* マウス位置の DrawingHolder を返す
* @param p
* @return
*/
public DrawingHolder findDrawing(Point p) {
DrawingHolder found = null;
int cnt = drawingList.size();
if (cnt > 0) {
for (int i = cnt; i > 0; i--) {
DrawingHolder d = drawingList.get(i-1);
if (d.contains(p)) {
found = d;
break;
}
}
}