remote.cpp

linux下的一款播放器

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: remote.cpp,v 1.2.2.3 2004/10/18 18:53:31 rggammon Exp $
 * 
 * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
 * 
 * The contents of this file, and the files included with this file,
 * are subject to the current version of the RealNetworks Public
 * Source License (the "RPSL") available at
 * http://www.helixcommunity.org/content/rpsl unless you have licensed
 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
 * will apply. You may also obtain the license terms directly from
 * RealNetworks.  You may not use this file except in compliance with
 * the RPSL or, if you have a valid RCSL with RealNetworks applicable
 * to this file, the RCSL.  Please see the applicable RPSL or RCSL for
 * the rights, obligations and limitations governing use of the
 * contents of the file.
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL") in which case the provisions of the GPL are applicable
 * instead of those above. If you wish to allow use of your version of
 * this file only under the terms of the GPL, and not to allow others
 * to use your version of this file under the terms of either the RPSL
 * or RCSL, indicate your decision by deleting the provisions above
 * and replace them with the notice and other provisions required by
 * the GPL. 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
 * RPSL, the RCSL or the GPL.
 * 
 * This file is part of the Helix DNA Technology. RealNetworks is the
 * developer of the Original Code and owns the copyrights in the
 * portions it created.
 * 
 * This file, and the files included with this file, is distributed
 * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
 * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
 * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
 * ENJOYMENT OR NON-INFRINGEMENT.
 * 
 * Technology Compatibility Kit Test Suite(s) Location:
 *    http://www.helixcommunity.org/content/tck
 * 
 * Contributor(s):
 * 
 * ***** END LICENSE BLOCK ***** */

#include "remote.h"

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xatom.h>

#include <gtk/gtk.h>
#include <gdk/gdkx.h>

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#define REMOTE_COMMAND_TIMEOUT     2 /* seconds */
#define MAX_WINDOW_RECURSION_DEPTH 2 /* Dig down through 2 levels of windows from the root */


static gboolean
check_children (Display* dpy, Window win, Atom atom, XID* xid, gint recursion_depth)
{
    unsigned long num_items, after;
    gchar *data;
    gboolean found = FALSE;
    Window root, parent;
    Window *children = NULL;
    unsigned int num_children, i;
    Atom type = None;
    int format;

    if(recursion_depth >= MAX_WINDOW_RECURSION_DEPTH)
    {
        return FALSE;
    }
    
    XQueryTree (dpy,
                win,
                &root,
                &parent,
                &children,
                &num_children);
                
    for(i = 0; i < num_children; i++)
    {
        XGetWindowProperty(dpy, children[i], atom,
                           0, (65536 / 32),
                           False, XA_STRING,
                           &type, &format,
                           &num_items, &after,
                           (unsigned char**)&data);

        if (type != None && format == 8 && data)
        {
            if(strncmp(HXPLAY_REMOTE_VERSION, data, num_items) == 0)
            {
                *xid = children[i];
                XFree(data);
                found = TRUE;
                break;
            }
            else
            {
                if (data)
                {
                    XFree(data);
                }
            }
        }
    }

    if(!found)
    {
        for (i = 0; i < num_children; i++)
        {
            found = check_children (dpy, children[i], atom, xid, recursion_depth + 1);
            if (found)
            {
                break;
            }
        }
    }

    if(children)
    {
        XFree(children);
    }
    
    return found;
}

static GdkWindow*
get_player_window(void)
{
    Atom hxplay_remote_version;
    Display* dpy;
    Window win;
    XID xid = 0;
    gboolean result;
    GdkWindow* hxplay_win = NULL;
        
    hxplay_remote_version = gdk_x11_get_xatom_by_name (HXPLAY_REMOTE_VERSION_PROP);
    
    GdkWindow* gdk_root = gdk_get_default_root_window();
    g_return_val_if_fail(gdk_root != NULL, NULL);
    
    dpy = GDK_WINDOW_XDISPLAY(gdk_root);
    win = GDK_WINDOW_XID(gdk_root);

    result = check_children (dpy, win, hxplay_remote_version, &xid, 0);
    if(result)
    {
        hxplay_win = gdk_window_foreign_new(xid);
    }

    return hxplay_win;
}

typedef struct
{
    GdkWindow* window;
    GdkAtom property_atom;
    GdkAtom xa_string_atom;
    gint value;
    gboolean is_set;
    
} HXRemoteResponse;

static GdkFilterReturn
remote_property_event_filter (GdkXEvent*  xevent,
                              GdkEvent*  /* event */,
                              gpointer   data)
{
    /* This filter is called before the GdkEvent is set. */
    XEvent* event = (XEvent*) xevent;
    
    if (event->type == PropertyNotify)
    {
        HXRemoteResponse* response = (HXRemoteResponse*) data;
        
