Launcher2 is now Launcher3.
Changes include
- moving from com.android.launcher{,2} to
com.android.launcher3
- removing wallpapers
- new temporary icon
Change-Id: I1eabd06059e94a8f3bdf6b620777bd1d2b7c212b
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
new file mode 100644
index 0000000..8716a33
--- /dev/null
+++ b/src/com/android/launcher3/PagedView.java
@@ -0,0 +1,1981 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ValueAnimator;
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.AttributeSet;
+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.Interpolator;
+import android.widget.Scroller;
+
+import com.android.launcher3.R;
+
+import java.util.ArrayList;
+
+/**
+ * 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 = 550;
+ protected static final int MAX_PAGE_SNAP_DURATION = 750;
+ 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 = 0.14f;
+
+ 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;
+
+ 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;
+
+ protected int mCurrentPage;
+ protected int mNextPage = INVALID_PAGE;
+ protected int mMaxScrollX;
+ protected Scroller mScroller;
+ private VelocityTracker mVelocityTracker;
+
+ private float mDownMotionX;
+ protected float mLastMotionX;
+ protected float mLastMotionXRemainder;
+ protected float mLastMotionY;
+ protected float mTotalMotionX;
+ private int mLastScreenCenter = -1;
+ private int[] mChildOffsets;
+ private int[] mChildRelativeOffsets;
+ private int[] mChildOffsetsWithLayoutScale;
+
+ 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 float ALPHA_QUANTIZE_LEVEL = 0.0001f;
+
+ protected int mTouchState = TOUCH_STATE_REST;
+ protected boolean mForceScreenScrolled = false;
+
+ protected OnLongClickListener mLongClickListener;
+
+ protected boolean mAllowLongPress = true;
+
+ protected int mTouchSlop;
+ private int mPagingTouchSlop;
+ private int mMaximumVelocity;
+ private int mMinimumWidth;
+ protected int mPageSpacing;
+ protected int mPageLayoutPaddingTop;
+ protected int mPageLayoutPaddingBottom;
+ protected int mPageLayoutPaddingLeft;
+ protected int mPageLayoutPaddingRight;
+ 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;
+
+ // 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;
+
+ // parameter that adjusts the layout to be optimized for pages with that scale factor
+ protected float mLayoutScale = 1.0f;
+
+ 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 = true;
+
+ // 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 mIsPageMoving = false;
+
+ // All syncs and layout passes are deferred until data is ready.
+ protected boolean mIsDataReady = false;
+
+ // Scrolling indicator
+ private ValueAnimator mScrollIndicatorAnimator;
+ private View mScrollIndicator;
+ private int mScrollIndicatorPaddingLeft;
+ private int mScrollIndicatorPaddingRight;
+ private boolean mHasScrollIndicator = true;
+ private boolean mShouldShowScrollIndicator = false;
+ private boolean mShouldShowScrollIndicatorImmediately = false;
+ protected static final int sScrollIndicatorFadeInDuration = 150;
+ protected static final int sScrollIndicatorFadeOutDuration = 650;
+ protected static final int sScrollIndicatorFlashDuration = 650;
+ private boolean mScrollingPaused = false;
+
+ // If set, will defer loading associated pages until the scrolling settles
+ private boolean mDeferLoadAssociatedPagesUntilScrollCompletes;
+
+ 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);
+ setPageSpacing(a.getDimensionPixelSize(R.styleable.PagedView_pageSpacing, 0));
+ mPageLayoutPaddingTop = a.getDimensionPixelSize(
+ R.styleable.PagedView_pageLayoutPaddingTop, 0);
+ mPageLayoutPaddingBottom = a.getDimensionPixelSize(
+ R.styleable.PagedView_pageLayoutPaddingBottom, 0);
+ mPageLayoutPaddingLeft = a.getDimensionPixelSize(
+ R.styleable.PagedView_pageLayoutPaddingLeft, 0);
+ mPageLayoutPaddingRight = a.getDimensionPixelSize(
+ R.styleable.PagedView_pageLayoutPaddingRight, 0);
+ mPageLayoutWidthGap = a.getDimensionPixelSize(
+ R.styleable.PagedView_pageLayoutWidthGap, 0);
+ mPageLayoutHeightGap = a.getDimensionPixelSize(
+ R.styleable.PagedView_pageLayoutHeightGap, 0);
+ mScrollIndicatorPaddingLeft =
+ a.getDimensionPixelSize(R.styleable.PagedView_scrollIndicatorPaddingLeft, 0);
+ mScrollIndicatorPaddingRight =
+ a.getDimensionPixelSize(R.styleable.PagedView_scrollIndicatorPaddingRight, 0);
+ a.recycle();
+
+ setHapticFeedbackEnabled(false);
+ init();
+ }
+
+ /**
+ * Initializes various states for this workspace.
