GTK+ 3 Reference Manual: GtkApplication

## GtkApplication GtkApplication — Application class |

## Functions

GtkApplication * | gtk_application_new ()
void | gtk_application_add_window ()
void | gtk_application_remove_window ()
GList * | gtk_application_get_windows ()
GtkWindow * | gtk_application_get_window_by_id ()
GtkWindow * | gtk_application_get_active_window ()
guint | gtk_application_inhibit ()
void | gtk_application_uninhibit ()
gboolean | gtk_application_is_inhibited ()
gboolean | gtk_application_prefers_app_menu ()
GMenuModel * | gtk_application_get_app_menu ()
void | gtk_application_set_app_menu ()
GMenuModel * | gtk_application_get_menubar ()
void | gtk_application_set_menubar ()
GMenu * | gtk_application_get_menu_by_id ()
void | gtk_application_add_accelerator ()
void | gtk_application_remove_accelerator ()
gchar ** | gtk_application_list_action_descriptions ()
gchar ** | gtk_application_get_accels_for_action ()
void | gtk_application_set_accels_for_action ()
gchar ** | gtk_application_get_actions_for_accel ()

## Properties

GtkWindow * | active-window | Read
GMenuModel * | app-menu | Read / Write
GMenuModel * | menubar | Read / Write
gboolean | register-session | Read / Write

## Signals

void | window-added | Run First
void | window-removed | Run First

## Types and Values

struct | GtkApplication
struct | GtkApplicationClass
enum | GtkApplicationInhibitFlags

## Object Hierarchy

        GObject
        ╰── GApplication
            ╰── GtkApplication

## Implemented Interfaces

GtkApplication implements GActionGroup and GActionMap.

## Includes

    #include <gtk/gtk.h>

## Description

GtkApplication is a class that handles many important aspects of a GTK+ application in a convenient fashion, without enforcing a one-size-fits-all application model.

Currently, GtkApplication handles GTK+ initialization, application uniqueness, session management, provides some basic scriptability and desktop shell integration by exporting actions and menus and manages a list of toplevel windows whose life-cycle is automatically tied to the life-cycle of your application.

While GtkApplication works fine with plain GtkWindows, it is recommended to use it together with GtkApplicationWindow.

When GDK threads are enabled, GtkApplication will acquire the GDK lock when invoking actions that arrive from other processes. The GDK lock is not touched for local action invocations. In order to have actions invoked in a predictable context it is therefore recommended that the GDK lock be held while invoking actions locally with `g_action_group_activate_action()`. The same applies to actions associated with GtkApplicationWindow and to the “activate” and 'open' GApplication methods.

#### Automatic resources

GtkApplication will automatically load menus from the GtkBuilder file located at "gtk/menus.ui", relative to the application's resource base path (see `g_application_set_resource_base_path()`). The menu with the ID "app-menu" is taken as the application's app menu and the menu with the ID "menubar" is taken as the application's menubar. Additional menus (most interesting submenus) can be named and accessed via `gtk_application_get_menu_by_id()` which allows for dynamic population of a part of the menu structure.

If the files "gtk/menus-appmenu.ui" or "gtk/menus-traditional.ui" are present then these files will be used in preference, depending on the value of `gtk_application_prefers_app_menu()`.

It is also possible to provide the menus manually using `gtk_application_set_app_menu()` and `gtk_application_set_menubar()`.

GtkApplication will also automatically setup an icon search path for the default icon theme by appending "icons" to the resource base path. This allows your application to easily store its icons as resources. See `gtk_icon_theme_add_resource_path()` for more information.

#### 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.

## Functions

### 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.

#### Parameters

application_id | The application ID. | [allow-none]
flags | the application flags |

#### Returns

a new GtkApplication instance

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.

#### Parameters

application | a GtkApplication |
window | a GtkWindow |

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.

#### Parameters

application | a GtkApplication |
window | a GtkWindow |

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.

#### Parameters

application | a GtkApplication |

#### Returns

a GList of GtkWindow.

[element-type GtkWindow][transfer none]

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.

#### Parameters

application | a GtkApplication |
id | an identifier number |

#### Returns

the window with ID `id` , or `NULL` if there is no window with this ID.

[transfer none]

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.

#### Parameters

application | a GtkApplication |

#### Returns

the active window.

[transfer none]

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.

#### Parameters

application | the GtkApplication |
window | a GtkWindow, or `NULL`. | [allow-none]
flags | what types of actions should be inhibited |
reason | a short, human-readable string that explains why these operations are inhibited. | [allow-none]

#### Returns

A non-zero cookie that is used to uniquely identify this request. It should be used as an argument to `gtk_application_uninhibit()` in order to remove the request. If the platform does not support inhibiting or the request failed for some reason, 0 is returned.

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.

#### Parameters

application | the GtkApplication |
cookie | a cookie that was returned by `gtk_application_inhibit()` |

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).

#### Parameters

application | the GtkApplication |
flags | what types of actions should be queried |

#### Returns

`TRUE` if any of the actions specified in `flags` are inhibited

Since 3.4

### gtk_application_prefers_app_menu ()

    gboolean
    gtk_application_prefers_app_menu (GtkApplication *application);

Determines if the desktop environment in which the application is running would prefer an application menu be shown.

If this function returns `TRUE` then the application should call `gtk_application_set_app_menu()` with the contents of an application menu, which will be shown by the desktop environment. If it returns `FALSE` then you should consider using an alternate approach, such as a menubar.

The value returned by this function is purely advisory and you are free to ignore it. If you call `gtk_application_set_app_menu()` even if the desktop environment doesn't support app menus, then a fallback will be provided.

