/**
* Invalidates items layout
*
* @param clearCaches if true then cached views will be cleared
*/
public void invalidateItemsLayout(boolean clearCaches) {
if (clearCaches) {
mRecycler.clearAll();
if (mItemsLayout != null) {
mItemsLayout.removeAllViews();
}
mScrollingOffset = 0;
} else if (mItemsLayout != null) {
// cache all items
mRecycler.recycleItems(mItemsLayout, mFirstItemIdx, new ItemsRange());
}
invalidate();
}
/**
* Returns view for specified item
*
* @param index the item index
* @return item view or empty view if index is out of bounds
*/
private View getItemView(int index) {
if (mViewAdapter == null || mViewAdapter.getItemsCount() == 0) {
return null;
}
int count = mViewAdapter.getItemsCount();
if (!isValidItemIndex(index)) {
return mViewAdapter.getEmptyItem(mRecycler.getEmptyItem(), mItemsLayout);
} else {
while (index < 0) {
index = count + index;
}
}
index %= count;
return mViewAdapter.getItem(index, mRecycler.getItem(), mItemsLayout);
}
/**
* Rebuilds spinnerwheel items if necessary. Caches all unused items.
*
* @return true if items are rebuilt
*/
protected boolean rebuildItems() {
boolean updated;
ItemsRange range = getItemsRange();
if (mItemsLayout != null) {
int first = mRecycler.recycleItems(mItemsLayout, mFirstItemIdx, range);
updated = mFirstItemIdx != first;
mFirstItemIdx = first;
} else {
createItemsLayout();
updated = true;
}
if (!updated) {
updated =
mFirstItemIdx != range.getFirst() || mItemsLayout.getChildCount() != range.getCount();
}
if (mFirstItemIdx > range.getFirst() && mFirstItemIdx <= range.getLast()) {
for (int i = mFirstItemIdx - 1; i >= range.getFirst(); i--) {
if (!addItemView(i, true)) {
break;
}
mFirstItemIdx = i;
}
} else {
mFirstItemIdx = range.getFirst();
}
int first = mFirstItemIdx;
for (int i = mItemsLayout.getChildCount(); i < range.getCount(); i++) {
if (!addItemView(mFirstItemIdx + i, false) && mItemsLayout.getChildCount() == 0) {
first++;
}
}
mFirstItemIdx = first;
return updated;
}