GI.Gdk.Objects.Screen

Screen objects are the GDK representation of the screen on which windows can be displayed and on which the pointer moves. X originally identified screens with physical screens, but nowadays it is more common to have a single Screen which combines several physical monitors (see screenGetNMonitors).

GdkScreen is used throughout GDK and GTK+ to specify which screen the top level windows are to be displayed on. it is also used to query the screen specification and default settings such as the default visual (screenGetSystemVisual), the dimensions of the physical monitors (screenGetMonitorGeometry), etc.

Exported types

newtype Screen

Memory-managed wrapper type.

Constructors

Screen (ManagedPtr Screen)

Instances

GObject Screen

Defined in GI.Gdk.Objects.Screen

Methods

gobjectType :: IO GType

HasParentTypes Screen

Defined in GI.Gdk.Objects.Screen

type ParentTypes Screen

Defined in GI.Gdk.Objects.Screen

type ParentTypes Screen = Object ': ([] :: [Type])

class (GObject o, IsDescendantOf Screen o) => IsScreen o

Type class for types which can be safely cast to Screen, for instance with toScreen.

Instances

(GObject o, IsDescendantOf Screen o) => IsScreen o

Defined in GI.Gdk.Objects.Screen

toScreen :: (MonadIO m, IsScreen o) => o -> m Screen

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

noScreen :: Maybe Screen

A convenience alias for Nothing :: Maybe Screen.

Methods

getActiveWindow

screenGetActiveWindow

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m (Maybe Window)

Returns: the currently active window, or Nothing.

Deprecated: (Since version 3.22)

Returns the screen’s currently active window.

On X11, this is done by inspecting the _NET_ACTIVE_WINDOW property on the root window, as described in the Extended Window Manager Hints. If there is no currently currently active window, or the window manager does not support the _NET_ACTIVE_WINDOW hint, this function returns Nothing.

On other platforms, this function may return Nothing, depending on whether it is implementable on that platform.

The returned window should be unrefed using objectUnref when no longer needed.

Since: 2.10

getDefault

screenGetDefault

Arguments

:: (HasCallStack, MonadIO m)

=> m (Maybe Screen)

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

Gets the default screen for the default display. (See gdk_display_get_default ()).

Since: 2.2

getDisplay

screenGetDisplay

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Display

Returns: the display to which screen belongs

Gets the display to which the screen belongs.

Since: 2.2

getFontOptions

screenGetFontOptions

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m (Maybe FontOptions)

Returns: the current font options, or Nothing if no default font options have been set.

Gets any options previously set with screenSetFontOptions.

Since: 2.10

getHeight

screenGetHeight

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Int32

Returns: the height of screen in pixels.

Deprecated: (Since version 3.22)Use per-monitor information instead

Gets the height of screen in pixels. The returned size is in ”application pixels”, not in ”device pixels” (see screenGetMonitorScaleFactor).

Since: 2.2

getHeightMm

screenGetHeightMm

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Int32

Returns: the heigth of screen in millimeters.

Deprecated: (Since version 3.22)Use per-monitor information instead

Returns the height of screen in millimeters.

Note that this value is somewhat ill-defined when the screen has multiple monitors of different resolution. It is recommended to use the monitor dimensions instead.

Since: 2.2

getMonitorAtPoint

screenGetMonitorAtPoint

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen.

-> Int32

x: the x coordinate in the virtual screen.

-> Int32

y: the y coordinate in the virtual screen.

-> m Int32

Returns: the monitor number in which the point (x,y) lies, or a monitor close to (x,y) if the point is not in any monitor.

Deprecated: (Since version 3.22)Use displayGetMonitorAtPoint instead

Returns the monitor number in which the point (x,y) is located.

Since: 2.2

getMonitorAtWindow

screenGetMonitorAtWindow

Arguments

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

=> a

screen: a Screen.

-> b

window: a Window

-> m Int32

Returns: the monitor number in which most of window is located, or if window does not intersect any monitors, a monitor, close to window.

Deprecated: (Since version 3.22)Use displayGetMonitorAtWindow instead

Returns the number of the monitor in which the largest area of the bounding rectangle of window resides.

Since: 2.2

getMonitorGeometry

screenGetMonitorGeometry

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Int32

monitorNum: the monitor number

-> m Rectangle

Deprecated: (Since version 3.22)Use monitorGetGeometry instead

Retrieves the Rectangle representing the size and position of the individual monitor within the entire screen area. The returned geometry is in ”application pixels”, not in ”device pixels” (see screenGetMonitorScaleFactor).

Monitor numbers start at 0. To obtain the number of monitors of screen, use screenGetNMonitors.

Note that the size of the entire screen area can be retrieved via screenGetWidth and screenGetHeight.

