Merge branch 'master' of ssh://android-git:29418/platform/packages/apps/Launcher2

1 files changed, 1272 insertions, 0 deletions

diff --git a/src/com/android/launcher2/PagedView.java b/src/com/android/launcher2/PagedView.java
new file mode 100644
index 000000000..e9829fbfa
--- /dev/null
+++ b/src/com/android/launcher2/PagedView.java
@@ -0,0 +1,1272 @@
+/*
+ * 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.launcher2;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.ActionMode;
+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.animation.Animation;
+import android.view.animation.Animation.AnimationListener;
+import android.view.animation.AnimationUtils;
+import android.widget.Checkable;
+import android.widget.LinearLayout;
+import android.widget.Scroller;
+
+import com.android.launcher.R;
+
+/**
+ * An abstraction of the original Workspace which supports browsing through a
+ * sequential list of "pages"
+ */
+public abstract class PagedView extends ViewGroup {
+    private static final String TAG = "PagedView";
+    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;
+    // The min drag distance to trigger a page shift (regardless of velocity)
+    private static final int MIN_LENGTH_FOR_MOVE = 200;
+
+    private static final int PAGE_SNAP_ANIMATION_DURATION = 1000;
+    protected static final float NANOTIME_DIV = 1000000000.0f;
+
+    // the velocity at which a fling gesture will cause us to snap to the next page
+    protected int mSnapVelocity = 500;
+
+    protected float mSmoothingTime;
+    protected float mTouchX;
+
+    protected boolean mFirstLayout = true;
+
+    protected int mCurrentPage;
+    protected int mNextPage = INVALID_PAGE;
+    protected Scroller mScroller;
+    private VelocityTracker mVelocityTracker;
+
+    private float mDownMotionX;
+    private float mLastMotionX;
+    private float mLastMotionY;
+    private int mLastScreenCenter = -1;
+
+    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 OnLongClickListener mLongClickListener;
+
+    private boolean mAllowLongPress = true;
+
+    private int mTouchSlop;
+    private int mPagingTouchSlop;
+    private int mMaximumVelocity;
+    protected int mPageSpacing;
+    protected int mPageLayoutPaddingTop;
+    protected int mPageLayoutPaddingBottom;
+    protected int mPageLayoutPaddingLeft;
+    protected int mPageLayoutPaddingRight;
+    protected int mPageLayoutWidthGap;
+    protected int mPageLayoutHeightGap;
+    protected int mCellCountX;
+    protected int mCellCountY;
+    protected boolean mCenterPagesVertically;
+
+    protected static final int INVALID_POINTER = -1;
+
+    protected int mActivePointerId = INVALID_POINTER;
+
+    private PageSwitchListener mPageSwitchListener;
+
+    private ArrayList<Boolean> mDirtyPageContent;
+    private boolean mDirtyPageAlpha;
+
+    // choice modes
+    protected static final int CHOICE_MODE_NONE = 0;
+    protected static final int CHOICE_MODE_SINGLE = 1;
+    // Multiple selection mode is not supported by all Launcher actions atm
+    protected static final int CHOICE_MODE_MULTIPLE = 2;
+
+    protected int mChoiceMode;
+    private ActionMode mActionMode;
+
+    protected PagedViewIconCache mPageViewIconCache;
+
+    // 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 mScrollX itself in its computeScroll method
+    // (SmoothPagedView does this)
+    protected boolean mDeferScrollUpdate = false;
+
+    protected boolean mIsPageMoving = false;
+
+    /**
+     * Simple cache mechanism for PagedViewIcon outlines.
