Example usage for android.view VelocityTracker obtain

List of usage examples for android.view VelocityTracker obtain

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Introduction

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

Prototype

static public VelocityTracker obtain()

Source Link

Document

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

Usage

From source file:org.telegram.android.support.widget.RecyclerView.java

@Override
public boolean onTouchEvent(MotionEvent e) {
    if (dispatchOnItemTouch(e)) {
        cancelTouch();/* w w  w.  j  av  a  2 s  .  c o  m*/
        return true;
    }

    final boolean canScrollHorizontally = mLayout.canScrollHorizontally();
    final boolean canScrollVertically = mLayout.canScrollVertically();

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

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

    switch (action) {
    case MotionEvent.ACTION_DOWN: {
        mScrollPointerId = MotionEventCompat.getPointerId(e, 0);
        mInitialTouchX = mLastTouchX = (int) (e.getX() + 0.5f);
        mInitialTouchY = mLastTouchY = (int) (e.getY() + 0.5f);
    }
        break;

    case MotionEventCompat.ACTION_POINTER_DOWN: {
        mScrollPointerId = MotionEventCompat.getPointerId(e, actionIndex);
        mInitialTouchX = mLastTouchX = (int) (MotionEventCompat.getX(e, actionIndex) + 0.5f);
        mInitialTouchY = mLastTouchY = (int) (MotionEventCompat.getY(e, actionIndex) + 0.5f);
    }
        break;

    case MotionEvent.ACTION_MOVE: {
        final int index = MotionEventCompat.findPointerIndex(e, mScrollPointerId);
        if (index < 0) {
            Log.e(TAG, "Error processing scroll; pointer index for id " + mScrollPointerId
                    + " not found. Did any MotionEvents get skipped?");
            return false;
        }

        final int x = (int) (MotionEventCompat.getX(e, index) + 0.5f);
        final int y = (int) (MotionEventCompat.getY(e, index) + 0.5f);
        if (mScrollState != SCROLL_STATE_DRAGGING) {
            final int dx = x - mInitialTouchX;
            final int dy = y - mInitialTouchY;
            boolean startScroll = false;
            if (canScrollHorizontally && Math.abs(dx) > mTouchSlop) {
                mLastTouchX = mInitialTouchX + mTouchSlop * (dx < 0 ? -1 : 1);
                startScroll = true;
            }
            if (canScrollVertically && Math.abs(dy) > mTouchSlop) {
                mLastTouchY = mInitialTouchY + mTouchSlop * (dy < 0 ? -1 : 1);
                startScroll = true;
            }
            if (startScroll) {
                setScrollState(SCROLL_STATE_DRAGGING);
            }
        }
        if (mScrollState == SCROLL_STATE_DRAGGING) {
            final int dx = x - mLastTouchX;
            final int dy = y - mLastTouchY;
            if (scrollByInternal(canScrollHorizontally ? -dx : 0, canScrollVertically ? -dy : 0, true, x, y)) {
                getParent().requestDisallowInterceptTouchEvent(true);
            }
        }
        mLastTouchX = x;
        mLastTouchY = y;
    }
        break;

    case MotionEventCompat.ACTION_POINTER_UP: {
        onPointerUp(e);
    }
        break;

    case MotionEvent.ACTION_UP: {
        mVelocityTracker.computeCurrentVelocity(1000, mMaxFlingVelocity);
        final float xvel = canScrollHorizontally
                ? -VelocityTrackerCompat.getXVelocity(mVelocityTracker, mScrollPointerId)
                : 0;
        final float yvel = canScrollVertically
                ? -VelocityTrackerCompat.getYVelocity(mVelocityTracker, mScrollPointerId)
                : 0;
        if (!((xvel != 0 || yvel != 0) && fling((int) xvel, (int) yvel))) {
            setScrollState(SCROLL_STATE_IDLE);
        }
        mVelocityTracker.clear();
        releaseGlows();
    }
        break;

    case MotionEvent.ACTION_CANCEL: {
        cancelTouch();
    }
        break;
    }

    return true;
}

From source file:com.tjych.swip.vertical.DirectionalViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*/*ww w. jav a2  s .  co m*/
     * This method JUST determines whether we want to intercept the motion.
     * If we return true, onMotionEvent will be called and we do the actual
     * scrolling there.
     */

    final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;

    // Always take care of the touch gesture being complete.
    if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
        // Release the drag.
        if (DEBUG)
            Log.v(TAG, "Intercept done!");
        mIsBeingDragged = false;
        mIsUnableToDrag = false;
        mActivePointerId = INVALID_POINTER;
        if (mVelocityTracker != null) {
            mVelocityTracker.recycle();
            mVelocityTracker = null;
        }
        return false;
    }

