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 displayGetMonitorAtSurface 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

GObject Display

Defined in GI.Gdk.Objects.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

HasParentTypes Display

Defined in GI.Gdk.Objects.Display

IsGValue (Maybe Display)

Convert Display to and from GValue. See toGValue and fromGValue.

Defined in GI.Gdk.Objects.Display

Methods

gvalueGType_ :: IO GType

gvalueSet_ :: Ptr GValue -> Maybe Display -> IO ()

gvalueGet_ :: Ptr GValue -> IO (Maybe 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

Click to display all available methods, including inherited ones

Methods

beep, bindProperty, bindPropertyFull, close, deviceIsGrabbed, flush, forceFloating, freezeNotify, getv, isClosed, isComposited, isFloating, isRgba, listSeats, mapKeycode, mapKeyval, notify, notifyByPspec, notifyStartupComplete, prepareGl, putEvent, ref, refSink, runDispose, stealData, stealQdata, supportsInputShapes, sync, thawNotify, translateKey, unref, watchClosure.

Getters

getAppLaunchContext, getClipboard, getData, getDefaultSeat, getMonitorAtSurface, getMonitors, getName, getPrimaryClipboard, getProperty, getQdata, getSetting, getStartupNotificationId.

Setters

setData, setDataFull, setProperty.

beep

displayBeep

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> m ()

Emits a short beep on display

close

displayClose

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> m ()

Closes the connection to the windowing system for the given display.

This cleans up associated resources.

deviceIsGrabbed

displayDeviceIsGrabbed

Arguments

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

=> a

display: a GdkDisplay

-> b

device: a GdkDevice

-> 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 GdkDisplay

-> 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 GdkDisplay

-> m AppLaunchContext

Returns: a new GdkAppLaunchContext for display

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

getClipboard

displayGetClipboard

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> 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 GdkDisplay, or Nothing if there is no default display

Gets the default GdkDisplay.

This is a convenience function for:

gdk_display_manager_get_default_display (gdk_display_manager_get ())

getDefaultSeat

displayGetDefaultSeat

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> m (Maybe Seat)

Returns: the default seat.

Returns the default GdkSeat for this display.

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

getMonitorAtSurface

displayGetMonitorAtSurface

Arguments

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

=> a

display: a GdkDisplay

-> b

surface: a GdkSurface

-> m Monitor

Returns: the monitor with the largest overlap with surface

Gets the monitor in which the largest area of surface resides.

Returns a monitor close to surface if it is outside of all monitors.

getMonitors

displayGetMonitors

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

self: a GdkDisplay

-> m ListModel

Returns: a GListModel of GdkMonitor

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 GdkDisplay

-> 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 GdkDisplay

-> 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 GdkDisplay

-> 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 GdkDisplay

-> m (Maybe Text)

Returns: the startup notification ID for display

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

isClosed

displayIsClosed

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> 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 GdkDisplay

-> 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 whether 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 GdkDisplay

-> m Bool

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

Returns whether 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.

On modern displays, this value is always True.

listSeats

displayListSeats

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> m [Seat]

Returns: the list of seats known to the GdkDisplay

Returns the list of seats known to display.

mapKeycode

displayMapKeycode

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> Word32

keycode: a keycode

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

Returns: True if there were any entries

Returns the keyvals bound to keycode.

The Nth GdkKeymapKey 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 GdkDisplay

-> 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 GdkDisplay

-> 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 Gtk.Window 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 GdkDisplay

Opens a display.

If opening the display fails, NULL is returned.

prepareGl

displayPrepareGl

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

self: a GdkDisplay

-> m ()

(Can throw GError)

Checks that OpenGL is available for self and ensures that it is properly initialized. When this fails, an error will be set describing the error and this function returns False.

Note that even if this function succeeds, creating a GdkGLContext may still fail.

This function is idempotent. Calling it multiple times will just return the same value or error.

You never need to call this function, GDK will call it automatically as needed. But you can use it as a check when setting up code that might make use of OpenGL.

Since: 4.4

putEvent

displayPutEvent

Arguments

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

=> a

display: a GdkDisplay

-> b

event: a GdkEvent

-> m ()

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

This function is only useful in very special situations and should not be used by applications.

supportsInputShapes

displaySupportsInputShapes

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> m Bool

Returns: True if surfaces with modified input shape are supported

Returns True if the display supports input shapes.

This means that surfaceSetInputRegion can be used to modify the input shape of surfaces on display.

On modern displays, this value is always True.

sync

displaySync

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> 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 [methodgdkX11.Display.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.

translateKey

displayTranslateKey

Arguments

:: (HasCallStack, MonadIO m, IsDisplay a)

=> a

display: a GdkDisplay

-> Word32

keycode: a keycode

-> [ModifierType]

state: a modifier state

-> Int32

group: active keyboard group

-> m (Bool, Word32, Int32, Int32, [ModifierType])

Returns: True if there was a keyval bound to keycode/state/group.

Translates the contents of a GdkEventKey into a keyval, effective group, and level.

Modifiers that affected the translation and are thus unavailable for application use are returned in consumedModifiers.

The effectiveGroup is the group that was actually used for the translation; some keys such as Enter are not affected by the active keyboard group. The level is derived from state.

consumedModifiers gives modifiers that should be masked out from state when comparing this key press to a keyboard shortcut. For instance, on a US keyboard, the plus symbol is shifted, so when comparing a key press to a <Control>plus accelerator <Shift> should be masked out.

This function should rarely be needed, since GdkEventKey already contains the translated keyval. It is exported for the benefit of virtualized test environments.

Properties

composited

True if the display properly composites the alpha channel.

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.

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.

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 DisplayClosedCallback

Arguments

 = Bool

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

-> IO ()

Emitted when the connection to the windowing system for display is closed.

afterDisplayClosed :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onDisplayClosed :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

opened

type DisplayOpenedCallback = IO ()

Emitted when the connection to the windowing system for display is opened.

afterDisplayOpened :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onDisplayOpened :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

seatAdded

type DisplaySeatAddedCallback

Arguments

 = Seat

seat: the seat that was just added

-> IO ()

Emitted whenever a new seat is made known to the windowing system.

afterDisplaySeatAdded :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onDisplaySeatAdded :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

seatRemoved

type DisplaySeatRemovedCallback

Arguments

 = Seat

seat: the seat that was just removed

-> IO ()

Emitted whenever a seat is removed by the windowing system.

afterDisplaySeatRemoved :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onDisplaySeatRemoved :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

settingChanged

type DisplaySettingChangedCallback

Arguments

 = Text

setting: the name of the setting that changed

-> IO ()

Emitted whenever a setting changes its value.

afterDisplaySettingChanged :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onDisplaySettingChanged :: (IsDisplay a, MonadIO m) => a -> ((?self :: 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