+ */
+ protected void init() {
+ mDirtyPageContent = new ArrayList<Boolean>();
+ mDirtyPageContent.ensureCapacity(32);
+ mScroller = new Scroller(getContext(), new ScrollInterpolator());
+ mCurrentPage = 0;
+ mCenterPagesVertically = true;
+
+ final ViewConfiguration configuration = ViewConfiguration.get(getContext());
+ mTouchSlop = configuration.getScaledTouchSlop();
+ mPagingTouchSlop = configuration.getScaledPagingTouchSlop();
+ mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
+ mDensity = getResources().getDisplayMetrics().density;
+
+ mFlingThresholdVelocity = (int) (FLING_THRESHOLD_VELOCITY * mDensity);
+ mMinFlingVelocity = (int) (MIN_FLING_VELOCITY * mDensity);
+ mMinSnapVelocity = (int) (MIN_SNAP_VELOCITY * mDensity);
+ setOnHierarchyChangeListener(this);
+ }
+
+ 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()) {
+ int offset = getChildOffset(mCurrentPage);
+ int relOffset = getRelativeChildOffset(mCurrentPage);
+ newX = offset - relOffset;
+ }
+ scrollTo(newX, 0);
+ mScroller.setFinalX(newX);
+ mScroller.forceFinished(true);
+ }
+
+ /**
+ * Called during AllApps/Home transitions to avoid unnecessary work. When that other animation
+ * ends, {@link #resumeScrolling()} should be called, along with
+ * {@link #updateCurrentPageScroll()} to correctly set the final state and re-enable scrolling.
+ */
+ void pauseScrolling() {
+ mScroller.forceFinished(true);
+ cancelScrollingIndicatorAnimations();
+ mScrollingPaused = true;
+ }
+
+ /**
+ * Enables scrolling again.
+ * @see #pauseScrolling()
+ */
+ void resumeScrolling() {
+ mScrollingPaused = false;
+ }
+ /**
+ * Sets the current page.
+ */
+ void setCurrentPage(int currentPage) {
+ if (!mScroller.isFinished()) {
+ mScroller.abortAnimation();
+ }
+ // don't introduce any checks like mCurrentPage == currentPage here-- if we change the
+ // the default
+ if (getChildCount() == 0) {
+ return;
+ }
+
+
+ mCurrentPage = Math.max(0, Math.min(currentPage, getPageCount() - 1));
+ updateCurrentPageScroll();
+ updateScrollingIndicator();
+ notifyPageSwitchListener();
+ invalidate();
+ }
+
+ protected void notifyPageSwitchListener() {
+ if (mPageSwitchListener != null) {
+ mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
+ }
+ }
+
+ 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() {
+ }
+
+ /**
+ * 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);
+ }
+ }
+
+ @Override
+ public void scrollBy(int x, int y) {
+ scrollTo(mUnboundedScrollX + x, getScrollY() + y);
+ }
+
+ @Override
+ public void scrollTo(int x, int y) {
+ 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) {
+ if (isRtl) {
+ overScroll(x - mMaxScrollX);
+ } else {
+ overScroll(x);
+ }
+ }
+ } else if (isXAfterLastPage) {
+ super.scrollTo(mMaxScrollX, y);
+ if (mAllowOverScroll) {
+ if (isRtl) {
+ overScroll(x);
+ } else {
+ overScroll(x - mMaxScrollX);
+ }
+ }
+ } else {
+ mOverScrollX = x;
+ super.scrollTo(x, y);
+ }
+
+ mTouchX = x;
+ mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
+ }
+
+ // 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()) {
+ scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
+ }
+ invalidate();
+ return true;
+ } else if (mNextPage != INVALID_PAGE) {
+ mCurrentPage = Math.max(0, Math.min(mNextPage, getPageCount() - 1));
+ 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();
+ }
+
+ // Notify the user when the page changes
+ AccessibilityManager accessibilityManager = (AccessibilityManager)
+ getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
+ if (accessibilityManager.isEnabled()) {
+ AccessibilityEvent ev =
+ AccessibilityEvent.obtain(AccessibilityEvent.TYPE_VIEW_SCROLLED);
+ ev.getText().add(getCurrentPageDescription());
+ sendAccessibilityEventUnchecked(ev);
+ }
+ return true;
+ }
+ return false;
+ }
+
+ @Override
+ public void computeScroll() {
+ computeScrollHelper();
+ }
+
+ @Override
+ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+ if (!mIsDataReady) {
+ super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+ return;
+ }
+
+ final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
+ final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
+ final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
+ int heightSize = MeasureSpec.getSize(heightMeasureSpec);
+ if (widthMode != MeasureSpec.EXACTLY) {
+ throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
+ }
+
+ // 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.
