Example usage for android.view VelocityTracker computeCurrentVelocity

Introduction

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

Prototype

public void computeCurrentVelocity(int units, float maxVelocity)

Source Link

Document

Compute the current velocity based on the points that have been collected.

Usage

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  .  j a va 2 s.c om*/

    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.kinth.mmspeed.ui.CustomViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (isScrollable == false) {
        return false;
    }//from   ww  w . j a  v a 2 s.  c  om
    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, 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.zhongsou.souyue.ui.UnScrollViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (!isCanScroll) {
        return false;
    }/*from w w w  . ja va  2  s  .c  om*/
    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, 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;
    }/*w  w  w. ja va  2s  .  c  o 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.vincestyling.traversaless.ViewPager.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 v  a  2 s .  c om

    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);
        mLastMotionX = MotionEventCompat.getX(ev, index);
        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.bm.wjsj.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 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;
}

From source file:com.yu.common.widget.ViewPagerLazy.java

@SuppressWarnings("deprecation")
@SuppressLint("ClickableViewAccessibility")
@Override/*  w w w. j  a v a2 s. c  o  m*/
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;
    }

    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.hxqc.mall.core.views.CustomScrollView.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    initVelocityTrackerIfNotExists();/*  www. ja va 2  s  .  c om*/

    MotionEvent vtev = MotionEvent.obtain(ev);

    final int actionMasked = MotionEventCompat.getActionMasked(ev);

    if (actionMasked == MotionEvent.ACTION_DOWN) {
        mNestedYOffset = 0;
    }
    vtev.offsetLocation(0, mNestedYOffset);

    switch (actionMasked) {
    case MotionEvent.ACTION_DOWN: {
        if (getChildCount() == 0) {
            return false;
        }
        if ((mIsBeingDragged = !mScroller.isFinished())) {
            final ViewParent parent = getParent();
            if (parent != null) {
                parent.requestDisallowInterceptTouchEvent(true);
            }
        }

        /*
         * 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
        mLastMotionY = (int) ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
        if (activePointerIndex == -1) {
            DebugLog.e(TAG, "Invalid pointerId=" + mActivePointerId + " in onTouchEvent");
            break;
        }

        final int y = (int) MotionEventCompat.getY(ev, activePointerIndex);
        int deltaY = mLastMotionY - y;
        if (dispatchNestedPreScroll(0, deltaY, mScrollConsumed, mScrollOffset)) {
            deltaY -= mScrollConsumed[1];
            vtev.offsetLocation(0, mScrollOffset[1]);
            mNestedYOffset += mScrollOffset[1];
        }
        if (!mIsBeingDragged && Math.abs(deltaY) > mTouchSlop) {
            final ViewParent parent = getParent();
            if (parent != null) {
                parent.requestDisallowInterceptTouchEvent(true);
            }
            mIsBeingDragged = true;
            if (deltaY > 0) {
                deltaY -= mTouchSlop;
            } else {
                deltaY += mTouchSlop;
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            mLastMotionY = y - mScrollOffset[1];

            final int oldY = getScrollY();
            final int range = getScrollRange();
            final int overscrollMode = ViewCompat.getOverScrollMode(this);
            boolean canOverscroll = overscrollMode == ViewCompat.OVER_SCROLL_ALWAYS
                    || (overscrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);

            // Calling overScrollByCompat will call onOverScrolled, which
            // calls onScrollChanged if applicable.
            if (overScrollByCompat(0, deltaY, 0, getScrollY(), 0, range, 0, 0, true)
                    && !hasNestedScrollingParent()) {
                // Break our velocity if we hit a scroll barrier.
                mVelocityTracker.clear();
            }

            final int scrolledDeltaY = getScrollY() - oldY;
            final int unconsumedY = deltaY - scrolledDeltaY;
            if (dispatchNestedScroll(0, scrolledDeltaY, 0, unconsumedY, mScrollOffset)) {
                mLastMotionY -= mScrollOffset[1];
                vtev.offsetLocation(0, mScrollOffset[1]);
                mNestedYOffset += mScrollOffset[1];
            } else if (canOverscroll) {
                ensureGlows();
                final int pulledToY = oldY + deltaY;
                if (pulledToY < 0) {
                    mEdgeGlowTop.onPull((float) deltaY / getHeight(),
                            MotionEventCompat.getX(ev, activePointerIndex) / getWidth());
                    if (!mEdgeGlowBottom.isFinished()) {
                        mEdgeGlowBottom.onRelease();
                    }
                } else if (pulledToY > range) {
                    mEdgeGlowBottom.onPull((float) deltaY / getHeight(),
                            1.f - MotionEventCompat.getX(ev, activePointerIndex) / getWidth());
                    if (!mEdgeGlowTop.isFinished()) {
                        mEdgeGlowTop.onRelease();
                    }
                }
                if (mEdgeGlowTop != null && (!mEdgeGlowTop.isFinished() || !mEdgeGlowBottom.isFinished())) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getYVelocity(velocityTracker, mActivePointerId);

            if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
                flingWithNestedDispatch(-initialVelocity);
            }

            mActivePointerId = INVALID_POINTER;
            endDrag();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged && getChildCount() > 0) {
            mActivePointerId = INVALID_POINTER;
            endDrag();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        mLastMotionY = (int) MotionEventCompat.getY(ev, index);
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionY = (int) MotionEventCompat.getY(ev,
                MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }

    if (mVelocityTracker != null) {
        mVelocityTracker.addMovement(vtev);
    }
    vtev.recycle();
    return true;
}

