GI.Gdk.Objects.Display

GdkDisplay objects are the GDK representation of a workstation.

Their purpose are two-fold:

• To manage and provide information about input devices (pointers, keyboards, etc)
• To manage and provide information about output devices (monitors, projectors, etc)

Most of the input device handling has been factored out into separate Seat objects. Every display has a one or more seats, which can be accessed with displayGetDefaultSeat and displayListSeats.

Output devices are represented by Monitor objects, which can be accessed with gdk_display_get_monitor() and similar APIs.

Exported types

newtype Display

Memory-managed wrapper type.

Constructors

Display (ManagedPtr Display)

Instances

Eq Display

Defined in GI.Gdk.Objects.Display

Methods

(==) :: Display -> Display -> Bool

(/=) :: Display -> Display -> Bool

IsGValue Display

Convert Display to and from GValue with toGValue and fromGValue.

Defined in GI.Gdk.Objects.Display

Methods

toGValue :: Display -> IO GValue

fromGValue :: GValue -> IO Display

ManagedPtrNewtype Display

Defined in GI.Gdk.Objects.Display

Methods

toManagedPtr :: Display -> ManagedPtr Display

TypedObject Display

Defined in GI.Gdk.Objects.Display

Methods

glibType :: IO GType

GObject Display

Defined in GI.Gdk.Objects.Display

HasParentTypes Display

Defined in GI.Gdk.Objects.Display

type ParentTypes Display

Defined in GI.Gdk.Objects.Display

type ParentTypes Display = '[Object]

class (GObject o, IsDescendantOf Display o) => IsDisplay o

Type class for types which can be safely cast to Display, for instance with toDisplay.

Instances

(GObject o, IsDescendantOf Display o) => IsDisplay o

Defined in GI.Gdk.Objects.Display

toDisplay :: (MonadIO m, IsDisplay o) => o -> m Display

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

Methods

Overloaded methods

beep

displayBeep

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m ()

Emits a short beep on display

close

displayClose

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m ()

Closes the connection to the windowing system for the given display, and cleans up associated resources.

deviceIsGrabbed

displayDeviceIsGrabbed

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a, IsDevice b)

=> a

display: a Display

-> b

device: a Device

-> m Bool

Returns: True if there is a grab in effect for device.

Returns True if there is an ongoing grab on device for display.

flush

displayFlush

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m ()

Flushes any requests queued for the windowing system; this happens automatically when the main loop blocks waiting for new events, but if your application is drawing without returning control to the main loop, you may need to call this function explicitly. A common case where this function needs to be called is when an application is executing drawing commands from a thread other than the thread where the main loop is running.

This is most useful for X11. On windowing systems where requests are handled synchronously, this function will do nothing.

getAppLaunchContext

displayGetAppLaunchContext

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m AppLaunchContext

Returns: a new AppLaunchContext for display. Free with objectUnref when done

Returns a AppLaunchContext suitable for launching applications on the given display.

getClipboard

displayGetClipboard

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Clipboard

Returns: the display's clipboard

Gets the clipboard used for copy/paste operations.

getDefault

displayGetDefault

Arguments

:: (HasCallStack, MonadIO m)

=> m (Maybe Display)

Returns: a Display, or Nothing if there is no default display.

Gets the default Display. This is a convenience function for: gdk_display_manager_get_default_display (gdk_display_manager_get ()).

getDefaultGroup

displayGetDefaultGroup

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Surface

Returns: The default group leader surface for display

Returns the default group leader surface for all toplevel surfaces on display. This surface is implicitly created by GDK. See gdk_surface_set_group().

getDefaultSeat

displayGetDefaultSeat

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m (Maybe Seat)

Returns: the default seat.

Returns the default Seat for this display.

Note that a display may not have a seat. In this case, this function will return Nothing.

getEvent

displayGetEvent

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m (Maybe Event)

Returns: the next Event to be processed, or Nothing if no events are pending

Gets the next Event to be processed for display, fetching events from the windowing system if necessary.

getMonitorAtSurface

displayGetMonitorAtSurface

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a, IsSurface b)

=> a

display: a Display

-> b

surface: a Surface

-> m Monitor

Returns: the monitor with the largest overlap with surface

Gets the monitor in which the largest area of surface resides, or a monitor close to surface if it is outside of all monitors.

getMonitors

displayGetMonitors

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

self: a Display

-> m ListModel

Returns: a ListModel of Monitor

Gets the list of monitors associated with this display.

