Example usage for android.view VelocityTracker obtain

List of usage examples for android.view VelocityTracker obtain

Introduction

In this page you can find the example usage for android.view VelocityTracker obtain.

Prototype

static public VelocityTracker obtain() 

Source Link

Document

Retrieve a new VelocityTracker object to watch the velocity of a motion.

Usage

From source file:com.jihf.swipbackhelper.ViewDragHelper.java

/**
 * Check if this event as provided to the parent view's
 * onInterceptTouchEvent should cause the parent to intercept the touch
 * event stream.//from  w w  w.j  av  a  2 s. c  o  m
 *
 * @param ev MotionEvent provided to onInterceptTouchEvent
 * @return true if the parent view should return true from
 * onInterceptTouchEvent
 */
public boolean shouldInterceptTouchEvent(MotionEvent ev) {
    final int action = MotionEventCompat.getActionMasked(ev);
    final int actionIndex = MotionEventCompat.getActionIndex(ev);

    if (action == MotionEvent.ACTION_DOWN) {
        // Reset things for a new event stream, just in case we didn't get
        // the whole previous stream.
        cancel();
    }

    switch (action) {
    case MotionEvent.ACTION_DOWN: {
        final float x = ev.getX();
        final float y = ev.getY();
        final int pointerId = MotionEventCompat.getPointerId(ev, 0);
        saveInitialMotion(x, y, pointerId);

        final View toCapture = findTopChildUnder((int) x, (int) y);

        // Catch a settling view if possible.
        tryCaptureViewForDrag(toCapture, pointerId);

        if (mDragState == STATE_SETTLING) {
            setDragState(STATE_DRAGGING);
        } else if (mDragState == STATE_IDLE) {
            final int edgesTouched = mInitialEdgeTouched[pointerId];
            if ((edgesTouched & mTrackingEdges) != 0) {
                mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
            }
            setDragState(STATE_JUDGING);
        }
        break;
    }
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
        final float x = MotionEventCompat.getX(ev, actionIndex);
        final float y = MotionEventCompat.getY(ev, actionIndex);
        saveInitialMotion(x, y, pointerId);
        break;
    }
    case MotionEvent.ACTION_MOVE: {
        if (mDragState == STATE_JUDGING) {
            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            if (mDragState == STATE_DRAGGING) {
                mVelocityTracker.addMovement(ev);
            }
            final int i = MotionEventCompat.findPointerIndex(ev, mActivePointerId);

            final float x = MotionEventCompat.getX(ev, i);
            final float y = MotionEventCompat.getY(ev, i);
            final float dx = x - mInitialMotionX[mActivePointerId];
            final float dy = y - mInitialMotionY[mActivePointerId];

            reportNewEdgeDrags(dx, dy, mActivePointerId);

            final View toCapture = findTopChildUnder((int) x, (int) y);
            int slop = checkTouchSlop(toCapture, dx, dy);

            if (slop == -1) {
                cancel();
            } else if (slop > 0 && tryCaptureViewForDrag(toCapture, mActivePointerId)) {
                break;
            }
            saveLastMotion(ev);
        }
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP: {
        final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
        clearMotionHistory(pointerId);
        break;
    }

    case MotionEvent.ACTION_UP: {
        releaseViewForPointerUp();
        cancel();
        break;
    }

    case MotionEvent.ACTION_CANCEL: {
        dispatchViewReleased(0, 0);
        cancel();
        break;
    }
    }
    return mDragState == STATE_DRAGGING;
}