    // Nothing more to do here if we have decided whether or not we
    // are dragging.
    if (action != MotionEvent.ACTION_DOWN) {
        if (mIsBeingDragged) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning true!");
            return true;
        }
        if (mIsUnableToDrag) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning false!");
            return false;
        }
    }

    switch (action) {
    case MotionEvent.ACTION_MOVE: {
        /*
         * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
         * whether the user has moved far enough from his original down touch.
         */

        /*
        * Locally do absolute value. mLastMotionY is set to the y value
        * of the down event.
        */
        final int activePointerId = mActivePointerId;
        if (activePointerId == INVALID_POINTER) {
            // If we don't have a valid id, the touch down wasn't on content.
            break;
        }

        final int pointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
        final float x = MotionEventCompat.getX(ev, pointerIndex);
        final float y = MotionEventCompat.getY(ev, pointerIndex);

        if (mOrientation == HORIZONTAL) {
            final float dx = x - mLastMotionX;
            final float xDiff = Math.abs(dx);
            final float yDiff = Math.abs(y - mInitialMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

            if (dx != 0 && !isGutterDrag(mLastMotionX, dx)
                    && canScroll(this, false, (int) dx, 0, (int) x, (int) y)) {
                // Nested view has scrollable area under this point. Let it be handled there.
                mLastMotionX = x;
                mLastMotionY = y;
                mIsUnableToDrag = true;
                return false;
            }
            if (xDiff > mTouchSlop && xDiff * 0.5f > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                setScrollState(SCROLL_STATE_DRAGGING);
                mLastMotionX = dx > 0 ? mInitialMotionX + mTouchSlop : mInitialMotionX - mTouchSlop;
                mLastMotionY = y;
                setScrollingCacheEnabled(true);
            } else if (yDiff > mTouchSlop) {
                // The finger has moved enough in the vertical
                // direction to be counted as a drag...  abort
                // any attempt to drag horizontally, to work correctly
                // with children that have scrolling containers.
                if (DEBUG)
                    Log.v(TAG, "Starting unable to drag!");
                mIsUnableToDrag = true;
            }
            if (mIsBeingDragged) {
                // Scroll to follow the motion event
                if (performDrag(x)) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        } else {
            final float dy = y - mLastMotionY;
            final float yDiff = Math.abs(dy);
            final float xDiff = Math.abs(x - mInitialMotionX);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

            if (dy != 0 && !isGutterDrag(mLastMotionY, dy)
                    && canScroll(this, false, 0, (int) dy, (int) x, (int) y)) {
                // Nested view has scrollable area under this point. Let it be handled there.
                mLastMotionX = x;
                mLastMotionY = y;
                mIsUnableToDrag = true;
                return false;
            }
            if (yDiff > mTouchSlop && yDiff * 0.5f > xDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                setScrollState(SCROLL_STATE_DRAGGING);
                mLastMotionX = x;
                mLastMotionY = dy > 0 ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop;
                setScrollingCacheEnabled(true);
            } else if (xDiff > mTouchSlop) {
                // The finger has moved enough in the horizontal
                // direction to be counted as a drag...  abort
                // any attempt to drag vertically, to work correctly
                // with children that have scrolling containers.
                if (DEBUG)
                    Log.v(TAG, "Starting unable to drag!");
                mIsUnableToDrag = true;
            }
            if (mIsBeingDragged) {
                // Scroll to follow the motion event
                if (performDrag(y)) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        }
        break;
    }

    case MotionEvent.ACTION_DOWN: {
        /*
         * Remember location of down touch.
         * ACTION_DOWN always refers to pointer index 0.
         */
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        mIsUnableToDrag = false;

        mScroller.computeScrollOffset();
        int scrollDistance = mOrientation == HORIZONTAL ? mScroller.getFinalX() - mScroller.getCurrX()
                : mScroller.getFinalY() - mScroller.getCurrY();

        if (mScrollState == SCROLL_STATE_SETTLING && Math.abs(scrollDistance) > mCloseEnough) {
            // Let the user 'catch' the pager as it animates.
            mScroller.abortAnimation();
            mPopulatePending = false;
            populate();
            mIsBeingDragged = true;
            setScrollState(SCROLL_STATE_DRAGGING);
        } else {
            completeScroll(false);
            mIsBeingDragged = false;
        }

        if (DEBUG)
            Log.v(TAG, "Down at " + mLastMotionX + "," + mLastMotionY + " mIsBeingDragged=" + mIsBeingDragged
                    + "mIsUnableToDrag=" + mIsUnableToDrag);
        break;
    }

    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        break;
    }

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

    /*
     * The only time we want to intercept motion events is if we are in the
     * drag mode.
     */
    return mIsBeingDragged;
}

