private int getHeight(final int index) {
int result = 0;
int columnCount = parent.getColumnCount();
boolean singleColumn = index == 0 && columnCount == 0;
boolean columnInRange = index >= 0 && index < columnCount;
if (singleColumn || columnInRange) {
result = parent.getItemHeight();
}
return result;
}
private int getTop(final int itemIndex) {
int relativeItemIndex = itemIndex - parent.getTopIndex();
int headerHeight = parent.getHeaderHeight();
int itemHeight = parent.getItemHeight();
return headerHeight + relativeItemIndex * itemHeight;
}