ROX-Filer/src/remote.c

   1 /*
   2  * $Id$
   3  *
   4  * ROX-Filer, filer for the ROX desktop project
   5  * Copyright (C) 2000, Thomas Leonard, <tal197@ecs.soton.ac.uk>.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the Free
   9  * Software Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along with
  18  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  19  * Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 /* This code is used to communicate between two copies of the filer:
  23  * If the filer is run and the same version of the filer is already
  24  * running on the same machine then the new copy simply asks the old
  25  * one deal with it and quits.
  26  */
  27
  28 #include "config.h"
  29
  30 #include <gdk/gdkx.h>
  31 #include <X11/X.h>
  32 #include <X11/Xatom.h>
  33 #include <gtk/gtk.h>
  34 #include <gtk/gtkinvisible.h>
  35
  36 #include "main.h"
  37 #include "support.h"
  38 #include "filer.h"
  39 #include "gui_support.h"
  40 #include "run.h"
  41 #include "remote.h"
  42
  43 static GdkAtom filer_atom;      /* _ROX_FILER_VERSION_HOST */
  44 static GdkAtom ipc_atom;        /* _ROX_FILER_OPEN */
  45
  46 /* Static prototypes */
  47 static GdkWindow *get_existing_ipc_window();
  48 static gboolean get_ipc_property(GdkWindow *window, Window *r_xid);
  49 static gboolean ipc_prop_changed(GtkWidget *window,
  50                                  GdkEventProperty *event,
  51                                  gpointer data);
  52
  53 /****************************************************************
  54  *                      EXTERNAL INTERFACE                      *
  55  ****************************************************************/
  56
  57
  58 /* Try to get an already-running filer to handle things (only if
  59  * new_copy is FALSE); TRUE if we succeed.
  60  * Create and IPC widget so that future filers can contact us.
  61  *
  62  * See main() for a description of 'to_open'.
  63  */
  64 gboolean remote_init(GString *to_open, gboolean new_copy)
  65 {
  66         guchar  *unique_id;
  67         GdkWindowPrivate        *window;
  68         GdkWindow               *existing_ipc_window;
  69         GtkWidget               *ipc_window;
  70
  71         unique_id = g_strdup_printf("_ROX_FILER_%s_%s",
  72                                 VERSION, our_host_name());
  73         filer_atom = gdk_atom_intern(unique_id, FALSE);
  74         g_free(unique_id);
  75
  76         ipc_atom = gdk_atom_intern("_ROX_FILER_OPEN", FALSE);
  77
  78         existing_ipc_window = new_copy ? NULL : get_existing_ipc_window();
  79         if (existing_ipc_window)
  80         {
  81                 gdk_property_change(existing_ipc_window, ipc_atom, XA_STRING, 8,
  82                         GDK_PROP_MODE_APPEND, to_open->str, to_open->len);
  83                 return TRUE;
  84         }
  85
  86         /* Note: possible race-condition here if two filers both
  87          * start at the same time and one isn't already running.
  88          * Oh well.
  89          */
  90
  91         ipc_window = gtk_invisible_new();
  92         gtk_widget_realize(ipc_window);
  93
  94         window = (GdkWindowPrivate *) ipc_window->window;
  95
  96         /* Make the IPC window contain a property pointing to
  97          * itself - this can then be used to check that it really
  98          * is an IPC window.
  99          */
 100         gdk_property_change(ipc_window->window, filer_atom,
 101                         XA_WINDOW, 32, GDK_PROP_MODE_REPLACE,
 102                         (guchar *) &window->xwindow, 1);
 103
 104         /* Get notified when the IPC property is changed */
 105         gtk_widget_add_events(ipc_window, GDK_PROPERTY_CHANGE_MASK);
 106         gtk_signal_connect(GTK_OBJECT(ipc_window), "property-notify-event",
 107                         GTK_SIGNAL_FUNC(ipc_prop_changed), NULL);
 108
 109         /* Make the root window contain a pointer to the IPC window */
 110         gdk_property_change(GDK_ROOT_PARENT(), filer_atom,
 111                         XA_WINDOW, 32, GDK_PROP_MODE_REPLACE,
 112                         (guchar *) &window->xwindow, 1);
 113
 114         return FALSE;
 115 }
 116
 117
 118 /****************************************************************
 119  *                      INTERNAL FUNCTIONS                      *
 120  ****************************************************************/
 121
 122 /* Get the remote IPC window of the already-running filer if there
 123  * is one.
 124  */
 125 static GdkWindow *get_existing_ipc_window()
 126 {
 127         Window          xid, xid_confirm;
 128         GdkWindow       *window;
 129
 130         if (!get_ipc_property(GDK_ROOT_PARENT(), &xid))
 131                 return NULL;
 132
 133         window = gdk_window_foreign_new(xid);
 134         if (!window)
 135                 return NULL;
 136
 137         if (!get_ipc_property(window, &xid_confirm) || xid_confirm != xid)
 138                 return NULL;
 139
 140         return window;
 141 }
 142
 143 /* Returns the 'rox_atom' property of 'window' */
 144 static gboolean get_ipc_property(GdkWindow *window, Window *r_xid)
 145 {
 146         guchar          *data;
 147         gint            format, length;
 148         gboolean        retval = FALSE;
 149
 150         if (gdk_property_get(window, filer_atom, XA_WINDOW, 0, 4,
 151                         FALSE, NULL, &format, &length, &data) && data)
 152         {
 153                 if (format == 32 && length == 4)
 154                 {
 155                         retval = TRUE;
 156                         *r_xid = *((Window *) data);
 157                 }
 158                 g_free(data);
 159         }
 160
 161         return retval;
 162 }
 163
 164
 165 static gboolean ipc_prop_changed(GtkWidget *window,
 166                                  GdkEventProperty *event,
 167                                  gpointer data)
 168 {
 169         if (event->atom == ipc_atom)
 170         {
 171                 gint    grab_len = 4096;
 172                 gint    length;
 173                 guchar  *data;
 174
 175                 while (1)
 176                 {
 177
 178                         if (!(gdk_property_get(window->window, ipc_atom,
 179                                         XA_STRING, 0, grab_len,
 180                                         TRUE, NULL, NULL,
 181                                         &length, &data) && data))
 182                                 return TRUE;    /* Error? */
 183
 184                         if (length >= grab_len)
 185                         {
 186                                 /* Didn't get all of it - try again */
 187                                 grab_len <<= 1;
 188                                 g_free(data);
 189                                 continue;
 190                         }
 191
 192                         data = g_realloc(data, length + 1);
 193                         data[length] = '\0';
 194
 195                         run_list(data);
 196
 197                         g_free(data);
 198                         break;
 199                 }
 200
 201                 return TRUE;
 202         }
 203
 204         return FALSE;
 205 }
 206