From source file:com.hxqc.mall.thirdshop.views.CustomScrollView.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    initVelocityTrackerIfNotExists();//from w  w w  . j  av  a  2s .c  om

    MotionEvent vtev = MotionEvent.obtain(ev);

    final int actionMasked = MotionEventCompat.getActionMasked(ev);

    if (actionMasked == MotionEvent.ACTION_DOWN) {
        mNestedYOffset = 0;
    }
    vtev.offsetLocation(0, mNestedYOffset);

    switch (actionMasked) {
    case MotionEvent.ACTION_DOWN: {
        if (getChildCount() == 0) {
            return false;
        }
        if ((mIsBeingDragged = !mScroller.isFinished())) {
            final ViewParent parent = getParent();
            if (parent != null) {
                parent.requestDisallowInterceptTouchEvent(true);
            }
        }

        /*
         * 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
        mLastMotionY = (int) ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
        if (activePointerIndex == -1) {
            DebugLog.e(TAG, "Invalid pointerId=" + mActivePointerId + " in onTouchEvent");
            break;
        }

        final int y = (int) MotionEventCompat.getY(ev, activePointerIndex);
        int deltaY = mLastMotionY - y;
        if (dispatchNestedPreScroll(0, deltaY, mScrollConsumed, mScrollOffset)) {
            deltaY -= mScrollConsumed[1];
            vtev.offsetLocation(0, mScrollOffset[1]);
            mNestedYOffset += mScrollOffset[1];
        }
        if (!mIsBeingDragged && Math.abs(deltaY) > mTouchSlop) {
            final ViewParent parent = getParent();
            if (parent != null) {
                parent.requestDisallowInterceptTouchEvent(true);
            }
            mIsBeingDragged = true;
            if (deltaY > 0) {
                deltaY -= mTouchSlop;
            } else {
                deltaY += mTouchSlop;
            }
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            mLastMotionY = y - mScrollOffset[1];

            final int oldY = getScrollY();
            final int range = getScrollRange();
            final int overscrollMode = ViewCompat.getOverScrollMode(this);
            boolean canOverscroll = overscrollMode == ViewCompat.OVER_SCROLL_ALWAYS
                    || (overscrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);

            // Calling overScrollByCompat will call onOverScrolled, which
            // calls onScrollChanged if applicable.
            if (overScrollByCompat(0, deltaY, 0, getScrollY(), 0, range, 0, 0, true)
                    && !hasNestedScrollingParent()) {
                // Break our velocity if we hit a scroll barrier.
                mVelocityTracker.clear();
            }

            final int scrolledDeltaY = getScrollY() - oldY;
            final int unconsumedY = deltaY - scrolledDeltaY;
            if (dispatchNestedScroll(0, scrolledDeltaY, 0, unconsumedY, mScrollOffset)) {
                mLastMotionY -= mScrollOffset[1];
                vtev.offsetLocation(0, mScrollOffset[1]);
                mNestedYOffset += mScrollOffset[1];
            } else if (canOverscroll) {
                ensureGlows();
                final int pulledToY = oldY + deltaY;
                if (pulledToY < 0) {
                    mEdgeGlowTop.onPull((float) deltaY / getHeight(),
                            MotionEventCompat.getX(ev, activePointerIndex) / getWidth());
                    if (!mEdgeGlowBottom.isFinished()) {
                        mEdgeGlowBottom.onRelease();
                    }
                } else if (pulledToY > range) {
                    mEdgeGlowBottom.onPull((float) deltaY / getHeight(),
                            1.f - MotionEventCompat.getX(ev, activePointerIndex) / getWidth());
                    if (!mEdgeGlowTop.isFinished()) {
                        mEdgeGlowTop.onRelease();
                    }
                }
                if (mEdgeGlowTop != null && (!mEdgeGlowTop.isFinished() || !mEdgeGlowBottom.isFinished())) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getYVelocity(velocityTracker, mActivePointerId);

            if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
                flingWithNestedDispatch(-initialVelocity);
            }

            mActivePointerId = INVALID_POINTER;
            endDrag();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged && getChildCount() > 0) {
            mActivePointerId = INVALID_POINTER;
            endDrag();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        mLastMotionY = (int) MotionEventCompat.getY(ev, index);
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionY = (int) MotionEventCompat.getY(ev,
                MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    default:
        break;
    }

    if (mVelocityTracker != null) {
        mVelocityTracker.addMovement(vtev);
    }
    vtev.recycle();
    return true;
}

From source file:com.chenglong.muscle.ui.LazyViewPager.java

/**
 * End a fake drag of the pager./*from w  ww. j ava 2  s  . c  om*/
 *
 * @see #beginFakeDrag()
 * @see #fakeDragBy(float)
 */
public void endFakeDrag() {
    if (!mFakeDragging) {
        throw new IllegalStateException("No fake drag in progress. Call beginFakeDrag first.");
    }
    final VelocityTracker velocityTracker = mVelocityTracker;
    velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
    int initialVelocity = (int) VelocityTrackerCompat.getYVelocity(velocityTracker, mActivePointerId);
    mPopulatePending = true;
    final int totalDelta = (int) (mLastMotionX - mInitialMotionX);
    final int scrollX = getScrollX();
    final int widthWithMargin = getWidth() + mPageMargin;
    final int currentPage = scrollX / widthWithMargin;
    final float pageOffset = (float) (scrollX % widthWithMargin) / widthWithMargin;
    int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
    setCurrentItemInternal(nextPage, true, true, initialVelocity);
    endDrag();
    mFakeDragging = false;
}