bus/at-spi-bus-launcher.c

   1 /* -*- mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
   2  *
   3  * at-spi-bus-launcher: Manage the a11y bus as a child process
   4  *
   5  * Copyright 2011 Red Hat, Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public
  18  * License along with this library; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include "config.h"
  24
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <signal.h>
  28 #include <sys/wait.h>
  29 #include <errno.h>
  30 #include <stdio.h>
  31
  32 #include <gio/gio.h>
  33 #ifdef HAVE_X11
  34 #include <X11/Xlib.h>
  35 #include <X11/Xatom.h>
  36 #endif
  37
  38 #define APP_CONTROL_OPERATION_SCREEN_READ "http://tizen.org/appcontrol/operation/read_screen"
  39 #include <appsvc.h>
  40 #include <vconf.h>
  41
  42 //uncomment if you want debug
  43 //#ifndef TIZEN_ENGINEER_MODE
  44 //#define TIZEN_ENGINEER_MODE
  45 //#endif
  46 #ifdef LOG_TAG
  47 #undef LOG_TAG
  48 #endif
  49
  50 #define LOG_TAG "ATSPI_BUS_LAUNCHER"
  51
  52 #include <dlog.h>
  53 #include <aul.h>
  54
  55 //uncomment this if you want log suring startup
  56 //seems like dlog is not working at startup time
  57 #define ATSPI_BUS_LAUNCHER_LOG_TO_FILE
  58
  59 #ifdef ATSPI_BUS_LAUNCHER_LOG_TO_FILE
  60 FILE *log_file;
  61 #ifdef LOGD
  62 #undef LOGD
  63 #endif
  64 #define LOGD(arg...) do {if (log_file) {fprintf(log_file, ##arg);fprintf(log_file, "\n"); fflush(log_file);}} while(0)
  65 #endif
  66
  67 static gboolean _launch_screen_reader_repeat_until_success(gpointer user_data);
  68
  69 typedef enum {
  70   A11Y_BUS_STATE_IDLE = 0,
  71   A11Y_BUS_STATE_READING_ADDRESS,
  72   A11Y_BUS_STATE_RUNNING,
  73   A11Y_BUS_STATE_ERROR
  74 } A11yBusState;
  75
  76 typedef struct {
  77   GMainLoop *loop;
  78   gboolean launch_immediately;
  79   gboolean a11y_enabled;
  80   gboolean screen_reader_enabled;
  81   GHashTable *client_watcher_id;
  82   GDBusConnection *session_bus;
  83   GSettings *a11y_schema;
  84   GSettings *interface_schema;
  85
  86   int launch_screen_reader_repeats;
  87   gboolean screen_reader_needed;
  88   int pid;
  89
  90   A11yBusState state;
  91
  92   /* -1 == error, 0 == pending, > 0 == running */
  93   int a11y_bus_pid;
  94   char *a11y_bus_address;
  95   int pipefd[2];
  96   char *a11y_launch_error_message;
  97 } A11yBusLauncher;
  98
  99 static A11yBusLauncher *_global_app = NULL;
 100
 101 static const gchar introspection_xml[] =
 102   "<node>"
 103   "  <interface name='org.a11y.Bus'>"
 104   "    <method name='GetAddress'>"
 105   "      <arg type='s' name='address' direction='out'/>"
 106   "    </method>"
 107   "  </interface>"
 108   "<interface name='org.a11y.Status'>"
 109   "<property name='IsEnabled' type='b' access='readwrite'/>"
 110   "<property name='ScreenReaderEnabled' type='b' access='readwrite'/>"
 111   "</interface>"
 112   "</node>";
 113 static GDBusNodeInfo *introspection_data = NULL;
 114
 115 static void
 116 setup_bus_child (gpointer data)
 117 {
 118   A11yBusLauncher *app = data;
 119   (void) app;
 120
 121   close (app->pipefd[0]);
 122   dup2 (app->pipefd[1], 3);
 123   close (app->pipefd[1]);
 124
 125   /* On Linux, tell the bus process to exit if this process goes away */
 126 #ifdef __linux
 127 #include <sys/prctl.h>
 128   prctl (PR_SET_PDEATHSIG, 15);
 129 #endif
 130 }
 131
 132 /**
 133  * unix_read_all_fd_to_string:
 134  *
 135  * Read all data from a file descriptor to a C string buffer.
