| /* GtkMainThread.java -- Wrapper for the GTK main thread, and some utilities. |
| Copyright (C) 2006 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.gtk; |
| |
| import gnu.java.awt.peer.NativeEventLoopRunningEvent; |
| |
| /** |
| * The Java thread representing the native GTK main loop, that is, |
| * GtkMainThread.mainThread, terminates when GtkToolkit.gtkMain() |
| * returns. That happens in response to the last window peer being |
| * disposed (see GtkWindowPeer.dispose). |
| * |
| * When GtkMainThread.destroyWindow is called for the last window, it |
| * in turn calls GtkMainThread.endMainThread, which calls gtk_quit. |
| * gtk_quit signals gtk_main to return, which causes GtkMainThread.run |
| * to return. |
| * |
| * There should only be one native GTK main loop running at any given |
| * time. In order to safely start and stop the GTK main loop, we use |
| * a running flag and corresponding runningLock. startMainThread will |
| * not return until the native GTK main loop has started, as confirmed |
| * by the native set_running_flag callback setting the running flag to |
| * true. Without this protection, gtk_quit could be called before the |
| * main loop has actually started, which causes GTK assertion |
| * failures. Likewise endMainThread will not return until the native |
| * GTK main loop has ended. |
| * |
| * post_running_flag_callback is called during gtk_main initialization |
| * and no window can be created before startMainThread returns. This |
| * ensures that calling post_running_flag_callback is the first action |
| * taken by the native GTK main loop. |
| * |
| * GtkMainThread.mainThread is started when the window count goes from |
| * zero to one. |
| * |
| * GtkMainThread keeps the AWT event queue informed of its status by |
| * posting NativeEventLoopRunningEvents. The AWT event queue uses |
| * this status to determine whether or not the AWT exit conditions |
| * have been met (see EventQueue.isShutdown). |
| */ |
| public class GtkMainThread extends Thread |
| { |
| /** Count of the number of open windows */ |
| private static int numberOfWindows = 0; |
| |
| /** Lock for the above */ |
| private static Object nWindowsLock = new Object(); |
| |
| /** Indicates whether or not the GTK main loop is running. */ |
| private static boolean running = false; |
| |
| /** Lock for the above. */ |
| private static Object runningLock = new Object(); |
| |
| /** The main thread instance (singleton) */ |
| public static GtkMainThread mainThread; |
| |
| /** Constructs a main thread */ |
| private GtkMainThread() |
| { |
| super("GTK main thread"); |
| } |
| |
| public void run () |
| { |
| GtkToolkit.gtkMain (); |
| } |
| |
| private static void setRunning(boolean running) |
| { |
| synchronized (runningLock) |
| { |
| GtkMainThread.running = running; |
| runningLock.notifyAll(); |
| } |
| } |
| |
| private static void startMainThread() |
| { |
| synchronized (runningLock) |
| { |
| if (!running) |
| { |
| mainThread = new GtkMainThread(); |
| mainThread.start(); |
| |
| while (!running) |
| { |
| try |
| { |
| runningLock.wait(); |
| } |
| catch (InterruptedException e) |
| { |
| System.err.println ("GtkMainThread.startMainThread:" |
| + " interrupted while waiting " |
| + " for GTK main loop to start"); |
| } |
| } |
| GtkGenericPeer.q() |
| .postEvent(new NativeEventLoopRunningEvent(Boolean.TRUE)); |
| } |
| } |
| } |
| |
| private static void endMainThread() |
| { |
| synchronized (runningLock) |
| { |
| if (running) |
| { |
| GtkToolkit.gtkQuit(); |
| |
| while (running) |
| { |
| try |
| { |
| runningLock.wait(); |
| } |
| catch (InterruptedException e) |
| { |
| System.err.println ("GtkMainThread.endMainThread:" |
| + " interrupted while waiting " |
| + " for GTK main loop to stop"); |
| } |
| } |
| GtkGenericPeer.q() |
| .postEvent(new NativeEventLoopRunningEvent(Boolean.FALSE)); |
| } |
| } |
| } |
| |
| public static void createWindow() |
| { |
| synchronized (nWindowsLock) |
| { |
| if (numberOfWindows == 0) |
| startMainThread(); |
| numberOfWindows++; |
| } |
| } |
| |
| public static void destroyWindow() |
| { |
| synchronized (nWindowsLock) |
| { |
| numberOfWindows--; |
| if (numberOfWindows == 0) |
| endMainThread(); |
| } |
| } |
| } |