+ */
+ int maxChildHeight = 0;
+
+ final int verticalPadding = getPaddingTop() + getPaddingBottom();
+ final int horizontalPadding = getPaddingLeft() + getPaddingRight();
+
+
+ // 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);
+ final int childCount = getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ // disallowing padding in paged view (just pass 0)
+ final View child = getPageAt(i);
+ final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+
+ int childWidthMode;
+ if (lp.width == LayoutParams.WRAP_CONTENT) {
+ childWidthMode = MeasureSpec.AT_MOST;
+ } else {
+ childWidthMode = MeasureSpec.EXACTLY;
+ }
+
+ int childHeightMode;
+ if (lp.height == LayoutParams.WRAP_CONTENT) {
+ childHeightMode = MeasureSpec.AT_MOST;
+ } else {
+ childHeightMode = MeasureSpec.EXACTLY;
+ }
+
+ final int childWidthMeasureSpec =
+ MeasureSpec.makeMeasureSpec(widthSize - horizontalPadding, childWidthMode);
+ final int childHeightMeasureSpec =
+ MeasureSpec.makeMeasureSpec(heightSize - verticalPadding, childHeightMode);
+
+ child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+ maxChildHeight = Math.max(maxChildHeight, child.getMeasuredHeight());
+ if (DEBUG) Log.d(TAG, "\tmeasure-child" + i + ": " + child.getMeasuredWidth() + ", "
+ + child.getMeasuredHeight());
+ }
+
+ if (heightMode == MeasureSpec.AT_MOST) {
+ heightSize = maxChildHeight + verticalPadding;
+ }
+
+ setMeasuredDimension(widthSize, heightSize);
+
+ // We can't call getChildOffset/getRelativeChildOffset until we set the measured dimensions.
+ // We also wait until we set the measured dimensions before flushing the cache as well, to
+ // ensure that the cache is filled with good values.
+ invalidateCachedOffsets();
+
+ if (childCount > 0) {
+ if (DEBUG) Log.d(TAG, "getRelativeChildOffset(): " + getMeasuredWidth() + ", "
+ + getChildWidth(0));
+
+ // Calculate the variable page spacing if necessary
+ if (mPageSpacing == AUTOMATIC_PAGE_SPACING) {
+ // The gap between pages in the PagedView should be equal to the gap from the page
+ // to the edge of the screen (so it is not visible in the current screen). To
+ // account for unequal padding on each side of the paged view, we take the maximum
+ // of the left/right gap and use that as the gap between each page.
+ int offset = getRelativeChildOffset(0);
+ int spacing = Math.max(offset, widthSize - offset -
+ getChildAt(0).getMeasuredWidth());
+ setPageSpacing(spacing);
+ }
+ }
+
+ updateScrollingIndicatorPosition();
+
+ if (childCount > 0) {
+ final int index = isLayoutRtl() ? 0 : childCount - 1;
+ mMaxScrollX = getChildOffset(index) - getRelativeChildOffset(index);
+ } else {
+ mMaxScrollX = 0;
+ }
+ }
+
+ protected void scrollToNewPageWithoutMovingPages(int newCurrentPage) {
+ int newX = getChildOffset(newCurrentPage) - getRelativeChildOffset(newCurrentPage);
+ int delta = newX - getScrollX();
+
+ final int pageCount = getChildCount();
+ for (int i = 0; i < pageCount; i++) {
+ View page = (View) getPageAt(i);
+ page.setX(page.getX() + delta);
+ }
+ setCurrentPage(newCurrentPage);
+ }
+
+ // A layout scale of 1.0f assumes that the pages, in their unshrunken state, have a
+ // scale of 1.0f. A layout scale of 0.8f assumes the pages have a scale of 0.8f, and
+ // tightens the layout accordingly
+ public void setLayoutScale(float childrenScale) {
+ mLayoutScale = childrenScale;
+ invalidateCachedOffsets();
+
+ // Now we need to do a re-layout, but preserving absolute X and Y coordinates
+ int childCount = getChildCount();
+ float childrenX[] = new float[childCount];
+ float childrenY[] = new float[childCount];
+ for (int i = 0; i < childCount; i++) {
+ final View child = getPageAt(i);
+ childrenX[i] = child.getX();
+ childrenY[i] = child.getY();
+ }
+ // Trigger a full re-layout (never just call onLayout directly!)