From source file:com.hxqc.mall.core.views.SlidingUpView.ViewDragHelper.java

/**
 * Check if this event as provided to the parent view's onInterceptTouchEvent should
 * cause the parent to intercept the touch event stream.
 *
 * @param ev MotionEvent provided to onInterceptTouchEvent
 * @return true if the parent view should return true from onInterceptTouchEvent
 */// ww  w  .j  av  a2  s  . co  m
public boolean shouldInterceptTouchEvent(MotionEvent ev) {
    DebugLog.i(TAG, "ViewDragHelper shouldInterceptTouchEvent ========  BEGIN");

    final int action = MotionEventCompat.getActionMasked(ev);
    final int actionIndex = MotionEventCompat.getActionIndex(ev);

    if (action == MotionEvent.ACTION_DOWN) {
        // Reset things for a new event stream, just in case we didn't get
        // the whole previous stream.
        cancel();
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    switch (action) {
    case MotionEvent.ACTION_DOWN: {
        final float x = ev.getX();
        final float y = ev.getY();
        final int pointerId = MotionEventCompat.getPointerId(ev, 0);
        saveInitialMotion(x, y, pointerId);

        final View toCapture = findTopChildUnder((int) x, (int) y);

        // Catch a settling view if possible.
        if (toCapture == mCapturedView && mDragState == STATE_SETTLING) {
            tryCaptureViewForDrag(toCapture, pointerId);
        }

        final int edgesTouched = mInitialEdgesTouched[pointerId];
        if ((edgesTouched & mTrackingEdges) != 0) {
            mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
        }
        break;
    }

    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
        final float x = MotionEventCompat.getX(ev, actionIndex);
        final float y = MotionEventCompat.getY(ev, actionIndex);

        saveInitialMotion(x, y, pointerId);

        // A ViewDragHelper can only manipulate one view at a time.
        if (mDragState == STATE_IDLE) {
            final int edgesTouched = mInitialEdgesTouched[pointerId];
            if ((edgesTouched & mTrackingEdges) != 0) {
                mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
            }
        } else if (mDragState == STATE_SETTLING) {
            // Catch a settling view if possible.
            final View toCapture = findTopChildUnder((int) x, (int) y);
            if (toCapture == mCapturedView) {
                tryCaptureViewForDrag(toCapture, pointerId);
            }
        }
        break;
    }

    case MotionEvent.ACTION_MOVE: {
        // First to cross a touch slop over a draggable view wins. Also report edge drags.
        final int pointerCount = MotionEventCompat.getPointerCount(ev);
        for (int i = 0; i < pointerCount && mInitialMotionX != null && mInitialMotionY != null; i++) {
            final int pointerId = MotionEventCompat.getPointerId(ev, i);
            if (pointerId >= mInitialMotionX.length || pointerId >= mInitialMotionY.length) {
                continue;
            }
            final float x = MotionEventCompat.getX(ev, i);
            final float y = MotionEventCompat.getY(ev, i);
            final float dx = x - mInitialMotionX[pointerId];
            final float dy = y - mInitialMotionY[pointerId];

            reportNewEdgeDrags(dx, dy, pointerId);
            if (mDragState == STATE_DRAGGING) {
                // Callback might have started an edge drag
                break;
            }

            final View toCapture = findTopChildUnder((int) mInitialMotionX[pointerId],
                    (int) mInitialMotionY[pointerId]);
            if (toCapture != null && checkTouchSlop(toCapture, dx, dy)
                    && tryCaptureViewForDrag(toCapture, pointerId)) {
                break;
            }
        }
        saveLastMotion(ev);
        break;
    }

    case MotionEventCompat.ACTION_POINTER_UP: {
        final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
        clearMotionHistory(pointerId);
        break;
    }

    case MotionEvent.ACTION_UP:
    case MotionEvent.ACTION_CANCEL: {
        cancel();
        break;
    }
    }
    DebugLog.i(TAG, "ViewDragHelper shouldInterceptTouchEvent ========== state : " + mDragState);
    return mDragState == STATE_DRAGGING;
}

From source file:com.appsummary.luoxf.mylibrary.swipbackhelper.ViewDragHelper.java