From source file:android.improving.utils.views.cardsview.OrientedViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*//from www. j  a v  a 2s . com
     * This method JUST determines whether we want to intercept the motion.
     * If we return true, onMotionEvent will be called and we do the actual
     * scrolling there.
     */

    final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;

    // Always take care of the touch gesture being complete.
    if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
        // Release the drag.
        if (DEBUG)
            Log.v(TAG, "Intercept done!");
        mIsBeingDragged = false;
        mIsUnableToDrag = false;
        mActivePointerId = INVALID_POINTER;
        if (mVelocityTracker != null) {
            mVelocityTracker.recycle();
            mVelocityTracker = null;
        }
        return false;
    }

    // Nothing more to do here if we have decided whether or not we
    // are dragging.
    if (action != MotionEvent.ACTION_DOWN) {
        if (mIsBeingDragged) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning true!");
            return true;
        }
        if (mIsUnableToDrag) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning false!");
            return false;
        }
    }

    switch (action) {
    case MotionEvent.ACTION_MOVE: {
        /*
         * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
         * whether the user has moved far enough from his original down touch.
         */

        /*
        * Locally do absolute value. mLastMotionY is set to the y value
        * of the down event.
        */
        final int activePointerId = mActivePointerId;
        if (activePointerId == INVALID_POINTER) {
            // If we don't have a valid id, the touch down wasn't on content.
            break;
        }

        final int pointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
        if (mOrientation == Orientation.VERTICAL) {
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float dy = y - mLastMotionY;
            final float yDiff = Math.abs(dy);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mInitialMotionX);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

            if (dy != 0 && !isGutterDrag(mLastMotionY, dy)
                    && canScroll(this, false, (int) dy, (int) x, (int) y)) {
                // Nested view has scrollable area under this point. Let it be handled there.
                mLastMotionX = x;
                mLastMotionY = y;
                mIsUnableToDrag = true;
                return false;
            }
            if (yDiff > mTouchSlop && yDiff * 0.5f > xDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                requestParentDisallowInterceptTouchEvent(true);
                setScrollState(SCROLL_STATE_DRAGGING);
                mLastMotionY = dy > 0 ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop;
                mLastMotionX = x;
                setScrollingCacheEnabled(true);
            } else if (xDiff > mTouchSlop) {
                // The finger has moved enough in the vertical
                // direction to be counted as a drag...  abort
                // any attempt to drag horizontally, to work correctly
                // with children that have scrolling containers.
                if (DEBUG)
                    Log.v(TAG, "Starting unable to drag!");
                mIsUnableToDrag = true;
            }
            if (mIsBeingDragged) {
                // Scroll to follow the motion event
                if (performDrag(y)) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        } else {
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float dx = x - mLastMotionX;
            final float xDiff = Math.abs(dx);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mInitialMotionY);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

            if (dx != 0 && !isGutterDrag(mLastMotionX, dx)
                    && canScroll(this, false, (int) dx, (int) x, (int) y)) {
                // Nested view has scrollable area under this point. Let it be handled there.
                mLastMotionX = x;
                mLastMotionY = y;
                mIsUnableToDrag = true;
                return false;
            }
            if (xDiff > mTouchSlop && xDiff * 0.5f > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                requestParentDisallowInterceptTouchEvent(true);
                setScrollState(SCROLL_STATE_DRAGGING);
                mLastMotionX = dx > 0 ? mInitialMotionX + mTouchSlop : mInitialMotionX - mTouchSlop;
                mLastMotionY = y;
                setScrollingCacheEnabled(true);
            } else if (yDiff > mTouchSlop) {
                // The finger has moved enough in the vertical
                // direction to be counted as a drag...  abort
                // any attempt to drag horizontally, to work correctly
                // with children that have scrolling containers.
                if (DEBUG)
                    Log.v(TAG, "Starting unable to drag!");
                mIsUnableToDrag = true;
            }
            if (mIsBeingDragged) {
                // Scroll to follow the motion event
                if (performDrag(x)) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        }
        break;
    }

    case MotionEvent.ACTION_DOWN: {
        /*
         * Remember location of down touch.
         * ACTION_DOWN always refers to pointer index 0.
         */
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        mIsUnableToDrag = false;

        mScroller.computeScrollOffset();
        if (mOrientation == Orientation.VERTICAL) {
            if (mScrollState == SCROLL_STATE_SETTLING
                    && Math.abs(mScroller.getFinalY() - mScroller.getCurrY()) > mCloseEnough) {
                // Let the user 'catch' the pager as it animates.
                mScroller.abortAnimation();
                mPopulatePending = false;
                populate();
                mIsBeingDragged = true;
                requestParentDisallowInterceptTouchEvent(true);
                setScrollState(SCROLL_STATE_DRAGGING);
            } else {
                completeScroll(false);
                mIsBeingDragged = false;
            }
        } else {
            if (mScrollState == SCROLL_STATE_SETTLING
                    && Math.abs(mScroller.getFinalX() - mScroller.getCurrX()) > mCloseEnough) {
                // Let the user 'catch' the pager as it animates.
                mScroller.abortAnimation();
                mPopulatePending = false;
                populate();
                mIsBeingDragged = true;
                requestParentDisallowInterceptTouchEvent(true);
                setScrollState(SCROLL_STATE_DRAGGING);
            } else {
                completeScroll(false);
                mIsBeingDragged = false;
            }
        }

