Source: kipc.h

/* This file is part of the KDE libraries

   Copyright (C) 1999 Mattias Ettrich (ettrich@kde.org)
   Copyright (C) 1999,2000 Geert Jansen <jansen@kde.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
*/

#ifndef __KIPC_h_Included__
#define __KIPC_h_Included__

#include <X11/X.h>
#include <X11/Xlib.h>
#undef Bool
#undef None // X11 headers... 
#undef Unsorted
#undef INT8
#undef INT32
#undef Status

/**
 * This class implements a very simple IPC mechanism for KDE. You can send 
 * a message of a predefined type to either a specific application, or to all 
 * KDE application on the current display. The message can carry one integer of
 * data.
 *
 * KIPC is mainly used in KDE for sending "Change Messages", i.e. a message to
 * all KDE apps that a certain setting (the font, for example) has changed. 
 * For anything more complex it is recommended to use DCOP -- the Desktop 
 * Communications Protocol.
 *
 * Messages with id code < 32 are called "System Messages". These are
 * directly handled by KApplication. Examples are: PaletteChanged and
 * StyleChanged. Messages with id code >= 32 are user messages. KApplication 
 * emits the signal kipcMessage(id,arg) for each user message it receives.
 *
 * KIPC is implemented using X11 ClientMessage events.
 *
 * @author Geert Jansen <jansen@kde.org>
 * @version $Id: kipc.h,v 1.9 2000/08/16 00:29:28 waba Exp $
 */ 
class KIPC
{
public:
    enum Message { PaletteChanged=0, FontChanged, StyleChanged,
	    BackgroundChanged, SettingsChanged, IconChanged,
	    UserMessage=32 };

    /**
     * Send a message to a specific application.
     *
     * @param msg The message to send.
     * @param w The window id of a toplevel window of the target application.
     * @param data An optional integer of data.
     */
    static void sendMessage(Message msg, Window w, int data=0);

    /**
     * Send a message to all KDE application on the current display.
     *
     * @param msg The message to send.
     * @param data An optional integer of data.
     */
    static void sendMessageAll(Message msg, int data=0);

private:
    /**
     * Used internally
     */
    static int dropError(Display *, XErrorEvent *);

    /**
     * Used internally
     */
    static long getSimpleProperty(Window w, Atom a);
};
#endif