+     */
+    class PagedViewIconCache {
+        private final HashMap<Object, Bitmap> iconOutlineCache = new HashMap<Object, Bitmap>();
+
+        public void clear() {
+            iconOutlineCache.clear();
+        }
+        public void addOutline(Object key, Bitmap b) {
+            iconOutlineCache.put(key, b);
+        }
+        public void removeOutline(Object key) {
+            if (iconOutlineCache.containsKey(key)) {
+                iconOutlineCache.remove(key);
+            }
+        }
+        public Bitmap getOutline(Object key) {
+            return iconOutlineCache.get(key);
+        }
+    }
+
+    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);
+        mChoiceMode = CHOICE_MODE_NONE;
+
+        TypedArray a = context.obtainStyledAttributes(attrs,
+                R.styleable.PagedView, defStyle, 0);
+        mPageSpacing = a.getDimensionPixelSize(R.styleable.PagedView_pageSpacing, 0);
+        mPageLayoutPaddingTop = a.getDimensionPixelSize(
+                R.styleable.PagedView_pageLayoutPaddingTop, 10);
+        mPageLayoutPaddingBottom = a.getDimensionPixelSize(
+                R.styleable.PagedView_pageLayoutPaddingBottom, 10);
+        mPageLayoutPaddingLeft = a.getDimensionPixelSize(
+                R.styleable.PagedView_pageLayoutPaddingLeft, 10);
+        mPageLayoutPaddingRight = a.getDimensionPixelSize(
+                R.styleable.PagedView_pageLayoutPaddingRight, 10);
+        mPageLayoutWidthGap = a.getDimensionPixelSize(
+                R.styleable.PagedView_pageLayoutWidthGap, -1);
+        mPageLayoutHeightGap = a.getDimensionPixelSize(
+                R.styleable.PagedView_pageLayoutHeightGap, -1);
+        a.recycle();
+
+        setHapticFeedbackEnabled(false);
+        init();
+    }
+
+    /**
+     * Initializes various states for this workspace.
+     */
+    protected void init() {
+        mDirtyPageContent = new ArrayList<Boolean>();
+        mDirtyPageContent.ensureCapacity(32);
+        mPageViewIconCache = new PagedViewIconCache();
+        mScroller = new Scroller(getContext());
+        mCurrentPage = 0;
+        mCenterPagesVertically = true;
+
+        final ViewConfiguration configuration = ViewConfiguration.get(getContext());
+        mTouchSlop = configuration.getScaledTouchSlop();
+        mPagingTouchSlop = configuration.getScaledPagingTouchSlop();
+        mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
+    }
+
+    public void setPageSwitchListener(PageSwitchListener pageSwitchListener) {
+        mPageSwitchListener = pageSwitchListener;
+        if (mPageSwitchListener != null) {
+            mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
+        }
+    }
+
+    /**
+     * Returns the index of the currently displayed page.
+     *
+     * @return The index of the currently displayed page.
+     */
+    int getCurrentPage() {
+        return mCurrentPage;
+    }
+
+    int getPageCount() {
+        return getChildCount();
+    }
+
+    View getPageAt(int index) {
+        return getChildAt(index);
+    }
+
+    int getScrollWidth() {
+        return getWidth();
+    }
+
+    /**
+     * Sets the current page.
