Example usage for android.view MotionEvent ACTION

Introduction

In this page you can find the example usage for android.view MotionEvent ACTION_MOVE.

Prototype

int ACTION_MOVE

To view the source code for android.view MotionEvent ACTION_MOVE.

Click Source Link

Document

Constant for #getActionMasked : A change has happened during a press gesture (between #ACTION_DOWN and #ACTION_UP ).

Usage

From source file:administrator.example.com.myscrollview.VerticalViewPager.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;
    } /* end of if */

    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;
    } /* end of if */

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

    if (mVelocityTracker == null) {
        mVelocityTracker = VelocityTracker.obtain();
    } /* end of if */
    mVelocityTracker.addMovement(ev);//from   w w  w. ja v a2 s .c  o m

    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
        mLastMotionY = mInitialMotionY = ev.getY();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        break;
    } /* end of case */
    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 (yDiff > mTouchSlop && yDiff > xDiff) {
                if (DEBUG)
                    Log.v(TAG, "Starting drag!");
                mIsBeingDragged = true;
                mLastMotionY = y;
                setScrollState(SCROLL_STATE_DRAGGING);
                setScrollingCacheEnabled(true);
            } /* end of if */
        } /* end of if */
        if (mIsBeingDragged) {
            // Scroll to follow the motion event
            final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
            final float y = MotionEventCompat.getY(ev, activePointerIndex);
            final float deltaY = mLastMotionY - y;
            mLastMotionY = y;
            float oldScrollY = getScrollY();
            float scrollY = oldScrollY + deltaY;
            final int height = getHeight();
            final int heightWithMargin = height + mPageMargin;

            final int lastItemIndex = mAdapter.getCount() - 1;
            final float topBound = Math.max(0, (mCurItem - 1) * heightWithMargin);
            final float bottomBound = Math.min(mCurItem + 1, lastItemIndex) * heightWithMargin;
            if (scrollY < topBound) {
                if (topBound == 0) {
                    float over = -scrollY;
                    needsInvalidate = mTopEdge.onPull(over / height);
                } /* end of if */
                scrollY = topBound;
            } else if (scrollY > bottomBound) {
                if (bottomBound == lastItemIndex * heightWithMargin) {
                    float over = scrollY - bottomBound;
                    needsInvalidate = mBottomEdge.onPull(over / height);
                } /* end of if */
                scrollY = bottomBound;
            } /* end of if */
            // Don't lose the rounded component
            mLastMotionY += scrollY - (int) scrollY;
            scrollTo(getScrollX(), (int) scrollY);
            pageScrolled((int) scrollY);
        } /* end of if */
        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 heightWithMargin = getHeight() + mPageMargin;
            final int scrollY = getScrollY();
            final int currentPage = scrollY / heightWithMargin;
            final float pageOffset = (float) (scrollY % heightWithMargin) / heightWithMargin;
            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);

            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mTopEdge.onRelease() | mBottomEdge.onRelease();
        } /* end of if */
        break;
    case MotionEvent.ACTION_CANCEL:
        if (mIsBeingDragged) {
            setCurrentItemInternal(mCurItem, true, true);
            mActivePointerId = INVALID_POINTER;
            endDrag();
            needsInvalidate = mTopEdge.onRelease() | mBottomEdge.onRelease();
        } /* end of if */
        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;
    } /* end of case */
    case MotionEventCompat.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        mLastMotionY = MotionEventCompat.getY(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
        break;
    } /* end of switch */
    if (needsInvalidate) {
        invalidate();
    } /* end of if */
    return true;
}

From source file:cc.flydev.launcher.Page.java

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (DISABLE_TOUCH_INTERACTION) {
        return false;
    }//w  w  w. j a v  a 2 s. com

    super.onTouchEvent(ev);

    // Skip touch handling if there are no pages to swipe
    if (getChildCount() <= 0)
        return super.onTouchEvent(ev);

    acquireVelocityTrackerAndAddMovement(ev);

    final int action = ev.getAction();

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

        // Remember where the motion event started
        mDownMotionX = mLastMotionX = ev.getX();
        mDownMotionY = mLastMotionY = ev.getY();
        mDownScrollX = getScrollX();
        float[] p = mapPointFromViewToParent(this, mLastMotionX, mLastMotionY);
        mParentDownMotionX = p[0];
        mParentDownMotionY = p[1];
        mLastMotionXRemainder = 0;
        mTotalMotionX = 0;
        mActivePointerId = ev.getPointerId(0);

        if (mTouchState == TOUCH_STATE_SCROLLING) {
            pageBeginMoving();
        }
        break;

    case MotionEvent.ACTION_MOVE:
        if (mTouchState == TOUCH_STATE_SCROLLING) {
            // Scroll to follow the motion event
            final int pointerIndex = ev.findPointerIndex(mActivePointerId);

            if (pointerIndex == -1)
                return true;

            final float x = ev.getX(pointerIndex);
            final float deltaX = mLastMotionX + mLastMotionXRemainder - x;

            mTotalMotionX += Math.abs(deltaX);