Since: 2.2

getMonitorHeightMm

screenGetMonitorHeightMm

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Int32

monitorNum: number of the monitor, between 0 and gdk_screen_get_n_monitors (screen)

-> m Int32

Returns: the height of the monitor, or -1 if not available

Deprecated: (Since version 3.22)Use monitorGetHeightMm instead

Gets the height in millimeters of the specified monitor.

Since: 2.14

getMonitorPlugName

screenGetMonitorPlugName

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Int32

monitorNum: number of the monitor, between 0 and gdk_screen_get_n_monitors (screen)

-> m (Maybe Text)

Returns: a newly-allocated string containing the name of the monitor, or Nothing if the name cannot be determined

Deprecated: (Since version 3.22)Use monitorGetModel instead

Returns the output name of the specified monitor. Usually something like VGA, DVI, or TV, not the actual product name of the display device.

Since: 2.14

getMonitorScaleFactor

screenGetMonitorScaleFactor

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: screen to get scale factor for

-> Int32

monitorNum: number of the monitor, between 0 and gdk_screen_get_n_monitors (screen)

-> m Int32

Returns: the scale factor

Deprecated: (Since version 3.22)Use monitorGetScaleFactor instead

Returns the internal scale factor that maps from monitor coordinates to the actual device pixels. On traditional systems this is 1, but on very high density outputs this can be a higher value (often 2).

This can be used if you want to create pixel based data for a particular monitor, but most of the time you’re drawing to a window where it is better to use windowGetScaleFactor instead.

Since: 3.10

getMonitorWidthMm

screenGetMonitorWidthMm

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Int32

monitorNum: number of the monitor, between 0 and gdk_screen_get_n_monitors (screen)

-> m Int32

Returns: the width of the monitor, or -1 if not available

Deprecated: (Since version 3.22)Use monitorGetWidthMm instead

Gets the width in millimeters of the specified monitor, if available.

Since: 2.14

getMonitorWorkarea

screenGetMonitorWorkarea

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Int32

monitorNum: the monitor number

-> m Rectangle

Deprecated: (Since version 3.22)Use monitorGetWorkarea instead

Retrieves the Rectangle representing the size and position of the “work area” on a monitor within the entire screen area. The returned geometry is in ”application pixels”, not in ”device pixels” (see screenGetMonitorScaleFactor).

The work area should be considered when positioning menus and similar popups, to avoid placing them below panels, docks or other desktop components.

Note that not all backends may have a concept of workarea. This function will return the monitor geometry if a workarea is not available, or does not apply.

Monitor numbers start at 0. To obtain the number of monitors of screen, use screenGetNMonitors.

Since: 3.4

getNMonitors

screenGetNMonitors

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Int32

Returns: number of monitors which screen consists of

Deprecated: (Since version 3.22)Use displayGetNMonitors instead

Returns the number of monitors which screen consists of.

Since: 2.2

getNumber

screenGetNumber

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Int32

Returns: the index

Deprecated: (Since version 3.22)

Gets the index of screen among the screens in the display to which it belongs. (See screenGetDisplay)

Since: 2.2

getPrimaryMonitor

screenGetPrimaryMonitor

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen.

-> m Int32

Returns: An integer index for the primary monitor, or 0 if none is configured.

Deprecated: (Since version 3.22)Use displayGetPrimaryMonitor instead

Gets the primary monitor for screen. The primary monitor is considered the monitor where the “main desktop” lives. While normal application windows typically allow the window manager to place the windows, specialized desktop applications such as panels should place themselves on the primary monitor.

If no primary monitor is configured by the user, the return value will be 0, defaulting to the first monitor.

Since: 2.20

getResolution

screenGetResolution

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Double

Returns: the current resolution, or -1 if no resolution has been set.

Gets the resolution for font handling on the screen; see screenSetResolution for full details.

Since: 2.10

getRgbaVisual

screenGetRgbaVisual

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m (Maybe Visual)

Returns: a visual to use for windows with an alpha channel or Nothing if the capability is not available.

Gets a visual to use for creating windows with an alpha channel. The windowing system on which GTK+ is running may not support this capability, in which case Nothing will be returned. Even if a non-Nothing value is returned, its possible that the window’s alpha channel won’t be honored when displaying the window on the screen: in particular, for X an appropriate windowing manager and compositing manager must be running to provide appropriate display.

This functionality is not implemented in the Windows backend.

For setting an overall opacity for a top-level window, see windowSetOpacity.

Since: 2.8

getRootWindow

screenGetRootWindow

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Window

Returns: the root window

Gets the root window of screen.

Since: 2.2

getSetting

screenGetSetting

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: the Screen where the setting is located

-> 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 Screen screen.

FIXME needs a list of valid settings here, or a link to more information.

Since: 2.2

getSystemVisual

screenGetSystemVisual

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen.

-> m Visual

Returns: the system visual

Get the system’s default visual for screen. This is the visual for the root window of the display. The return value should not be freed.

