CtkApplication

CtkApplication — Application class

Functions

Properties

CtkWindow * active-window Read
GMenuModel * app-menu Read / Write
GMenuModel * menubar Read / Write
gboolean register-session Read / Write
gboolean screensaver-active Read

Signals

void query-end Run First
void window-added Run First
void window-removed Run First

Types and Values

Object Hierarchy

    GObject
    ╰── GApplication
        ╰── CtkApplication

Implemented Interfaces

CtkApplication implements GActionGroup and GActionMap.

Includes

#include <ctk/ctk.h>

Description

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

Currently, CtkApplication handles CTK+ 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 CtkApplication works fine with plain CtkWindows, it is recommended to use it together with CtkApplicationWindow.

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

Automatic resources

CtkApplication will automatically load menus from the CtkBuilder resource located at "ctk/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 ctk_application_get_menu_by_id() which allows for dynamic population of a part of the menu structure.

If the resources "ctk/menus-appmenu.ui" or "ctk/menus-traditional.ui" are present then these files will be used in preference, depending on the value of ctk_application_prefers_app_menu(). If the resource "ctk/menus-common.ui" is present it will be loaded as well. This is useful for storing items that are referenced from both "ctk/menus-appmenu.ui" and "ctk/menus-traditional.ui".

It is also possible to provide the menus manually using ctk_application_set_app_menu() and ctk_application_set_menubar().

CtkApplication 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 ctk_icon_theme_add_resource_path() for more information.

If there is a resource located at "ctk/help-overlay.ui" which defines a CtkShortcutsWindow with ID "help_overlay" then CtkApplication associates an instance of this shortcuts window with each CtkApplicationWindow and sets up keyboard accelerators (Control-F1 and Control-?) to open it. To create a menu item that displays the shortcuts window, associate the item with the action win.show-help-overlay.

A simple application

A simple example

CtkApplication 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 ctk_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

ctk_application_new ()

CtkApplication *
ctk_application_new (const gchar *application_id,
                     GApplicationFlags flags);

Creates a new CtkApplication instance.

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

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

Note that commandline arguments are not passed to ctk_init(). All CTK+ 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 CTK+ commandline arguments, you can explicitly call ctk_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 CTK+ 3.6 or later.

Parameters

application_id

The application ID.

[allow-none]

flags

the application flags

 

Returns

a new CtkApplication instance

Since: 3.0


ctk_application_add_window ()

void
ctk_application_add_window (CtkApplication *application,
                            CtkWindow *window);

Adds a window to application .

This call can only happen after the application has started; typically, you should add new application windows in response to the emission of the “activate” signal.

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 ctk_application_remove_window().

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

Parameters

application

a CtkApplication

 

window

a CtkWindow

 

Since: 3.0


ctk_application_remove_window ()

void
ctk_application_remove_window (CtkApplication *application,
                               CtkWindow *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 CtkApplication

 

window

a CtkWindow

 

Since: 3.0


ctk_application_get_windows ()

GList *
ctk_application_get_windows (CtkApplication *application);

Gets a list of the CtkWindows 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 CtkApplication

 

Returns

a GList of CtkWindow.

[element-type CtkWindow][transfer none]

Since: 3.0


ctk_application_get_window_by_id ()

CtkWindow *
ctk_application_get_window_by_id (CtkApplication *application,
                                  guint id);

Returns the CtkApplicationWindow with the given ID.

The ID of a CtkApplicationWindow can be retrieved with ctk_application_window_get_id().

Parameters

application

a CtkApplication

 

id

an identifier number

 

Returns

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

[nullable][transfer none]

Since: 3.6


ctk_application_get_active_window ()

CtkWindow *
ctk_application_get_active_window (CtkApplication *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 CtkApplication

 

Returns

the active window, or NULL if there isn't one.

[transfer none][nullable]

Since: 3.6


ctk_application_inhibit ()

guint
ctk_application_inhibit (CtkApplication *application,
                         CtkWindow *window,
                         CtkApplicationInhibitFlags 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 ctk_application_uninhibit() to remove the inhibitor. Note that an application can have multiple inhibitors, and all of them 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 CtkApplication

 

window

a CtkWindow, 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 ctk_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


ctk_application_uninhibit ()

void
ctk_application_uninhibit (CtkApplication *application,
                           guint cookie);

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

Parameters

application

the CtkApplication

 

cookie

a cookie that was returned by ctk_application_inhibit()

 

Since: 3.4


ctk_application_is_inhibited ()

gboolean
ctk_application_is_inhibited (CtkApplication *application,
                              CtkApplicationInhibitFlags flags);

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

Note that this information may not be available (for example when the application is running in a sandbox).

Parameters

application

the CtkApplication

 

flags

what types of actions should be queried

 

Returns

TRUE if any of the actions specified in flags are inhibited

Since: 3.4


ctk_application_prefers_app_menu ()

gboolean
ctk_application_prefers_app_menu (CtkApplication *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 ctk_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 ctk_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 ctk_application_set_app_menu() anyway, then this menu will be replaced with your own.

Parameters

application

a CtkApplication

 

Returns

TRUE if you should set an app menu

Since: 3.14


ctk_application_get_app_menu ()

GMenuModel *
ctk_application_get_app_menu (CtkApplication *application);

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

Parameters

application

a CtkApplication

 

Returns

the application menu of application or NULL if no application menu has been set.

[transfer none][nullable]

Since: 3.4


ctk_application_set_app_menu ()

void
ctk_application_set_app_menu (CtkApplication *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 CtkApplication

 

app_menu

a GMenuModel, or NULL.

