/* QtRepaintThread.java -- Repaint thread implementation Copyright (C) 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath 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, or (at your option) any later version. GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package gnu.java.awt.peer.qt; /** * This class does repainting of Component back-buffers. It is undesirable to * do this directly from the paint callback in QtComponentPeer, because that * is executed from the main thread. Thus, if a call is made at the same time * which requires execution by the main thread, and this is sharing a lock with * paint(), then a deadlock will occur, which must be avoided. In general, * the main Qt thread should avoid calling into java code as far as possible. * */ public class QtRepaintThread extends Thread { static class RepaintComponent { public QtComponentPeer curr; public RepaintComponent next; public RepaintComponent(QtComponentPeer p) { curr = p; next = null; } } RepaintComponent component; boolean busy; public QtRepaintThread() { component = null; } public void run() { while( true ) { try { busy = false; // Wait for a repaint sleep(1000); } catch (InterruptedException ie) { // peform the repaint. No interruptions please. busy = true; while( component != null ) { component.curr.paintBackBuffer(); // update the back-buffer. component.curr.QtUpdate(); // trigger a native repaint event component = component.next; } } catch (Throwable x) { System.err.println("Exception in paint thread:"); x.printStackTrace(System.err); } } } /** * Enqueue a component for repainting. */ public synchronized void queueComponent(QtComponentPeer p) { if( component == null ) component = new RepaintComponent(p); else { RepaintComponent r = component; while( r.next != null ) r = r.next; r.next = new RepaintComponent(p); } if( !busy ) interrupt(); } }