/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or 
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the NPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef SWITCHTOUITHREAD_H
#define SWITCHTOUITHREAD_H

#include "nsISupports.h"

// foreward declaration
struct MethodInfo;

/**
 * Switch thread to match the thread the widget was created in so messages will be dispatched.
 */

class nsSwitchToUIThread {

public:
    virtual bool CallMethod(MethodInfo *info) = 0;

};

//
// Structure used for passing the information necessary for synchronously 
// invoking a method on the GUI thread...
//
struct MethodInfo {
	nsISupports			*widget;
    nsSwitchToUIThread	*target;
    uint32				methodId;
    int					nArgs;
    uint32				*args;

    MethodInfo(nsISupports *ref, nsSwitchToUIThread *obj, uint32 id, int numArgs = 0, uint32 *arguments = 0)
    {
		widget = ref;
		NS_ADDREF(ref);
		target   = obj;
		methodId = id;
		nArgs    = numArgs;
		args = new uint32 [numArgs];
		memcpy(args, arguments, sizeof(uint32) * numArgs);
    }

	~MethodInfo()
	{
		delete [] args;
		NS_RELEASE(widget);
	}

    bool Invoke() { return target->CallMethod(this); }
};

#endif // TOUITHRD_H