A simple application

A simple example

GtkApplication optionally registers with a session manager of the users session (if you set the “register-session” property) and offers various functionality related to the session life-cycle.

An application can block various ways to end the session with the gtk_application_inhibit() function. Typical use cases for this kind of inhibiting are long-running, uninterruptible operations, such as burning a CD or performing a disk backup. The session manager may not honor the inhibitor, but it can be expected to inform the user about the negative consequences of ending the session while inhibitors are present.

gtk_application_new ()

GtkApplication *
gtk_application_new (const gchar *application_id,
                     GApplicationFlags flags);

Creates a new GtkApplication instance.

When using GtkApplication, it is not necessary to call gtk_init() manually. It is called as soon as the application gets registered as the primary instance.

Concretely, gtk_init() is called in the default handler for the “startup” signal. Therefore, GtkApplication subclasses should chain up in their “startup” handler before using any GTK+ API.

Note that commandline arguments are not passed to gtk_init(). All GTK+ functionality that is available via commandline arguments can also be achieved by setting suitable environment variables such as G_DEBUG, so this should not be a big problem. If you absolutely must support GTK+ commandline arguments, you can explicitly call gtk_init() before creating the application instance.

If non-NULL, the application ID must be valid. See g_application_id_is_valid().

If no application ID is given then some features (most notably application uniqueness) will be disabled. A null application ID is only allowed with GTK+ 3.6 or later.

Since 3.0

gtk_application_add_window ()

void
gtk_application_add_window (GtkApplication *application,
                            GtkWindow *window);

Adds a window to application .

This call is equivalent to setting the “application” property of window to application .

Normally, the connection between the application and the window will remain until the window is destroyed, but you can explicitly remove it with gtk_application_remove_window().

GTK+ will keep the application running as long as it has any windows.

Since 3.0

gtk_application_remove_window ()

void
gtk_application_remove_window (GtkApplication *application,
                               GtkWindow *window);

Remove a window from application .

If window belongs to application then this call is equivalent to setting the “application” property of window to NULL.

The application may stop running as a result of a call to this function.

Since 3.0

gtk_application_get_windows ()

GList *
gtk_application_get_windows (GtkApplication *application);

Gets a list of the GtkWindows associated with application .

The list is sorted by most recently focused window, such that the first element is the currently focused window. (Useful for choosing a parent for a transient window.)

The list that is returned should not be modified in any way. It will only remain valid until the next focus change or window creation or deletion.

Since 3.0

gtk_application_get_window_by_id ()

GtkWindow *
gtk_application_get_window_by_id (GtkApplication *application,
                                  guint id);

Returns the GtkApplicationWindow with the given ID.

Since 3.6

gtk_application_get_active_window ()

GtkWindow *
gtk_application_get_active_window (GtkApplication *application);

Gets the “active” window for the application.

The active window is the one that was most recently focused (within the application). This window may not have the focus at the moment if another application has it -- this is just the most recently-focused window within this application.

Since 3.6

gtk_application_inhibit ()

guint
gtk_application_inhibit (GtkApplication *application,
                         GtkWindow *window,
                         GtkApplicationInhibitFlags flags,
                         const gchar *reason);

Inform the session manager that certain types of actions should be inhibited. This is not guaranteed to work on all platforms and for all types of actions.

Applications should invoke this method when they begin an operation that should not be interrupted, such as creating a CD or DVD. The types of actions that may be blocked are specified by the flags parameter. When the application completes the operation it should call gtk_application_uninhibit() to remove the inhibitor. Note that an application can have multiple inhibitors, and all of the must be individually removed. Inhibitors are also cleared when the application exits.

Applications should not expect that they will always be able to block the action. In most cases, users will be given the option to force the action to take place.

Reasons should be short and to the point.

If window is given, the session manager may point the user to this window to find out more about why the action is inhibited.

Since 3.4

gtk_application_uninhibit ()

void
gtk_application_uninhibit (GtkApplication *application,
                           guint cookie);

Removes an inhibitor that has been established with gtk_application_inhibit(). Inhibitors are also cleared when the application exits.

Since 3.4

gtk_application_is_inhibited ()

gboolean
gtk_application_is_inhibited (GtkApplication *application,
                              GtkApplicationInhibitFlags flags);

Determines if any of the actions specified in flags are currently inhibited (possibly by another application).

Since 3.4

gtk_application_get_app_menu ()

GMenuModel *
gtk_application_get_app_menu (GtkApplication *application);

Returns the menu model that has been set with gtk_application_set_app_menu().

Since 3.4

gtk_application_set_app_menu ()

void
gtk_application_set_app_menu (GtkApplication *application,
                              GMenuModel *app_menu);

Sets or unsets the application menu for application .