/**
 * Check if this event as provided to the parent view's
 * onInterceptTouchEvent should cause the parent to intercept the touch
 * event stream./* w  w  w.j  av a 2 s .c  o  m*/
 *
 * @param ev MotionEvent provided to onInterceptTouchEvent
 * @return true if the parent view should return true from
 * onInterceptTouchEvent
 */
public boolean shouldInterceptTouchEvent(MotionEvent ev) {
    final int action = MotionEventCompat.getActionMasked(ev);
    final int actionIndex = MotionEventCompat.getActionIndex(ev);

    if (action == MotionEvent.ACTION_DOWN) {
        // Reset things for a new event stream, just in case we didn't get
        // the whole previous stream.
        cancel();
    }

    switch (action) {
    case MotionEvent.ACTION_DOWN: {
        final float x = ev.getX();
        final float y = ev.getY();
        final int pointerId = MotionEventCompat.getPointerId(ev, 0);
        saveInitialMotion(x, y, pointerId);

        final View toCapture = findTopChildUnder((int) x, (int) y);

        // Catch a settling view if possible.
        tryCaptureViewForDrag(toCapture, pointerId);

        if (mDragState == STATE_SETTLING) {
            setDragState(STATE_DRAGGING);
        } else if (mDragState == STATE_IDLE) {
            final int edgesTouched = mInitialEdgeTouched[pointerId];
            if ((edgesTouched & mTrackingEdges) != 0) {
                mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
            }
            setDragState(STATE_JUDGING);
        }
        break;
    }
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
        final float x = MotionEventCompat.getX(ev, actionIndex);
        final float y = MotionEventCompat.getY(ev, actionIndex);
        saveInitialMotion(x, y, pointerId);
        break;
    }
    case MotionEvent.ACTION_MOVE: {
        if (mDragState == STATE_JUDGING) {
            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            if (mDragState == STATE_DRAGGING)
                mVelocityTracker.addMovement(ev);
            final int i = MotionEventCompat.findPointerIndex(ev, mActivePointerId);

            final float x = MotionEventCompat.getX(ev, i);
            final float y = MotionEventCompat.getY(ev, i);
            final float dx = x - mInitialMotionX[mActivePointerId];
            final float dy = y - mInitialMotionY[mActivePointerId];

            reportNewEdgeDrags(dx, dy, mActivePointerId);

            final View toCapture = findTopChildUnder((int) x, (int) y);
            int slop = checkTouchSlop(toCapture, dx, dy);

            if (slop == -1)
                cancel();
            else if (slop > 0 && tryCaptureViewForDrag(toCapture, mActivePointerId)) {
                break;
            }
            saveLastMotion(ev);
        }
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP: {
        final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
        clearMotionHistory(pointerId);
        break;
    }

    case MotionEvent.ACTION_UP: {
        releaseViewForPointerUp();
        cancel();
        break;
    }

    case MotionEvent.ACTION_CANCEL: {
        dispatchViewReleased(0, 0);
        cancel();
        break;
    }