+ int widthSpec = MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY);
+ int heightSpec = MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY);
+ requestLayout();
+ measure(widthSpec, heightSpec);
+ layout(getLeft(), getTop(), getRight(), getBottom());
+ for (int i = 0; i < childCount; i++) {
+ final View child = getPageAt(i);
+ child.setX(childrenX[i]);
+ child.setY(childrenY[i]);
+ }
+
+ // Also, the page offset has changed (since the pages are now smaller);
+ // update the page offset, but again preserving absolute X and Y coordinates
+ scrollToNewPageWithoutMovingPages(mCurrentPage);
+ }
+
+ public void setPageSpacing(int pageSpacing) {
+ mPageSpacing = pageSpacing;
+ invalidateCachedOffsets();
+ }
+
+ @Override
+ protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+ if (!mIsDataReady) {
+ return;
+ }
+
+ if (DEBUG) Log.d(TAG, "PagedView.onLayout()");
+ final int verticalPadding = getPaddingTop() + getPaddingBottom();
+ final int childCount = getChildCount();
+ final boolean isRtl = isLayoutRtl();
+
+ final int startIndex = isRtl ? childCount - 1 : 0;
+ final int endIndex = isRtl ? -1 : childCount;
+ final int delta = isRtl ? -1 : 1;
+ int childLeft = getRelativeChildOffset(startIndex);
+ for (int i = startIndex; i != endIndex; i += delta) {
+ final View child = getPageAt(i);
+ if (child.getVisibility() != View.GONE) {
+ final int childWidth = getScaledMeasuredWidth(child);
+ final int childHeight = child.getMeasuredHeight();
+ int childTop = getPaddingTop();
+ if (mCenterPagesVertically) {
+ childTop += ((getMeasuredHeight() - verticalPadding) - childHeight) / 2;
+ }
+
+ if (DEBUG) Log.d(TAG, "\tlayout-child" + i + ": " + childLeft + ", " + childTop);
+ child.layout(childLeft, childTop,
+ childLeft + child.getMeasuredWidth(), childTop + childHeight);
+ childLeft += childWidth + mPageSpacing;
+ }
+ }
+
+ if (mFirstLayout && mCurrentPage >= 0 && mCurrentPage < getChildCount()) {
+ setHorizontalScrollBarEnabled(false);
+ updateCurrentPageScroll();
+ setHorizontalScrollBarEnabled(true);
+ mFirstLayout = false;
+ }
+ }
+
+ protected void screenScrolled(int screenCenter) {
+ if (isScrollingIndicatorEnabled()) {
+ updateScrollingIndicator();
+ }
+ 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();
+ }
+ }
+
+ @Override
+ public void onChildViewAdded(View parent, View child) {
+ // This ensures that when children are added, they get the correct transforms / alphas
+ // in accordance with any scroll effects.
+ mForceScreenScrolled = true;
+ invalidate();
+ invalidateCachedOffsets();
+ }
+
+ @Override
+ public void onChildViewRemoved(View parent, View child) {
+ }
+
+ protected void invalidateCachedOffsets() {
+ int count = getChildCount();
+ if (count == 0) {
+ mChildOffsets = null;
+ mChildRelativeOffsets = null;
+ mChildOffsetsWithLayoutScale = null;
+ return;
+ }
+
+ mChildOffsets = new int[count];
+ mChildRelativeOffsets = new int[count];
+ mChildOffsetsWithLayoutScale = new int[count];
+ for (int i = 0; i < count; i++) {
+ mChildOffsets[i] = -1;
+ mChildRelativeOffsets[i] = -1;
+ mChildOffsetsWithLayoutScale[i] = -1;
+ }
+ }
+
+ protected int getChildOffset(int index) {
+ final boolean isRtl = isLayoutRtl();
+ int[] childOffsets = Float.compare(mLayoutScale, 1f) == 0 ?
+ mChildOffsets : mChildOffsetsWithLayoutScale;
+
+ if (childOffsets != null && childOffsets[index] != -1) {
+ return childOffsets[index];
+ } else {
+ if (getChildCount() == 0)
+ return 0;
+
+ final int startIndex = isRtl ? getChildCount() - 1 : 0;
+ final int endIndex = isRtl ? index : index;
+ final int delta = isRtl ? -1 : 1;
+ int offset = getRelativeChildOffset(startIndex);
+ for (int i = startIndex; i != endIndex; i += delta) {
+ offset += getScaledMeasuredWidth(getPageAt(i)) + mPageSpacing;
+ }
+ if (childOffsets != null) {
+ childOffsets[index] = offset;
+ }
+ return offset;
+ }
+ }
+
+ protected int getRelativeChildOffset(int index) {
+ if (mChildRelativeOffsets != null && mChildRelativeOffsets[index] != -1) {
