Merge tag '1.4' into fox

[fw/altos] / altosuilib / GrabNDrag.java

diff --git a/altosuilib/GrabNDrag.java b/altosuilib/GrabNDrag.java
new file mode 100644 (file)
index 0000000..4426f7a
--- /dev/null
+++ b/altosuilib/GrabNDrag.java
@@ -0,0 +1,55 @@
+/*
+ * 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; version 2 of the License.
+ *
+ * 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_2;
+
+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);
+               }
+       }
+}