+     */
+    void setCurrentPage(int currentPage) {
+        if (!mScroller.isFinished()) mScroller.abortAnimation();
+        if (getChildCount() == 0) return;
+
+        mCurrentPage = Math.max(0, Math.min(currentPage, getPageCount() - 1));
+        int newX = getChildOffset(mCurrentPage) - getRelativeChildOffset(mCurrentPage);
+        scrollTo(newX, 0);
+        mScroller.setFinalX(newX);
+
+        invalidate();
+        notifyPageSwitchListener();
+    }
+
+    protected void notifyPageSwitchListener() {
+        if (mPageSwitchListener != null) {
+            mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
+        }
+    }
+
+    private void pageBeginMoving() {
+        mIsPageMoving = true;
+        onPageBeginMoving();
+    }
+
+    private void pageEndMoving() {
+        onPageEndMoving();
+        mIsPageMoving = false;
+    }
+
+    // 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 scrollTo(int x, int y) {
+        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()) {
+            mDirtyPageAlpha = true;
+            scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
+            invalidate();
+            return true;
+        } else if (mNextPage != INVALID_PAGE) {
+            mDirtyPageAlpha = true;
+            mCurrentPage = Math.max(0, Math.min(mNextPage, getPageCount() - 1));
+            mNextPage = INVALID_PAGE;
+            notifyPageSwitchListener();
+            pageEndMoving();
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public void computeScroll() {
+        computeScrollHelper();
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
+        final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
+        if (widthMode != MeasureSpec.EXACTLY) {
+            throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
+        }
+
+        final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
+        final int heightSize = MeasureSpec.getSize(heightMeasureSpec);
+        if (heightMode != MeasureSpec.EXACTLY) {
+            throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
+        }
+
+        // The children are given the same width and height as the workspace
+        // unless they were set to WRAP_CONTENT
+        final int childCount = getChildCount();
+        for (int i = 0; i < childCount; i++) {
+            // disallowing padding in paged view (just pass 0)
+            final View child = getChildAt(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, childWidthMode);
+            final int childHeightMeasureSpec =
+                MeasureSpec.makeMeasureSpec(heightSize, childHeightMode);
+
+            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
+        }
+
+        setMeasuredDimension(widthSize, heightSize);
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        if (mFirstLayout && mCurrentPage >= 0 && mCurrentPage < getChildCount()) {
+            setHorizontalScrollBarEnabled(false);
+            int newX = getChildOffset(mCurrentPage) - getRelativeChildOffset(mCurrentPage);
+            scrollTo(newX, 0);
+            mScroller.setFinalX(newX);
+            setHorizontalScrollBarEnabled(true);
+            mFirstLayout = false;
+        }
+
+        final int childCount = getChildCount();
+        int childLeft = 0;
+        if (childCount > 0) {
+            childLeft = getRelativeChildOffset(0);
+        }
+
+        for (int i = 0; i < childCount; i++) {
+            final View child = getChildAt(i);
+            if (child.getVisibility() != View.GONE) {
+                final int childWidth = child.getMeasuredWidth();
+                final int childHeight = (mCenterPagesVertically ?
+                        (getMeasuredHeight() - child.getMeasuredHeight()) / 2 : 0);
+                child.layout(childLeft, childHeight,
+                        childLeft + childWidth, childHeight + child.getMeasuredHeight());
+                childLeft += childWidth + mPageSpacing;
+            }
+        }
+    }
+
+    protected void updateAdjacentPagesAlpha() {
+        if (mFadeInAdjacentScreens) {
+            if (mDirtyPageAlpha || (mTouchState == TOUCH_STATE_SCROLLING) || !mScroller.isFinished()) {
+                int halfScreenSize = getMeasuredWidth() / 2;
+                int screenCenter = mScrollX + halfScreenSize;
+                final int childCount = getChildCount();
+                for (int i = 0; i < childCount; ++i) {
+                    View layout = (View) getChildAt(i);
+                    int childWidth = layout.getMeasuredWidth();
+                    int halfChildWidth = (childWidth / 2);
+                    int childCenter = getChildOffset(i) + halfChildWidth;
+
+                    // On the first layout, we may not have a width nor a proper offset, so for now
+                    // we should just assume full page width (and calculate the offset according to
+                    // that).