 136  */
 137 static gboolean
 138 unix_read_all_fd_to_string (int      fd,
 139                             char    *buf,
 140                             ssize_t  max_bytes)
 141 {
 142   ssize_t bytes_read;
 143
 144   while (max_bytes > 1 && (bytes_read = read (fd, buf, MAX (4096, max_bytes - 1))))
 145     {
 146       if (bytes_read < 0)
 147         return FALSE;
 148       buf += bytes_read;
 149       max_bytes -= bytes_read;
 150     }
 151   *buf = '\0';
 152   return TRUE;
 153 }
 154
 155 static void
 156 on_bus_exited (GPid     pid,
 157                gint     status,
 158                gpointer data)
 159 {
 160   A11yBusLauncher *app = data;
 161
 162   app->a11y_bus_pid = -1;
 163   app->state = A11Y_BUS_STATE_ERROR;
 164   if (app->a11y_launch_error_message == NULL)
 165     {
 166       if (WIFEXITED (status))
 167         app->a11y_launch_error_message = g_strdup_printf ("Bus exited with code %d", WEXITSTATUS (status));
 168       else if (WIFSIGNALED (status))
 169         app->a11y_launch_error_message = g_strdup_printf ("Bus killed by signal %d", WTERMSIG (status));
 170       else if (WIFSTOPPED (status))
 171         app->a11y_launch_error_message = g_strdup_printf ("Bus stopped by signal %d", WSTOPSIG (status));
 172     }
 173   g_main_loop_quit (app->loop);
 174 }
 175
 176 static gboolean
 177 ensure_a11y_bus (A11yBusLauncher *app)
 178 {
 179   GPid pid;
 180   char *argv[] = { DBUS_DAEMON, NULL, "--nofork", "--print-address", "3", NULL };
 181   char addr_buf[2048];
 182   GError *error = NULL;
 183
 184   if (app->a11y_bus_pid != 0)
 185     return FALSE;
 186
 187   argv[1] = g_strdup_printf ("--config-file=%s/at-spi2/accessibility.conf", SYSCONFDIR);
 188
 189   if (pipe (app->pipefd) < 0)
 190     g_error ("Failed to create pipe: %s", strerror (errno));
 191
 192   if (!g_spawn_async (NULL,
 193                       argv,
 194                       NULL,
 195                       G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD,
 196                       setup_bus_child,
 197                       app,
 198                       &pid,
 199                       &error))
 200     {
 201       app->a11y_bus_pid = -1;
 202       app->a11y_launch_error_message = g_strdup (error->message);
 203       g_clear_error (&error);
 204       goto error;
 205     }
 206
 207   close (app->pipefd[1]);
 208   app->pipefd[1] = -1;
 209
 210   g_child_watch_add (pid, on_bus_exited, app);
 211
 212   app->state = A11Y_BUS_STATE_READING_ADDRESS;
 213   app->a11y_bus_pid = pid;
 214   LOGD("Launched a11y bus, child is %ld", (long) pid);
 215   if (!unix_read_all_fd_to_string (app->pipefd[0], addr_buf, sizeof (addr_buf)))
 216     {
 217       app->a11y_launch_error_message = g_strdup_printf ("Failed to read address: %s", strerror (errno));
 218       kill (app->a11y_bus_pid, SIGTERM);
 219       goto error;
 220     }
 221   close (app->pipefd[0]);
 222   app->pipefd[0] = -1;
 223   app->state = A11Y_BUS_STATE_RUNNING;
 224
 225   /* Trim the trailing newline */
 226   app->a11y_bus_address = g_strchomp (g_strdup (addr_buf));
 227   LOGD("a11y bus address: %s", app->a11y_bus_address);
 228
 229 #ifdef HAVE_X11
 230   {
 231     Display *display = XOpenDisplay (NULL);
 232     if (display)
 233       {
 234         Atom bus_address_atom = XInternAtom (display, "AT_SPI_BUS", False);
 235         XChangeProperty (display,
 236                          XDefaultRootWindow (display),
 237                          bus_address_atom,
 238                          XA_STRING, 8, PropModeReplace,
 239                          (guchar *) app->a11y_bus_address, strlen (app->a11y_bus_address));
 240         XFlush (display);
 241         XCloseDisplay (display);
 242       }
 243   }
 244 #endif
 245
 246   if (argv[1]) g_free(argv[1]);
 247
 248   return TRUE;
 249
 250  error:
 251   if (argv[1]) g_free(argv[1]);
 252   close (app->pipefd[0]);