Applications are similarly free not to set an app menu even if the desktop environment wants to show one. In that case, a fallback will also be created by the desktop environment (GNOME, for example, uses a menu with only a "Quit" item in it).

The value returned by this function never changes. Once it returns a particular value, it is guaranteed to always return the same value.

You may only call this function after the application has been registered and after the base startup handler has run. You're most likely to want to use this from your own startup handler. It may also make sense to consult this function while constructing UI (in activate, open or an action activation handler) in order to determine if you should show a gear menu or not.

This function will return `FALSE` on Mac OS and a default app menu will be created automatically with the "usual" contents of that menu typical to most Mac OS applications. If you call `gtk_application_set_app_menu()` anyway, then this menu will be replaced with your own.

#### Parameters

application | a GtkApplication |

#### Returns

`TRUE` if you should set an app menu

Since 3.14

### 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()`.

#### Parameters

application | a GtkApplication |

#### Returns

the application menu of `application` .

[transfer none]

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.

#### Parameters

application | a GtkApplication |
app_menu | a GMenuModel, or `NULL`. | [allow-none]

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()`.

#### Parameters

application | a GtkApplication |

#### Returns

the menubar for windows of `application` .

[transfer none]

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.

#### Parameters

application | a GtkApplication |
menubar | a GMenuModel, or `NULL`. | [allow-none]

Since 3.4

### gtk_application_get_menu_by_id ()

    GMenu *
    gtk_application_get_menu_by_id (GtkApplication *application,
                                    const gchar *id);

Gets a menu from automatically loaded resources. See Automatic resources for more information.

#### Parameters

application | a GtkApplication |
id | the id of the menu to look up |

#### Returns

Gets the menu with the given id from the automatically loaded resources.

[transfer none]

Since 3.14

### gtk_application_add_accelerator ()

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

`gtk_application_add_accelerator` has been deprecated since version 3.14 and should not be used in newly-written code.

Use `gtk_application_set_accels_for_action()` instead

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.

#### Parameters

application | a GtkApplication |
accelerator | accelerator string |
action_name | the name of the action to activate |
parameter | parameter to pass when activating the action, or `NULL` if the action does not accept an activation parameter. | [allow-none]

Since 3.4

### gtk_application_remove_accelerator ()

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

`gtk_application_remove_accelerator` has been deprecated since version 3.14 and should not be used in newly-written code.

Use `gtk_application_set_accels_for_action()` instead

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

#### Parameters

application | a GtkApplication |
action_name | the name of the action to activate |
parameter | parameter to pass when activating the action, or `NULL` if the action does not accept an activation parameter. | [allow-none]

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()`.

#### Parameters

application | a GtkApplication |

#### Returns

a `NULL`-terminated array of strings, free with `g_strfreev()` when done.

[transfer full]

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.

#### Parameters

application | a GtkApplication |
detailed_action_name | a detailed action name, specifying an action and target to obtain accelerators for |

#### Returns

accelerators for `detailed_action_name` , as a `NULL`-terminated array. Free with `g_strfreev()` when no longer needed.

[transfer full]

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` .

#### Parameters

application | a GtkApplication |
detailed_action_name | a detailed action name, specifying an action and target to associate accelerators with |
accels | a list of accelerators in the format understood by `gtk_accelerator_parse()`. | [array zero-terminated=1]

Since 3.12

### gtk_application_get_actions_for_accel ()

    gchar **
    gtk_application_get_actions_for_accel (GtkApplication *application,
                                           const gchar *accel);

Returns the list of actions (possibly empty) that `accel` maps to. Each item in the list is a detailed action name in the usual form.

This might be useful to discover if an accel already exists in order to prevent installation of a conflicting accelerator (from an accelerator editor or a plugin system, for example). Note that having more than one action per accelerator may not be a bad thing and might make sense in cases where the actions never appear in the same context.

In case there are no actions for a given accelerator, an empty array is returned. `NULL` is never returned.

It is a programmer error to pass an invalid accelerator string. If you are unsure, check it with `gtk_accelerator_parse()` first.

#### Parameters

application | a GtkApplication |
accel | an accelerator that can be parsed by `gtk_accelerator_parse()` |

#### Returns

a `NULL`-terminated array of actions for `accel` .

[transfer full]

Since 3.14

## Types and Values

### 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);
    };

#### Members

GApplicationClass `parent_class`; | The parent class. |
`window_added` () | Signal emitted when a GtkWindow is added to application through `gtk_application_add_window()`. |
`window_removed` () | Signal emitted when a GtkWindow is removed from application, either as a side-effect of being destroyed or explicitly through `gtk_application_remove_window()`. |

### enum GtkApplicationInhibitFlags

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

#### Members

GTK_APPLICATION_INHIBIT_LOGOUT | Inhibit ending the user session by logging out or by shutting down the computer |
GTK_APPLICATION_INHIBIT_SWITCH | Inhibit user switching |
GTK_APPLICATION_INHIBIT_SUSPEND | Inhibit suspending the session or computer |
GTK_APPLICATION_INHIBIT_IDLE | Inhibit the session being marked as idle (and possibly locked) |

Since 3.4

## Property Details

### 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

## Signal Details

### 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()`.

#### Parameters

application | the GtkApplication which emitted the signal |
window | the newly-added GtkWindow |
user_data | user data set when the signal handler was connected. |

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()`.

#### Parameters

application | the GtkApplication which emitted the signal |
window | the GtkWindow that is being removed |
user_data | user data set when the signal handler was connected. |

Flags: Run First

Since 3.2