[gnome-shell/T27795: 47/138] shell-app-system: Add support to identify apps that are starting up

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 5727d7e3736b5b234ee9652aec4c0576bad008d1
Author: Mario Sanchez Prada <mario endlessm com>
Date:   Mon Jun 5 17:18:40 2017 +0100

    shell-app-system: Add support to identify apps that are starting up

 src/shell-app-system.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 src/shell-app-system.h |  2 ++
 2 files changed, 42 insertions(+), 1 deletion(-)
---
diff --git a/src/shell-app-system.c b/src/shell-app-system.c
index 3ba25f27fb..d215b7a395 100644
--- a/src/shell-app-system.c
+++ b/src/shell-app-system.c
@@ -72,6 +72,7 @@ struct _ShellAppSystem
 
 struct _ShellAppSystemPrivate {
   GHashTable *running_apps;
+  GHashTable *starting_apps;
   GHashTable *id_to_app;
   GHashTable *startup_wm_class_to_id;
   GList *installed_apps;
@@ -280,6 +281,7 @@ shell_app_system_init (ShellAppSystem *self)
   self->priv = priv = shell_app_system_get_instance_private (self);
 
   priv->running_apps = g_hash_table_new_full (NULL, NULL, (GDestroyNotify) g_object_unref, NULL);
+  priv->starting_apps = g_hash_table_new_full (NULL, NULL, (GDestroyNotify) g_object_unref, NULL);
   priv->id_to_app = g_hash_table_new_full (g_str_hash, g_str_equal,
                                            NULL,
                                            (GDestroyNotify)g_object_unref);
@@ -299,6 +301,7 @@ shell_app_system_finalize (GObject *object)
   ShellAppSystemPrivate *priv = self->priv;
 
   g_hash_table_destroy (priv->running_apps);
+  g_hash_table_destroy (priv->starting_apps);
   g_hash_table_destroy (priv->id_to_app);
   g_hash_table_destroy (priv->startup_wm_class_to_id);
   g_list_free_full (priv->installed_apps, g_object_unref);
@@ -528,10 +531,32 @@ _shell_app_system_notify_app_state_changed (ShellAppSystem *self,
                                             g_variant_new_string (app_info_id));
         }
       g_hash_table_insert (self->priv->running_apps, g_object_ref (app), NULL);
+      g_hash_table_remove (self->priv->starting_apps, app);
       break;
     case SHELL_APP_STATE_STARTING:
+      g_hash_table_insert (self->priv->starting_apps, g_object_ref (app), NULL);
       break;
     case SHELL_APP_STATE_STOPPED:
+      /* Applications associated to multiple .desktop files (e.g. gnome-control-center)
+       * will create different ShellApp instances during the startup process when not
+       * launched via the main .desktop file: one initial instance for the .desktop file
+       * originally launched (that will end up in the starting_apps table) and a different
+       * one associated to the main .desktop file for the application.
+       *
+       * Thus, we can not rely on the initial ShellApp being removed from the starting_apps
+       * table in the SHELL_APP_STATE_RUNNING case above because the instance will be different
+       * than the one being added to running_apps, resulting in a rogue ShellApp instance being
+       * kept forever in the starting_apps table, that will confuse the shell.
+       *
+       * The solution is to make sure that we remove that rogue ShellApp instance from the
+       * starting_apps table, if needed, when moving to SHELL_APP_STATE_STOPPED, since that
+       * state change will be enforced from _shell_app_handle_startup_sequence() for this kind
+       * of apps launched from a secondary .desktop file, before moving the real ShellApp instance
+       * into the running state.
+       */
+      if (g_hash_table_contains (self->priv->starting_apps, app))
+        g_hash_table_remove (self->priv->starting_apps, app);
+
       if (g_hash_table_remove (self->priv->running_apps, app) && app_info_id != NULL)
         {
           emtr_event_recorder_record_stop (emtr_event_recorder_get_default (),
@@ -560,7 +585,7 @@ GSList *
 shell_app_system_get_running (ShellAppSystem *self)
 {
   gpointer key, value;
-  GSList *ret;
+  GSList *ret = NULL;
   GHashTableIter iter;
 
   g_hash_table_iter_init (&iter, self->priv->running_apps);
@@ -573,6 +598,14 @@ shell_app_system_get_running (ShellAppSystem *self)
       ret = g_slist_prepend (ret, app);
     }
 
+  g_hash_table_iter_init (&iter, self->priv->starting_apps);
+  while (g_hash_table_iter_next (&iter, &key, &value))
+    {
+      ShellApp *app = key;
+
+      ret = g_slist_prepend (ret, app);
+    }
+
   ret = g_slist_sort (ret, (GCompareFunc)shell_app_compare);
 
   return ret;
@@ -620,3 +653,9 @@ shell_app_system_get_installed (ShellAppSystem *self)
 
   return priv->installed_apps;
 }
+
+gboolean
+shell_app_system_has_starting_apps (ShellAppSystem *self)
+{
+  return g_hash_table_size (self->priv->starting_apps) > 0;
+}
diff --git a/src/shell-app-system.h b/src/shell-app-system.h
index d236b3b5f3..7d669745f0 100644
--- a/src/shell-app-system.h
+++ b/src/shell-app-system.h
@@ -31,4 +31,6 @@ char         ***shell_app_system_search                    (const char *search_s
 
 GList          *shell_app_system_get_installed             (ShellAppSystem  *self);
 
+gboolean        shell_app_system_has_starting_apps         (ShellAppSystem  *self);
+
 #endif /* __SHELL_APP_SYSTEM_H__ */