 253   close (app->pipefd[1]);
 254   app->state = A11Y_BUS_STATE_ERROR;
 255
 256   return FALSE;
 257 }
 258
 259 static void
 260 handle_method_call (GDBusConnection       *connection,
 261                     const gchar           *sender,
 262                     const gchar           *object_path,
 263                     const gchar           *interface_name,
 264                     const gchar           *method_name,
 265                     GVariant              *parameters,
 266                     GDBusMethodInvocation *invocation,
 267                     gpointer               user_data)
 268 {
 269   A11yBusLauncher *app = user_data;
 270
 271   if (g_strcmp0 (method_name, "GetAddress") == 0)
 272     {
 273       ensure_a11y_bus (app);
 274       if (app->a11y_bus_pid > 0)
 275         g_dbus_method_invocation_return_value (invocation,
 276                                                g_variant_new ("(s)", app->a11y_bus_address));
 277       else
 278         g_dbus_method_invocation_return_dbus_error (invocation,
 279                                                     "org.a11y.Bus.Error",
 280                                                     app->a11y_launch_error_message);
 281     }
 282 }
 283
 284 static GVariant *
 285 handle_get_property  (GDBusConnection       *connection,
 286                       const gchar           *sender,
 287                       const gchar           *object_path,
 288                       const gchar           *interface_name,
 289                       const gchar           *property_name,
 290                     GError **error,
 291                     gpointer               user_data)
 292 {
 293   A11yBusLauncher *app = user_data;
 294
 295   if (g_strcmp0 (property_name, "IsEnabled") == 0)
 296     return g_variant_new ("b", app->a11y_enabled);
 297   else if (g_strcmp0 (property_name, "ScreenReaderEnabled") == 0)
 298     return g_variant_new ("b", app->screen_reader_enabled);
 299   else
 300     return NULL;
 301 }
 302
 303 static void
 304 handle_a11y_enabled_change (A11yBusLauncher *app, gboolean enabled,
 305                                gboolean notify_gsettings)
 306 {
 307   GVariantBuilder builder;
 308   GVariantBuilder invalidated_builder;
 309
 310   if (enabled == app->a11y_enabled)
 311     return;
 312
 313   app->a11y_enabled = enabled;
 314
 315   if (notify_gsettings && app->interface_schema)
 316     {
 317       g_settings_set_boolean (app->interface_schema, "toolkit-accessibility",
 318                               enabled);
 319       g_settings_sync ();
 320     }
 321
 322   g_variant_builder_init (&builder, G_VARIANT_TYPE_ARRAY);
 323   g_variant_builder_init (&invalidated_builder, G_VARIANT_TYPE ("as"));
 324   g_variant_builder_add (&builder, "{sv}", "IsEnabled",
 325                          g_variant_new_boolean (enabled));
 326
 327   g_dbus_connection_emit_signal (app->session_bus, NULL, "/org/a11y/bus",
 328                                  "org.freedesktop.DBus.Properties",
 329                                  "PropertiesChanged",
 330                                  g_variant_new ("(sa{sv}as)", "org.a11y.Status",
 331                                                 &builder,
 332                                                 &invalidated_builder),
 333                                  NULL);
 334   g_variant_builder_clear (&builder);
 335   g_variant_builder_clear (&invalidated_builder);
 336 }
 337
 338 static void
 339 handle_screen_reader_enabled_change (A11yBusLauncher *app, gboolean enabled,
 340                                gboolean notify_gsettings)
 341 {
 342   GVariantBuilder builder;
 343   GVariantBuilder invalidated_builder;
 344
 345   if (enabled == app->screen_reader_enabled)
 346     return;
 347
 348   app->screen_reader_enabled = enabled;
 349
 350   if (notify_gsettings && app->a11y_schema)
 351     {
