shell: Make singletons owned by ShellGlobal

This means also means they will be cleaned up when disposing
ShellGlobal, which will then mean signals tied to the GObject lifetime
will be disconnected.

Closes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/6536
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2722>

src/shell-app-cache.c

@@ -4,6 +4,8 @@
 
 #include "shell-app-cache-private.h"
 
+#include "shell-global-private.h"
+
 /**
  * SECTION:shell-app-cache
  * @title: ShellAppCache
@@ -82,15 +84,7 @@ cache_state_new (void)
 ShellAppCache *
 shell_app_cache_get_default (void)
 {
-  static ShellAppCache *instance;
-
-  if (instance == NULL)
-    {
-      instance = g_object_new (SHELL_TYPE_APP_CACHE, NULL);
-      g_object_add_weak_pointer (G_OBJECT (instance), (gpointer *)&instance);
-    }
-
-  return instance;
+  return shell_global_get_app_cache (shell_global_get ());
 }
 
 static void

src/shell-app-system.c

@@ -308,12 +308,7 @@ shell_app_system_finalize (GObject *object)
 ShellAppSystem *
 shell_app_system_get_default (void)
 {
-  static ShellAppSystem *instance = NULL;
-
-  if (instance == NULL)
-    instance = g_object_new (SHELL_TYPE_APP_SYSTEM, NULL);
-
-  return instance;
+  return shell_global_get_app_system (shell_global_get ());
 }
 
 /**

src/shell-app-usage.c

@@ -763,10 +763,5 @@ on_enable_monitoring_key_changed (GSettings     *settings,
 ShellAppUsage *
 shell_app_usage_get_default (void)
 {
-  static ShellAppUsage *instance;
-
-  if (instance == NULL)
-    instance = g_object_new (SHELL_TYPE_APP_USAGE, NULL);
-
-  return instance;
+  return shell_global_get_app_usage (shell_global_get ());
 }

src/shell-global-private.h

@@ -6,6 +6,8 @@
 
 #include <gjs/gjs.h>
 
+#include "shell-app-cache-private.h"
+
 void _shell_global_init            (const char *first_property_name,
                                     ...);
 void _shell_global_set_plugin      (ShellGlobal  *global,
@@ -15,6 +17,8 @@ void        _shell_global_destroy_gjs_context (ShellGlobal  *global);
 
 GjsContext *_shell_global_get_gjs_context (ShellGlobal  *global);
 
+ShellAppCache * shell_global_get_app_cache (ShellGlobal *global);
+
 gboolean _shell_global_check_xdnd_event (ShellGlobal  *global,
                                          XEvent       *xev);
 

src/shell-global.c

@@ -39,6 +39,8 @@
 #include "shell-global-private.h"
 #include "shell-perf-log.h"
 #include "shell-window-tracker.h"
+#include "shell-app-usage.h"
+#include "shell-app-cache-private.h"
 #include "shell-wm.h"
 #include "shell-util.h"
 #include "st.h"
@@ -72,6 +74,11 @@ struct _ShellGlobal {
   GFile *userdatadir_path;
   GFile *runtime_state_path;
 
+  ShellWindowTracker *window_tracker;
+  ShellAppSystem *app_system;
+  ShellAppCache *app_cache;
+  ShellAppUsage *app_usage;
+
   StFocusManager *focus_manager;
 
   guint work_count;
@@ -479,6 +486,11 @@ shell_global_finalize (GObject *object)
   g_clear_object (&global->js_context);
   g_object_unref (global->settings);
 
+  g_clear_object (&global->window_tracker);
+  g_clear_object (&global->app_system);
+  g_clear_object (&global->app_cache);
+  g_clear_object (&global->app_usage);
+
   the_object = NULL;
 
   g_cancellable_cancel (global->switcheroo_cancellable);
@@ -720,6 +732,7 @@ _shell_global_init (const char *first_property_name,
 ShellGlobal *
 shell_global_get (void)
 {
+  g_return_val_if_fail (the_object, NULL);
   return the_object;
 }
 
@@ -1915,3 +1928,63 @@ _shell_global_notify_shutdown (ShellGlobal *global)
 {
   g_signal_emit (global, shell_global_signals[SHUTDOWN], 0);
 }
+
+/**
+ * shell_global_get_window_tracker:
+ *
+ * Gets window tracker.
+ *
+ * Return value: (transfer none): the window tracker
+ */
+ShellWindowTracker *
+shell_global_get_window_tracker (ShellGlobal *global)
+{
+  if (!global->window_tracker)
+    global->window_tracker = g_object_new (SHELL_TYPE_WINDOW_TRACKER, NULL);
+  return global->window_tracker;
+}
+
+/**
+ * shell_global_get_app_system:
+ *
+ * Gets app system.
+ *
+ * Return value: (transfer none): the app system
+ */
+ShellAppSystem *
+shell_global_get_app_system (ShellGlobal *global)
+{
+  if (!global->app_system)
+    global->app_system = g_object_new (SHELL_TYPE_APP_SYSTEM, NULL);
+  return global->app_system;
+}
+
+/**
+ * shell_global_get_app_cache:
+ *
+ * Gets app cache.
+ *
+ * Return value: (transfer none): the app cache
+ */
+ShellAppCache *
+shell_global_get_app_cache (ShellGlobal *global)
+{
+  if (!global->app_cache)
+    global->app_cache = g_object_new (SHELL_TYPE_APP_CACHE, NULL);
+  return global->app_cache;
+}
+
+/**
+ * shell_global_get_app_usage:
+ *
+ * Gets app usage.
+ *
+ * Return value: (transfer none): the app usage
+ */
+ShellAppUsage *
+shell_global_get_app_usage (ShellGlobal *global)
+{
+  if (!global->app_usage)
+    global->app_usage = g_object_new (SHELL_TYPE_APP_USAGE, NULL);
+  return global->app_usage;
+}

src/shell-global.h

@@ -9,6 +9,10 @@
 
 G_BEGIN_DECLS
 
+#include "shell-window-tracker.h"
+#include "shell-app-system.h"
+#include "shell-app-usage.h"
+
 #define SHELL_TYPE_GLOBAL (shell_global_get_type ())
 G_DECLARE_FINAL_TYPE (ShellGlobal, shell_global, SHELL, GLOBAL, GObject)
 
@@ -89,6 +93,12 @@ GVariant * shell_global_get_persistent_state    (ShellGlobal  *global,
                                                  const char   *property_type,
                                                  const char   *property_name);
 
+ShellWindowTracker * shell_global_get_window_tracker (ShellGlobal *global);
+
+ShellAppSystem *     shell_global_get_app_system     (ShellGlobal *global);
+
+ShellAppUsage *      shell_global_get_app_usage      (ShellGlobal *global);
+
 G_END_DECLS
 
 #endif /* __SHELL_GLOBAL_H__ */

src/shell-window-tracker.c

@@ -824,10 +824,5 @@ shell_startup_sequence_get_app (MetaStartupSequence *sequence)
 ShellWindowTracker *
 shell_window_tracker_get_default (void)
 {
-  static ShellWindowTracker *instance;
-
-  if (instance == NULL)
-    instance = g_object_new (SHELL_TYPE_WINDOW_TRACKER, NULL);
-
-  return instance;
+  return shell_global_get_window_tracker (shell_global_get ());
 }