    }
    return mDragState == STATE_DRAGGING;
}

From source file:com.yao.zhihudaily.tool.LazyViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (mFakeDragging) {
        // A fake drag is in progress already, ignore this real one
        // but still eat the touch events.
        // (It is likely that the user is multi-touching the screen.)
        return true;
    }/*from   w w w . ja v a  2s . co  m*/
    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        // Don't handle edge touches immediately -- they may actually belong to one of our
        // descendants.
        return false;
    }
    if (mAdapter == null || mAdapter.getCount() == 0) {
        // Nothing to present or scroll; nothing to touch.
        return false;
    }
    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);
    final int action = ev.getAction();
    boolean needsInvalidate = false;
    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        /*
         * If being flinged and user touches, stop the fling. isFinished
         * will be false if being flinged.
         */
        completeScroll();
        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final float deltaX = mLastMotionX - x;
            mLastMotionX = x;
            float oldScrollX = getScrollX();
            float scrollX = oldScrollX + deltaX;
            final int width = getWidth();
            final int widthWithMargin = width + mPageMargin;
            final int lastItemIndex = mAdapter.getCount() - 1;
            final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
            final float rightBound = Math.min(mCurItem + 1, lastItemIndex) * widthWithMargin;
            if (scrollX < leftBound) {
                if (leftBound == 0) {
                    float over = -scrollX;
                    needsInvalidate = mLeftEdge.onPull(over / width);
                }
                scrollX = leftBound;
            } else if (scrollX > rightBound) {
                if (rightBound == lastItemIndex * widthWithMargin) {
                    float over = scrollX - rightBound;
                    needsInvalidate = mRightEdge.onPull(over / width);
                }
                scrollX = rightBound;
            }
            // Don't lose the rounded component
            mLastMotionX += scrollX - (int) scrollX;
            scrollTo((int) scrollX, getScrollY());
            if (mOnPageChangeListener != null) {
                final int position = (int) scrollX / widthWithMargin;
                final int positionOffsetPixels = (int) scrollX % widthWithMargin;
                final float positionOffset = (float) positionOffsetPixels / widthWithMargin;
                mOnPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int widthWithMargin = getWidth() + mPageMargin;
            final int scrollX = getScrollX();
            final int currentPage = scrollX / widthWithMargin;
            int nextPage = initialVelocity > 0 ? currentPage : currentPage + 1;
            setCurrentItemInternal(nextPage, true, true, initialVelocity);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, true, true);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float x = MotionEventCompat.getX(ev, index);
        mLastMotionX = x;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        invalidate();
    }
    return true;
}

From source file:cn.d.fesa.wuf.ui.view.LazyViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (mFakeDragging) {
        // A fake drag is in progress already, ignore this real one
        // but still eat the touch events.
        // (It is likely that the user is multi-touching the screen.)
        return true;
    }//from   w w  w.j  a v  a  2s  .c o m

    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        // Don't handle edge touches immediately -- they may actually belong to one of our
        // descendants.
        return false;
    }

    if (mAdapter == null || mAdapter.getCount() == 0) {
        // Nothing to present or scroll; nothing to touch.
        return false;
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    final int action = ev.getAction();
    boolean needsInvalidate = false;

    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        /*
         * If being flinged and user touches, stop the fling. isFinished
         * will be false if being flinged.
         */
        completeScroll();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final float deltaX = mLastMotionX - x;
            mLastMotionX = x;
            float oldScrollX = getScrollX();
            float scrollX = oldScrollX + deltaX;
            final int width = getWidth();
            final int widthWithMargin = width + mPageMargin;

            final int lastItemIndex = mAdapter.getCount() - 1;
            final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
            final float rightBound = Math.min(mCurItem + 1, lastItemIndex) * widthWithMargin;
            if (scrollX < leftBound) {
                if (leftBound == 0) {
                    float over = -scrollX;
                    needsInvalidate = mLeftEdge.onPull(over / width);
                }
                scrollX = leftBound;
            } else if (scrollX > rightBound) {
                if (rightBound == lastItemIndex * widthWithMargin) {
                    float over = scrollX - rightBound;
                    needsInvalidate = mRightEdge.onPull(over / width);
                }
                scrollX = rightBound;
            }
            // Don't lose the rounded component
            mLastMotionX += scrollX - (int) scrollX;
            scrollTo((int) scrollX, getScrollY());
            if (mOnPageChangeListener != null) {
                final int position = (int) scrollX / widthWithMargin;
                final int positionOffsetPixels = (int) scrollX % widthWithMargin;
                final float positionOffset = (float) positionOffsetPixels / widthWithMargin;
                mOnPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int widthWithMargin = getWidth() + mPageMargin;
            final int scrollX = getScrollX();
            final int currentPage = scrollX / widthWithMargin;
            int nextPage = initialVelocity > 0 ? currentPage : currentPage + 1;
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, true, true);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float x = MotionEventCompat.getX(ev, index);
        mLastMotionX = x;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        invalidate();
    }
    return true;
}

