Example usage for android.view VelocityTracker computeCurrentVelocity

List of usage examples for android.view VelocityTracker computeCurrentVelocity

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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:bw.com.yunifangstore.view.LazyViewPager.java

/**
 * End a fake drag of the pager./*  ww  w  . j  a  v  a2 s .  c  o  m*/
 *
 * @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;
    if ((Math.abs(initialVelocity) > mMinimumVelocity)
            || Math.abs(mInitialMotionX - mLastMotionX) >= (getWidth() / 3)) {
        if (mLastMotionX > mInitialMotionX) {
            setCurrentItemInternal(mCurItem - 1, true, true);
        } else {
            setCurrentItemInternal(mCurItem + 1, true, true);
        }
    } else {
        setCurrentItemInternal(mCurItem, true, true);
    }
    endDrag();

    mFakeDragging = false;
}

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  ww  .j  ava  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.icloud.listenbook.base.view.DraggableGridViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    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;
    }//  w  w w . java 2s .co m

    if (mPageCount <= 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: {
        // ?
        mScroller.abortAnimation();
        // Remember where the motion event started
        // ??
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);

        DEBUG_LOG("Down at " + mLastMotionX + "," + mLastMotionY + " mIsBeingDragged=" + mIsBeingDragged
                + " mIsUnableToDrag=" + mIsUnableToDrag);
        //  ? 
        if (!mIsBeingDragged && mScrollState == SCROLL_STATE_IDLE) {
            mLastPosition = getPositionByXY((int) mLastMotionX, (int) mLastMotionY);
        } else {
            mLastPosition = -1;
        }

        // 
        if (mLastPosition >= 0) {
            mLastDownTime = System.currentTimeMillis();
        } else {
            mLastDownTime = Long.MAX_VALUE;
        }
        DEBUG_LOG("Down at mLastPosition=" + mLastPosition);
        mLastDragged = -1;
        break;
    }
    case MotionEvent.ACTION_MOVE: {
        final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
        final float x = MotionEventCompat.getX(ev, pointerIndex);
        final float y = MotionEventCompat.getY(ev, pointerIndex);
        // ?
        if (mLastDragged >= 0) {
            // change draw location of dragged visual
            // ? ?
            final View v = getChildAt(mLastDragged);
            final int l = getScrollX() + (int) x - v.getWidth() / 2;
            final int t = getScrollY() + (int) y - v.getHeight() / 2;
            v.layout(l, t, l + v.getWidth(), t + v.getHeight());

            // check for new target hover
            // 
            if (mScrollState == SCROLL_STATE_IDLE) {
                final int target = getTargetByXY((int) x, (int) y);
                // ?? ??
                if (target != -1 && mLastTarget != target) {
                    animateGap(target);
                    mLastTarget = target;
                    DEBUG_LOG("Moved to mLastTarget=" + mLastTarget);
                }
                // edge holding
                /**
                 * ? 
                 * */
                final int edge = getEdgeByXY((int) x, (int) y);
                if (mLastEdge == -1) {
                    if (edge != mLastEdge) {
                        mLastEdge = edge;
                        mLastEdgeTime = System.currentTimeMillis();
                    }
                } else {
                    // ?? 1.2 ?
                    if (edge != mLastEdge) {
                        mLastEdge = -1;
                    } else {
                        if ((System.currentTimeMillis() - mLastEdgeTime) >= EDGE_HOLD_DURATION) {
                            // ???
                            performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
                            triggerSwipe(edge);
                            mLastEdge = -1;
                        }
                    }
                }
            }
        }
        // ?
        else if (!mIsBeingDragged) {
            final float xDiff = Math.abs(x - mLastMotionX);
            final float yDiff = Math.abs(y - mLastMotionY);
            DEBUG_LOG("Moved to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            // ?? ???
            if (xDiff > mTouchSlop && xDiff > yDiff) {
                DEBUG_LOG("Starting drag!");
                mIsBeingDragged = true;
                requestParentDisallowInterceptTouchEvent(true);
                mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop
                        : mInitialMotionX - mTouchSlop;
                mLastMotionY = y;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            }
        }
        // Not else! Note that mIsBeingDragged can be set above.

        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            // ?
            needsInvalidate |= performDrag(x);
        }
        // ??? ?
        else if (mLastPosition >= 0) {
            final int currentPosition = getPositionByXY((int) x, (int) y);
            DEBUG_LOG("Moved to currentPosition=" + currentPosition);
            // ?
            if (currentPosition == mLastPosition) {

