public void mousePressed(MouseEvent evt) {
// User has pressed the mouse. Find the shape that the user has clicked on, if
// any. If there is a shape at the position when the mouse was clicked, then
// start dragging it. If the user was holding down the shift key, then bring
// the dragged shape to the front, in front of all the other shapes.
int x = evt.getX(); // x-coordinate of point where mouse was clicked
int y = evt.getY(); // y-coordinate of point
for (int i = shapes.size() - 1; i >= 0; i--) { // check shapes from front to back
Shape s = (Shape) shapes.get(i);
if (s.containsPoint(x, y)) {
shapeBeingDragged = s;
prevDragX = x;
prevDragY = y;
if (evt.isShiftDown()) { // Bring the shape to the front by moving it to
shapes.remove(s); // the end of the list of shapes.
shapes.add(s);
repaint(); // repaint canvas to show shape in front of other shapes
}
return;
}
}
}