From source file:com.cyanogenmod.filemanager.ui.widgets.ViewDragHelper.java

/**
 * Process a touch event received by the parent view. This method will dispatch callback events
 * as needed before returning. The parent view's onTouchEvent implementation should call this.
 *
 * @param ev The touch event received by the parent view
 *//*w  w  w.j  ava2  s.co m*/
public void processTouchEvent(MotionEvent ev) {
    final int action = ev.getActionMasked();
    final int actionIndex = ev.getActionIndex();

    if (action == MotionEvent.ACTION_DOWN) {
        // Reset things for a new event stream, just in case we didn't get
        // the whole previous stream.
        cancel();
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    switch (action) {
    case MotionEvent.ACTION_DOWN: {
        final float x = ev.getX();
        final float y = ev.getY();
        final int pointerId = ev.getPointerId(0);
        final View toCapture = findTopChildUnder((int) x, (int) y);

        saveInitialMotion(x, y, pointerId);

        // Since the parent is already directly processing this touch event,
        // there is no reason to delay for a slop before dragging.
        // Start immediately if possible.
        tryCaptureViewForDrag(toCapture, pointerId);

        final int edgesTouched = mInitialEdgesTouched[pointerId];
        if ((edgesTouched & mTrackingEdges) != 0) {
            mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
        }
        break;
    }

    case MotionEvent.ACTION_POINTER_DOWN: {
        final int pointerId = ev.getPointerId(actionIndex);
        final float x = ev.getX(actionIndex);
        final float y = ev.getY(actionIndex);

        saveInitialMotion(x, y, pointerId);

        // A ViewDragHelper can only manipulate one view at a time.
        if (mDragState == STATE_IDLE) {
            // If we're idle we can do anything! Treat it like a normal down event.

            final View toCapture = findTopChildUnder((int) x, (int) y);
            tryCaptureViewForDrag(toCapture, pointerId);

            final int edgesTouched = mInitialEdgesTouched[pointerId];
            if ((edgesTouched & mTrackingEdges) != 0) {
                mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
            }
        } else if (isCapturedViewUnder((int) x, (int) y)) {
            // We're still tracking a captured view. If the same view is under this
            // point, we'll swap to controlling it with this pointer instead.
            // (This will still work if we're "catching" a settling view.)

            tryCaptureViewForDrag(mCapturedView, pointerId);
        }
        break;
    }

    case MotionEvent.ACTION_MOVE: {
        if (mDragState == STATE_DRAGGING) {
            final int index = ev.findPointerIndex(mActivePointerId);
            final float x = ev.getX(index);
            final float y = ev.getY(index);
            final int idx = (int) (x - mLastMotionX[mActivePointerId]);
            final int idy = (int) (y - mLastMotionY[mActivePointerId]);

            dragTo(mCapturedView.getLeft() + idx, mCapturedView.getTop() + idy, idx, idy);

            saveLastMotion(ev);
        } else {
            // Check to see if any pointer is now over a draggable view.
            final int pointerCount = ev.getPointerCount();
            for (int i = 0; i < pointerCount; i++) {
                final int pointerId = ev.getPointerId(i);
                final float x = ev.getX(i);
                final float y = ev.getY(i);
                final float dx = x - mInitialMotionX[pointerId];
                final float dy = y - mInitialMotionY[pointerId];

                reportNewEdgeDrags(dx, dy, pointerId);
                if (mDragState == STATE_DRAGGING) {
                    // Callback might have started an edge drag.
                    break;
                }

                final View toCapture = findTopChildUnder((int) x, (int) y);
                if (checkTouchSlop(toCapture, dx, dy) && tryCaptureViewForDrag(toCapture, pointerId)) {
                    break;
                }
            }
            saveLastMotion(ev);
        }
        break;
    }

