@Nullable
public static Range<Integer> getExpandControlRange(final JTree aTree, final TreePath path) {
TreeModel treeModel = aTree.getModel();
final BasicTreeUI basicTreeUI = (BasicTreeUI) aTree.getUI();
Icon expandedIcon = basicTreeUI.getExpandedIcon();
Range<Integer> box = null;
if (path != null && !treeModel.isLeaf(path.getLastPathComponent())) {
int boxWidth;
Insets i = aTree.getInsets();
if (expandedIcon != null) {
boxWidth = expandedIcon.getIconWidth();
} else {
boxWidth = 8;
}
int boxLeftX = i != null ? i.left : 0;
boolean leftToRight = aTree.getComponentOrientation().isLeftToRight();
int depthOffset = getDepthOffset(aTree);
int totalChildIndent = basicTreeUI.getLeftChildIndent() + basicTreeUI.getRightChildIndent();
if (leftToRight) {
boxLeftX +=
((path.getPathCount() + depthOffset - 2) * totalChildIndent
+ basicTreeUI.getLeftChildIndent())
- boxWidth / 2;
}
int boxRightX = boxLeftX + boxWidth;
box = new Range<Integer>(boxLeftX, boxRightX);
}
return box;
}