+                    if (childWidth <= 0) {
+                        childWidth = getMeasuredWidth();
+                        childCenter = (i * childWidth) + (childWidth / 2);
+                    }
+
+                    int d = halfChildWidth;
+                    int distanceFromScreenCenter = childCenter - screenCenter;
+                    if (distanceFromScreenCenter > 0) {
+                        if (i > 0) {
+                            d += getChildAt(i - 1).getMeasuredWidth() / 2;
+                        }
+                    } else {
+                        if (i < childCount - 1) {
+                            d += getChildAt(i + 1).getMeasuredWidth() / 2;
+                        }
+                    }
+                    d += mPageSpacing;
+
+                    // Preventing potential divide-by-zero
+                    d = Math.max(1, d);
+
+                    float dimAlpha = (float) (Math.abs(distanceFromScreenCenter)) / d;
+                    dimAlpha = Math.max(0.0f, Math.min(1.0f, (dimAlpha * dimAlpha)));
+                    float alpha = 1.0f - dimAlpha;
+
+                    if (alpha < ALPHA_QUANTIZE_LEVEL) {
+                        alpha = 0.0f;
+                    } else if (alpha > 1.0f - ALPHA_QUANTIZE_LEVEL) {
+                        alpha = 1.0f;
+                    }
+
+                    if (Float.compare(alpha, layout.getAlpha()) != 0) {
+                        layout.setAlpha(alpha);
+                    }
+                }
+                mDirtyPageAlpha = false;
+            }
+        }
+    }
+
+    protected void screenScrolled(int screenCenter) {
+    }
+
+    @Override
+    protected void dispatchDraw(Canvas canvas) {
+        int halfScreenSize = getMeasuredWidth() / 2;
+        int screenCenter = mScrollX + halfScreenSize;
+
+        if (screenCenter != mLastScreenCenter) {
+            screenScrolled(screenCenter);
+            updateAdjacentPagesAlpha();
+            mLastScreenCenter = screenCenter;
+        }
+
+        // Find out which screens are visible; as an optimization we only call draw on them
+        // As an optimization, this code assumes that all pages have the same width as the 0th
+        // page.
+        final int pageCount = getChildCount();
+        if (pageCount > 0) {
+            final int pageWidth = getChildAt(0).getMeasuredWidth();
+            final int screenWidth = getMeasuredWidth();
+            int x = getRelativeChildOffset(0) + pageWidth;
+            int leftScreen = 0;
+            int rightScreen = 0;
+            while (x <= mScrollX) {
+                leftScreen++;
+                x += pageWidth + mPageSpacing;
+                // replace above line with this if you don't assume all pages have same width as 0th
+                // page:
+                // x += getChildAt(leftScreen).getMeasuredWidth();
+            }
+            rightScreen = leftScreen;
+            while (x < mScrollX + screenWidth) {
+                rightScreen++;
+                x += pageWidth + mPageSpacing;
+                // replace above line with this if you don't assume all pages have same width as 0th
+                // page:
+                //if (rightScreen < pageCount) {
+                //    x += getChildAt(rightScreen).getMeasuredWidth();
+                //}
+            }
+            rightScreen = Math.min(getChildCount() - 1, rightScreen);
+
+            final long drawingTime = getDrawingTime();
+            for (int i = leftScreen; i <= rightScreen; i++) {
+                drawChild(canvas, getChildAt(i), drawingTime);
+            }
+        }
+    }
+
+    @Override
+    public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
+        int page = 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) {
+            v.requestFocus(direction, previouslyFocusedRect);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean dispatchUnhandledMove(View focused, int direction) {
+        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) {
+        if (mCurrentPage >= 0 && mCurrentPage < getPageCount()) {
+            getPageAt(mCurrentPage).addFocusables(views, direction);
+        }
+        if (direction == View.FOCUS_LEFT) {
+            if (mCurrentPage > 0) {
+                getPageAt(mCurrentPage - 1).addFocusables(views, direction);
+            }
+        } else if (direction == View.FOCUS_RIGHT){
+            if (mCurrentPage < getPageCount() - 1) {
+                getPageAt(mCurrentPage + 1).addFocusables(views, direction);
+            }
+        }
+    }
+
+    /**
+     * 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 = getChildAt(mCurrentPage);
+            currentPage.cancelLongPress();
+        }
+        super.requestDisallowInterceptTouchEvent(disallowIntercept);
+    }
+
+    @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.
