@Override
public void onPageScrollStateChanged(int scrollState) {
if (hardwaredDisabled) {
hardwaredDisabled = false;
enableHWAcceleration(nativeView);
}
mPager.requestDisallowInterceptTouchEvent(scrollState != ViewPager.SCROLL_STATE_IDLE);
if (scrollState == ViewPager.SCROLL_STATE_DRAGGING) {
updateCurrentPageDuringScroll = true;
((ScrollableViewProxy) proxy).fireScrollStart(mCurIndex, mViews.get(mCurIndex));
} else if ((scrollState == ViewPager.SCROLL_STATE_IDLE) && isValidScroll) {
int oldIndex = mCurIndex;
{
updateCurrentPageDuringScroll = false;
((ScrollableViewProxy) proxy).fireScrollEnd(mCurIndex, mViews.get(mCurIndex));
}
if (mCurIndex >= 0) {
// if (oldIndex >=0 && oldIndex != mCurIndex && oldIndex < mViews.size()) {
// // Don't know what these focused and unfocused
// // events are good for, but they were in our previous
// // scrollable implementation.
// // cf.
// https://github.com/appcelerator/titanium_mobile/blob/20335d8603e2708b59a18bafbb91b7292278de8e/android/modules/ui/src/ti/modules/titanium/ui/widget/TiScrollableView.java#L260
// TiEventHelper.fireFocused(mViews.get(oldIndex));
// }
//
// TiEventHelper.fireUnfocused(mViews.get(mCurIndex));
if (oldIndex >= 0) {
// oldIndex will be -1 if the view has just
// been created and is setting currentPage
// to something other than 0. In that case we
// don't want a `scrollend` to fire.
((ScrollableViewProxy) proxy).fireScrollEnd(mCurIndex, mViews.get(mCurIndex));
}
if (shouldShowPager()) {
showPager();
}
}
// If we don't use this state variable to check if it's a valid
// scroll, this event will fire when the view is first created
// because on creation, the scroll state is initialized to
// `idle` and this handler is called.
isValidScroll = false;
} else if (scrollState == ViewPager.SCROLL_STATE_SETTLING) {
updateCurrentPageDuringScroll = false;
((ScrollableViewProxy) proxy).fireDragEnd(mCurIndex, mViews.get(mCurIndex));
// Note that we just fired a `dragend` so the `onPageSelected`
// handler below doesn't fire a `scrollend`. Read below comment.
justFiredDragEnd = true;
}
}
private void setCurrentPageIndex(int newPage, boolean animated) {
if (newPage == mCurIndex) return;
mCurIndex = newPage;
proxy.setProperty(TiC.PROPERTY_CURRENT_PAGE, mCurIndex);
updateCacheSize();
((ScrollableViewProxy) proxy).firePageChange(mCurIndex, mViews.get(mCurIndex));
}
public void showPager() {
View v = null;
v = mContainer.findViewById(PAGE_LEFT);
if (v != null) {
v.setVisibility(mCurIndex > 0 ? View.VISIBLE : View.INVISIBLE);
}
v = mContainer.findViewById(PAGE_RIGHT);
if (v != null) {
v.setVisibility(mCurIndex < (mViews.size() - 1) ? View.VISIBLE : View.INVISIBLE);
}
mPagingControl.setVisibility(View.VISIBLE);
((ScrollableViewProxy) proxy).setPagerTimeout();
}
@Override
public void onPageScrolled(
int positionRoundedDown, float positionOffset, int positionOffsetPixels) {
if (hardwaredDisabled) {
hardwaredDisabled = false;
enableHWAcceleration(nativeView);
}
isValidScroll = true;
int oldIndex = mCurIndex;
// When we touch and drag the view and hold it inbetween the second
// and third sub-view, this function will have been called with values
// similar to:
// positionRoundedDown: 1
// positionOffset: 0.5
// ie, the first parameter is always rounded down; the second parameter
// is always just an offset between the current and next view, it does
// not take into account the current view.
// If we add positionRoundedDown to positionOffset, positionOffset will
// have the 'correct' value; ie, will be a natural number when we're on
// one particular view, something.5 when inbetween views, etc.
float positionFloat = positionOffset + positionRoundedDown;
// `positionFloat` can now be used to calculate the correct value for
// the current index. We add 0.5 so that positionFloat will be rounded
// half up; ie, if it has a value of 1.5, it will be rounded up to 2; if
// it has a value of 1.4, it will be rounded down to 1.
int index = Math.min(Math.max((int) Math.floor(positionFloat + 0.5), 0), mViews.size() - 1);
if (updateCurrentPageDuringScroll) {
setCurrentPageIndex(index, true);
}
((ScrollableViewProxy) proxy).fireScroll(mCurIndex, positionFloat, mViews.get(mCurIndex));
// Note that we didn't just fire a `dragend`. See the above comment
// in `onPageSelected`.
justFiredDragEnd = false;
// Force the container to redraw on scrolling.
// Without this the outer pages render initially and then stay static
nativeView.invalidate();
}
@Override
public void onPageSelected(int page) {
setCurrentPageIndex(page, true);
updateCurrentPageDuringScroll = false;
// If we didn't just fire a `dragend` event then this is the case
// where a user drags the view and settles it on a different view.
// Since the OS settling logic is never run, the
// `onPageScrollStateChanged` handler is never run, and therefore
// we forgot to inform the Javascripters that the user just scrolled
// their thing.
if (!justFiredDragEnd && mCurIndex != -1 && mCurIndex < mViews.size()) {
((ScrollableViewProxy) proxy).fireScrollEnd(mCurIndex, mViews.get(mCurIndex));
if (shouldShowPager()) {
showPager();
}
}
}