This can only be done in the primary instance of the application, after it has been registered. “startup” is a good place to call this.

The application menu is a single menu containing items that typically impact the application as a whole, rather than acting on a specific window or document. For example, you would expect to see “Preferences” or “Quit” in an application menu, but not “Save” or “Print”.

If supported, the application menu will be rendered by the desktop environment.

Use the base GActionMap interface to add actions, to respond to the user selecting these menu items.

Since 3.4

gtk_application_get_menubar ()

GMenuModel *
gtk_application_get_menubar (GtkApplication *application);

Returns the menu model that has been set with gtk_application_set_menubar().

Since 3.4

gtk_application_set_menubar ()

void
gtk_application_set_menubar (GtkApplication *application,
                             GMenuModel *menubar);

Sets or unsets the menubar for windows of application .

This is a menubar in the traditional sense.

This can only be done in the primary instance of the application, after it has been registered. “startup” is a good place to call this.

Depending on the desktop environment, this may appear at the top of each window, or at the top of the screen. In some environments, if both the application menu and the menubar are set, the application menu will be presented as if it were the first item of the menubar. Other environments treat the two as completely separate -- for example, the application menu may be rendered by the desktop shell while the menubar (if set) remains in each individual window.

Use the base GActionMap interface to add actions, to respond to the user selecting these menu items.

Since 3.4

gtk_application_add_accelerator ()

void
gtk_application_add_accelerator (GtkApplication *application,
                                 const gchar *accelerator,
                                 const gchar *action_name,
                                 GVariant *parameter);

Installs an accelerator that will cause the named action to be activated when the key combination specificed by accelerator is pressed.

accelerator must be a string that can be parsed by gtk_accelerator_parse(), e.g. "<Primary>q" or “<Control><Alt>p”.

action_name must be the name of an action as it would be used in the app menu, i.e. actions that have been added to the application are referred to with an “app.” prefix, and window-specific actions with a “win.” prefix.

GtkApplication also extracts accelerators out of “accel” attributes in the GMenuModels passed to gtk_application_set_app_menu() and gtk_application_set_menubar(), which is usually more convenient than calling this function for each accelerator.

Since 3.4

gtk_application_remove_accelerator ()

void
gtk_application_remove_accelerator (GtkApplication *application,
                                    const gchar *action_name,
                                    GVariant *parameter);

Removes an accelerator that has been previously added with gtk_application_add_accelerator().

Since 3.4

gtk_application_list_action_descriptions ()

gchar **
gtk_application_list_action_descriptions
                               (GtkApplication *application);

Lists the detailed action names which have associated accelerators. See gtk_application_set_accels_for_action().

Since 3.12

gtk_application_get_accels_for_action ()

gchar **
gtk_application_get_accels_for_action (GtkApplication *application,
                                       const gchar *detailed_action_name);

Gets the accelerators that are currently associated with the given action.

Since 3.12

gtk_application_set_accels_for_action ()

void
gtk_application_set_accels_for_action (GtkApplication *application,
                                       const gchar *detailed_action_name,
                                       const gchar * const *accels);

Sets zero or more keyboard accelerators that will trigger the given action. The first item in accels will be the primary accelerator, which may be displayed in the UI.

To remove all accelerators for an action, use an empty, zero-terminated array for accels .

Since 3.12

struct GtkApplication

struct GtkApplication;

struct GtkApplicationClass

struct GtkApplicationClass {
  GApplicationClass parent_class;


  void (*window_added)   (GtkApplication *application,
                          GtkWindow      *window);
  void (*window_removed) (GtkApplication *application,
                          GtkWindow      *window);
};

enum GtkApplicationInhibitFlags

Types of user actions that may be blocked by gtk_application_inhibit().

Since 3.4

The “active-window” property

  “active-window”            GtkWindow *

The window which most recently had focus.

Flags: Read

The “app-menu” property

  “app-menu”                 GMenuModel *

The GMenuModel for the application menu.

Flags: Read / Write

The “menubar” property

  “menubar”                  GMenuModel *

The GMenuModel for the menubar.

Flags: Read / Write

The “register-session” property

  “register-session”         gboolean

Set this property to TRUE to register with the session manager.

Flags: Read / Write

Default value: FALSE

Since 3.4

The “window-added” signal

void
user_function (GtkApplication *application,
               GtkWindow      *window,
               gpointer        user_data)

Emitted when a GtkWindow is added to application through gtk_application_add_window().

Flags: Run First

Since 3.2

The “window-removed” signal

void
user_function (GtkApplication *application,
               GtkWindow      *window,
               gpointer        user_data)

Emitted when a GtkWindow is removed from application , either as a side-effect of being destroyed or explicitly through gtk_application_remove_window().

Flags: Run First

Since 3.2