+         */
+
+        /*
+         * 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;
+                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) && !handlePagingClicks() &&
+                        (mTouchState != TOUCH_STATE_NEXT_PAGE)) {
+                    if (getChildCount() > 0) {
+                        int width = getMeasuredWidth();
+                        int offset = getRelativeChildOffset(mCurrentPage);
+                        if (x < offset - mPageSpacing) {
+                            mTouchState = TOUCH_STATE_PREV_PAGE;
+                        } else if (x > (width - offset + mPageSpacing)) {
+                            mTouchState = TOUCH_STATE_NEXT_PAGE;
+                        }
+                    }
+                }
+                break;
+            }
+
+            case MotionEvent.ACTION_CANCEL:
+            case MotionEvent.ACTION_UP:
+                mTouchState = TOUCH_STATE_REST;
+                mAllowLongPress = false;
+                mActivePointerId = INVALID_POINTER;
+                break;
+
+            case MotionEvent.ACTION_POINTER_UP:
+                onSecondaryPointerUp(ev);
+                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 animateClickFeedback(View v, final Runnable r) {
+        // animate the view slightly to show click feedback running some logic after it is "pressed"
+        Animation anim = AnimationUtils.loadAnimation(getContext(), 
+                R.anim.paged_view_click_feedback);
+        anim.setAnimationListener(new AnimationListener() {
+            @Override
+            public void onAnimationStart(Animation animation) {}
+            @Override
+            public void onAnimationRepeat(Animation animation) {
+                r.run();
+            }
+            @Override
+            public void onAnimationEnd(Animation animation) {}
+        });
+        v.startAnimation(anim);
+    }
+
+    /*
+     * 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) {
+        /*
+         * Locally do absolute value. mLastMotionX is set to the y value
+         * of the down event.
+         */
+        final int pointerIndex = ev.findPointerIndex(mActivePointerId);
+        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 = mTouchSlop;
+        boolean xPaged = xDiff > mPagingTouchSlop;
+        boolean xMoved = xDiff > touchSlop;
+        boolean yMoved = yDiff > touchSlop;
+
+        if (xMoved || yMoved) {
+            if (mUsePagingTouchSlop ? xPaged : xMoved) {
+                // Scroll if the user moved far enough along the X axis
+                mTouchState = TOUCH_STATE_SCROLLING;
+                mLastMotionX = x;
+                mTouchX = mScrollX;
+                mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
+                pageBeginMoving();
+            }
+            // Either way, cancel any pending longpress
+            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 boolean handlePagingClicks() {
+        return false;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent 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();
+            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 int deltaX = (int) (mLastMotionX - x);
+                mLastMotionX = x;
+
+                int sx = getScrollX();
+                if (deltaX < 0) {
+                    if (sx > 0) {
+                        mTouchX += Math.max(-mTouchX, deltaX);
+                        mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
+                        if (!mDeferScrollUpdate) {
+                            scrollBy(Math.max(-sx, deltaX), 0);
+                        } else {
+                            // This will trigger a call to computeScroll() on next drawChild() call
+                            invalidate();
+                        }
+                    }
+                } else if (deltaX > 0) {
+                    final int lastChildIndex = getChildCount() - 1;
+                    final int availableToScroll = getChildOffset(lastChildIndex) -
+                        getRelativeChildOffset(lastChildIndex) - sx;
+                    if (availableToScroll > 0) {
+                        mTouchX += Math.min(availableToScroll, deltaX);
+                        mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
+                        if (!mDeferScrollUpdate) {
+                            scrollBy(Math.min(availableToScroll, deltaX), 0);
+                        } else {
+                            // This will trigger a call to computeScroll() on next drawChild() call