            // Only scroll and update mLastMotionX if we have moved some discrete amount.  We
            // keep the remainder because we are actually testing if we've moved from the last
            // scrolled position (which is discrete).
            if (Math.abs(deltaX) >= 1.0f) {
                mTouchX += deltaX;
                mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                if (!mDeferScrollUpdate) {
                    scrollBy((int) deltaX, 0);
                    if (DEBUG)
                        Log.d(TAG, "onTouchEvent().Scrolling: " + deltaX);
                } else {
                    invalidate();
                }
                mLastMotionX = x;
                mLastMotionXRemainder = deltaX - (int) deltaX;
            } else {
                awakenScrollBars();
            }
        } else if (mTouchState == TOUCH_STATE_REORDERING) {
            // Update the last motion position
            mLastMotionX = ev.getX();
            mLastMotionY = ev.getY();

            // Update the parent down so that our zoom animations take this new movement into
            // account
            float[] pt = mapPointFromViewToParent(this, mLastMotionX, mLastMotionY);
            mParentDownMotionX = pt[0];
            mParentDownMotionY = pt[1];
            updateDragViewTranslationDuringDrag();

            // Find the closest page to the touch point
            final int dragViewIndex = indexOfChild(mDragView);

            // Change the drag view if we are hovering over the drop target
            boolean isHoveringOverDelete = isHoveringOverDeleteDropTarget((int) mParentDownMotionX,
                    (int) mParentDownMotionY);
            setPageHoveringOverDeleteDropTarget(dragViewIndex, isHoveringOverDelete);

            if (DEBUG)
                Log.d(TAG, "mLastMotionX: " + mLastMotionX);
            if (DEBUG)
                Log.d(TAG, "mLastMotionY: " + mLastMotionY);
            if (DEBUG)
                Log.d(TAG, "mParentDownMotionX: " + mParentDownMotionX);
            if (DEBUG)
                Log.d(TAG, "mParentDownMotionY: " + mParentDownMotionY);

            final int pageUnderPointIndex = getNearestHoverOverPageIndex();
            if (pageUnderPointIndex > -1 && pageUnderPointIndex != indexOfChild(mDragView)
                    && !isHoveringOverDelete) {
                mTempVisiblePagesRange[0] = 0;
                mTempVisiblePagesRange[1] = getPageCount() - 1;
                getOverviewModePages(mTempVisiblePagesRange);
                if (mTempVisiblePagesRange[0] <= pageUnderPointIndex
                        && pageUnderPointIndex <= mTempVisiblePagesRange[1]
                        && pageUnderPointIndex != mSidePageHoverIndex && mScroller.isFinished()) {
                    mSidePageHoverIndex = pageUnderPointIndex;
                    mSidePageHoverRunnable = new Runnable() {
                        @Override
                        public void run() {
                            // Setup the scroll to the correct page before we swap the views
                            snapToPage(pageUnderPointIndex);

                            // For each of the pages between the paged view and the drag view,
                            // animate them from the previous position to the new position in
                            // the layout (as a result of the drag view moving in the layout)
                            int shiftDelta = (dragViewIndex < pageUnderPointIndex) ? -1 : 1;
                            int lowerIndex = (dragViewIndex < pageUnderPointIndex) ? dragViewIndex + 1
                                    : pageUnderPointIndex;
                            int upperIndex = (dragViewIndex > pageUnderPointIndex) ? dragViewIndex - 1
                                    : pageUnderPointIndex;
                            for (int i = lowerIndex; i <= upperIndex; ++i) {
                                View v = getChildAt(i);
                                // dragViewIndex < pageUnderPointIndex, so after we remove the
                                // drag view all subsequent views to pageUnderPointIndex will
                                // shift down.
                                int oldX = getViewportOffsetX() + getChildOffset(i);
                                int newX = getViewportOffsetX() + getChildOffset(i + shiftDelta);

                                // Animate the view translation from its old position to its new
                                // position
                                AnimatorSet anim = (AnimatorSet) v.getTag(ANIM_TAG_KEY);
                                if (anim != null) {
                                    anim.cancel();
                                }