+ return mChildRelativeOffsets[index];
+ } else {
+ final int padding = getPaddingLeft() + getPaddingRight();
+ final int offset = getPaddingLeft() +
+ (getMeasuredWidth() - padding - getChildWidth(index)) / 2;
+ if (mChildRelativeOffsets != null) {
+ mChildRelativeOffsets[index] = offset;
+ }
+ return offset;
+ }
+ }
+
+ protected int getScaledMeasuredWidth(View child) {
+ // This functions are called enough times that it actually makes a difference in the
+ // profiler -- so just inline the max() here
+ final int measuredWidth = child.getMeasuredWidth();
+ final int minWidth = mMinimumWidth;
+ final int maxWidth = (minWidth > measuredWidth) ? minWidth : measuredWidth;
+ return (int) (maxWidth * mLayoutScale + 0.5f);
+ }
+
+ protected void getVisiblePages(int[] range) {
+ final boolean isRtl = isLayoutRtl();
+ final int pageCount = getChildCount();
+
+ if (pageCount > 0) {
+ final int screenWidth = getMeasuredWidth();
+ int leftScreen = isRtl ? pageCount - 1 : 0;
+ int rightScreen = 0;
+ int endIndex = isRtl ? 0 : pageCount - 1;
+ int delta = isRtl ? -1 : 1;
+ View currPage = getPageAt(leftScreen);
+ while (leftScreen != endIndex &&
+ currPage.getX() + currPage.getWidth() -
+ currPage.getPaddingRight() < getScrollX()) {
+ leftScreen += delta;
+ currPage = getPageAt(leftScreen);
+ }
+ rightScreen = leftScreen;
+ currPage = getPageAt(rightScreen + delta);
+ while (rightScreen != endIndex &&
+ currPage.getX() - currPage.getPaddingLeft() < getScrollX() + screenWidth) {
+ rightScreen += delta;
+ currPage = getPageAt(rightScreen + delta);
+ }
+ range[0] = Math.min(leftScreen, rightScreen);
+ range[1] = Math.max(leftScreen, rightScreen);
+ } else {
+ range[0] = -1;
+ range[1] = -1;
+ }
+ }
+
+ protected boolean shouldDrawChild(View child) {
+ return child.getAlpha() > 0;
+ }
+
+ @Override
+ protected void dispatchDraw(Canvas canvas) {
+ int halfScreenSize = getMeasuredWidth() / 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;
+ }
+
+ // Find out which screens are visible; as an optimization we only call draw on them
+ final int pageCount = getChildCount();
+ if (pageCount > 0) {
+ 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());
+
+ for (int i = getChildCount() - 1; i >= 0; i--) {
+ final View v = getPageAt(i);
+ if (mForceDrawAllChildrenNextFrame ||
+ (leftScreen <= i && i <= rightScreen && shouldDrawChild(v))) {
+ drawChild(canvas, v, 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 > (getMeasuredWidth() - getRelativeChildOffset(mCurrentPage) + mPageSpacing));
+ } else {
+ return (x < getRelativeChildOffset(mCurrentPage) - 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 < getRelativeChildOffset(mCurrentPage) - mPageSpacing);
+ } else {
+ return (x > (getMeasuredWidth() - getRelativeChildOffset(mCurrentPage) + mPageSpacing));
+ }
+
+ }
+
+ @Override
+ public boolean onInterceptTouchEvent(MotionEvent ev) {
+ /*
+ * 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);
+ break;
+ }
+ // 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)
+ }
+
+ case MotionEvent.ACTION_DOWN: {
+ final float x = ev.getX();
+ final float y = ev.getY();
+ // Remember location of down touch
+ mDownMotionX = x;
+ mLastMotionX = x;
+ mLastMotionY = y;
+ mLastMotionXRemainder = 0;
+ mTotalMotionX = 0;
+ mActivePointerId = ev.getPointerId(0);
+ mAllowLongPress = true;
+
+ /*
+ * 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);
+ if (finishedScrolling) {
+ mTouchState = TOUCH_STATE_REST;
+ mScroller.abortAnimation();
+ } else {
+ mTouchState = TOUCH_STATE_SCROLLING;
+ }
+
+ // check if this can be the beginning of a tap on the side of the pages
+ // to scroll the current page
+ 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:
+ mTouchState = TOUCH_STATE_REST;
+ mAllowLongPress = false;
+ mActivePointerId = INVALID_POINTER;
+ releaseVelocityTracker();
+ 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) {
+ /*
+ * Locally do absolute value. mLastMotionX is set to the y value
+ * of the down event.