    case MotionEvent.ACTION_POINTER_UP: {
        final int pointerId = ev.getPointerId(actionIndex);
        if (mDragState == STATE_DRAGGING && pointerId == mActivePointerId) {
            // Try to find another pointer that's still holding on to the captured view.
            int newActivePointer = INVALID_POINTER;
            final int pointerCount = ev.getPointerCount();
            for (int i = 0; i < pointerCount; i++) {
                final int id = ev.getPointerId(i);
                if (id == mActivePointerId) {
                    // This one's going away, skip.
                    continue;
                }

                final float x = ev.getX(i);
                final float y = ev.getY(i);
                if (findTopChildUnder((int) x, (int) y) == mCapturedView
                        && tryCaptureViewForDrag(mCapturedView, id)) {
                    newActivePointer = mActivePointerId;
                    break;
                }
            }

            if (newActivePointer == INVALID_POINTER) {
                // We didn't find another pointer still touching the view, release it.
                releaseViewForPointerUp();
            }
        }
        clearMotionHistory(pointerId);
        break;
    }

    case MotionEvent.ACTION_UP: {
        if (mDragState == STATE_DRAGGING) {
            releaseViewForPointerUp();
        }
        cancel();
        break;
    }

    case MotionEvent.ACTION_CANCEL: {
        if (mDragState == STATE_DRAGGING) {
            dispatchViewReleased(0, 0);
        }
        cancel();
        break;
    }
    }
}

From source file:com.zhuo.tong.view.LazyViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {

    if (mFakeDragging) {
        // A fake drag is in progress already, ignore this real one
        // but still eat the touch events.
        // (It is likely that the user is multi-touching the screen.)
        return true;
    }/*  w w w .  j  ava 2 s. co m*/

    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        // Don't handle edge touches immediately -- they may actually belong to one of our
        // descendants.
        return false;
    }

    if (mAdapter == null || mAdapter.getCount() == 0) {
        // Nothing to present or scroll; nothing to touch.
        return false;
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    final int action = ev.getAction();
    boolean needsInvalidate = false;

    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        /*
         * If being flinged and user touches, stop the fling. isFinished
         * will be false if being flinged.
         */
        completeScroll();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final float deltaX = mLastMotionX - x;
            mLastMotionX = x;
            float oldScrollX = getScrollX();
            float scrollX = oldScrollX + deltaX;
            final int width = getWidth();
            final int widthWithMargin = width + mPageMargin;

            final int lastItemIndex = mAdapter.getCount() - 1;
            final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
            final float rightBound = Math.min(mCurItem + 1, lastItemIndex) * widthWithMargin;
            if (scrollX < leftBound) {
                if (leftBound == 0) {
                    float over = -scrollX;
                    needsInvalidate = mLeftEdge.onPull(over / width);
                }
                scrollX = leftBound;
            } else if (scrollX > rightBound) {
                if (rightBound == lastItemIndex * widthWithMargin) {
                    float over = scrollX - rightBound;
                    needsInvalidate = mRightEdge.onPull(over / width);
                }
                scrollX = rightBound;
            }
            // Don't lose the rounded component
            mLastMotionX += scrollX - (int) scrollX;
            scrollTo((int) scrollX, getScrollY());
            if (mOnPageChangeListener != null) {
                final int position = (int) scrollX / widthWithMargin;
                final int positionOffsetPixels = (int) scrollX % widthWithMargin;
                final float positionOffset = (float) positionOffsetPixels / widthWithMargin;
                mOnPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int widthWithMargin = getWidth() + mPageMargin;
            final int scrollX = getScrollX();
            final int currentPage = scrollX / widthWithMargin;
            int nextPage = initialVelocity > 0 ? currentPage : currentPage + 1;
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, true, true);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float x = MotionEventCompat.getX(ev, index);
        mLastMotionX = x;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        invalidate();
    }
    return true;
}