Subsequent calls to this function will always return the same list for the same display.

You can listen to the GListModel[itemsChanged](#g:signal:itemsChanged) signal on this list to monitor changes to the monitor of this display.

getName

displayGetName

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Text

Returns: a string representing the display name. This string is owned by GDK and should not be modified or freed.

Gets the name of the display.

getPrimaryClipboard

displayGetPrimaryClipboard

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Clipboard

Returns: the primary clipboard

Gets the clipboard used for the primary selection. On backends where the primary clipboard is not supported natively, GDK emulates this clipboard locally.

getSetting

displayGetSetting

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> Text

name: the name of the setting

-> GValue

value: location to store the value of the setting

-> m Bool

Returns: True if the setting existed and a value was stored in value, False otherwise

Retrieves a desktop-wide setting such as double-click time for the display.

getStartupNotificationId

displayGetStartupNotificationId

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Text

Returns: the startup notification ID for display, or Nothing

Gets the startup notification ID for a Wayland display, or Nothing if no ID has been defined.

hasPending

displayHasPending

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Bool

Returns: True if there are events ready to be processed.

Returns whether the display has events that are waiting to be processed.

isClosed

displayIsClosed

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Bool

Returns: True if the display is closed.

Finds out if the display has been closed.

isComposited

displayIsComposited

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Bool

Returns: Whether surfaces with RGBA visuals can reasonably be expected to have their alpha channels drawn correctly on the screen.

Returns whether surfaces can reasonably be expected to have their alpha channel drawn correctly on the screen. Check displayIsRgba for wether the display supports an alpha channel.

On X11 this function returns whether a compositing manager is compositing on display.

On modern displays, this value is always True.

isRgba

displayIsRgba

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Bool

Returns: True if surfaces are created with an alpha channel or False if the display does not support this functionality.

Returns wether surfaces on this display are created with an alpha channel.

Even if a True is returned, it is possible that the surface’s alpha channel won’t be honored when displaying the surface on the screen: in particular, for X an appropriate windowing manager and compositing manager must be running to provide appropriate display. Use displayIsComposited to check if that is the case.

For setting an overall opacity for a top-level surface, see gdk_surface_set_opacity().

On modern displays, this value is always True.

listSeats

displayListSeats

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m [Seat]

Returns: the list of seats known to the Display

Returns the list of seats known to display.

mapKeycode

displayMapKeycode

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> Word32

keycode: a keycode

-> m (Bool, [KeymapKey], [Word32])

Returns: True if there were any entries

Returns the keyvals bound to keycode. The Nth KeymapKey in keys is bound to the Nth keyval in keyvals.

When a keycode is pressed by the user, the keyval from this list of entries is selected by considering the effective keyboard group and level.

Free the returned arrays with free.

mapKeyval

displayMapKeyval

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> Word32

keyval: a keyval, such as KEY_a, KEY_Up, KEY_Return, etc.

-> m (Bool, [KeymapKey])

Returns: True if keys were found and returned

Obtains a list of keycode/group/level combinations that will generate keyval. Groups and levels are two kinds of keyboard mode; in general, the level determines whether the top or bottom symbol on a key is used, and the group determines whether the left or right symbol is used.

On US keyboards, the shift key changes the keyboard level, and there are no groups. A group switch key might convert a keyboard between Hebrew to English modes, for example.

GdkEventKey contains a group field that indicates the active keyboard group. The level is computed from the modifier mask.

The returned array should be freed with free.

notifyStartupComplete

displayNotifyStartupComplete

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> Text

startupId: a startup-notification identifier, for which notification process should be completed

-> m ()

Indicates to the GUI environment that the application has finished loading, using a given identifier.