 352       g_settings_set_boolean (app->a11y_schema, "screen-reader-enabled",
 353                               enabled);
 354       g_settings_sync ();
 355     }
 356
 357   g_variant_builder_init (&builder, G_VARIANT_TYPE_ARRAY);
 358   g_variant_builder_init (&invalidated_builder, G_VARIANT_TYPE ("as"));
 359   g_variant_builder_add (&builder, "{sv}", "ScreenReaderEnabled",
 360                          g_variant_new_boolean (enabled));
 361
 362   g_dbus_connection_emit_signal (app->session_bus, NULL, "/org/a11y/bus",
 363                                  "org.freedesktop.DBus.Properties",
 364                                  "PropertiesChanged",
 365                                  g_variant_new ("(sa{sv}as)", "org.a11y.Status",
 366                                                 &builder,
 367                                                 &invalidated_builder),
 368                                  NULL);
 369   g_variant_builder_clear (&builder);
 370   g_variant_builder_clear (&invalidated_builder);
 371 }
 372
 373 static gboolean
 374 is_client_connected(A11yBusLauncher *app)
 375 {
 376   guint watchers = g_hash_table_size(app->client_watcher_id);
 377   LOGD("clients connected: %d", watchers);
 378   return watchers > 0;
 379 }
 380
 381 static void
 382 remove_client_watch(A11yBusLauncher *app,
 383                                   const gchar     *sender)
 384 {
 385   LOGD("Remove client watcher for %s", sender);
 386   guint watcher_id = GPOINTER_TO_UINT(g_hash_table_lookup(app->client_watcher_id, sender));
 387   if (watcher_id)
 388     g_bus_unwatch_name(watcher_id);
 389
 390   g_hash_table_remove(app->client_watcher_id, sender);
 391   if (!is_client_connected(app))
 392     handle_a11y_enabled_change (app, FALSE, TRUE);
 393 }
 394
 395 static void
 396 on_client_name_vanished (GDBusConnection *connection,
 397                                        const gchar     *name,
 398                                        gpointer         user_data)
 399 {
 400   A11yBusLauncher *app = user_data;
 401   remove_client_watch(app, name);
 402 }
 403
 404 static void
 405 add_client_watch(A11yBusLauncher *app,
 406                                const gchar     *sender)
 407 {
 408   LOGD("Add client watcher for %s", sender);
 409
 410   if (g_hash_table_contains(app->client_watcher_id, sender))
 411     {
 412       LOGI("Watcher for %s already registered", sender);
 413       return;
 414     }
 415
 416   guint watcher_id = g_bus_watch_name(G_BUS_TYPE_SESSION,
 417                      sender,
 418                      G_BUS_NAME_WATCHER_FLAGS_NONE,
 419                      NULL,
 420                      on_client_name_vanished,
 421                      app,
 422                      NULL);
 423
 424   g_hash_table_insert(app->client_watcher_id, g_strdup(sender), GUINT_TO_POINTER(watcher_id));
 425   handle_a11y_enabled_change (app, TRUE, TRUE);
 426 }
 427
 428 static gboolean
 429 handle_set_property  (GDBusConnection       *connection,
 430                       const gchar           *sender,
 431                       const gchar           *object_path,
 432                       const gchar           *interface_name,
 433                       const gchar           *property_name,
 434                       GVariant *value,
 435                     GError **error,
 436                     gpointer               user_data)
 437 {
 438   A11yBusLauncher *app = user_data;
 439   const gchar *type = g_variant_get_type_string (value);
 440   gboolean enabled;
 441
 442   if (g_strcmp0 (type, "b") != 0)
 443     {
 444       g_set_error (error, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS,
 445                        "org.a11y.Status.%s expects a boolean but got %s", property_name, type);
 446       return FALSE;
 447     }
 448
 449   enabled = g_variant_get_boolean (value);
 450
 451   if (g_strcmp0 (property_name, "IsEnabled") == 0)
 452     {