+ */
+ final int pointerIndex = ev.findPointerIndex(mActivePointerId);
+ if (pointerIndex == -1) {
+ return;
+ }
+ final float x = ev.getX(pointerIndex);
+ final float y = ev.getY(pointerIndex);
+ 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 = getScrollX();
+ mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
+ pageBeginMoving();
+ }
+ // Either way, cancel any pending longpress
+ cancelCurrentPageLongPress();
+ }
+ }
+
+ 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 getScrollProgress(int screenCenter, View v, int page) {
+ final int halfScreenSize = getMeasuredWidth() / 2;
+
+ int totalDistance = getScaledMeasuredWidth(v) + mPageSpacing;
+ int delta = screenCenter - (getChildOffset(page) -
+ getRelativeChildOffset(page) + halfScreenSize);
+
+ float scrollProgress = delta / (totalDistance * 1.0f);
+ scrollProgress = Math.min(scrollProgress, 1.0f);
+ scrollProgress = Math.max(scrollProgress, -1.0f);
+ return scrollProgress;
+ }
+
+ // 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 void acceleratedOverScroll(float amount) {
+ int screenSize = getMeasuredWidth();
+
+ // 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;
+
+ // Clamp this factor, f, to -1 < f < 1
+ if (Math.abs(f) >= 1) {
+ f /= Math.abs(f);
+ }
+
+ int overScrollAmount = (int) Math.round(f * screenSize);
+ if (amount < 0) {
+ mOverScrollX = overScrollAmount;
+ super.scrollTo(0, getScrollY());
+ } else {
+ mOverScrollX = mMaxScrollX + overScrollAmount;
+ super.scrollTo(mMaxScrollX, getScrollY());
+ }
+ invalidate();
+ }
+
+ protected void dampedOverScroll(float amount) {
+ int screenSize = getMeasuredWidth();
+
+ 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(0, getScrollY());
+ } else {
+ mOverScrollX = mMaxScrollX + overScrollAmount;
+ super.scrollTo(mMaxScrollX, 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;
+ }
+
+ @Override
+ public boolean onTouchEvent(MotionEvent 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()) {
+ mScroller.abortAnimation();
+ }
+
+ // Remember where the motion event started
+ mDownMotionX = mLastMotionX = ev.getX();
+ mLastMotionXRemainder = 0;
+ mTotalMotionX = 0;
+ mActivePointerId = ev.getPointerId(0);
+ if (mTouchState == TOUCH_STATE_SCROLLING) {
+ pageBeginMoving();
+ }
+ break;
+
+ case MotionEvent.ACTION_MOVE:
+ if (mTouchState == TOUCH_STATE_SCROLLING) {
+ // Scroll to follow the motion event
+ final int pointerIndex = ev.findPointerIndex(mActivePointerId);
+ 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 {
+ 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 = getScaledMeasuredWidth(getPageAt(mCurrentPage));
+ 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;
+
+ // 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 (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 {
+ onUnhandledTap(ev);
+ }
+ mTouchState = TOUCH_STATE_REST;
+ mActivePointerId = INVALID_POINTER;
+ releaseVelocityTracker();
+ break;
+
+ case MotionEvent.ACTION_CANCEL:
+ if (mTouchState == TOUCH_STATE_SCROLLING) {
+ snapToDestination();
+ }
+ mTouchState = TOUCH_STATE_REST;
+ mActivePointerId = INVALID_POINTER;
+ releaseVelocityTracker();
+ break;
+
+ case MotionEvent.ACTION_POINTER_UP:
+ onSecondaryPointerUp(ev);
+ break;
+ }
+
+ return true;
+ }
+
+ @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.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();
+ }
+ }
+ }
+
+ protected void onUnhandledTap(MotionEvent ev) {}
+
+ @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 getChildIndexForRelativeOffset(int relativeOffset) {
+ final boolean isRtl = isLayoutRtl();
+ final int childCount = getChildCount();
+ int left;
+ int right;
+ final int startIndex = isRtl ? childCount - 1 : 0;
+ final int endIndex = isRtl ? -1 : childCount;
+ final int delta = isRtl ? -1 : 1;
+ for (int i = startIndex; i != endIndex; i += delta) {
+ left = getRelativeChildOffset(i);
+ right = (left + getScaledMeasuredWidth(getPageAt(i)));
+ if (left <= relativeOffset && relativeOffset <= right) {
+ return i;
+ }
+ }
+ return -1;
+ }
+
+ protected int getChildWidth(int index) {
+ // This functions are called enough times that it actually makes a difference in the
+ // profiler -- so just inline the max() here
+ final int measuredWidth = getPageAt(index).getMeasuredWidth();
+ final int minWidth = mMinimumWidth;
+ return (minWidth > measuredWidth) ? minWidth : measuredWidth;
+ }
+
+ int getPageNearestToCenterOfScreen() {
+ int minDistanceFromScreenCenter = Integer.MAX_VALUE;