        if (DEBUG)
            Log.v(TAG, "Down at " + mLastMotionX + "," + mLastMotionY + " mIsBeingDragged=" + mIsBeingDragged
                    + "mIsUnableToDrag=" + mIsUnableToDrag);
        break;
    }

    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        break;
    }

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

    /*
     * The only time we want to intercept motion events is if we are in the
     * drag mode.
     */
    return mIsBeingDragged;
}

From source file:com.example.eventtest.CustomViews.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;
    }//from  w w  w .j  a  v a 2s. 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: {
        mScroller.abortAnimation();
        mPopulatePending = false;
        populate();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            if (pointerIndex == -1) {
                // A child has consumed some touch events and put us into an inconsistent state.
                needsInvalidate = resetTouch();
                break;
            }
            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;
                requestParentDisallowInterceptTouchEvent(true);
                mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop
                        : mInitialMotionX - mTouchSlop;
                mLastMotionY = y;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);

                // Disallow Parent Intercept, just in case
                ViewParent parent = getParent();
                if (parent != null) {
                    parent.requestDisallowInterceptTouchEvent(true);
                }
            }
        }
        // Not else! Note that mIsBeingDragged can be set above.
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            needsInvalidate |= performDrag(x);
        }
        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 width = getClientWidth();
            final int scrollX = getScrollX();
            final ItemInfo ii = infoForCurrentScrollPosition();
            final float marginOffset = (float) mPageMargin / width;
            final int currentPage = ii.position;
            final float pageOffset = (((float) scrollX / width) - ii.offset) / (ii.widthFactor + marginOffset);
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final int totalDelta = (int) (x - mInitialMotionX);
            int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            needsInvalidate = resetTouch();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            scrollToItem(mCurItem, true, 0, false);
            needsInvalidate = resetTouch();
        }
        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.ifnoif.androidtestdemo.customview.VViewPager.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  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: {
        mScroller.abortAnimation();
        mPopulatePending = false;
        populate();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            if (pointerIndex == -1) {
                // A child has consumed some touch events and put us into an inconsistent state.
                needsInvalidate = resetTouch();
                break;
            }
            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 (yDiff > mTouchSlop && yDiff > xDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                requestParentDisallowInterceptTouchEvent(true);
                mLastMotionY = y - mInitialMotionY > 0 ? mInitialMotionY + mTouchSlop
                        : mInitialMotionY - mTouchSlop;
                mLastMotionX = x;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);

                // Disallow Parent Intercept, just in case
                ViewParent parent = getParent();
                if (parent != null) {
                    parent.requestDisallowInterceptTouchEvent(true);
                }
            }
        }
        // Not else! Note that mIsBeingDragged can be set above.
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float y = MotionEventCompat.getY(ev, activePointerIndex);
            needsInvalidate |= performDrag(y);
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = (int) VelocityTrackerCompat.getYVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int height = getClientHeight();
            final int scrollY = getScrollY();
            final ItemInfo ii = infoForCurrentScrollPosition();
            final int currentPage = ii.position;
            final float pageOffset = (((float) scrollY / height) - ii.offset) / ii.heightFactor;
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float y = MotionEventCompat.getY(ev, activePointerIndex);
            final int totalDelta = (int) (y - mInitialMotionY);
            int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            needsInvalidate = resetTouch();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            scrollToItem(mCurItem, true, 0, false);
            needsInvalidate = resetTouch();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);
        final float y = MotionEventCompat.getY(ev, index);
        mLastMotionY = y;
        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionY = MotionEventCompat.getY(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    }
    if (needsInvalidate) {
        ViewCompat.postInvalidateOnAnimation(this);
    }
    return true;
}

From source file:com.example.myronlg.cardviewpagerdemo.MultiCardViewPager.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  va  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: {
        mScroller.abortAnimation();
        mPopulatePending = false;
        populate();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        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;
                requestParentDisallowInterceptTouchEvent(true);
                mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop
                        : mInitialMotionX - mTouchSlop;
                mLastMotionY = y;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);