                // 1S?
                if ((System.currentTimeMillis() - mLastDownTime) >= LONG_CLICK_DURATION) {
                    if (onItemLongClick(currentPosition)) {
                        performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
                        mLastDragged = mLastPosition;
                        requestParentDisallowInterceptTouchEvent(true);
                        mLastTarget = -1;
                        animateDragged();
                        mLastPosition = -1;
                    }
                    mLastDownTime = Long.MAX_VALUE;
                }
            } else {
                mLastPosition = -1;
            }
        }
        break;
    }
    case MotionEvent.ACTION_UP: {
        DEBUG_LOG("Touch up!!!");
        final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
        final float x = MotionEventCompat.getX(ev, pointerIndex);
        final float y = MotionEventCompat.getY(ev, pointerIndex);
        //  ?
        if (mLastDragged >= 0) {
            rearrange();
        } else if
        //  ??
        (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
            final int width = getWidth();
            final int scrollX = getScrollX();
            final int currentPage = scrollX / width;
            final int offsetPixels = scrollX - currentPage * width;
            final float pageOffset = (float) offsetPixels / (float) width;
            final int totalDelta = (int) (x - mInitialMotionX);
            int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
        } else if (mLastPosition >= 0) {
            final int currentPosition = getPositionByXY((int) x, (int) y);
            DEBUG_LOG("Touch up!!! currentPosition=" + currentPosition);
            if (currentPosition == mLastPosition) {
                onItemClick(currentPosition);
            }
        }
        break;
    }
    case MotionEvent.ACTION_CANCEL:
        DEBUG_LOG("Touch cancel!!!");
        //  ? 
        if (mLastDragged >= 0) {
            rearrange();
        } else
        // ???
        if (mIsBeingDragged) {
            scrollToItem(mCurItem, true, 0, false);
            mActivePointerId = INVALID_POINTER;
            endDrag();
        }
        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) {
        ViewCompat.postInvalidateOnAnimation(this);
    }
    return true;
}

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

/**
 * End a fake drag of the pager.//  w w w .  j av  a  2 s.co  m
 * 
 * @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;
    if ((Math.abs(initialVelocity) > mMinimumVelocity)
            || Math.abs(mInitialMotionX - mLastMotionX) >= (getWidth() / 3)) {
        if (mLastMotionX > mInitialMotionX) {
            setCurrentItemInternal(mCurItem - 1, false, false);
        } else {
            setCurrentItemInternal(mCurItem + 1, false, false);
        }
    } else {
        setCurrentItemInternal(mCurItem, false, false);
    }
    endDrag();

    mFakeDragging = false;
}

From source file:com.jzh.stuapp.view.MyViewPager.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (mFakeDragging) {
        return true;
    }/*from w  ww.  j  ava2  s.  c  o m*/

    if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
        return false;
    }

    if (mAdapter == null || mAdapter.getCount() == 0) {
        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();

        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) {
            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;
            }
            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.oguzbabaoglu.cardpager.CardPager.java

@Override
public boolean onTouchEvent(@NonNull MotionEvent ev) {

    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;
    }//from   w w w. j a  va2s. c  o  m

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

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

    final int action = ev.getAction();

    switch (action & MotionEventCompat.ACTION_MASK) {

    case MotionEvent.ACTION_DOWN:

        // Do not interfere with the settling action.
        if (scrollState != SCROLL_STATE_SETTLING) {
            scroller.abortAnimation();
            populatePending = false;
            populate();
        }

        // Remember where the motion event started
        lastMotionX = initialMotionX = ev.getX();
        lastMotionY = initialMotionY = ev.getY();
        activePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;

    case MotionEvent.ACTION_MOVE:
        if (!dragInProgress) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - lastMotionX);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - lastMotionY);

            if (xDiff > touchSlop && xDiff > yDiff) {

                dragInProgress = true;
                lastMotionX = x - initialMotionX > 0 ? initialMotionX + touchSlop : initialMotionX - touchSlop;
                lastMotionY = y;
                setScrollState(SCROLL_STATE_DRAGGING);

                // Disallow Parent Intercept, just in case
                requestParentDisallowInterceptTouchEvent(true);
            }
        }
        // Not else! Note that dragInProgress can be set above.
        if (dragInProgress) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            performDrag(x);
        }
        break;

    case MotionEvent.ACTION_UP:

        if (!dragInProgress) {
            break;
        }

        final VelocityTracker velocityTracker = this.velocityTracker;
        velocityTracker.computeCurrentVelocity(1000, maximumVelocity);
        final int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, activePointerId);

        populatePending = true;

        final int width = getClientWidth();
        final int scrollX = getScrollX();
        final ItemInfo ii = infoForCurrentScrollPosition();
        final int currentPage = ii.position;
        final float pageOffset = ((float) scrollX / width) - ii.offset;
        final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
        final float x = MotionEventCompat.getX(ev, activePointerIndex);
        final int totalDelta = (int) (x - initialMotionX);
        final int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);

        setCurrentItemInternal(nextPage, true, true, initialVelocity);
        activePointerId = INVALID_POINTER;
        endDrag();
        break;

    case MotionEvent.ACTION_CANCEL:

        if (!dragInProgress) {
            break;
        }

        scrollToItem(currentItem, true, 0);
        activePointerId = INVALID_POINTER;
        endDrag();
        break;

    case MotionEventCompat.ACTION_POINTER_DOWN:
        final int index = MotionEventCompat.getActionIndex(ev);
        lastMotionX = MotionEventCompat.getX(ev, index);
        activePointerId = MotionEventCompat.getPointerId(ev, index);
        break;

    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        lastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, activePointerId));
        break;
    }

    return true;
}

From source file:bw.com.yunifangstore.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  ww 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 false;
}

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;
    }/*from w  w  w .j av  a  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.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;
    }/*from  w ww  .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;
    }/*ww  w .ja  va2  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;
}