+ int minDistanceFromScreenCenterIndex = -1;
+ int screenCenter = getScrollX() + (getMeasuredWidth() / 2);
+ final int childCount = getChildCount();
+ for (int i = 0; i < childCount; ++i) {
+ View layout = (View) getPageAt(i);
+ int childWidth = getScaledMeasuredWidth(layout);
+ int halfChildWidth = (childWidth / 2);
+ int childCenter = getChildOffset(i) + halfChildWidth;
+ int distanceFromScreenCenter = Math.abs(childCenter - screenCenter);
+ if (distanceFromScreenCenter < minDistanceFromScreenCenter) {
+ minDistanceFromScreenCenter = distanceFromScreenCenter;
+ minDistanceFromScreenCenterIndex = i;
+ }
+ }
+ return minDistanceFromScreenCenterIndex;
+ }
+
+ protected void snapToDestination() {
+ snapToPage(getPageNearestToCenterOfScreen(), PAGE_SNAP_ANIMATION_DURATION);
+ }
+
+ 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 = Math.max(0, Math.min(whichPage, getChildCount() - 1));
+ int halfScreenSize = getMeasuredWidth() / 2;
+
+ if (DEBUG) Log.d(TAG, "snapToPage.getChildOffset(): " + getChildOffset(whichPage));
+ if (DEBUG) Log.d(TAG, "snapToPageWithVelocity.getRelativeChildOffset(): "
+ + getMeasuredWidth() + ", " + getChildWidth(whichPage));
+ final int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
+ int delta = newX - mUnboundedScrollX;
+ int duration = 0;
+
+ if (Math.abs(velocity) < mMinFlingVelocity) {
+ // 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, PAGE_SNAP_ANIMATION_DURATION);
+ 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));
+ duration = Math.min(duration, MAX_PAGE_SNAP_DURATION);
+
+ snapToPage(whichPage, delta, duration);
+ }
+
+ protected void snapToPage(int whichPage) {
+ snapToPage(whichPage, PAGE_SNAP_ANIMATION_DURATION);
+ }
+
+ protected void snapToPage(int whichPage, int duration) {
+ whichPage = Math.max(0, Math.min(whichPage, getPageCount() - 1));
+
+ if (DEBUG) Log.d(TAG, "snapToPage.getChildOffset(): " + getChildOffset(whichPage));
+ if (DEBUG) Log.d(TAG, "snapToPage.getRelativeChildOffset(): " + getMeasuredWidth() + ", "
+ + getChildWidth(whichPage));
+ int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
+ final int sX = mUnboundedScrollX;
+ final int delta = newX - sX;
+ snapToPage(whichPage, delta, duration);
+ }
+
+ protected void snapToPage(int whichPage, int delta, int duration) {
+ mNextPage = whichPage;
+
+ View focusedChild = getFocusedChild();
+ if (focusedChild != null && whichPage != mCurrentPage &&
+ focusedChild == getPageAt(mCurrentPage)) {
+ focusedChild.clearFocus();
+ }
+
+ pageBeginMoving();
+ awakenScrollBars(duration);
+ if (duration == 0) {
+ duration = Math.abs(delta);
+ }
+
+ if (!mScroller.isFinished()) mScroller.abortAnimation();
+ mScroller.startScroll(mUnboundedScrollX, 0, delta, 0, duration);
+
+ // Load associated pages immediately if someone else is handling the scroll, otherwise defer
+ // loading associated pages until the scroll settles
+ if (mDeferScrollUpdate) {
+ loadAssociatedPages(mNextPage);
+ } else {
+ mDeferLoadAssociatedPagesUntilScrollCompletes = true;
+ }
+ notifyPageSwitchListener();
+ invalidate();
+ }
+
+ public void scrollLeft() {
+ if (mScroller.isFinished()) {
+ if (mCurrentPage > 0) snapToPage(mCurrentPage - 1);
+ } else {
+ if (mNextPage > 0) snapToPage(mNextPage - 1);
+ }
+ }
+
+ public void scrollRight() {
+ if (mScroller.isFinished()) {
+ if (mCurrentPage < getChildCount() -1) snapToPage(mCurrentPage + 1);
+ } else {
+ if (mNextPage < getChildCount() -1) snapToPage(mNextPage + 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;
+ }
+
+ /**
+ * 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
+ mScroller.forceFinished(true);
+ mNextPage = INVALID_PAGE;
+
+ // 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();
+ }
+ }
+
+ protected View getScrollingIndicator() {
+ // We use mHasScrollIndicator to prevent future lookups if there is no sibling indicator
+ // found
+ if (mHasScrollIndicator && mScrollIndicator == null) {
+ ViewGroup parent = (ViewGroup) getParent();
+ if (parent != null) {
+ mScrollIndicator = (View) (parent.findViewById(R.id.paged_view_indicator));
+ mHasScrollIndicator = mScrollIndicator != null;
+ if (mHasScrollIndicator) {
+ mScrollIndicator.setVisibility(View.VISIBLE);
+ }
+ }
+ }
+ return mScrollIndicator;
+ }
+
+ protected boolean isScrollingIndicatorEnabled() {
+ return true;
+ }
+
+ Runnable hideScrollingIndicatorRunnable = new Runnable() {
+ @Override
+ public void run() {
+ hideScrollingIndicator(false);
+ }
+ };