                // Disallow Parent Intercept, just in case
                ViewParent parent = getParent();
                if (parent != null) {
                    parent.requestDisallowInterceptTouchEvent(true);
                }
            }
        }
        // Not else! Note that mIsBeingDragged can be set above.
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            needsInvalidate |= performDrag(x);
        }
        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 width = getClientWidth();
            final int scrollX = getScrollX();
            final ItemInfo ii = infoForCurrentScrollPosition();
            final int currentPage = ii.position;
            final float pageOffset = (((float) scrollX / width) - ii.offset) / ii.widthFactor;
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float x = MotionEventCompat.getX(ev, activePointerIndex);
            final int totalDelta = (int) (x - mInitialMotionX);
            if (Math.abs(initialVelocity) < 4000) {
                int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
                setCurrentItemInternal(nextPage, true, true, initialVelocity);
            } else {
                fling = true;
                //                        Log.e("Velocity", initialVelocity + "");
                mScroller.fling(getScrollX(), getScrollY(), -initialVelocity, 0, minScrollX, maxScrollX,
                        getScrollY(), getScrollY());
            }

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mLeftEdge.onRelease() | mRightEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            scrollToItem(mCurItem, true, 0, 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) {
        ViewCompat.postInvalidateOnAnimation(this);
    }
    return true;
}

From source file:example.luojing.androidsourceanalysis.ViewPager.java

/**
 * ?//  w w w . ja  v a  2 s.  c  o m
 */
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*
     * This method JUST determines whether we want to intercept the motion.
     * If we return true, onMotionEvent will be called and we do the actual
     * scrolling there.
     */

    final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;

    // Always take care of the touch gesture being complete.
    if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
        // Release the drag.
        if (DEBUG)
            Log.v(TAG, "Intercept done!");
        resetTouch();
        return false;
    }

    // Nothing more to do here if we have decided whether or not we
    // are dragging.
    if (action != MotionEvent.ACTION_DOWN) {
        if (mIsBeingDragged) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning true!");
            return true;
        }
        if (mIsUnableToDrag) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning false!");
            return false;
        }
    }

    switch (action) {
    case MotionEvent.ACTION_MOVE: {
        /*
         * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
         * whether the user has moved far enough from his original down touch.
         */

        /*
        * Locally do absolute value. mLastMotionY is set to the y value
        * of the down event.
        */
        final int activePointerId = mActivePointerId;
        if (activePointerId == INVALID_POINTER) {
            // If we don't have a valid id, the touch down wasn't on content.
            break;
        }

        final int pointerIndex = ev.findPointerIndex(activePointerId);
        final float x = ev.getX(pointerIndex);
        final float dx = x - mLastMotionX;
        final float xDiff = Math.abs(dx);
        final float y = ev.getY(pointerIndex);
        final float yDiff = Math.abs(y - mInitialMotionY);
        if (DEBUG)
            Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

        if (dx != 0 && !isGutterDrag(mLastMotionX, dx) && canScroll(this, false, (int) dx, (int) x, (int) y)) {
            // Nested view has scrollable area under this point. Let it be handled there.
            mLastMotionX = x;
            mLastMotionY = y;
            mIsUnableToDrag = true;
            return false;
        }
        if (xDiff > mTouchSlop && xDiff * 0.5f > yDiff) {
            if (DEBUG)
                Log.v(TAG, "Starting drag!");
            mIsBeingDragged = true;
            requestParentDisallowInterceptTouchEvent(true);
            setScrollState(SCROLL_STATE_DRAGGING);
            mLastMotionX = dx > 0 ? mInitialMotionX + mTouchSlop : mInitialMotionX - mTouchSlop;
            mLastMotionY = y;
            setScrollingCacheEnabled(true);
        } else if (yDiff > mTouchSlop) {
            // The finger has moved enough in the vertical
            // direction to be counted as a drag...  abort
            // any attempt to drag horizontally, to work correctly
            // with children that have scrolling containers.
            if (DEBUG)
                Log.v(TAG, "Starting unable to drag!");
            mIsUnableToDrag = true;
        }
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            if (performDrag(x)) {
                ViewCompat.postInvalidateOnAnimation(this);
            }
        }
        break;
    }

    case MotionEvent.ACTION_DOWN: {
        /*
         * Remember location of down touch.
         * ACTION_DOWN always refers to pointer index 0.
         */
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = ev.getPointerId(0);
        mIsUnableToDrag = false;

        mIsScrollStarted = true;
        mScroller.computeScrollOffset();
        if (mScrollState == SCROLL_STATE_SETTLING
                && Math.abs(mScroller.getFinalX() - mScroller.getCurrX()) > mCloseEnough) {
            // Let the user 'catch' the pager as it animates.
            mScroller.abortAnimation();
            mPopulatePending = false;
            populate();
            mIsBeingDragged = true;
            requestParentDisallowInterceptTouchEvent(true);
            setScrollState(SCROLL_STATE_DRAGGING);
        } else {
            completeScroll(false);
            mIsBeingDragged = false;
        }

        if (DEBUG) {
            Log.v(TAG, "Down at " + mLastMotionX + "," + mLastMotionY + " mIsBeingDragged=" + mIsBeingDragged
                    + "mIsUnableToDrag=" + mIsUnableToDrag);
        }
        break;
    }

