GI.Gtk.Objects.Application

Application 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 ApplicationWindow.

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 actionGroupActivateAction. The same applies to actions associated with ApplicationWindow and to the “activate” and “open” Application methods.

## {automatic-resources}

Application will automatically load menus from the Builder resource located at "gtk/menus.ui", relative to the application's resource base path (see applicationSetResourceBasePath). 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 applicationGetMenuById which allows for dynamic population of a part of the menu structure.

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

It is also possible to provide the menus manually using applicationSetAppMenu and applicationSetMenubar.

Application 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 iconThemeAddResourcePath for more information.

If there is a resource located at "gtk/help-overlay.ui" which defines a ShortcutsWindow with ID "help_overlay" then GtkApplication associates an instance of this shortcuts window with each ApplicationWindow 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.

## {gtkapplication}

A simple example

GtkApplication optionally registers with a session manager of the users session (if you set the Application: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 applicationInhibit 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.

## {seealso} HowDoI: Using GtkApplication, Getting Started with GTK+: Basics

Exported types

newtype Application

Memory-managed wrapper type.

Constructors

Application (ManagedPtr Application)

Instances

GObject Application

Defined in GI.Gtk.Objects.Application

Methods

gobjectType :: Application -> IO GType

IsApplication Application

Defined in GI.Gtk.Objects.Application

IsActionMap Application

Defined in GI.Gtk.Objects.Application

IsActionGroup Application

Defined in GI.Gtk.Objects.Application

IsObject Application

Defined in GI.Gtk.Objects.Application

IsApplication Application

Defined in GI.Gtk.Objects.Application

class GObject o => IsApplication o

Type class for types which can be safely cast to Application, for instance with toApplication.

Instances

(GObject a, (UnknownAncestorError Application a :: Constraint)) => IsApplication a

Defined in GI.Gtk.Objects.Application

IsApplication Application

Defined in GI.Gtk.Objects.Application

toApplication :: (MonadIO m, IsApplication o) => o -> m Application

Cast to Application, for types for which this is known to be safe. For general casts, use castTo.

noApplication :: Maybe Application

A convenience alias for Nothing :: Maybe Application.

Methods

addAccelerator

applicationAddAccelerator

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Text

accelerator: accelerator string

-> Text

actionName: the name of the action to activate

-> Maybe GVariant

parameter: parameter to pass when activating the action, or Nothing if the action does not accept an activation parameter

-> m ()

Deprecated: (Since version 3.14)Use applicationSetAccelsForAction 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 acceleratorParse, e.g. "<Primary>q" or “<Control><Alt>p”.

actionName 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 applicationSetAppMenu and applicationSetMenubar, which is usually more convenient than calling this function for each accelerator.

Since: 3.4

addWindow

applicationAddWindow

Arguments

:: (HasCallStack, MonadIO m, IsApplication a, IsWindow b)

=> a

application: a Application

-> b

window: a Window

-> m ()

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 Application::activate signal.

This call is equivalent to setting the Window: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 applicationRemoveWindow.

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

Since: 3.0

getAccelsForAction

applicationGetAccelsForAction

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Text

detailedActionName: a detailed action name, specifying an action and target to obtain accelerators for

-> m [Text]

Returns: accelerators for detailedActionName, as a Nothing-terminated array. Free with strfreev when no longer needed

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

Since: 3.12

getActionsForAccel

applicationGetActionsForAccel

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Text

accel: an accelerator that can be parsed by acceleratorParse

-> m [Text]

Returns: a Nothing-terminated array of actions for 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. Nothing is never returned.

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

Since: 3.14

getActiveWindow

applicationGetActiveWindow

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> m (Maybe Window)

Returns: the active window, or Nothing if there isn't one.

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

getAppMenu

applicationGetAppMenu

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> m (Maybe MenuModel)

Returns: the application menu of application or Nothing if no application menu has been set.

Returns the menu model that has been set with applicationSetAppMenu.

Since: 3.4

getMenuById

applicationGetMenuById

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Text

id: the id of the menu to look up

-> m Menu

Returns: Gets the menu with the given id from the automatically loaded resources

Gets a menu from automatically loaded resources. See [Automatic resources][automatic-resources] for more information.

Since: 3.14

getMenubar

applicationGetMenubar

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> m MenuModel

Returns: the menubar for windows of application

Returns the menu model that has been set with applicationSetMenubar.

Since: 3.4

getWindowById

applicationGetWindowById

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Word32

id: an identifier number

-> m (Maybe Window)

Returns: the window with ID id, or Nothing if there is no window with this ID

Returns the ApplicationWindow with the given ID.

The ID of a ApplicationWindow can be retrieved with applicationWindowGetId.