+                            invalidate();
+                        }
+                    }
+                } 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);
+                boolean isfling = Math.abs(deltaX) > MIN_LENGTH_FOR_FLING;
+                boolean isSignificantMove = Math.abs(deltaX) > MIN_LENGTH_FOR_MOVE;
+
+                final int snapVelocity = mSnapVelocity;
+                if ((isSignificantMove && deltaX > 0 ||
+                        (isfling && velocityX > snapVelocity)) &&
+                        mCurrentPage > 0) {
+                    snapToPageWithVelocity(mCurrentPage - 1, velocityX);
+                } else if ((isSignificantMove && deltaX < 0 ||
+                        (isfling && velocityX < -snapVelocity)) &&
+                        mCurrentPage < getChildCount() - 1) {
+                    snapToPageWithVelocity(mCurrentPage + 1, velocityX);
+                } else {
+                    snapToDestination();
+                }
+            } else if (mTouchState == TOUCH_STATE_PREV_PAGE && !handlePagingClicks()) {
+                // 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 && !handlePagingClicks()) {
+                // 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();
+                }
+            }
+            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;
+    }
+
+    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);
+            mActivePointerId = ev.getPointerId(newPointerIndex);
+            if (mVelocityTracker != null) {
+                mVelocityTracker.clear();
+            }
+        }
+    }
+
+    @Override
+    public void requestChildFocus(View child, View focused) {
+        super.requestChildFocus(child, focused);
+        int page = indexOfChild(child);
+        if (page >= 0 && !isInTouchMode()) {
+            snapToPage(page);
+        }
+    }
+
+    protected int getChildIndexForRelativeOffset(int relativeOffset) {
+        final int childCount = getChildCount();
+        int left;
+        int right;
+        for (int i = 0; i < childCount; ++i) {
+            left = getRelativeChildOffset(i);
+            right = (left + getChildAt(i).getMeasuredWidth());
+            if (left <= relativeOffset && relativeOffset <= right) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    protected int getRelativeChildOffset(int index) {
+        return (getMeasuredWidth() - getChildAt(index).getMeasuredWidth()) / 2;
+    }
+
+    protected int getChildOffset(int index) {
+        if (getChildCount() == 0)
+            return 0;
+
+        int offset = getRelativeChildOffset(0);
+        for (int i = 0; i < index; ++i) {
+            offset += getChildAt(i).getMeasuredWidth() + mPageSpacing;
+        }
+        return offset;
+    }
+
+    int getPageNearestToCenterOfScreen() {
+        int minDistanceFromScreenCenter = getMeasuredWidth();
+        int minDistanceFromScreenCenterIndex = -1;
+        int screenCenter = mScrollX + (getMeasuredWidth() / 2);
+        final int childCount = getChildCount();
+        for (int i = 0; i < childCount; ++i) {
+            View layout = (View) getChildAt(i);
+            int childWidth = layout.getMeasuredWidth();
+            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);
+    }
+
+    protected void snapToPageWithVelocity(int whichPage, int velocity) {
+        // We ignore velocity in this implementation, but children (e.g. SmoothPagedView)
+        // can use it
+        snapToPage(whichPage);
+    }
+
+    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));
+
+        int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
+        final int sX = getScrollX();
+        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 == getChildAt(mCurrentPage)) {
+            focusedChild.clearFocus();
+        }
+
+        pageBeginMoving();
+        awakenScrollBars(duration);
+        if (duration == 0) {
+            duration = Math.abs(delta);
+        }
+
+        if (!mScroller.isFinished()) mScroller.abortAnimation();
+        mScroller.startScroll(getScrollX(), 0, delta, 0, duration);
+
+        // only load some associated pages
+        loadAssociatedPages(mNextPage);
+        notifyPageSwitchListener();
+        invalidate();
+    }
+
+    @Override
+    protected Parcelable onSaveInstanceState() {
+        final SavedState state = new SavedState(super.onSaveInstanceState());
+        state.currentPage = mCurrentPage;
+        return state;
+    }
+
+    @Override
+    protected void onRestoreInstanceState(Parcelable state) {
