private boolean isFirstItemVisible() {
final Adapter adapter = mRefreshableView.getAdapter();
if (null == adapter || adapter.isEmpty()) {
if (DEBUG) {
Log.d(LOG_TAG, "isFirstItemVisible. Empty View.");
}
return true;
} else {
/**
* This check should really just be: mRefreshableView.getFirstVisiblePosition() == 0, but
* PtRListView internally use a HeaderView which messes the positions up. For now we'll just
* add one to account for it and rely on the inner condition which checks getTop().
*/
if (mRefreshableView.getFirstVisiblePosition() <= 1) {
final View firstVisibleChild = mRefreshableView.getChildAt(0);
if (firstVisibleChild != null) {
return firstVisibleChild.getTop() >= mRefreshableView.getTop();
}
}
}
return false;
}
private boolean isLastItemVisible() {
final Adapter adapter = mRefreshableView.getAdapter();
if (null == adapter || adapter.isEmpty()) {
if (DEBUG) {
Log.d(LOG_TAG, "isLastItemVisible. Empty View.");
}
return true;
} else {
final int lastItemPosition = mRefreshableView.getCount() - 1;
final int lastVisiblePosition = mRefreshableView.getLastVisiblePosition();
if (DEBUG) {
Log.d(
LOG_TAG,
"isLastItemVisible. Last Item Position: "
+ lastItemPosition
+ " Last Visible Pos: "
+ lastVisiblePosition);
}
/**
* This check should really just be: lastVisiblePosition == lastItemPosition, but PtRListView
* internally uses a FooterView which messes the positions up. For me we'll just subtract one
* to account for it and rely on the inner condition which checks getBottom().
*/
if (lastVisiblePosition >= lastItemPosition - 1) {
final int childIndex = lastVisiblePosition - mRefreshableView.getFirstVisiblePosition();
final View lastVisibleChild = mRefreshableView.getChildAt(childIndex);
if (lastVisibleChild != null) {
return lastVisibleChild.getBottom() <= mRefreshableView.getBottom();
}
}
}
return false;
}
public void onScroll(
final AbsListView view,
final int firstVisibleItem,
final int visibleItemCount,
final int totalItemCount) {
if (DEBUG) {
Log.d(
LOG_TAG,
"First Visible: "
+ firstVisibleItem
+ ". Visible Count: "
+ visibleItemCount
+ ". Total Items:"
+ totalItemCount);
}
/**
* Set whether the Last Item is Visible. lastVisibleItemIndex is a zero-based index, so we minus
* one totalItemCount to check
*/
if (null != mOnLastItemVisibleListener) {
mLastItemVisible =
(totalItemCount > 0) && (firstVisibleItem + visibleItemCount >= totalItemCount - 1);
}
// If we're showing the indicator, check positions...
if (getShowIndicatorInternal()) {
updateIndicatorViewsVisibility();
}
// Finally call OnScrollListener if we have one
if (null != mOnScrollListener) {
mOnScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
}
}