 453       if (enabled)
 454         add_client_watch(app, sender);
 455       else
 456         remove_client_watch(app, sender);
 457       return TRUE;
 458     }
 459   else if (g_strcmp0 (property_name, "ScreenReaderEnabled") == 0)
 460     {
 461       handle_screen_reader_enabled_change (app, enabled, TRUE);
 462       return TRUE;
 463     }
 464   else
 465     {
 466       g_set_error (error, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS,
 467                        "Unknown property '%s'", property_name);
 468       return FALSE;
 469     }
 470 }
 471
 472 static const GDBusInterfaceVTable bus_vtable =
 473 {
 474   handle_method_call,
 475   NULL, /* handle_get_property, */
 476   NULL  /* handle_set_property */
 477 };
 478
 479 static const GDBusInterfaceVTable status_vtable =
 480 {
 481   NULL, /* handle_method_call */
 482   handle_get_property,
 483   handle_set_property
 484 };
 485
 486 static void
 487 on_bus_acquired (GDBusConnection *connection,
 488                  const gchar     *name,
 489                  gpointer         user_data)
 490 {
 491   A11yBusLauncher *app = user_data;
 492   GError *error;
 493   guint registration_id;
 494
 495   if (connection == NULL)
 496     {
 497       g_main_loop_quit (app->loop);
 498       return;
 499     }
 500   app->session_bus = connection;
 501
 502   if (app->launch_immediately)
 503     {
 504       ensure_a11y_bus (app);
 505       if (app->state == A11Y_BUS_STATE_ERROR)
 506         {
 507           g_main_loop_quit (app->loop);
 508           return;
 509         }
 510     }
 511
 512   error = NULL;
 513   registration_id = g_dbus_connection_register_object (connection,
 514                                                        "/org/a11y/bus",
 515                                                        introspection_data->interfaces[0],
 516                                                        &bus_vtable,
 517                                                        _global_app,
 518                                                        NULL,
 519                                                        &error);
 520   if (registration_id == 0)
 521     {
 522       g_error ("%s", error->message);
 523       g_clear_error (&error);
 524     }
 525
 526   g_dbus_connection_register_object (connection,
 527                                      "/org/a11y/bus",
 528                                      introspection_data->interfaces[1],
 529                                      &status_vtable,
 530                                      _global_app,
 531                                      NULL,
 532                                      NULL);
 533 }
 534
 535 static void
 536 on_name_lost (GDBusConnection *connection,
 537               const gchar     *name,
 538               gpointer         user_data)
 539 {
 540   A11yBusLauncher *app = user_data;
 541   if (app->session_bus == NULL
 542       && connection == NULL
 543       && app->a11y_launch_error_message == NULL)
 544     app->a11y_launch_error_message = g_strdup ("Failed to connect to session bus");
 545   g_main_loop_quit (app->loop);
 546 }
 547
 548 static void
 549 on_name_acquired (GDBusConnection *connection,
 550                   const gchar     *name,
 551                   gpointer         user_data)
 552 {
 553   A11yBusLauncher *app = user_data;
 554   (void) app;
 555 }
 556
 557 static int sigterm_pipefd[2];
 558
 559 static void
 560 sigterm_handler (int signum)
 561 {
 562   write (sigterm_pipefd[1], "X", 1);
 563 }
 564
 565 static gboolean
 566 on_sigterm_pipe (GIOChannel  *channel,
 567                  GIOCondition condition,
 568                  gpointer     data)
 569 {
 570   A11yBusLauncher *app = data;
 571
 572   g_main_loop_quit (app->loop);
 573
 574   return FALSE;
 575 }
 576
 577 static void
 578 init_sigterm_handling (A11yBusLauncher *app)
 579 {
 580   GIOChannel *sigterm_channel;