                                v.setTranslationX(oldX - newX);
                                anim = new AnimatorSet();
                                anim.setDuration(REORDERING_REORDER_REPOSITION_DURATION);
                                anim.playTogether(ObjectAnimator.ofFloat(v, "translationX", 0f));
                                anim.start();
                                v.setTag(anim);
                            }

                            removeView(mDragView);
                            onRemoveView(mDragView, false);
                            addView(mDragView, pageUnderPointIndex);
                            onAddView(mDragView, pageUnderPointIndex);
                            mSidePageHoverIndex = -1;
                            mPageIndicator.setActiveMarker(getNextPage());
                        }
                    };
                    postDelayed(mSidePageHoverRunnable, REORDERING_SIDE_PAGE_HOVER_TIMEOUT);
                }
            } else {
                removeCallbacks(mSidePageHoverRunnable);
                mSidePageHoverIndex = -1;
            }
        } else {
            determineScrollingStart(ev);
        }
        break;

    case MotionEvent.ACTION_UP:
        if (mTouchState == TOUCH_STATE_SCROLLING) {
            final int activePointerId = mActivePointerId;
            final int pointerIndex = ev.findPointerIndex(activePointerId);
            final float x = ev.getX(pointerIndex);
            final VelocityTracker velocityTracker = mVelocityTracker;
            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
            int velocityX = (int) velocityTracker.getXVelocity(activePointerId);
            final int deltaX = (int) (x - mDownMotionX);
            final int pageWidth = getPageAt(mCurrentPage).getMeasuredWidth();
            boolean isSignificantMove = Math.abs(deltaX) > pageWidth * SIGNIFICANT_MOVE_THRESHOLD;

            mTotalMotionX += Math.abs(mLastMotionX + mLastMotionXRemainder - x);

            boolean isFling = mTotalMotionX > MIN_LENGTH_FOR_FLING
                    && Math.abs(velocityX) > mFlingThresholdVelocity;

            if (!mFreeScroll) {
                // In the case that the page is moved far to one direction and then is flung
                // in the opposite direction, we use a threshold to determine whether we should
                // just return to the starting page, or if we should skip one further.
                boolean returnToOriginalPage = false;
                if (Math.abs(deltaX) > pageWidth * RETURN_TO_ORIGINAL_PAGE_THRESHOLD
                        && Math.signum(velocityX) != Math.signum(deltaX) && isFling) {
                    returnToOriginalPage = true;
                }

                int finalPage;
                // We give flings precedence over large moves, which is why we short-circuit our
                // test for a large move if a fling has been registered. That is, a large
                // move to the left and fling to the right will register as a fling to the right.
                final boolean isRtl = isLayoutRtl();
                boolean isDeltaXLeft = isRtl ? deltaX > 0 : deltaX < 0;
                boolean isVelocityXLeft = isRtl ? velocityX > 0 : velocityX < 0;
                if (((isSignificantMove && !isDeltaXLeft && !isFling) || (isFling && !isVelocityXLeft))
                        && mCurrentPage > 0) {
                    finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage - 1;
                    snapToPageWithVelocity(finalPage, velocityX);
                } else if (((isSignificantMove && isDeltaXLeft && !isFling) || (isFling && isVelocityXLeft))
                        && mCurrentPage < getChildCount() - 1) {
                    finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage + 1;
                    snapToPageWithVelocity(finalPage, velocityX);
                } else {
                    snapToDestination();
                }
            } else if (mTouchState == TOUCH_STATE_PREV_PAGE) {
                // at this point we have not moved beyond the touch slop
                // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                // we can just page
                int nextPage = Math.max(0, mCurrentPage - 1);
                if (nextPage != mCurrentPage) {
                    snapToPage(nextPage);
                } else {
                    snapToDestination();
                }
            } else {
                if (!mScroller.isFinished()) {
                    mScroller.abortAnimation();
                }

                float scaleX = getScaleX();
                int vX = (int) (-velocityX * scaleX);
                int initialScrollX = (int) (getScrollX() * scaleX);

                mScroller.fling(initialScrollX, getScrollY(), vX, 0, Integer.MIN_VALUE, Integer.MAX_VALUE, 0,
                        0);
                invalidate();
            }
        } else if (mTouchState == TOUCH_STATE_NEXT_PAGE) {
            // at this point we have not moved beyond the touch slop
            // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
            // we can just page
            int nextPage = Math.min(getChildCount() - 1, mCurrentPage + 1);
            if (nextPage != mCurrentPage) {
                snapToPage(nextPage);
            } else {
                snapToDestination();
            }
        } else if (mTouchState == TOUCH_STATE_REORDERING) {
            // Update the last motion position
            mLastMotionX = ev.getX();
            mLastMotionY = ev.getY();