Since: 2.2

getToplevelWindows

screenGetToplevelWindows

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: The Screen where the toplevels are located.

-> m [Window]

Returns: list of toplevel windows, free with g_list_free()

Obtains a list of all toplevel windows known to GDK on the screen screen. A toplevel window is a child of the root window (see getDefaultRootWindow).

The returned list should be freed with g_list_free(), but its elements need not be freed.

Since: 2.2

getWidth

screenGetWidth

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Int32

Returns: the width of screen in pixels.

Deprecated: (Since version 3.22)Use per-monitor information instead

Gets the width of screen in pixels. The returned size is in ”application pixels”, not in ”device pixels” (see screenGetMonitorScaleFactor).

Since: 2.2

getWidthMm

screenGetWidthMm

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Int32

Returns: the width of screen in millimeters.

Deprecated: (Since version 3.22)Use per-monitor information instead

Gets the width of screen in millimeters.

Note that this value is somewhat ill-defined when the screen has multiple monitors of different resolution. It is recommended to use the monitor dimensions instead.

Since: 2.2

getWindowStack

screenGetWindowStack

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m [Window]

Returns: a list of GdkWindows for the current window stack, or Nothing.

Returns a List of GdkWindows representing the current window stack.

On X11, this is done by inspecting the _NET_CLIENT_LIST_STACKING property on the root window, as described in the Extended Window Manager Hints. If the window manager does not support the _NET_CLIENT_LIST_STACKING hint, this function returns Nothing.

On other platforms, this function may return Nothing, depending on whether it is implementable on that platform.

The returned list is newly allocated and owns references to the windows it contains, so it should be freed using g_list_free() and its windows unrefed using objectUnref when no longer needed.

Since: 2.10

height

screenHeight

Arguments

:: (HasCallStack, MonadIO m)

=> m Int32

Returns: the height of the default screen in pixels.

Deprecated: (Since version 3.22)Use per-monitor information

Gets the height of the default screen in pixels. The returned size is in ”application pixels”, not in ”device pixels” (see screenGetMonitorScaleFactor).

heightMm

screenHeightMm

Arguments

:: (HasCallStack, MonadIO m)

=> m Int32

Returns: the height of the default screen in millimeters, though it is not always correct.

Deprecated: (Since version 3.22)Use per-monitor information

Returns the height of the default screen in millimeters. Note that on many X servers this value will not be correct.

isComposited

screenIsComposited

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Bool

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

Returns whether windows with an RGBA visual can reasonably be expected to have their alpha channel drawn correctly on the screen.

On X11 this function returns whether a compositing manager is compositing screen.

Since: 2.10

listVisuals

screenListVisuals

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: the relevant Screen.

-> m [Visual]

Returns: a list of visuals; the list must be freed, but not its contents

Lists the available visuals for the specified screen. A visual describes a hardware image data format. For example, a visual might support 24-bit color, or 8-bit color, and might expect pixels to be in a certain format.

Call g_list_free() on the return value when you’re finished with it.

Since: 2.2

makeDisplayName

screenMakeDisplayName

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> m Text

Returns: a newly allocated string, free with free

Deprecated: (Since version 3.22)

Determines the name to pass to displayOpen to get a Display with this screen as the default screen.

Since: 2.2

setFontOptions

screenSetFontOptions

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Maybe FontOptions

options: a FontOptions, or Nothing to unset any previously set default font options.

-> m ()

Sets the default font options for the screen. These options will be set on any Context’s newly created with pangoContextGetForScreen. Changing the default set of font options does not affect contexts that have already been created.

Since: 2.10

setResolution

screenSetResolution

Arguments

:: (HasCallStack, MonadIO m, IsScreen a)

=> a

screen: a Screen

-> Double

dpi: the resolution in “dots per inch”. (Physical inches aren’t actually involved; the terminology is conventional.)

-> m ()

Sets the resolution for font handling on the screen. This is a scale factor between points specified in a FontDescription and cairo units. The default value is 96, meaning that a 10 point font will be 13 units high. (10 * 96. / 72. = 13.3).

Since: 2.10

width

screenWidth

Arguments

:: (HasCallStack, MonadIO m)

=> m Int32

Returns: the width of the default screen in pixels.

Deprecated: (Since version 3.22)Use per-monitor information

Gets the width of the default screen in pixels. The returned size is in ”application pixels”, not in ”device pixels” (see screenGetMonitorScaleFactor).

widthMm

screenWidthMm

Arguments

:: (HasCallStack, MonadIO m)

=> m Int32

Returns: the width of the default screen in millimeters, though it is not always correct.

Deprecated: (Since version 3.22)Use per-monitor information

Returns the width of the default screen in millimeters. Note that on many X servers this value will not be correct.