    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        break;
    }

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

    /*
     * The only time we want to intercept motion events is if we are in the
     * drag mode.
     */
    return mIsBeingDragged;
}

From source file:com.tjych.swip.vertical.DirectionalViewPager.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 .j  ava 2 s .co  m*/

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

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

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

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

    switch (action & MotionEventCompat.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        mScroller.abortAnimation();
        mPopulatePending = false;
        populate();
        mIsBeingDragged = true;
        setScrollState(SCROLL_STATE_DRAGGING);

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        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 (mOrientation == HORIZONTAL) {
                if (xDiff > mTouchSlop && xDiff > yDiff) {
                    if (DEBUG)
                        Log.v(TAG, "Starting drag!");
                    mIsBeingDragged = true;
                    mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop
                            : mInitialMotionX - mTouchSlop;
                    mLastMotionY = y;
                    setScrollState(SCROLL_STATE_DRAGGING);
                    setScrollingCacheEnabled(true);
                }
            } else {
                if (yDiff > mTouchSlop && yDiff > xDiff) {
                    if (DEBUG)
                        Log.v(TAG, "Starting drag!");
                    mIsBeingDragged = true;
                    mLastMotionX = x;
                    mLastMotionY = y - mInitialMotionY > 0 ? mInitialMotionY + mTouchSlop
                            : mInitialMotionY - mTouchSlop;
                    ;
                    setScrollState(SCROLL_STATE_DRAGGING);
                    setScrollingCacheEnabled(true);
                }
            }
        }
        // Not else! Note that mIsBeingDragged can be set above.
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);

            final float coord = mOrientation == HORIZONTAL ? MotionEventCompat.getX(ev, activePointerIndex)
                    : MotionEventCompat.getY(ev, activePointerIndex);

            needsInvalidate |= performDrag(coord);
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int initialVelocity = mOrientation == HORIZONTAL
                    ? (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId)
                    : (int) VelocityTrackerCompat.getYVelocity(velocityTracker, mActivePointerId);
            mPopulatePending = true;
            final int dimension = getClientDimension();
            final int scrollCoord = getScrollCoord();
            final ItemInfo ii = infoForCurrentScrollPosition();
            final int currentPage = ii.position;
            final float pageOffset = (((float) scrollCoord / dimension) - ii.offset) / ii.dimensionFactor;
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float coord = mOrientation == HORIZONTAL ? MotionEventCompat.getX(ev, activePointerIndex)
                    : MotionEventCompat.getY(ev, activePointerIndex);
            final int totalDelta = mOrientation == HORIZONTAL ? (int) (coord - mInitialMotionX)
                    : (int) (coord - mInitialMotionY);
            int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mStartEdge.onRelease() | mEndEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            scrollToItem(mCurItem, true, 0, false);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mStartEdge.onRelease() | mEndEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        final int index = MotionEventCompat.getActionIndex(ev);

        if (mOrientation == HORIZONTAL) {
            final float coord = MotionEventCompat.getX(ev, index);
            mLastMotionX = coord;
        } else {
            final float coord = MotionEventCompat.getY(ev, index);
            mLastMotionY = coord;
        }

        mActivePointerId = MotionEventCompat.getPointerId(ev, index);
        break;
    }
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);

        if (mOrientation == HORIZONTAL) {
            mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        } else {
            mLastMotionY = MotionEventCompat.getY(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        }

        break;
    }
    if (needsInvalidate) {
        ViewCompat.postInvalidateOnAnimation(this);
    }
    return true;
}

From source file:android.improving.utils.views.cardsview.OrientedViewPager.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  va 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: {
        mScroller.abortAnimation();
        mPopulatePending = false;
        populate();

        // Remember where the motion event started
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    }
    case MotionEvent.ACTION_MOVE:
        if (!mIsBeingDragged) {
            final int pointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float y = MotionEventCompat.getY(ev, pointerIndex);
            final float yDiff = Math.abs(y - mLastMotionY);
            final float x = MotionEventCompat.getX(ev, pointerIndex);
            final float xDiff = Math.abs(x - mLastMotionX);
            if (DEBUG)
                Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);
            if (mOrientation == Orientation.VERTICAL) {
                if (yDiff > mTouchSlop && yDiff > xDiff) {
                    if (DEBUG)
                        Log.v(TAG, "Starting drag!");
                    mIsBeingDragged = true;
                    requestParentDisallowInterceptTouchEvent(true);
                    mLastMotionY = y - mInitialMotionY > 0 ? mInitialMotionY + mTouchSlop
                            : mInitialMotionY - mTouchSlop;
                    mLastMotionX = x;
                    setScrollState(SCROLL_STATE_DRAGGING);
                    setScrollingCacheEnabled(true);