            // Update the parent down so that our zoom animations take this new movement into
            // account
            float[] pt = mapPointFromViewToParent(this, mLastMotionX, mLastMotionY);
            mParentDownMotionX = pt[0];
            mParentDownMotionY = pt[1];
            updateDragViewTranslationDuringDrag();
            boolean handledFling = false;
            if (!DISABLE_FLING_TO_DELETE) {
                // Check the velocity and see if we are flinging-to-delete
                PointF flingToDeleteVector = isFlingingToDelete();
                if (flingToDeleteVector != null) {
                    onFlingToDelete(flingToDeleteVector);
                    handledFling = true;
                }
            }
            if (!handledFling
                    && isHoveringOverDeleteDropTarget((int) mParentDownMotionX, (int) mParentDownMotionY)) {
                onDropToDelete();
            }
        } else {
            if (!mCancelTap) {
                onUnhandledTap(ev);
            }
        }

        // Remove the callback to wait for the side page hover timeout
        removeCallbacks(mSidePageHoverRunnable);
        // End any intermediate reordering states
        resetTouchState();
        break;

    case MotionEvent.ACTION_CANCEL:
        if (mTouchState == TOUCH_STATE_SCROLLING) {
            snapToDestination();
        }
        resetTouchState();
        break;

    case MotionEvent.ACTION_POINTER_UP:
        onSecondaryPointerUp(ev);
        releaseVelocityTracker();
        break;
    }

    return true;
}

From source file:com.brantapps.viewpagerindicator.vertical.VerticalViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*//from  w  w w  .  j a v a  2s  .  c om
     * 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);
        // BrantApps Change: Was final float xDiff = Math.abs(x - mLastMotionX);
        final float xDiff = Math.abs(x - mLastMotionX);
        final float y = MotionEventCompat.getY(ev, pointerIndex);
        // BrantApps Change: Renamed dx to dy and changed access from mLastMotionX to mLastMotionY
        final float dy = y - mLastMotionY;
        // BrantApps Change: Was final float yDiff = Math.abs(y - mLastMotionY);
        final float yDiff = Math.abs(dy);
        if (DEBUG)
            Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff);

        // BrantApps Change: Replaced 4 uses in next two if blocks of mLastMotionX to mLastMotionY
        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.
            mInitialMotionY = mLastMotionY = y;
            mLastMotionY = y;
            mIsUnableToDrag = true;
            return false;
        }
        // BrantApps Change: Was if (xDiff > mTouchSlop && xDiff > yDiff) {
        if (yDiff > mTouchSlop && yDiff > xDiff) {
            if (DEBUG)
                Log.v(TAG, "Starting drag!");
            mIsBeingDragged = true;
            setScrollState(SCROLL_STATE_DRAGGING);
            mLastMotionY = dy > 0 ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop;
            setScrollingCacheEnabled(true);
        } else {
            if (xDiff > mTouchSlop) {
                // BrantApps Change: Swapped uses of horizontal and vertical within comment
                // 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
            // BrantApps Change: Was if (performDrag(x)) {
            if (performDrag(y)) {
                ViewCompat.postInvalidateOnAnimation(this);
            }
        }
        break;
    }

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

        mScroller.computeScrollOffset();
        // BrantApps Change: Changed call to getFinalX() to getFinalY() and getCurrX() to getCurrY()
        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;
            setScrollState(SCROLL_STATE_DRAGGING);
        } else {
            completeScroll();
            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.chenglong.muscle.ui.LazyViewPager.java

/**
 * Fake drag by an offset in pixels. You must have called
 * {@link #beginFakeDrag()} first.//from   w w  w  .  j a  va  2s.c o  m
 *
 * @param xOffset Offset in pixels to drag by.
 * @see #beginFakeDrag()
 * @see #endFakeDrag()
 */
public void fakeDragBy(float xOffset) {
    if (!mFakeDragging) {
        throw new IllegalStateException("No fake drag in progress. Call beginFakeDrag first.");
    }
    mLastMotionX += xOffset;
    float scrollX = getScrollX() - xOffset;
    final int width = getWidth();
    final int widthWithMargin = width + mPageMargin;
    final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
    final float rightBound = Math.min(mCurItem + 1, mAdapter.getCount() - 1) * widthWithMargin;
    if (scrollX < leftBound) {
        scrollX = leftBound;
    } else if (scrollX > rightBound) {
        scrollX = rightBound;
    }
    // Don't lose the rounded component
    mLastMotionX += scrollX - (int) scrollX;
    scrollTo((int) scrollX, getScrollY());
    pageScrolled((int) scrollX);
    // Synthesize an event for the VelocityTracker.
    final long time = SystemClock.uptimeMillis();
    final MotionEvent ev = MotionEvent.obtain(mFakeDragBeginTime, time, MotionEvent.ACTION_MOVE, mLastMotionX,
            0, 0);
    mVelocityTracker.addMovement(ev);
    ev.recycle();
}