+        SavedState savedState = (SavedState) state;
+        super.onRestoreInstanceState(savedState.getSuperState());
+        if (savedState.currentPage != -1) {
+            mCurrentPage = savedState.currentPage;
+        }
+    }
+
+    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 == getChildAt(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];
+            }
+        };
+    }
+
+    public void loadAssociatedPages(int page) {
+        if (mContentIsRefreshable) {
+            final int count = getChildCount();
+            if (page < count) {
+                int lowerPageBound = getAssociatedLowerPageBound(page);
+                int upperPageBound = getAssociatedUpperPageBound(page);
+                for (int i = 0; i < count; ++i) {
+                    final ViewGroup layout = (ViewGroup) getChildAt(i);
+                    final int childCount = layout.getChildCount();
+                    if (lowerPageBound <= i && i <= upperPageBound) {
+                        if (mDirtyPageContent.get(i)) {
+                            syncPageItems(i);
+                            mDirtyPageContent.set(i, false);
+                        }
+                    } else {
+                        if (childCount > 0) {
+                            layout.removeAllViews();
+                        }
+                        mDirtyPageContent.set(i, true);
+                    }
+                }
+            }
+        }
+    }
+
+    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);
+    }
+
+    protected void startChoiceMode(int mode, ActionMode.Callback callback) {
+        if (isChoiceMode(CHOICE_MODE_NONE)) {
+            mChoiceMode = mode;
+            mActionMode = startActionMode(callback);
+        }
+    }
+
+    public void endChoiceMode() {
+        if (!isChoiceMode(CHOICE_MODE_NONE)) {
+            mChoiceMode = CHOICE_MODE_NONE;
+            resetCheckedGrandchildren();
+            if (mActionMode != null) mActionMode.finish();
+            mActionMode = null;
+        }
+    }
+
+    protected boolean isChoiceMode(int mode) {
+        return mChoiceMode == mode;
+    }
+
+    protected ArrayList<Checkable> getCheckedGrandchildren() {
+        ArrayList<Checkable> checked = new ArrayList<Checkable>();
+        final int childCount = getChildCount();
+        for (int i = 0; i < childCount; ++i) {
+            final ViewGroup layout = (ViewGroup) getChildAt(i);
+            final int grandChildCount = layout.getChildCount();
+            for (int j = 0; j < grandChildCount; ++j) {
+                final View v = layout.getChildAt(j);
+                if (v instanceof Checkable && ((Checkable) v).isChecked()) {
+                    checked.add((Checkable) v);
+                }
+            }
+        }
+        return checked;
+    }
+
+    /**
+     * If in CHOICE_MODE_SINGLE and an item is checked, returns that item.
+     * Otherwise, returns null.
+     */
+    protected Checkable getSingleCheckedGrandchild() {
+        if (mChoiceMode == CHOICE_MODE_SINGLE) {
+            final int childCount = getChildCount();
+            for (int i = 0; i < childCount; ++i) {
+                final ViewGroup layout = (ViewGroup) getChildAt(i);
+                final int grandChildCount = layout.getChildCount();
+                for (int j = 0; j < grandChildCount; ++j) {
+                    final View v = layout.getChildAt(j);
+                    if (v instanceof Checkable && ((Checkable) v).isChecked()) {
+                        return (Checkable) v;
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
+    public Object getChosenItem() {
+        View checkedView = (View) getSingleCheckedGrandchild();
+        if (checkedView != null) {
+            return checkedView.getTag();
+        }
+        return null;
+    }
+
+    protected void resetCheckedGrandchildren() {
+        // loop through children, and set all of their children to _not_ be checked
+        final ArrayList<Checkable> checked = getCheckedGrandchildren();
+        for (int i = 0; i < checked.size(); ++i) {
+            final Checkable c = checked.get(i);
+            c.setChecked(false);
+        }
+    }
+
+    /**
+     * 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);
+
+    public void invalidatePageData() {
+        if (mContentIsRefreshable) {
+            // Update all the pages
+            syncPages();
+
+            // 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);
+            mDirtyPageAlpha = true;
+            updateAdjacentPagesAlpha();
+            requestLayout();
+        }
+    }
+}