From source file:com.example.show.NoPreloadViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (mFakeDragging) {
        // A fake drag is in progress already, ignore this real one  
        // but still eat the touch events.  
        // (It is likely that the user is multi-touching the screen.)  
        return true;
    }/* w  w  w.  j  a  va2s  . c  o  m*/

    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        // Don't handle edge touches immediately -- they may actually belong to one of our  
        // descendants.  
        return false;
    }

    if (mAdapter == null || mAdapter.getCount() == 0) {
        // Nothing to present or scroll; nothing to touch.  
        return false;
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    final int action = ev.getAction();
    boolean needsInvalidate = false;

    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        /* 
         * If being flinged and user touches, stop the fling. isFinished 
         * will be false if being flinged. 
         */
        completeScroll();

        // Remember where the motion event started  
        mLastMotionX = mInitialMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event  
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final float deltaX = mLastMotionX - x;
            mLastMotionX = x;
            float oldScrollX = getScrollX();
            float scrollX = oldScrollX + deltaX;
            final int width = getWidth();
            final int widthWithMargin = width + mPageMargin;

            final int lastItemIndex = mAdapter.getCount() - 1;
            final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
            final float rightBound = Math.min(mCurItem + 1, lastItemIndex) * widthWithMargin;
            if (scrollX < leftBound) {
                if (leftBound == 0) {
                    float over = -scrollX;
                    needsInvalidate = mLeftEdge.onPull(over / width);
                }
                scrollX = leftBound;
            } else if (scrollX > rightBound) {
                if (rightBound == lastItemIndex * widthWithMargin) {
                    float over = scrollX - rightBound;
                    needsInvalidate = mRightEdge.onPull(over / width);
                }
                scrollX = rightBound;
            }
            // Don't lose the rounded component  
            mLastMotionX += scrollX - (int) scrollX;
            scrollTo((int) scrollX, getScrollY());
            if (mOnPageChangeListener != null) {
                final int position = (int) scrollX / widthWithMargin;
                final int positionOffsetPixels = (int) scrollX % widthWithMargin;
                final float positionOffset = (float) positionOffsetPixels / widthWithMargin;
                mOnPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int widthWithMargin = getWidth() + mPageMargin;
            final int scrollX = getScrollX();
            final int currentPage = scrollX / widthWithMargin;
            int nextPage = initialVelocity > 0 ? currentPage : currentPage + 1;
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, true, true);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float x = MotionEventCompat.getX(ev, index);
        mLastMotionX = x;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        invalidate();
    }
    return true;
}

From source file:com.wevalue.view.LazyViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (!scrollble) {
        return true;
    }/*  www  .j  ava  2s . co m*/
    if (mFakeDragging) {
        // A fake drag is in progress already, ignore this real one
        // but still eat the touch events.
        // (It is likely that the user is multi-touching the screen.)
        return true;
    }

    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        // Don't handle edge touches immediately -- they may actually belong
        // to one of our
        // descendants.
        return false;
    }

    if (mAdapter == null || mAdapter.getCount() == 0) {
        // Nothing to present or scroll; nothing to touch.
        return false;
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    final int action = ev.getAction();
    boolean needsInvalidate = false;

    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        /*
         * If being flinged and user touches, stop the fling. isFinished will be false if being flinged.
         */
        completeScroll();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final float deltaX = mLastMotionX - x;
            mLastMotionX = x;
            float oldScrollX = getScrollX();
            float scrollX = oldScrollX + deltaX;
            final int width = getWidth();
            final int widthWithMargin = width + mPageMargin;