From source file:beichen.douban.ui.view.LazyViewPager.java

/**
 * Fake drag by an offset in pixels. You must have called
 * {@link #beginFakeDrag()} first.//  ww  w . jav a 2  s  .co m
 * 
 * @param xOffset
 *            Offset in pixels to drag by.
 * @see #beginFakeDrag()
 * @see #endFakeDrag()
 */
public void fakeDragBy(float xOffset) {
    if (!mFakeDragging) {
        throw new IllegalStateException("No fake drag in progress. Call beginFakeDrag first.");
    }

    mLastMotionX += xOffset;
    float scrollX = getScrollX() - xOffset;
    final int width = getWidth();
    final int widthWithMargin = width + mPageMargin;

    final float leftBound = Math.max(0, (mCurItem - 1) * widthWithMargin);
    final float rightBound = Math.min(mCurItem + 1, mAdapter.getCount() - 1) * widthWithMargin;
    if (scrollX < leftBound) {
        scrollX = leftBound;
    } else if (scrollX > rightBound) {
        scrollX = rightBound;
    }
    // Don't lose the rounded component
    mLastMotionX += scrollX - (int) scrollX;
    scrollTo((int) scrollX, getScrollY());
    pageScrolled((int) scrollX);

    // Synthesize an event for the VelocityTracker.
    final long time = SystemClock.uptimeMillis();
    final MotionEvent ev = MotionEvent.obtain(mFakeDragBeginTime, time, MotionEvent.ACTION_MOVE, mLastMotionX,
            0, 0);
    mVelocityTracker.addMovement(ev);
    ev.recycle();
}

From source file:android.support.custom.view.VerticalViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*/*from www .  j  a  va 2  s .c om*/
     * 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 - mLastMotionY);
        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.
            mInitialMotionY = mLastMotionY = y;
            mLastMotionX = x;
            mIsUnableToDrag = true;
            return false;
        }
        if (yDiff > mTouchSlop && yDiff > xDiff) {
            if (DEBUG)
                Log.v(TAG, "Starting drag!");
            mIsBeingDragged = true;
            setScrollState(SCROLL_STATE_DRAGGING);
            mLastMotionY = dy > 0 ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop;
            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.
         */
        mLastMotionY = mInitialMotionY = ev.getY();
        mLastMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        mIsUnableToDrag = false;

        mScroller.computeScrollOffset();
        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;
            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.boding.view.dialog.VerticalViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    if (!canScroll)
        return false;
    /*/*  w w  w  .j  av  a2 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 - mLastMotionY);
        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.
            mInitialMotionY = mLastMotionY = y;
            mLastMotionX = x;
            mIsUnableToDrag = true;
            return false;
        }
        if (yDiff > mTouchSlop && yDiff > xDiff) {
            if (DEBUG)
                Log.v(TAG, "Starting drag!");
            mIsBeingDragged = true;
            setScrollState(SCROLL_STATE_DRAGGING);
            mLastMotionY = dy > 0 ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop;
            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.
         */
        mLastMotionY = mInitialMotionY = ev.getY();
        mLastMotionX = ev.getX();
        mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
        mIsUnableToDrag = false;

        mScroller.computeScrollOffset();
        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;
            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.borqs.se.addobject.AddObjectViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*//from   www. jav a2s. c om
     * 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.
        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) {
            return true;
        }
        if (mIsUnableToDrag) {
            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 yDiff = Math.abs(y - mInitialMotionY);

        if (xDiff > mTouchSlop) {
            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.
            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 (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;
            setScrollState(SCROLL_STATE_DRAGGING);
        } else {
            completeScroll(false);
            mIsBeingDragged = false;
        }

        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.bloomimpact.bancus.ui.views.VerticalViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*//  w  w w  . j a v a  2 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 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 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();
        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;
        }

        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.android.internal.widget.ViewPager.java

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    /*/*  www. j  ava  2s .  c om*/
     * 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() & MotionEvent.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, "Being dragged, intercept returning true!");
            return true;
        }
        if (mIsUnableToDrag) {
            if (DEBUG)
                Log.v(TAG, "Unable to drag, 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)) {
                postInvalidateOnAnimation();
            }
        }
        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;

        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 MotionEvent.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;
}

Example usage for android.view MotionEvent ACTION_MOVE

Introduction

Prototype

Document

Usage