Properties

fontOptions

No description available in the introspection data.

constructScreenFontOptions :: IsScreen o => Ptr () -> IO (GValueConstruct o)

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

getScreenFontOptions :: (MonadIO m, IsScreen o) => o -> m (Ptr ())

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

get screen #fontOptions

setScreenFontOptions :: (MonadIO m, IsScreen o) => o -> Ptr () -> m ()

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

set screen [ #fontOptions := value ]

resolution

No description available in the introspection data.

constructScreenResolution :: IsScreen o => Double -> IO (GValueConstruct o)

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

getScreenResolution :: (MonadIO m, IsScreen o) => o -> m Double

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

get screen #resolution

setScreenResolution :: (MonadIO m, IsScreen o) => o -> Double -> m ()

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

set screen [ #resolution := value ]

Signals

compositedChanged

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

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

type ScreenCompositedChangedCallback = IO ()

The ::composited-changed signal is emitted when the composited status of the screen changes

Since: 2.10

afterScreenCompositedChanged :: (IsScreen a, MonadIO m) => a -> ScreenCompositedChangedCallback -> m SignalHandlerId

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

after screen #compositedChanged callback

genClosure_ScreenCompositedChanged :: MonadIO m => ScreenCompositedChangedCallback -> m (GClosure C_ScreenCompositedChangedCallback)

Wrap the callback into a GClosure.

mk_ScreenCompositedChangedCallback :: C_ScreenCompositedChangedCallback -> IO (FunPtr C_ScreenCompositedChangedCallback)

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

noScreenCompositedChangedCallback :: Maybe ScreenCompositedChangedCallback

A convenience synonym for Nothing :: Maybe ScreenCompositedChangedCallback.

onScreenCompositedChanged :: (IsScreen a, MonadIO m) => a -> ScreenCompositedChangedCallback -> m SignalHandlerId

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

on screen #compositedChanged callback

wrap_ScreenCompositedChangedCallback :: ScreenCompositedChangedCallback -> C_ScreenCompositedChangedCallback

Wrap a ScreenCompositedChangedCallback into a C_ScreenCompositedChangedCallback.

monitorsChanged

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

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

type ScreenMonitorsChangedCallback = IO ()

The ::monitors-changed signal is emitted when the number, size or position of the monitors attached to the screen change.

Only for X11 and OS X for now. A future implementation for Win32 may be a possibility.

Since: 2.14

afterScreenMonitorsChanged :: (IsScreen a, MonadIO m) => a -> ScreenMonitorsChangedCallback -> m SignalHandlerId

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

after screen #monitorsChanged callback

genClosure_ScreenMonitorsChanged :: MonadIO m => ScreenMonitorsChangedCallback -> m (GClosure C_ScreenMonitorsChangedCallback)

Wrap the callback into a GClosure.

mk_ScreenMonitorsChangedCallback :: C_ScreenMonitorsChangedCallback -> IO (FunPtr C_ScreenMonitorsChangedCallback)

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

noScreenMonitorsChangedCallback :: Maybe ScreenMonitorsChangedCallback

A convenience synonym for Nothing :: Maybe ScreenMonitorsChangedCallback.

onScreenMonitorsChanged :: (IsScreen a, MonadIO m) => a -> ScreenMonitorsChangedCallback -> m SignalHandlerId

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

on screen #monitorsChanged callback

wrap_ScreenMonitorsChangedCallback :: ScreenMonitorsChangedCallback -> C_ScreenMonitorsChangedCallback

Wrap a ScreenMonitorsChangedCallback into a C_ScreenMonitorsChangedCallback.

sizeChanged

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

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

type ScreenSizeChangedCallback = IO ()

The ::size-changed signal is emitted when the pixel width or height of a screen changes.

Since: 2.2

afterScreenSizeChanged :: (IsScreen a, MonadIO m) => a -> ScreenSizeChangedCallback -> m SignalHandlerId

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

after screen #sizeChanged callback

genClosure_ScreenSizeChanged :: MonadIO m => ScreenSizeChangedCallback -> m (GClosure C_ScreenSizeChangedCallback)

Wrap the callback into a GClosure.

mk_ScreenSizeChangedCallback :: C_ScreenSizeChangedCallback -> IO (FunPtr C_ScreenSizeChangedCallback)

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

noScreenSizeChangedCallback :: Maybe ScreenSizeChangedCallback

A convenience synonym for Nothing :: Maybe ScreenSizeChangedCallback.

onScreenSizeChanged :: (IsScreen a, MonadIO m) => a -> ScreenSizeChangedCallback -> m SignalHandlerId

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

on screen #sizeChanged callback

wrap_ScreenSizeChangedCallback :: ScreenSizeChangedCallback -> C_ScreenSizeChangedCallback

Wrap a ScreenSizeChangedCallback into a C_ScreenSizeChangedCallback.