File: GrabNDrag.java

package info (click to toggle)
altos 1.6.8-5
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 63,748 kB
  • ctags: 36,577
  • sloc: ansic: 92,100; java: 36,273; makefile: 6,495; xml: 3,096; sh: 1,971; pascal: 1,581
file content (56 lines) | stat: -rw-r--r-- 1,672 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
/*
 * Copyright © 2010 Anthony Towns <aj@erisian.com.au>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 */

package org.altusmetrum.altosuilib_11;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;

class GrabNDrag extends MouseInputAdapter {
	private JComponent scroll;
	private Point startPt = new Point();

	public GrabNDrag(JComponent scroll) {
		this.scroll = scroll;
		scroll.addMouseMotionListener(this);
		scroll.addMouseListener(this);
		scroll.setAutoscrolls(true);
	}

	public static boolean grab_n_drag(MouseEvent e) {
		return e.getModifiers() == InputEvent.BUTTON1_MASK;
	}

	public void mousePressed(MouseEvent e) {
		if (grab_n_drag(e))
			startPt.setLocation(e.getPoint());
	}
	public void mouseDragged(MouseEvent e) {
		if (grab_n_drag(e)) {
			int xd = e.getX() - startPt.x;
			int yd = e.getY() - startPt.y;

			Rectangle r = scroll.getVisibleRect();
			r.x -= xd;
			r.y -= yd;
			scroll.scrollRectToVisible(r);
		}
	}
}