GTK+ will call this function automatically for GtkWindow with custom startup-notification identifier unless gtk_window_set_auto_startup_notification() is called to disable that feature.

open

displayOpen

Arguments

:: (HasCallStack, MonadIO m)

=> Text

displayName: the name of the display to open

-> m (Maybe Display)

Returns: a Display, or Nothing if the display could not be opened

Opens a display.

peekEvent

displayPeekEvent

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m (Maybe Event)

Returns: the first Event on the event queue

Gets a copy of the first Event in the display’s event queue, without removing the event from the queue. (Note that this function will not get more events from the windowing system. It only checks the events that have already been moved to the GDK event queue.)

putEvent

displayPutEvent

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a, IsEvent b)

=> a

display: a Display

-> b

event: a Event

-> m ()

Appends the given event onto the front of the event queue for display.

supportsInputShapes

displaySupportsInputShapes

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m Bool

Returns: True if surfaces with modified input shape are supported

Returns True if gdk_surface_input_shape_combine_mask() can be used to modify the input shape of surfaces on display.

sync

displaySync

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a Display

-> m ()

Flushes any requests queued for the windowing system and waits until all requests have been handled. This is often used for making sure that the display is synchronized with the current state of the program. Calling displaySync before gdk_error_trap_pop() makes sure that any errors generated from earlier requests are handled before the error trap is removed.

This is most useful for X11. On windowing systems where requests are handled synchronously, this function will do nothing.

Properties

composited

True if the display properly composits the alpha channel. See displayIsComposited for details.

getDisplayComposited :: (MonadIO m, IsDisplay o) => o -> m Bool

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

get display #composited

inputShapes

True if the display supports input shapes. See displaySupportsInputShapes for details.

getDisplayInputShapes :: (MonadIO m, IsDisplay o) => o -> m Bool

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

get display #inputShapes

rgba

True if the display supports an alpha channel. See displayIsRgba for details.

getDisplayRgba :: (MonadIO m, IsDisplay o) => o -> m Bool

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

get display #rgba

Signals

closed

type C_DisplayClosedCallback = Ptr () -> CInt -> Ptr () -> IO ()

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

type DisplayClosedCallback

Arguments

 = Bool

isError: True if the display was closed due to an error

-> IO ()

The closed signal is emitted when the connection to the windowing system for display is closed.

afterDisplayClosed :: (IsDisplay a, MonadIO m) => a -> DisplayClosedCallback -> m SignalHandlerId

Connect a signal handler for the closed signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after display #closed callback

genClosure_DisplayClosed :: MonadIO m => DisplayClosedCallback -> m (GClosure C_DisplayClosedCallback)

Wrap the callback into a GClosure.

mk_DisplayClosedCallback :: C_DisplayClosedCallback -> IO (FunPtr C_DisplayClosedCallback)

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

noDisplayClosedCallback :: Maybe DisplayClosedCallback

A convenience synonym for Nothing :: Maybe DisplayClosedCallback.

onDisplayClosed :: (IsDisplay a, MonadIO m) => a -> DisplayClosedCallback -> m SignalHandlerId

Connect a signal handler for the closed signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on display #closed callback

wrap_DisplayClosedCallback :: DisplayClosedCallback -> C_DisplayClosedCallback

Wrap a DisplayClosedCallback into a C_DisplayClosedCallback.

opened

type C_DisplayOpenedCallback = Ptr () -> Ptr () -> IO ()

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

type DisplayOpenedCallback = IO ()

The opened signal is emitted when the connection to the windowing system for display is opened.

afterDisplayOpened :: (IsDisplay a, MonadIO m) => a -> DisplayOpenedCallback -> m SignalHandlerId

Connect a signal handler for the opened signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after display #opened callback

genClosure_DisplayOpened :: MonadIO m => DisplayOpenedCallback -> m (GClosure C_DisplayOpenedCallback)

Wrap the callback into a GClosure.

mk_DisplayOpenedCallback :: C_DisplayOpenedCallback -> IO (FunPtr C_DisplayOpenedCallback)

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

noDisplayOpenedCallback :: Maybe DisplayOpenedCallback

A convenience synonym for Nothing :: Maybe DisplayOpenedCallback.

onDisplayOpened :: (IsDisplay a, MonadIO m) => a -> DisplayOpenedCallback -> m SignalHandlerId

Connect a signal handler for the opened signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on display #opened callback

wrap_DisplayOpenedCallback :: DisplayOpenedCallback -> C_DisplayOpenedCallback

Wrap a DisplayOpenedCallback into a C_DisplayOpenedCallback.

seatAdded

type C_DisplaySeatAddedCallback = Ptr () -> Ptr Seat -> Ptr () -> IO ()

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

type DisplaySeatAddedCallback

Arguments

 = Seat

seat: the seat that was just added

-> IO ()

