeView(dragView);
                  onRemoveView(dragView, true);
              }
          };
      }
  
      public void onFlingToDelete(PointF vel) {
          final long startTime = AnimationUtils.currentAnimationTimeMillis();
  
          // NOTE: Because it takes time for the first frame of animation to actually be
          // called and we expect the animation to be a continuation of the fling, we have
          // to account for the time that has elapsed since the fling finished.  And since
          // we don't have a startDelay, we will always get call to update when we call
          // start() (which we want to ignore).
          final TimeInterpolator tInterpolator = new TimeInterpolator() {
              private int mCount = -1;
              private long mStartTime;
              private float mOffset;
              /* Anonymous inner class ctor */ {
                  mStartTime = startTime;
              }
  
              @Override
              public float getInterpolation(float t) {
                  if (mCount < 0) {
                      mCount++;
                  } else if (mCount == 0) {
                      mOffset = Math.min(0.5f, (float) (AnimationUtils.currentAnimationTimeMillis() -
                              mStartTime) / FLING_TO_DELETE_FADE_OUT_DURATION);
                      mCount++;
                  }
                  return Math.min(1f, mOffset + t);
              }
          };
  
          final Rect from = new Rect();
          final View dragView = mDragView;
          from.left = (int) dragView.getTranslationX();
          from.top = (int) dragView.getTranslationY();
          AnimatorUpdateListener updateCb = new FlingAlongVectorAnimatorUpdateListener(dragView, vel,
                  from, startTime, FLING_TO_DELETE_FRICTION);
  
          final Runnable onAnimationEndRunnable = createPostDeleteAnimationRunnable(dragView);
  
          // Create and start the animation
          ValueAnimator mDropAnim = new ValueAnimator();
          mDropAnim.setInterpolator(tInterpolator);
          mDropAnim.setDuration(FLING_TO_DELETE_FADE_OUT_DURATION);
          mDropAnim.setFloatValues(0f, 1f);
          mDropAnim.addUpdateListener(updateCb);
          mDropAnim.addListener(new AnimatorListenerAdapter() {
              public void onAnimationEnd(Animator animation) {
                  onAnimationEndRunnable.run();
              }
          });
          mDropAnim.start();
          mDeferringForDelete = true;
      }
  
      /* Drag to delete */
      private boolean isHoveringOverDeleteDropTarget(int x, int y) {
          if (mDeleteDropTarget != null) {
              mAltTmpRect.set(0, 0, 0, 0);
              View parent = (View) mDeleteDropTarget.getParent();
              if (parent != null) {
                  parent.getGlobalVisibleRect(mAltTmpRect);
              }
              mDeleteDropTarget.getGlobalVisibleRect(mTmpRect);
              mTmpRect.offset(-mAltTmpRect.left, -mAltTmpRect.top);
              return mTmpRect.contains(x, y);
          }
          return false;
      }
  
      protected void setPageHoveringOverDeleteDropTarget(int viewIndex, boolean isHovering) {}
  
      private void onDropToDelete() {
          final View dragView = mDragView;
  
          final float toScale = 0f;
          final float toAlpha = 0f;
  
          // Create and start the complex animation
          ArrayList<Animator> animations = new ArrayList<Animator>();
          AnimatorSet motionAnim = new AnimatorSet();
          motionAnim.setInterpolator(new DecelerateInterpolator(2));
          motionAnim.playTogether(
                  ObjectAnimator.ofFloat(dragView, "scaleX", toScale),
                  ObjectAnimator.ofFloat(dragView, "scaleY", toScale));
          animations.add(motionAnim);
  
          AnimatorSet alphaAnim = new AnimatorSet();
          alphaAnim.setInterpolator(new LinearInterpolator());
          alphaAnim.playTogether(
                  ObjectAnimator.ofFloat(dragView, "alpha", toAlpha));
          animations.add(alphaAnim);
  
          final Runnable onAnimationEndRunnable = createPostDeleteAnimationRunnable(dragView);
  
          AnimatorSet anim = new AnimatorSet();
          anim.playTogether(animations);
          anim.setDuration(DRAG_TO_DELETE_FADE_OUT_DURATION);
          anim.addListener(new AnimatorListenerAdapter() {
              public void onAnimationEnd(Animator animation) {
                  onAnimationEndRunnable.run();
              }
          });
          anim.start();
  
          mDeferringForDelete = true;
      }
  
      /* Accessibility */
      @Override
      public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
          super.onInitializeAccessibilityNodeInfo(info);
          info.setScrollable(getPageCount() > 1);
          if (getCurrentPage() < getPageCount() - 1) {
              info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
          }
          if (getCurrentPage() > 0) {
              info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
          }
      }
  
      @Override
      public void sendAccessibilityEvent(int eventType) {
          // Don't let the view send real scroll events.
          if (eventType != AccessibilityEvent.TYPE_VIEW_SCROLLED) {
              super.sendAccessibilityEvent(eventType);
          }
      }
  
      @Override
      public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
          super.onInitializeAccessibilityEvent(event);
          event.setScrollable(true);
      }
  
      @Override
      public boolean performAccessibilityAction(int action, Bundle arguments) {
          if (super.performAccessibilityAction(action, arguments)) {
              return true;
          }
          switch (action) {
              case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: {
                  if (getCurrentPage() < getPageCount() - 1) {
                      scrollRight();
                      return true;
                  }
              } break;
              case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: {
                  if (getCurrentPage() > 0) {
                      scrollLeft();
                      return true;
                  }
              } break;
          }
          return false;
      }
  
      protected String getCurrentPageDescription() {
          return String.format(getContext().getString(R.string.default_scroll_format),
                  getNextPage() + 1, getChildCount());
      }
  
      @Override
      public boolean onHoverEvent(android.view.MotionEvent event) {
          return true;
      }
  }
  