                    // Disallow Parent Intercept, just in case
                    ViewParent parent = getParent();
                    if (parent != null) {
                        parent.requestDisallowInterceptTouchEvent(true);
                    }
                }
            } else {
                if (xDiff > mTouchSlop && xDiff > yDiff) {
                    if (DEBUG)
                        Log.v(TAG, "Starting drag!");
                    mIsBeingDragged = true;
                    requestParentDisallowInterceptTouchEvent(true);
                    mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop
                            : mInitialMotionX - mTouchSlop;
                    mLastMotionY = y;
                    setScrollState(SCROLL_STATE_DRAGGING);
                    setScrollingCacheEnabled(true);

                    // Disallow Parent Intercept, just in case
                    ViewParent parent = getParent();
                    if (parent != null) {
                        parent.requestDisallowInterceptTouchEvent(true);
                    }
                }
            }
        }
        // Not else! Note that mIsBeingDragged can be set above.
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            if (mOrientation == Orientation.VERTICAL) {
                final float y = MotionEventCompat.getY(ev, activePointerIndex);
                needsInvalidate |= performDrag(y);
            } else {
                final float x = MotionEventCompat.getX(ev, activePointerIndex);
                needsInvalidate |= performDrag(x);
            }
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mIsBeingDragged) {
            int currentPage;
            int initialVelocity;
            int totalDelta;
            float pageOffset;
            if (mOrientation == Orientation.VERTICAL) {
                final VelocityTracker velocityTracker = mVelocityTracker;
                velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                initialVelocity = (int) VelocityTrackerCompat.getYVelocity(velocityTracker, mActivePointerId);
                mPopulatePending = true;
                final int height = getClientSize();
                final int scrollY = getScrollY();
                final ItemInfo ii = infoForCurrentScrollPosition();
                currentPage = ii.position;
                pageOffset = (((float) scrollY / height) - ii.offset) / ii.sizeFactor;
                final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
                final float y = MotionEventCompat.getY(ev, activePointerIndex);
                totalDelta = (int) (y - mInitialMotionY);
            } else {
                final VelocityTracker velocityTracker = mVelocityTracker;
                velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker, mActivePointerId);
                mPopulatePending = true;
                final int width = getClientSize();
                final int scrollX = getScrollX();
                final ItemInfo ii = infoForCurrentScrollPosition();
                currentPage = ii.position;
                pageOffset = (((float) scrollX / width) - ii.offset) / ii.sizeFactor;
                final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
                final float x = MotionEventCompat.getX(ev, activePointerIndex);
                totalDelta = (int) (x - mInitialMotionX);
            }
            int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, totalDelta);
            setCurrentItemInternal(nextPage, true, true, initialVelocity);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mTopLeftEdge.onRelease() | mRightBottomEdge.onRelease();
        }
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            scrollToItem(mCurItem, true, 0, false);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mTopLeftEdge.onRelease() | mRightBottomEdge.onRelease();
        }
        break;
    case MotionEventCompat.ACTION_POINTER_DOWN: {
        int index;
        if (mOrientation == Orientation.VERTICAL) {
            index = MotionEventCompat.getActionIndex(ev);
            final float y = MotionEventCompat.getY(ev, index);
            mLastMotionY = y;
        } else {
            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);
        if (mOrientation == Orientation.VERTICAL) {
            mLastMotionY = MotionEventCompat.getY(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        } else {
            mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        }
        break;
    }
    if (needsInvalidate) {
        ViewCompat.postInvalidateOnAnimation(this);
    }
    return true;
}

From source file:cn.androidy.materialdesignsample.ryanharterviewpager.ViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*//  ww  w  .ja va2  s.c  o  m
     * This method JUST determines whether we want to intercept the motion.
     * If we return true, onMotionEvent will be called and we do the actual
     * scrolling there.
     */

    final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;

    // Always take care of the touch gesture being complete.
    if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
        // Release the drag.
        if (DEBUG)
            Log.v(TAG, "Intercept done!");
        mIsBeingDragged = false;
        mIsUnableToDrag = false;
        mActivePointerId = INVALID_POINTER;
        if (mVelocityTracker != null) {
            mVelocityTracker.recycle();
            mVelocityTracker = null;
        }
        return false;
    }