+ protected void flashScrollingIndicator(boolean animated) {
+ removeCallbacks(hideScrollingIndicatorRunnable);
+ showScrollingIndicator(!animated);
+ postDelayed(hideScrollingIndicatorRunnable, sScrollIndicatorFlashDuration);
+ }
+
+ protected void showScrollingIndicator(boolean immediately) {
+ mShouldShowScrollIndicator = true;
+ mShouldShowScrollIndicatorImmediately = true;
+ if (getChildCount() <= 1) return;
+ if (!isScrollingIndicatorEnabled()) return;
+
+ mShouldShowScrollIndicator = false;
+ getScrollingIndicator();
+ if (mScrollIndicator != null) {
+ // Fade the indicator in
+ updateScrollingIndicatorPosition();
+ mScrollIndicator.setVisibility(View.VISIBLE);
+ cancelScrollingIndicatorAnimations();
+ if (immediately || mScrollingPaused) {
+ mScrollIndicator.setAlpha(1f);
+ } else {
+ mScrollIndicatorAnimator = LauncherAnimUtils.ofFloat(mScrollIndicator, "alpha", 1f);
+ mScrollIndicatorAnimator.setDuration(sScrollIndicatorFadeInDuration);
+ mScrollIndicatorAnimator.start();
+ }
+ }
+ }
+
+ protected void cancelScrollingIndicatorAnimations() {
+ if (mScrollIndicatorAnimator != null) {
+ mScrollIndicatorAnimator.cancel();
+ }
+ }
+
+ protected void hideScrollingIndicator(boolean immediately) {
+ if (getChildCount() <= 1) return;
+ if (!isScrollingIndicatorEnabled()) return;
+
+ getScrollingIndicator();
+ if (mScrollIndicator != null) {
+ // Fade the indicator out
+ updateScrollingIndicatorPosition();
+ cancelScrollingIndicatorAnimations();
+ if (immediately || mScrollingPaused) {
+ mScrollIndicator.setVisibility(View.INVISIBLE);
+ mScrollIndicator.setAlpha(0f);
+ } else {
+ mScrollIndicatorAnimator = LauncherAnimUtils.ofFloat(mScrollIndicator, "alpha", 0f);
+ mScrollIndicatorAnimator.setDuration(sScrollIndicatorFadeOutDuration);
+ mScrollIndicatorAnimator.addListener(new AnimatorListenerAdapter() {
+ private boolean cancelled = false;
+ @Override
+ public void onAnimationCancel(android.animation.Animator animation) {
+ cancelled = true;
+ }
+ @Override
+ public void onAnimationEnd(Animator animation) {
+ if (!cancelled) {
+ mScrollIndicator.setVisibility(View.INVISIBLE);
+ }
+ }
+ });
+ mScrollIndicatorAnimator.start();
+ }
+ }
+ }
+
+ /**
+ * To be overridden by subclasses to determine whether the scroll indicator should stretch to
+ * fill its space on the track or not.
+ */
+ protected boolean hasElasticScrollIndicator() {
+ return true;
+ }
+
+ private void updateScrollingIndicator() {
+ if (getChildCount() <= 1) return;
+ if (!isScrollingIndicatorEnabled()) return;
+
+ getScrollingIndicator();
+ if (mScrollIndicator != null) {
+ updateScrollingIndicatorPosition();
+ }
+ if (mShouldShowScrollIndicator) {
+ showScrollingIndicator(mShouldShowScrollIndicatorImmediately);
+ }
+ }
+
+ private void updateScrollingIndicatorPosition() {
+ final boolean isRtl = isLayoutRtl();
+ if (!isScrollingIndicatorEnabled()) return;
+ if (mScrollIndicator == null) return;
+ int numPages = getChildCount();
+ int pageWidth = getMeasuredWidth();
+ int trackWidth = pageWidth - mScrollIndicatorPaddingLeft - mScrollIndicatorPaddingRight;
+ int indicatorWidth = mScrollIndicator.getMeasuredWidth() -
+ mScrollIndicator.getPaddingLeft() - mScrollIndicator.getPaddingRight();
+
+ float scrollPos = isRtl ? mMaxScrollX - getScrollX() : getScrollX();
+ float offset = Math.max(0f, Math.min(1f, (float) scrollPos / mMaxScrollX));
+ if (isRtl) {
+ offset = 1f - offset;
+ }
+ int indicatorSpace = trackWidth / numPages;
+ int indicatorPos = (int) (offset * (trackWidth - indicatorSpace)) + mScrollIndicatorPaddingLeft;
+ if (hasElasticScrollIndicator()) {
+ if (mScrollIndicator.getMeasuredWidth() != indicatorSpace) {
+ mScrollIndicator.getLayoutParams().width = indicatorSpace;
+ mScrollIndicator.requestLayout();
+ }
+ } else {
+ int indicatorCenterOffset = indicatorSpace / 2 - indicatorWidth / 2;
+ indicatorPos += indicatorCenterOffset;
+ }
+ mScrollIndicator.setTranslationX(indicatorPos);
+ }
+
+ public void showScrollIndicatorTrack() {
+ }
+
+ public void hideScrollIndicatorTrack() {
+ }
+
+ /* 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 onInitializeAccessibilityEvent(AccessibilityEvent event) {
+ super.onInitializeAccessibilityEvent(event);
+ event.setScrollable(true);
+ if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED) {
+ event.setFromIndex(mCurrentPage);
+ event.setToIndex(mCurrentPage);
+ event.setItemCount(getChildCount());
+ }
+ }
+
+ @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;
+ }
+}