 581
 582   if (pipe (sigterm_pipefd) < 0)
 583     g_error ("Failed to create pipe: %s", strerror (errno));
 584   signal (SIGTERM, sigterm_handler);
 585
 586   sigterm_channel = g_io_channel_unix_new (sigterm_pipefd[0]);
 587   g_io_add_watch (sigterm_channel,
 588                   G_IO_IN | G_IO_ERR | G_IO_HUP,
 589                   on_sigterm_pipe,
 590                   app);
 591 }
 592
 593 static gboolean
 594 already_running ()
 595 {
 596 #ifdef HAVE_X11
 597   Atom AT_SPI_BUS;
 598   Atom actual_type;
 599   Display *bridge_display;
 600   int actual_format;
 601   unsigned char *data = NULL;
 602   unsigned long nitems;
 603   unsigned long leftover;
 604   gboolean result = FALSE;
 605
 606   bridge_display = XOpenDisplay (NULL);
 607   if (!bridge_display)
 608               return FALSE;
 609
 610   AT_SPI_BUS = XInternAtom (bridge_display, "AT_SPI_BUS", False);
 611   XGetWindowProperty (bridge_display,
 612                       XDefaultRootWindow (bridge_display),
 613                       AT_SPI_BUS, 0L,
 614                       (long) BUFSIZ, False,
 615                       (Atom) 31, &actual_type, &actual_format,
 616                       &nitems, &leftover, &data);
 617
 618   if (data)
 619   {
 620     GDBusConnection *bus;
 621     bus = g_dbus_connection_new_for_address_sync ((const gchar *)data, 0,
 622                                                   NULL, NULL, NULL);
 623     if (bus != NULL)
 624       {
 625         result = TRUE;
 626         g_object_unref (bus);
 627       }
 628   }
 629
 630   XCloseDisplay (bridge_display);
 631   return result;
 632 #else
 633   return FALSE;
 634 #endif
 635 }
 636
 637 static GSettings *
 638 get_schema (const gchar *name)
 639 {
 640   const char * const *schemas = NULL;
 641   gint i;
 642
 643   schemas = g_settings_list_schemas ();
 644   for (i = 0; schemas[i]; i++)
 645   {
 646     if (!strcmp (schemas[i], name))
 647       return g_settings_new (schemas[i]);
 648   }
 649
 650   return NULL;
 651 }
 652
 653 static void
 654 gsettings_key_changed (GSettings *gsettings, const gchar *key, void *user_data)
 655 {
 656   gboolean new_val = g_settings_get_boolean (gsettings, key);
 657
 658   if (!strcmp (key, "toolkit-accessibility"))
 659     handle_a11y_enabled_change (_global_app, new_val, FALSE);
 660   else if (!strcmp (key, "screen-reader-enabled"))
 661     handle_screen_reader_enabled_change (_global_app, new_val, FALSE);
 662 }
 663
 664 static int
 665 _screen_reader_dead_tracker (int pid, void *data)
 666 {
 667   A11yBusLauncher *app = data;
 668
 669   if (app->pid > 0 && pid == app->pid)
 670     {
 671       LOGE("screen reader is dead, pid: %d, restarting", pid);
 672       app->pid = 0;
 673       g_timeout_add_seconds (2, _launch_screen_reader_repeat_until_success, app);
 674     }
 675   return 0;
 676 }
 677
 678 static gboolean
 679 _launch_screen_reader(gpointer user_data, gboolean by_vconf_change)
 680 {
 681    A11yBusLauncher *bl = user_data;
 682    LOGD("Launching screen reader");
 683
 684    bundle *kb = NULL;
 685    gboolean ret = FALSE;
 686
 687    kb = bundle_create();
 688
 689    if (kb == NULL)
 690      {
 691         LOGD("Can't create bundle");
 692         return FALSE;
 693      }
 694
 695    if (by_vconf_change)
 696      {
 697         if (bundle_add_str(kb, "by_vconf_change", "yes") != BUNDLE_ERROR_NONE)
 698           {
 699              LOGD("Can't add information to bundle");
 700           }
 701      }
 702
 703    int operation_error = appsvc_set_operation(kb, APP_CONTROL_OPERATION_SCREEN_READ);
 704    LOGD("appsvc_set_operation: %i", operation_error);
 705
 706    bl->pid = appsvc_run_service(kb, 0, NULL, NULL);
 707
 708    if (bl->pid > 0)
 709      {
 710         LOGD("Screen reader launched with pid: %i", bl->pid);
 711         LOGD("registering screen reader dead tracker");