    // Nothing more to do here if we have decided whether or not we
    // are dragging.
    if (action != MotionEvent.ACTION_DOWN) {
        if (mIsBeingDragged) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning true!");
            return true;
        }
        if (mIsUnableToDrag) {
            if (DEBUG)
                Log.v(TAG, "Intercept returning false!");
            return false;
        }
    }

    switch (action) {
    case MotionEvent.ACTION_MOVE: {
        /*
         * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
         * whether the user has moved far enough from his original down touch.
         */

        /*
        * Locally do absolute value. mLastMotionY is set to the y value
        * of the down event.
        */
        final int activePointerId = mActivePointerId;
        if (activePointerId == INVALID_POINTER) {
            // If we don't have a valid id, the touch down wasn't on content.
            break;
        }

        final int pointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
        final float x = MotionEventCompat.getX(ev, pointerIndex);
        final float dx = x - mLastMotionX;
        final float xDiff = Math.abs(dx);
        final float y = MotionEventCompat.getY(ev, pointerIndex);
        final float dy = y - mLastMotionY;
        final float yDiff = Math.abs(y - mInitialMotionY);
        if (DEBUG)
            Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

        if (isOrientationHorizontal()) {
            if (dx != 0 && !isGutterDrag(mLastMotionX, dx)
                    && canScroll(this, false, (int) dx, (int) x, (int) y)) {
                // Nested view has scrollable area under this point. Let it be handled there.
                mLastMotionX = x;
                mLastMotionY = y;
                mIsUnableToDrag = true;
                return false;
            }
            if (xDiff > mTouchSlop && xDiff * 0.5f > yDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                setScrollState(SCROLL_STATE_DRAGGING);
                mLastMotionX = dx > 0 ? mInitialMotionX + mTouchSlop : mInitialMotionX - mTouchSlop;
                mLastMotionY = y;
                setScrollingCacheEnabled(true);
            } else if (yDiff > mTouchSlop) {
                // The finger has moved enough in the vertical
                // direction to be counted as a drag...  abort
                // any attempt to drag horizontally, to work correctly
                // with children that have scrolling containers.
                if (DEBUG)
                    Log.v(TAG, "Starting unable to drag!");
                mIsUnableToDrag = true;
            }
            if (mIsBeingDragged) {
                // Scroll to follow the motion event
                if (performDrag(x)) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        } else {
            if (dy != 0 && !isGutterDrag(mLastMotionY, dy)
                    && canScroll(this, false, (int) dx, (int) x, (int) y)) {
                // Nested view has scrollable area under this point. Let it be handled there.
                mLastMotionX = x;
                mLastMotionY = y;
                mIsUnableToDrag = true;
                return false;
            }
            if (yDiff > mTouchSlop && yDiff * 0.5f > xDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                setScrollState(SCROLL_STATE_DRAGGING);
                mLastMotionY = dy > 0 ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop;
                mLastMotionX = x;
                setScrollingCacheEnabled(true);
            } else if (xDiff > mTouchSlop) {
                // The finger has moved enough in the vertical
                // direction to be counted as a drag...  abort
                // any attempt to drag horizontally, to work correctly
                // with children that have scrolling containers.
                if (DEBUG)
                    Log.v(TAG, "Starting unable to drag!");
                mIsUnableToDrag = true;
            }
            if (mIsBeingDragged) {
                // Scroll to follow the motion event
                if (performDrag(y)) {
                    ViewCompat.postInvalidateOnAnimation(this);
                }
            }
        }
        break;
    }

    case MotionEvent.ACTION_DOWN: {
        /*
         * Remember location of down touch.
         * ACTION_DOWN always refers to pointer index 0.
         */
        mLastMotionX = mInitialMotionX = ev.getX();
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        mIsUnableToDrag = false;

        mScroller.computeScrollOffset();
        int distance = 0;
        if (isOrientationHorizontal()) {
            distance = Math.abs(mScroller.getFinalX() - mScroller.getCurrX());
        } else {
            distance = Math.abs(mScroller.getFinalY() - mScroller.getCurrY());
        }
        if (mScrollState == SCROLL_STATE_SETTLING && distance > mCloseEnough) {
            // Let the user 'catch' the pager as it animates.
            mScroller.abortAnimation();
            mPopulatePending = false;
            populate();
            mIsBeingDragged = true;
            setScrollState(SCROLL_STATE_DRAGGING);
        } else {
            completeScroll(false);
            mIsBeingDragged = false;
        }

        if (DEBUG)
            Log.v(TAG, "Down at " + mLastMotionX + "," + mLastMotionY + " mIsBeingDragged=" + mIsBeingDragged
                    + "mIsUnableToDrag=" + mIsUnableToDrag);
        break;
    }

    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        break;
    }

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

    /*
     * The only time we want to intercept motion events is if we are in the
     * drag mode.
     */
    return mIsBeingDragged;
}