// Returns the distance that over the scroll limit.
public int startScroll(int distance, int min, int max) {
int currPosition = mScroller.getCurrX();
int finalPosition = mScroller.isFinished() ? currPosition : mScroller.getFinalX();
int newPosition = Utils.clamp(finalPosition + distance, min, max);
if (newPosition != currPosition) {
mScroller.startScroll(currPosition, 0, newPosition - currPosition, 0, 0);
}
return finalPosition + distance - newPosition;
}
public boolean isFinished() {
if (isPreGingerbread) {
return scroller.isFinished();
} else {
return overScroller.isFinished();
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
initVelocityTrackerIfNotExists();
mVelocityTracker.addMovement(event);
float currentTouchY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if (!mOverScroller.isFinished()) {
mOverScroller.abortAnimation();
}
mLastTouchY = currentTouchY;
break;
case MotionEvent.ACTION_MOVE:
float differentY = currentTouchY - mLastTouchY;
mLastTouchY = currentTouchY;
if (Math.abs(differentY) > 0) {
scrollBy(0, (int) -differentY);
}
break;
case MotionEvent.ACTION_CANCEL:
recycleVelocityTracker();
if (!mOverScroller.isFinished()) {
mOverScroller.abortAnimation();
}
break;
case MotionEvent.ACTION_UP:
mVelocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int initialVelocity = (int) mVelocityTracker.getYVelocity();
if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
fling(-initialVelocity);
}
recycleVelocityTracker();
break;
}
return true;
}
private boolean touchEvent(MotionEvent ev) {
initVelocityTrackerIfNotExists();
mVelocityTracker.addMovement(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
{
if (getChildCount() == 0 || !inScrollArea(ev)) {
return false;
}
if ((mIsBeingDragged = !mScroller.isFinished())) {
final ViewParent parent = getParent();
if (parent != null) {
parent.requestDisallowInterceptTouchEvent(true);
}
}
/*
* If being flinged and user touches, stop the fling. isFinished will be false
* if being flinged.
*/
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
// Remember where the motion event started
mLastMotionX = (int) ev.getX();
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE:
final int activePointerIndex = ev.findPointerIndex(mActivePointerId);
if (activePointerIndex == -1) {
Log.e(TAG, "Invalid pointerId=" + mActivePointerId + " in onTouchEvent");
break;
}
final int x = (int) ev.getX(activePointerIndex);
int deltaX = mLastMotionX - x;
if (!mIsBeingDragged && Math.abs(deltaX) > mTouchSlop) {
final ViewParent parent = getParent();
if (parent != null) {
parent.requestDisallowInterceptTouchEvent(true);
}
mIsBeingDragged = true;
if (deltaX > 0) {
deltaX -= mTouchSlop;
} else {
deltaX += mTouchSlop;
}
}
if (mIsBeingDragged) {
// Scroll to follow the motion event
mLastMotionX = x;
final int oldX = getScrollX();
final int oldY = getScrollY();
final int range = getScrollRange();
final int overscrollMode = getOverScrollMode();
final boolean canOverscroll =
overscrollMode == OVER_SCROLL_ALWAYS
|| (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);
if (overScrollBy(deltaX, 0, getScrollX(), 0, range, 0, mOverscrollDistance, 0, true)) {
// Break our velocity if we hit a scroll barrier.
mVelocityTracker.clear();
}
onScrollChanged(getScrollX(), getScrollY(), oldX, oldY);
}
break;
case MotionEvent.ACTION_UP:
if (mIsBeingDragged) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int initialVelocity = (int) velocityTracker.getXVelocity(mActivePointerId);
if (getChildCount() > 0) {
if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
fling(-initialVelocity);
} else {
int finalX = getScrollX();
finalX = getScrollXFromFinalX(finalX);
if (mScroller.springBack(getScrollX(), getScrollY(), finalX, finalX, 0, 0)) {
postInvalidateOnAnimation();
}
}
}
mActivePointerId = INVALID_POINTER;
mIsBeingDragged = false;
recycleVelocityTracker();
}
break;
case MotionEvent.ACTION_CANCEL:
if (mIsBeingDragged && getChildCount() > 0) {
if (mScroller.springBack(getScrollX(), getScrollY(), 0, getScrollRange(), 0, 0)) {
postInvalidateOnAnimation();
}
mActivePointerId = INVALID_POINTER;
mIsBeingDragged = false;
recycleVelocityTracker();
}
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
break;
}
return true;
}
@Override
public boolean isFinished() {
return mScroller.isFinished();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// return super.onTouchEvent(event);
// int height = getHeight();
initVelocityTrackerIfNotExists();
mVelocityTracker.addMovement(event);
int action = event.getActionMasked();
if (action == MotionEvent.ACTION_DOWN) {
if (!mIsDown) {
mIsDown = true;
mDownPt.x = event.getX();
mDownPt.y = event.getY();
mDownedScrollPt.x = getScrollX();
mDownedScrollPt.y = getScrollY();
// initOrResetVelocityTracker();
// mVelocityTracker.addMovement(event);
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
}
} else if (action == MotionEvent.ACTION_MOVE) {
if (mIsDown) {
float x = event.getX();
float y = event.getY();
float sx = -(x - mDownPt.x) + mDownedScrollPt.x;
float sy = -(y - mDownPt.y) + mDownedScrollPt.y;
scrollTo((int) sx, (int) sy);
// initVelocityTrackerIfNotExists();
// mVelocityTracker.addMovement(event);
}
} else if (action == MotionEvent.ACTION_UP) {
if (mIsDown) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int initialVelocity = (int) velocityTracker.getYVelocity(event.getPointerId(0));
int initialVelocitx = (int) velocityTracker.getXVelocity(event.getPointerId(0));
fling(-initialVelocitx, -initialVelocity);
recycleVelocityTracker();
mIsDown = false;
}
} else if (action == MotionEvent.ACTION_CANCEL) {
if (mIsDown) {
if (mScroller.springBack(
getScrollX(), getScrollY(), 0, getScrollRangeX(), 0, getScrollRangeY())) {
// postInvalidateOnAnimation();
postInvalidate();
}
recycleVelocityTracker();
mIsDown = false;
}
}
return true;
}
/** Stops the scroller and any current fling. */
void stopScroller() {
Log.d(TAG, "stopScroller: ");
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
}
/** Returns whether the overscroller is scrolling. */
boolean isScrolling() {
Log.d(TAG, "isScrolling: ");
return !mScroller.isFinished();
}