 712         aul_listen_app_dead_signal(_screen_reader_dead_tracker, bl);
 713         ret = TRUE;
 714      }
 715    else
 716      {
 717         LOGD("Can't start screen-reader - error code: %i", bl->pid);
 718      }
 719
 720
 721    bundle_free(kb);
 722    return ret;
 723 }
 724
 725 static gboolean
 726 _launch_screen_reader_repeat_until_success(gpointer user_data) {
 727     A11yBusLauncher *bl = user_data;
 728
 729     if (bl->launch_screen_reader_repeats > 100 || bl->pid > 0)
 730       {
 731          //do not try anymore
 732          return FALSE;
 733       }
 734
 735     gboolean ret = _launch_screen_reader(user_data, FALSE);
 736
 737     if (ret)
 738       {
 739          //we managed to
 740          bl->launch_screen_reader_repeats = 0;
 741          return FALSE;
 742       }
 743     //try again
 744     return TRUE;
 745 }
 746
 747 static gboolean
 748 _terminate_screen_reader(A11yBusLauncher *bl)
 749 {
 750    LOGD("Terminating screen reader");
 751    int ret;
 752    int ret_aul;
 753    if (bl->pid <= 0)
 754      return FALSE;
 755
 756
 757    LOGD("unregistering screen reader dead tracker");
 758    aul_listen_app_dead_signal(NULL, NULL);
 759
 760    int status = aul_app_get_status_bypid(bl->pid);
 761
 762    if (status < 0)
 763      {
 764        LOGD("App with pid %d already terminated", bl->pid);
 765        bl->pid = 0;
 766        return TRUE;
 767      }
 768
 769    LOGD("terminate process with pid %d", bl->pid);
 770    ret_aul = aul_terminate_pid(bl->pid);
 771    if (ret_aul >= 0)
 772      {
 773         LOGD("Terminating with aul_terminate_pid: return is %d", ret_aul);
 774         bl->pid = 0;
 775         return TRUE;
 776      }
 777    else
 778      LOGD("aul_terminate_pid failed: return is %d", ret_aul);
 779
 780    LOGD("Unable to terminate process using aul api. Sending SIGTERM signal");
 781    ret = kill(bl->pid, SIGTERM);
 782    if (!ret)
 783      {
 784         bl->pid = 0;
 785         return TRUE;
 786      }
 787
 788    LOGD("Unable to terminate process: %d with api or signal.", bl->pid);
 789    return FALSE;
 790 }
 791
 792 void screen_reader_cb(keynode_t *node, void *user_data)
 793 {
 794    A11yBusLauncher *bl = user_data;
 795    int ret;
 796
 797    ret = vconf_keynode_get_bool(node);
 798    LOGD("vconf_keynode_get_bool(node): %i", ret);
 799    if (ret < 0)
 800      return;
 801
 802    //check if process really exists (e.g didn't crash)
 803    if (bl->pid > 0)
 804      {
 805         int err = kill(bl->pid,0);
 806         //process doesn't exist
 807         if (err == ESRCH)
 808           bl->pid = 0;
 809      }
 810
 811    bl->screen_reader_needed = ret;
 812    LOGD("bl->screen_reader_needed: %i, bl->pid: %i", ret, bl->pid);
 813    if (!bl->screen_reader_needed && (bl->pid > 0))
 814      _terminate_screen_reader(bl);
 815    else if (bl->screen_reader_needed && (bl->pid <= 0))
 816      _launch_screen_reader(bl, TRUE);
 817 }
 818
 819 int
 820 main (int    argc,
 821       char **argv)
 822 {
 823 #ifdef ATSPI_BUS_LAUNCHER_LOG_TO_FILE
 824   log_file = fopen("/tmp/at-spi-bus-launcher.log", "a");
 825 #endif
 826
 827   LOGD("Starting atspi bus launcher");
 828   int name_owner_id;
 829   gboolean a11y_set = FALSE;
 830   gboolean screen_reader_set = FALSE;
 831   gint i;
 832
 833   if (already_running ())
 834     {
 835        LOGD("atspi bus launcher is already running");
 836        return 0;
 837     }
 838
 839   _global_app = g_slice_new0 (A11yBusLauncher);
 840   _global_app->loop = g_main_loop_new (NULL, FALSE);
 841   _global_app->launch_screen_reader_repeats = 0;
 842   _global_app->client_watcher_id = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
 843
 844   for (i = 1; i < argc; i++)
 845     {
 846       if (!strcmp (argv[i], "--launch-immediately"))
 847         _global_app->launch_immediately = TRUE;
 848       else if (sscanf (argv[i], "--a11y=%d", &_global_app->a11y_enabled) == 2)