Since: 3.6

getWindows

applicationGetWindows

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> m [Window]

Returns: a List of Window

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

inhibit

applicationInhibit

Arguments

:: (HasCallStack, MonadIO m, IsApplication a, IsWindow b)

=> a

application: the Application

-> Maybe b

window: a Window, or Nothing

-> [ApplicationInhibitFlags]

flags: what types of actions should be inhibited

-> Maybe Text

reason: a short, human-readable string that explains why these operations are inhibited

-> m Word32

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

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 applicationUninhibit 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.

Since: 3.4

isInhibited

applicationIsInhibited

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: the Application

-> [ApplicationInhibitFlags]

flags: what types of actions should be queried

-> m Bool

Returns: True if any of the actions specified in flags are inhibited

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).

Since: 3.4

listActionDescriptions

applicationListActionDescriptions

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> m [Text]

Returns: a Nothing-terminated array of strings, free with strfreev when done

Lists the detailed action names which have associated accelerators. See applicationSetAccelsForAction.

Since: 3.12

new

applicationNew

Arguments

:: (HasCallStack, MonadIO m)

=> Maybe Text

applicationId: The application ID.

-> [ApplicationFlags]

flags: the application flags

-> m (Maybe Application)

Returns: a new Application instance

Creates a new Application instance.

When using Application, it is not necessary to call init manually. It is called as soon as the application gets registered as the primary instance.

Concretely, init is called in the default handler for the Application::startup signal. Therefore, Application subclasses should chain up in their Application::startup handler before using any GTK+ API.

Note that commandline arguments are not passed to 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 init before creating the application instance.

If non-Nothing, the application ID must be valid. See applicationIdIsValid.

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

prefersAppMenu

applicationPrefersAppMenu

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> m Bool

Returns: True if you should set an app menu

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 applicationSetAppMenu 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 applicationSetAppMenu 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 applicationSetAppMenu anyway, then this menu will be replaced with your own.

Since: 3.14

removeAccelerator

applicationRemoveAccelerator

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Text

actionName: the name of the action to activate

-> Maybe GVariant

parameter: parameter to pass when activating the action, or Nothing if the action does not accept an activation parameter

-> m ()

Deprecated: (Since version 3.14)Use applicationSetAccelsForAction instead

Removes an accelerator that has been previously added with applicationAddAccelerator.

Since: 3.4

removeWindow

applicationRemoveWindow

Arguments

:: (HasCallStack, MonadIO m, IsApplication a, IsWindow b)

=> a

application: a Application

-> b

window: a Window

-> m ()

Remove a window from application.

If window belongs to application then this call is equivalent to setting the Window:application property of window to Nothing.

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

Since: 3.0

setAccelsForAction

applicationSetAccelsForAction

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: a Application

-> Text

detailedActionName: a detailed action name, specifying an action and target to associate accelerators with

-> [Text]

accels: a list of accelerators in the format understood by acceleratorParse

-> m ()

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 detailedActionName, see actionParseDetailedName and actionPrintDetailedName.

Since: 3.12

setAppMenu

applicationSetAppMenu

Arguments

:: (HasCallStack, MonadIO m, IsApplication a, IsMenuModel b)

=> a

application: a Application

-> Maybe b

appMenu: a MenuModel, or Nothing

-> m ()

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. Application::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 ActionMap interface to add actions, to respond to the user selecting these menu items.

Since: 3.4

setMenubar

applicationSetMenubar

Arguments

:: (HasCallStack, MonadIO m, IsApplication a, IsMenuModel b)

=> a

application: a Application

-> Maybe b

menubar: a MenuModel, or Nothing

-> m ()

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. Application::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 ActionMap interface to add actions, to respond to the user selecting these menu items.

Since: 3.4

uninhibit

applicationUninhibit

Arguments

:: (HasCallStack, MonadIO m, IsApplication a)

=> a

application: the Application

-> Word32

cookie: a cookie that was returned by applicationInhibit

-> m ()

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

Since: 3.4

Properties

activeWindow

No description available in the introspection data.

getApplicationActiveWindow :: (MonadIO m, IsApplication o) => o -> m (Maybe Window)

Get the value of the “active-window” property. When overloading is enabled, this is equivalent to

get application #activeWindow

appMenu

No description available in the introspection data.

clearApplicationAppMenu :: (MonadIO m, IsApplication o) => o -> m ()

Set the value of the “app-menu” property to Nothing. When overloading is enabled, this is equivalent to

clear #appMenu

constructApplicationAppMenu :: (IsApplication o, IsMenuModel a) => a -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “app-menu” property. This is rarely needed directly, but it is used by new.

getApplicationAppMenu :: (MonadIO m, IsApplication o) => o -> m (Maybe MenuModel)

Get the value of the “app-menu” property. When overloading is enabled, this is equivalent to

get application #appMenu

setApplicationAppMenu :: (MonadIO m, IsApplication o, IsMenuModel a) => o -> a -> m ()

Set the value of the “app-menu” property. When overloading is enabled, this is equivalent to

set application [ #appMenu := value ]

menubar

No description available in the introspection data.