[allow-none]

Since: 3.4


ctk_application_get_menubar ()

GMenuModel *
ctk_application_get_menubar (CtkApplication *application);

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

Parameters

application

a CtkApplication

 

Returns

the menubar for windows of application .

[transfer none]

Since: 3.4


ctk_application_set_menubar ()

void
ctk_application_set_menubar (CtkApplication *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 CtkApplication

 

menubar

a GMenuModel, or NULL.

[allow-none]

Since: 3.4


ctk_application_get_menu_by_id ()

GMenu *
ctk_application_get_menu_by_id (CtkApplication *application,
                                const gchar *id);

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

Parameters

application

a CtkApplication

 

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


ctk_application_add_accelerator ()

void
ctk_application_add_accelerator (CtkApplication *application,
                                 const gchar *accelerator,
                                 const gchar *action_name,
                                 GVariant *parameter);

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

Use ctk_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 ctk_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.

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

Parameters

application

a CtkApplication

 

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


ctk_application_remove_accelerator ()

void
ctk_application_remove_accelerator (CtkApplication *application,
                                    const gchar *action_name,
                                    GVariant *parameter);

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

Use ctk_application_set_accels_for_action() instead

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

Parameters

application

a CtkApplication

 

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


ctk_application_list_action_descriptions ()

gchar **
ctk_application_list_action_descriptions
                               (CtkApplication *application);

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

Parameters

application

a CtkApplication

 

Returns

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

[transfer full]

Since: 3.12


ctk_application_get_accels_for_action ()

gchar **
ctk_application_get_accels_for_action (CtkApplication *application,
                                       const gchar *detailed_action_name);

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

Parameters

application

a CtkApplication

 

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


ctk_application_set_accels_for_action ()

void
ctk_application_set_accels_for_action (CtkApplication *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 .

For the detailed_action_name , see g_action_parse_detailed_name() and g_action_print_detailed_name().

Parameters

application

a CtkApplication

 

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 ctk_accelerator_parse().

[array zero-terminated=1]

Since: 3.12


ctk_application_get_actions_for_accel ()

gchar **
ctk_application_get_actions_for_accel (CtkApplication *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 ctk_accelerator_parse() first.

Parameters

application

a CtkApplication

 

accel

an accelerator that can be parsed by ctk_accelerator_parse()

 

Returns

a NULL-terminated array of actions for accel .

[transfer full]

Since: 3.14

Types and Values

struct CtkApplication

struct CtkApplication;

struct CtkApplicationClass

struct CtkApplicationClass {
  GApplicationClass parent_class;

  void (*window_added)   (CtkApplication *application,
                          CtkWindow      *window);
  void (*window_removed) (CtkApplication *application,
                          CtkWindow      *window);
};

Members

window_added ()

Signal emitted when a CtkWindow is added to application through ctk_application_add_window().

 

window_removed ()

Signal emitted when a CtkWindow is removed from application, either as a side-effect of being destroyed or explicitly through ctk_application_remove_window().

 

enum CtkApplicationInhibitFlags

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

Members

CTK_APPLICATION_INHIBIT_LOGOUT

Inhibit ending the user session by logging out or by shutting down the computer

 

CTK_APPLICATION_INHIBIT_SWITCH

Inhibit user switching

 

CTK_APPLICATION_INHIBIT_SUSPEND

Inhibit suspending the session or computer

 

CTK_APPLICATION_INHIBIT_IDLE

Inhibit the session being marked as idle (and possibly locked)

 

Since: 3.4

Property Details

The “active-window” property

  “active-window”            CtkWindow *

The window which most recently had focus.

Owner: CtkApplication

Flags: Read


The “app-menu” property

  “app-menu”                 GMenuModel *

The GMenuModel for the application menu.

Owner: CtkApplication

Flags: Read / Write


The “menubar” property

  “menubar”                  GMenuModel *

The GMenuModel for the menubar.

Owner: CtkApplication

Flags: Read / Write


The “register-session” property

  “register-session”         gboolean

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

Owner: CtkApplication

Flags: Read / Write

Default value: FALSE

Since: 3.4


The “screensaver-active” property

  “screensaver-active”       gboolean

This property is TRUE if CTK+ believes that the screensaver is currently active. CTK+ only tracks session state (including this) when “register-session” is set to TRUE.

Tracking the screensaver state is supported on Linux.

Owner: CtkApplication

Flags: Read

Default value: FALSE

Since: 3.24

Signal Details

The “query-end” signal

void
user_function (CtkApplication *application,
               gpointer        user_data)

Emitted when the session manager is about to end the session, only if “register-session” is TRUE. Applications can connect to this signal and call ctk_application_inhibit() with CTK_APPLICATION_INHIBIT_LOGOUT to delay the end of the session until state has been saved.

Parameters

application

the CtkApplication which emitted the signal

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First

Since: 3.24.8


The “window-added” signal

void
user_function (CtkApplication *application,
               CtkWindow      *window,
               gpointer        user_data)

Emitted when a CtkWindow is added to application through ctk_application_add_window().

Parameters

application

the CtkApplication which emitted the signal

 

window

the newly-added CtkWindow

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First

Since: 3.2


The “window-removed” signal

void
user_function (CtkApplication *application,
               CtkWindow      *window,
               gpointer        user_data)

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

Parameters

application

the CtkApplication which emitted the signal

 

window

the CtkWindow that is being removed

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First

Since: 3.2