 849         a11y_set = TRUE;
 850       else if (sscanf (argv[i], "--screen-reader=%d",
 851                        &_global_app->screen_reader_enabled) == 2)
 852         screen_reader_set = TRUE;
 853     else
 854       g_error ("usage: %s [--launch-immediately] [--a11y=0|1] [--screen-reader=0|1]", argv[0]);
 855     }
 856
 857   _global_app->interface_schema = get_schema ("org.gnome.desktop.interface");
 858   _global_app->a11y_schema = get_schema ("org.gnome.desktop.a11y.applications");
 859
 860   if (!a11y_set)
 861     {
 862       _global_app->a11y_enabled = _global_app->interface_schema
 863                                   ? g_settings_get_boolean (_global_app->interface_schema, "toolkit-accessibility")
 864                                   : _global_app->launch_immediately;
 865     }
 866
 867   if (!screen_reader_set)
 868     {
 869       _global_app->screen_reader_enabled = _global_app->a11y_schema
 870                                   ? g_settings_get_boolean (_global_app->a11y_schema, "screen-reader-enabled")
 871                                   : FALSE;
 872     }
 873
 874   if (_global_app->interface_schema)
 875     g_signal_connect (_global_app->interface_schema,
 876                       "changed::toolkit-accessibility",
 877                       G_CALLBACK (gsettings_key_changed), _global_app);
 878
 879   if (_global_app->a11y_schema)
 880     g_signal_connect (_global_app->a11y_schema,
 881                       "changed::screen-reader-enabled",
 882                       G_CALLBACK (gsettings_key_changed), _global_app);
 883
 884   init_sigterm_handling (_global_app);
 885
 886   introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
 887   g_assert (introspection_data != NULL);
 888
 889   name_owner_id = g_bus_own_name (G_BUS_TYPE_SESSION,
 890                                   "org.a11y.Bus",
 891                                   G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT,
 892                                   on_bus_acquired,
 893                                   on_name_acquired,
 894                                   on_name_lost,
 895                                   _global_app,
 896                                   NULL);
 897
 898   int ret = vconf_get_bool(VCONFKEY_SETAPPL_ACCESSIBILITY_TTS, &_global_app->screen_reader_needed);
 899   if (ret != 0)
 900     {
 901       LOGD("Could not read VCONFKEY_SETAPPL_ACCESSIBILITY_TTS key value.\n");
 902       return FALSE;
 903     }
 904   ret = vconf_notify_key_changed(VCONFKEY_SETAPPL_ACCESSIBILITY_TTS, screen_reader_cb, _global_app);
 905   if(ret != 0)
 906     {
 907       LOGD("Could not add information level callback\n");
 908       return FALSE;
 909     }
 910   if (_global_app->screen_reader_needed)
 911     g_timeout_add_seconds(2,_launch_screen_reader_repeat_until_success, _global_app);
 912
 913   g_main_loop_run (_global_app->loop);
 914
 915   if (_global_app->a11y_bus_pid > 0)
 916     kill (_global_app->a11y_bus_pid, SIGTERM);
 917
 918   /* Clear the X property if our bus is gone; in the case where e.g.
 919    * GDM is launching a login on an X server it was using before,
 920    * we don't want early login processes to pick up the stale address.
 921    */
 922 #ifdef HAVE_X11
 923   {
 924     Display *display = XOpenDisplay (NULL);
 925     if (display)
 926       {
 927         Atom bus_address_atom = XInternAtom (display, "AT_SPI_BUS", False);
 928         XDeleteProperty (display,
 929                          XDefaultRootWindow (display),
 930                          bus_address_atom);
 931
 932         XFlush (display);
 933         XCloseDisplay (display);
 934       }
 935   }
 936 #endif
 937
 938   if (_global_app->a11y_launch_error_message)
 939     {
 940       g_printerr ("Failed to launch bus: %s", _global_app->a11y_launch_error_message);
 941       return 1;
 942     }
 943   return 0;
 944 }