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@users.sourceforge.net>.
   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 "global.h"
  37
  38 #include "main.h"
  39 #include "support.h"
  40 #include "gui_support.h"
  41 #include "run.h"
  42 #include "remote.h"
  43
  44 static GdkAtom filer_atom;      /* _ROX_FILER_VERSION_HOST */
  45 static GdkAtom ipc_atom;        /* _ROX_FILER_OPEN */
  46
  47 /* Static prototypes */
  48 static GdkWindow *get_existing_ipc_window();
  49 static gboolean get_ipc_property(GdkWindow *window, Window *r_xid);
  50 static gboolean ipc_prop_changed(GtkWidget *window,
  51                                  GdkEventProperty *event,
  52                                  gpointer data);
  53
  54 /****************************************************************
  55  *                      EXTERNAL INTERFACE                      *
  56  ****************************************************************/
  57
  58
  59 /* Try to get an already-running filer to handle things (only if
  60  * new_copy is FALSE); TRUE if we succeed.
  61  * Create and IPC widget so that future filers can contact us.
  62  *
  63  * See main() for a description of 'to_open'.
  64  */
  65 gboolean remote_init(GString *to_open, gboolean new_copy)
  66 {
  67         guchar  *unique_id;
  68         GdkWindowPrivate        *window;
  69         GdkWindow               *existing_ipc_window;
  70         GtkWidget               *ipc_window;
  71
  72         unique_id = g_strdup_printf("_ROX_FILER_%s_%s",
  73                                 VERSION, our_host_name());
  74         filer_atom = gdk_atom_intern(unique_id, FALSE);
  75         g_free(unique_id);
  76
  77         ipc_atom = gdk_atom_intern("_ROX_FILER_OPEN", FALSE);
  78
  79         existing_ipc_window = new_copy ? NULL : get_existing_ipc_window();
  80         if (existing_ipc_window)
  81         {
  82                 gdk_property_change(existing_ipc_window, ipc_atom, XA_STRING, 8,
  83                         GDK_PROP_MODE_APPEND, to_open->str, to_open->len);
  84                 return TRUE;
  85         }
  86
  87         /* Note: possible race-condition here if two filers both
  88          * start at the same time and one isn't already running.
  89          * Oh well.
  90          */
  91
  92         ipc_window = gtk_invisible_new();
  93         gtk_widget_realize(ipc_window);
  94
  95         window = (GdkWindowPrivate *) ipc_window->window;
  96
  97         /* Make the IPC window contain a property pointing to
  98          * itself - this can then be used to check that it really
  99          * is an IPC window.
 100          */
 101         gdk_property_change(ipc_window->window, filer_atom,
 102                         XA_WINDOW, 32, GDK_PROP_MODE_REPLACE,
 103                         (guchar *) &window->xwindow, 1);
 104
 105         /* Get notified when the IPC property is changed */
 106         gtk_widget_add_events(ipc_window, GDK_PROPERTY_CHANGE_MASK);
 107         gtk_signal_connect(GTK_OBJECT(ipc_window), "property-notify-event",
 108                         GTK_SIGNAL_FUNC(ipc_prop_changed), NULL);
 109
 110         /* Make the root window contain a pointer to the IPC window */
 111         gdk_property_change(GDK_ROOT_PARENT(), filer_atom,
 112                         XA_WINDOW, 32, GDK_PROP_MODE_REPLACE,
 113                         (guchar *) &window->xwindow, 1);
 114
 115         return FALSE;
 116 }
 117
 118
 119 /****************************************************************
 120  *                      INTERNAL FUNCTIONS                      *
 121  ****************************************************************/
 122
 123 /* Get the remote IPC window of the already-running filer if there
 124  * is one.
 125  */
 126 static GdkWindow *get_existing_ipc_window()
 127 {
 128         Window          xid, xid_confirm;
 129         GdkWindow       *window;
 130
 131         if (!get_ipc_property(GDK_ROOT_PARENT(), &xid))
 132                 return NULL;
 133
 134         window = gdk_window_foreign_new(xid);
 135         if (!window)
 136                 return NULL;
 137
 138         if (!get_ipc_property(window, &xid_confirm) || xid_confirm != xid)
 139                 return NULL;
 140
 141         return window;
 142 }
 143
 144 /* Returns the 'rox_atom' property of 'window' */
 145 static gboolean get_ipc_property(GdkWindow *window, Window *r_xid)
 146 {
 147         guchar          *data;
 148         gint            format, length;
 149         gboolean        retval = FALSE;
 150
 151         if (gdk_property_get(window, filer_atom, XA_WINDOW, 0, 4,
 152                         FALSE, NULL, &format, &length, &data) && data)
 153         {
 154                 if (format == 32 && length == 4)
 155                 {
 156                         retval = TRUE;
 157                         *r_xid = *((Window *) data);
 158                 }
 159                 g_free(data);
 160         }
 161
 162         return retval;
 163 }
 164
 165
 166 static gboolean ipc_prop_changed(GtkWidget *window,
 167                                  GdkEventProperty *event,
 168                                  gpointer data)
 169 {
 170         if (event->atom == ipc_atom)
 171         {
 172                 gint    grab_len = 4096;
 173                 gint    length;
 174                 guchar  *data;
 175
 176                 while (1)
 177                 {
 178
 179                         if (!(gdk_property_get(window->window, ipc_atom,
 180                                         XA_STRING, 0, grab_len,
 181                                         TRUE, NULL, NULL,
 182                                         &length, &data) && data))
 183                                 return TRUE;    /* Error? */
 184
 185                         if (length >= grab_len)
 186                         {
 187                                 /* Didn't get all of it - try again */
 188                                 grab_len <<= 1;
 189                                 g_free(data);
 190                                 continue;
 191                         }
 192
 193                         data = g_realloc(data, length + 1);
 194                         data[length] = '\0';
 195
 196                         run_list(data);
 197
 198                         g_free(data);
 199                         break;
 200                 }
 201
 202                 return TRUE;
 203         }
 204
 205         return FALSE;
 206 }
 207