public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (mScrollDisabled) return true;
View v = mChildViews.get(mCurrent);
if (v != null) {
Rect bounds = getScrollBounds(v);
switch (directionOfTravel(velocityX, velocityY)) {
case MOVING_LEFT:
if (bounds.left >= 0) {
// Fling off to the left bring next view onto screen
View vl = mChildViews.get(mCurrent + 1);
if (vl != null) {
slideViewOntoScreen(vl);
return true;
}
}
break;
case MOVING_RIGHT:
if (bounds.right <= 0) {
// Fling off to the right bring previous view onto screen
View vr = mChildViews.get(mCurrent - 1);
if (vr != null) {
slideViewOntoScreen(vr);
return true;
}
}
break;
}
mScrollerLastX = mScrollerLastY = 0;
// If the page has been dragged out of bounds then we want to spring back
// nicely. fling jumps back into bounds instantly, so we don't want to use
// fling in that case. On the other hand, we don't want to forgo a fling
// just because of a slightly off-angle drag taking us out of bounds other
// than in the direction of the drag, so we test for out of bounds only
// in the direction of travel.
//
// Also don't fling if out of bounds in any direction by more than fling
// margin
Rect expandedBounds = new Rect(bounds);
expandedBounds.inset(-FLING_MARGIN, -FLING_MARGIN);
if (withinBoundsInDirectionOfTravel(bounds, velocityX, velocityY)
&& expandedBounds.contains(0, 0)) {
mScroller.fling(
0,
0,
(int) velocityX,
(int) velocityY,
bounds.left,
bounds.right,
bounds.top,
bounds.bottom);
post(this);
}
}
return true;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
mScaleGestureDetector.onTouchEvent(event);
if (!mScaling) mGestureDetector.onTouchEvent(event);
if (event.getActionMasked() == MotionEvent.ACTION_DOWN) {
mUserInteracting = true;
}
if (event.getActionMasked() == MotionEvent.ACTION_UP) {
mScrollDisabled = false;
mUserInteracting = false;
View v = mChildViews.get(mCurrent);
if (v != null) {
if (mScroller.isFinished()) {
// If, at the end of user interaction, there is no
// current inertial scroll in operation then animate
// the view onto screen if necessary
slideViewOntoScreen(v);
}
if (mScroller.isFinished()) {
// If still there is no inertial scroll in operation
// then the layout is stable
postSettle(v);
}
}
}
requestLayout();
return true;
}
public void moveToNext() {
View v = mChildViews.get(mCurrent + 1);
if (v != null) slideViewOntoScreen(v);
}
public void moveToPrevious() {
View v = mChildViews.get(mCurrent - 1);
if (v != null) slideViewOntoScreen(v);
}