        GdkAtom atom = gdk_x11_xatom_to_atom(event->xproperty.atom);

        if (atom == response->property_atom &&
            event->xproperty.state == PropertyNewValue)
        {
            GdkAtom type = 0;
            gint format = 0;
            gint length = 0;
            gchar* ret_str = NULL;

            /* Retrieve the result */
            gdk_property_get(response->window,
                             response->property_atom,
                             response->xa_string_atom,
                             0,
                             G_MAXLONG - 3,
                             TRUE,
                             &type,
                             &format,
                             &length,
                             (guchar**) &ret_str);

            if(length > 0 && format == 8 && ret_str)
            {
                response->value = atoi(ret_str);
            }
            else
            {
                response->value = -1;
            }
            g_free(ret_str);

            response->is_set = TRUE;
            gtk_main_quit();
        }
    }
    
    return GDK_FILTER_CONTINUE;
}

static gboolean
remote_timeout (gpointer)
{
    gtk_main_quit();
    return TRUE; // Will be removed via gtk_timeout_remove
}

gboolean
hxremote_launch_player (const gchar* url)
{
    gboolean got_lock;
    
    GdkWindow* hxplay_win;   
    GdkAtom hxplay_remote_version_atom;
    GdkAtom hxplay_remote_lock_atom;
    GdkAtom hxplay_remote_command_atom;
    GdkAtom hxplay_remote_response_atom;
    GdkAtom xa_string_atom;
    
    GdkAtom type;
    gint format;
    gint length;

    gchar* lock_str;
    gchar* command_str;
    gchar* data;

    HXRemoteResponse response;
    memset(&response, 0, sizeof(response));
    
    hxplay_win = get_player_window();

    if(!hxplay_win)
    {
        return FALSE;
    }

    gdk_window_set_events(hxplay_win, GDK_PROPERTY_CHANGE_MASK);
    gdk_window_add_filter(hxplay_win,
                          remote_property_event_filter,
                          &response);
    
    hxplay_remote_version_atom  = gdk_atom_intern(HXPLAY_REMOTE_VERSION_PROP,
                                                  FALSE);
    hxplay_remote_lock_atom     = gdk_atom_intern(HXPLAY_REMOTE_LOCK_PROP,
                                                  FALSE);
    hxplay_remote_command_atom  = gdk_atom_intern(HXPLAY_REMOTE_COMMAND_PROP,
                                                  FALSE);
    hxplay_remote_response_atom = gdk_atom_intern(HXPLAY_REMOTE_RESPONSE_PROP,
                                                  FALSE);
    xa_string_atom              = gdk_x11_xatom_to_atom(XA_STRING);

    lock_str = g_strdup_printf("pid%d", getpid());
    command_str = g_strdup_printf("OpenURL \"%s\"", url);

    /* Get a lock */
    do
    {
        type = 0;
        format = 0;
        length = 0;
        data = NULL;
        
        gdk_x11_grab_server ();

        gdk_property_get(hxplay_win,
                         hxplay_remote_lock_atom,
                         xa_string_atom,
                         0,
                         G_MAXLONG - 3,
                         FALSE,
                         &type,
                         &format,
                         &length,
                         (guchar**)&data);
        if(data)
        {
            g_free(data);
        }

        if(type == xa_string_atom)
        {
            gdk_property_change (hxplay_win,
                                 hxplay_remote_lock_atom,
                                 xa_string_atom,
                                 8,
                                 GDK_PROP_MODE_REPLACE,
                                 (const guchar*) lock_str,
                                 strlen(lock_str) + 1);
            got_lock = TRUE;
        }
        
        gdk_x11_ungrab_server ();
        gdk_flush();

        if(!got_lock)
        {
            /* Sleep for 0.5 seconds */
            usleep(500000);
        }

    } while(!got_lock);

    /* Set our request */
    gdk_property_change (hxplay_win,
                         hxplay_remote_command_atom,
                         xa_string_atom,
                         8,
                         GDK_PROP_MODE_REPLACE,
                         (const guchar*) command_str,
                         strlen(command_str) + 1);

    /* Wait for a response */
    response.window = hxplay_win;
    response.property_atom = hxplay_remote_response_atom;
    response.xa_string_atom = xa_string_atom;

    gint timeout_id;
    timeout_id = gtk_timeout_add(1000 * REMOTE_COMMAND_TIMEOUT,
                                 remote_timeout,
                                 NULL);
    gtk_main();

    gtk_timeout_remove(timeout_id);

    /* Remove our lock */
    gdk_property_get(hxplay_win,
                     hxplay_remote_lock_atom,
                     xa_string_atom,
                     0,
                     0,
                     TRUE,
                     &type,
                     &format,
                     &length,
                     (guchar**)&data);
    if(data)
    {
        g_free(data);
    }

    g_free(lock_str);
    g_free(command_str);
        
    return (response.value == 0);
}