The seatAdded signal is emitted whenever a new seat is made known to the windowing system.

afterDisplaySeatAdded :: (IsDisplay a, MonadIO m) => a -> DisplaySeatAddedCallback -> m SignalHandlerId

Connect a signal handler for the seatAdded signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after display #seatAdded callback

genClosure_DisplaySeatAdded :: MonadIO m => DisplaySeatAddedCallback -> m (GClosure C_DisplaySeatAddedCallback)

Wrap the callback into a GClosure.

mk_DisplaySeatAddedCallback :: C_DisplaySeatAddedCallback -> IO (FunPtr C_DisplaySeatAddedCallback)

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

noDisplaySeatAddedCallback :: Maybe DisplaySeatAddedCallback

A convenience synonym for Nothing :: Maybe DisplaySeatAddedCallback.

onDisplaySeatAdded :: (IsDisplay a, MonadIO m) => a -> DisplaySeatAddedCallback -> m SignalHandlerId

Connect a signal handler for the seatAdded signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on display #seatAdded callback

wrap_DisplaySeatAddedCallback :: DisplaySeatAddedCallback -> C_DisplaySeatAddedCallback

Wrap a DisplaySeatAddedCallback into a C_DisplaySeatAddedCallback.

seatRemoved

type C_DisplaySeatRemovedCallback = Ptr () -> Ptr Seat -> Ptr () -> IO ()

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

type DisplaySeatRemovedCallback

Arguments

 = Seat

seat: the seat that was just removed

-> IO ()

The seatRemoved signal is emitted whenever a seat is removed by the windowing system.

afterDisplaySeatRemoved :: (IsDisplay a, MonadIO m) => a -> DisplaySeatRemovedCallback -> m SignalHandlerId

Connect a signal handler for the seatRemoved signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after display #seatRemoved callback

genClosure_DisplaySeatRemoved :: MonadIO m => DisplaySeatRemovedCallback -> m (GClosure C_DisplaySeatRemovedCallback)

Wrap the callback into a GClosure.

mk_DisplaySeatRemovedCallback :: C_DisplaySeatRemovedCallback -> IO (FunPtr C_DisplaySeatRemovedCallback)

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

noDisplaySeatRemovedCallback :: Maybe DisplaySeatRemovedCallback

A convenience synonym for Nothing :: Maybe DisplaySeatRemovedCallback.

onDisplaySeatRemoved :: (IsDisplay a, MonadIO m) => a -> DisplaySeatRemovedCallback -> m SignalHandlerId

Connect a signal handler for the seatRemoved signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on display #seatRemoved callback

wrap_DisplaySeatRemovedCallback :: DisplaySeatRemovedCallback -> C_DisplaySeatRemovedCallback

Wrap a DisplaySeatRemovedCallback into a C_DisplaySeatRemovedCallback.

settingChanged

type C_DisplaySettingChangedCallback = Ptr () -> CString -> Ptr () -> IO ()

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

type DisplaySettingChangedCallback

Arguments

 = Text

setting: the name of the setting that changed

-> IO ()

The settingChanged signal is emitted whenever a setting changes its value.

afterDisplaySettingChanged :: (IsDisplay a, MonadIO m) => a -> DisplaySettingChangedCallback -> m SignalHandlerId

Connect a signal handler for the settingChanged signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after display #settingChanged callback

genClosure_DisplaySettingChanged :: MonadIO m => DisplaySettingChangedCallback -> m (GClosure C_DisplaySettingChangedCallback)

Wrap the callback into a GClosure.

mk_DisplaySettingChangedCallback :: C_DisplaySettingChangedCallback -> IO (FunPtr C_DisplaySettingChangedCallback)

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

noDisplaySettingChangedCallback :: Maybe DisplaySettingChangedCallback

A convenience synonym for Nothing :: Maybe DisplaySettingChangedCallback.

onDisplaySettingChanged :: (IsDisplay a, MonadIO m) => a -> DisplaySettingChangedCallback -> m SignalHandlerId

Connect a signal handler for the settingChanged signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on display #settingChanged callback

wrap_DisplaySettingChangedCallback :: DisplaySettingChangedCallback -> C_DisplaySettingChangedCallback

Wrap a DisplaySettingChangedCallback into a C_DisplaySettingChangedCallback.