clearApplicationMenubar :: (MonadIO m, IsApplication o) => o -> m ()

Set the value of the “menubar” property to Nothing. When overloading is enabled, this is equivalent to

clear #menubar

constructApplicationMenubar :: (IsApplication o, IsMenuModel a) => a -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “menubar” property. This is rarely needed directly, but it is used by new.

getApplicationMenubar :: (MonadIO m, IsApplication o) => o -> m MenuModel

Get the value of the “menubar” property. When overloading is enabled, this is equivalent to

get application #menubar

setApplicationMenubar :: (MonadIO m, IsApplication o, IsMenuModel a) => o -> a -> m ()

Set the value of the “menubar” property. When overloading is enabled, this is equivalent to

set application [ #menubar := value ]

registerSession

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

Since: 3.4

constructApplicationRegisterSession :: IsApplication o => Bool -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “register-session” property. This is rarely needed directly, but it is used by new.

getApplicationRegisterSession :: (MonadIO m, IsApplication o) => o -> m Bool

Get the value of the “register-session” property. When overloading is enabled, this is equivalent to

get application #registerSession

setApplicationRegisterSession :: (MonadIO m, IsApplication o) => o -> Bool -> m ()

Set the value of the “register-session” property. When overloading is enabled, this is equivalent to

set application [ #registerSession := value ]

screensaverActive

This property is True if GTK+ believes that the screensaver is currently active. GTK+ only tracks session state (including this) when Application::register-session is set to True.

Tracking the screensaver state is supported on Linux.

Since: 3.24

getApplicationScreensaverActive :: (MonadIO m, IsApplication o) => o -> m Bool

Get the value of the “screensaver-active” property. When overloading is enabled, this is equivalent to

get application #screensaverActive

Signals

windowAdded

type ApplicationWindowAddedCallback

Arguments

 = Window

window: the newly-added Window

-> IO ()

Emitted when a Window is added to application through applicationAddWindow.

Since: 3.2

type C_ApplicationWindowAddedCallback = Ptr () -> Ptr Window -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

afterApplicationWindowAdded :: (IsApplication a, MonadIO m) => a -> ApplicationWindowAddedCallback -> m SignalHandlerId

Connect a signal handler for the “window-added” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after application #windowAdded callback

genClosure_ApplicationWindowAdded :: ApplicationWindowAddedCallback -> IO Closure

Wrap the callback into a Closure.

mk_ApplicationWindowAddedCallback :: C_ApplicationWindowAddedCallback -> IO (FunPtr C_ApplicationWindowAddedCallback)

Generate a function pointer callable from C code, from a C_ApplicationWindowAddedCallback.

noApplicationWindowAddedCallback :: Maybe ApplicationWindowAddedCallback

A convenience synonym for Nothing :: Maybe ApplicationWindowAddedCallback.

onApplicationWindowAdded :: (IsApplication a, MonadIO m) => a -> ApplicationWindowAddedCallback -> m SignalHandlerId

Connect a signal handler for the “window-added” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on application #windowAdded callback

wrap_ApplicationWindowAddedCallback :: ApplicationWindowAddedCallback -> C_ApplicationWindowAddedCallback

Wrap a ApplicationWindowAddedCallback into a C_ApplicationWindowAddedCallback.

windowRemoved

type ApplicationWindowRemovedCallback

Arguments

 = Window

window: the Window that is being removed

-> IO ()

Emitted when a Window is removed from application, either as a side-effect of being destroyed or explicitly through applicationRemoveWindow.

Since: 3.2

type C_ApplicationWindowRemovedCallback = Ptr () -> Ptr Window -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

afterApplicationWindowRemoved :: (IsApplication a, MonadIO m) => a -> ApplicationWindowRemovedCallback -> m SignalHandlerId

Connect a signal handler for the “window-removed” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after application #windowRemoved callback

genClosure_ApplicationWindowRemoved :: ApplicationWindowRemovedCallback -> IO Closure

Wrap the callback into a Closure.

mk_ApplicationWindowRemovedCallback :: C_ApplicationWindowRemovedCallback -> IO (FunPtr C_ApplicationWindowRemovedCallback)

Generate a function pointer callable from C code, from a C_ApplicationWindowRemovedCallback.

noApplicationWindowRemovedCallback :: Maybe ApplicationWindowRemovedCallback

A convenience synonym for Nothing :: Maybe ApplicationWindowRemovedCallback.

onApplicationWindowRemoved :: (IsApplication a, MonadIO m) => a -> ApplicationWindowRemovedCallback -> m SignalHandlerId

Connect a signal handler for the “window-removed” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on application #windowRemoved callback

wrap_ApplicationWindowRemovedCallback :: ApplicationWindowRemovedCallback -> C_ApplicationWindowRemovedCallback

Wrap a ApplicationWindowRemovedCallback into a C_ApplicationWindowRemovedCallback.