            final int lastItemIndex = mAdapter.getCount() - 1;
            final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
            final float rightBound = Math.min(mCurItem + 1, lastItemIndex) * widthWithMargin;
            if (scrollX < leftBound) {
                if (leftBound == 0) {
                    float over = -scrollX;
                    needsInvalidate = mLeftEdge.onPull(over / width);
                }
                scrollX = leftBound;
            } else if (scrollX > rightBound) {
                if (rightBound == lastItemIndex * widthWithMargin) {
                    float over = scrollX - rightBound;
                    needsInvalidate = mRightEdge.onPull(over / width);
                }
                scrollX = rightBound;
            }
            // Don't lose the rounded component
            mLastMotionX += scrollX - (int) scrollX;
            scrollTo((int) scrollX, getScrollY());
            if (mOnPageChangeListener != null) {
                final int position = (int) scrollX / widthWithMargin;
                final int positionOffsetPixels = (int) scrollX % widthWithMargin;
                final float positionOffset = (float) positionOffsetPixels / widthWithMargin;
                mOnPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int widthWithMargin = getWidth() + mPageMargin;
            final int scrollX = getScrollX();
            final int currentPage = scrollX / widthWithMargin;
            int nextPage = initialVelocity > 0 ? currentPage : currentPage + 1;
            setCurrentItemInternal(nextPage, false, false, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, false, false);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float x = MotionEventCompat.getX(ev, index);
        mLastMotionX = x;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        invalidate();
    }
    return true;
}

From source file:com.cnpeng.cnpeng_mydemosfrom2016_12.a_12_GetLocalFiles_VP_FM.CustomNoPreLoadViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (mFakeDragging) {
        // A fake drag is in progress already, ignore this real one  
        // but still eat the touch events.  
        // (It is likely that the user is multi-touching the screen.)  
        return true;
    }/*from  w w w .ja  v  a 2 s  . c o m*/

    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        // Don't handle edge touches immediately -- they may actually belong to one of our  
        // descendants.  
        return false;
    }

    if (mAdapter == null || mAdapter.getCount() == 0) {
        // Nothing to present or scroll; nothing to touch.  
        return false;
    }

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    }
    mVelocityTracker.addMovement(ev);

    final int action = ev.getAction();
    boolean needsInvalidate = false;

    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        /* 
         * If being flinged and user touches, stop the fling. isFinished 
         * will be false if being flinged. 
         */
        completeScroll();

        // Remember where the motion event started  
        mLastMotionX = mInitialMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            if (DEBUG) {
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            }
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                if (DEBUG) {
                    Log.v(TAG, "Starting drag!");
                }
                mIsBeingDragged = true;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event  
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final float deltaX = mLastMotionX - x;
            mLastMotionX = x;
            float oldScrollX = getScrollX();
            float scrollX = oldScrollX + deltaX;
            final int width = getWidth();
            final int widthWithMargin = width + mPageMargin;

            final int lastItemIndex = mAdapter.getCount() - 1;
            final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
            final float rightBound = Math.min(mCurItem + 1, lastItemIndex) * widthWithMargin;
            if (scrollX < leftBound) {
                if (leftBound == 0) {
                    float over = -scrollX;
                    needsInvalidate = mLeftEdge.onPull(over / width);
                }
                scrollX = leftBound;
            } else if (scrollX > rightBound) {
                if (rightBound == lastItemIndex * widthWithMargin) {
                    float over = scrollX - rightBound;
                    needsInvalidate = mRightEdge.onPull(over / width);
                }
                scrollX = rightBound;
            }
            // Don't lose the rounded component  
            mLastMotionX += scrollX - (int) scrollX;
            scrollTo((int) scrollX, getScrollY());
            if (mOnPageChangeListener != null) {
                final int position = (int) scrollX / widthWithMargin;
                final int positionOffsetPixels = (int) scrollX % widthWithMargin;
                final float positionOffset = (float) positionOffsetPixels / widthWithMargin;
                mOnPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int widthWithMargin = getWidth() + mPageMargin;
            final int scrollX = getScrollX();
            final int currentPage = scrollX / widthWithMargin;
            int nextPage = initialVelocity > 0 ? currentPage : currentPage + 1;
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, true, true);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float x = MotionEventCompat.getX(ev, index);
        mLastMotionX = x;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        invalidate();
    }
    return true;
}