mbt

/*
 * intercept-wm-close.c - WM_DELETE_WINDOW experiment, part 2
 * Copyright (C) 2009 Michael B. Trausch <[email protected]>
 *
 * Determines whether or not we can intercept an WM_DELETE_WINDOW
 * event, such that we would be able to direct a window back to the
 * system tray instead of actually delete it.
 */

// Standard UNIX includes
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// GNU readline
#include <readline/readline.h>
#include <readline/history.h>

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

// glib and gdk
#include <glib.h>
#include <gdk/gdk.h>

#define RETVAL_SUCCESS 0
#define RETVAL_NO_X11_DISPLAY 1
#define RETVAL_GDK_FAILED 2

GdkFilterReturn
cb(GdkXEvent *xev, GdkEvent *ev, gpointer data) {
  XEvent *real_xev = (XEvent *)xev;
  if(real_xev->type == ClientMessage) {
    fprintf(stdout, "Got an event.\n");
    fprintf(stdout, "  ... for window %ld.\n", real_xev->xclient.window);
  }

  return(GDK_FILTER_CONTINUE);
}

int
main(int argc, char *argv[]) {
  GdkDisplay *gd = NULL;
  GdkAtom wm_delete_window;
  int found = 0;
  Window w = (Window)0;
  char *line = NULL;
  gboolean gdkis = FALSE;
  GMainLoop *gml = NULL;

  gml = g_main_loop_new(NULL, FALSE);

  gdkis = gdk_init_check(&argc, &argv);
  if(gdkis == FALSE) {
    fprintf(stderr, "Cannot open display, exiting.\n");
    exit(RETVAL_NO_X11_DISPLAY);
  }

  gd = gdk_display_open(NULL);

  wm_delete_window = gdk_atom_intern("WM_DELETE_WINDOW", FALSE);

  while(!found) {
  try_again:
    line = readline("Enter the X11 ID to intercept WM_DELETE_WINDOW for: ");

    if(line == NULL) {
      fprintf(stderr, "Error: invalid window ID\n");
      goto try_again;
    }

    w = (Window)atol(line);

    GdkWindow *gw = gdk_window_foreign_new((GdkNativeWindow)w);
    if(gw != NULL) {
      found = 1;
    } else {
      fprintf(stderr, "Error: window ID %ld did not return a result.\n", w);
    }
  }

  fprintf(stdout, "Broke out of the loop, found the window.\n");
  gdk_display_add_client_message_filter(gd, wm_delete_window, cb, NULL);
  gdk_window_add_filter(gw, cb, NULL);

  g_main_loop_run(gml);
}