Maintainer	gtk2hs-users@lists.sourceforge.net
Stability	provisional
Portability	portable (depends on GHC)
Safe Haskell	None
Language	Haskell98

Graphics.UI.Gtk.Gdk.Screen

Contents

Detail
Class Hierarchy
Types
Methods
Attributes
Signals

Description

Object representing a physical screen

Module available since Gdk version 2.2

Synopsis

Detail

Screen objects are the GDK representation of a physical screen. It 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 colormap (screenGetDefaultColormap), the screen width (screenGetWidth), etc.

Note that a screen may consist of multiple monitors which are merged to form a large screen area.

Class Hierarchy

| GObject
| +----Screen

Types

data Screen Source

Instances

Eq Screen Source
Ord Screen Source
GObjectClass Screen Source
ScreenClass Screen Source

class GObjectClass o => ScreenClass o Source

Instances

ScreenClass Screen Source

castToScreen :: GObjectClass obj => obj -> Screen Source

gTypeScreen :: GType Source

toScreen :: ScreenClass o => o -> Screen Source

Methods

screenGetDefault Source

Arguments

:: IO (Maybe Screen)

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

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

screenGetSystemColormap Source

Arguments

:: Screen
-> IO Colormap	returns the default colormap for `screen`.

Gets the system default colormap for screen

Removed in Gtk3.

screenGetRGBAColormap Source

Arguments

:: Screen
-> IO (Maybe Colormap)	returns a colormap to use for windows with an alpha channel or `Nothing` if the capability is not available.

Gets a colormap to use for creating windows or pixmaps 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.

Available since Gdk version 2.8

Removed in Gtk3.

screenGetDefaultColormap Source

Arguments

:: Screen
-> IO Colormap	returns the default `Colormap`.

Deprecated: instead of 'screenGetDefaultColormap obj' use 'get obj screenDefaultColormap'

screenSetDefaultColormap Source

Arguments

:: Screen
-> Colormap	`colormap` - a `Colormap`
-> IO ()

Deprecated: instead of 'screenSetDefaultColormap obj value' use 'set obj [ screenDefaultColormap := value ]'

screenGetSystemVisual Source

Arguments

:: Screen
-> IO Visual	returns the system visual

Get the system's default visual for screen. This is the visual for the root window of the display.

screenIsComposited Source

Arguments

:: Screen
-> IO 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.

Available since Gdk version 2.10

screenGetRootWindow Source

Arguments

:: Screen
-> IO DrawWindow	returns the root window

Gets the root window of screen.

screenGetDisplay Source

Arguments

:: Screen
-> IO Display	returns the display to which `screen` belongs

Gets the display to which the screen belongs.

screenGetNumber Source

Arguments

:: Screen
-> IO Int	returns the index

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

screenGetWidth Source

Arguments

:: Screen
-> IO Int	returns the width of `screen` in pixels.

Gets the width of screen in pixels

screenGetHeight Source

Arguments

:: Screen
-> IO Int	returns the height of `screen` in pixels.

Gets the height of screen in pixels

screenGetWidthMm :: Screen -> IO Int Source

screenGetHeightMm :: Screen -> IO Int Source

screenGetWidthMM Source

Arguments

:: Screen
-> IO Int	returns the width of `screen` in millimeters.

Gets the width of screen in millimeters. Note that on some X servers this value will not be correct.

screenGetHeightMM Source

Arguments

:: Screen
-> IO Int	returns the heigth of `screen` in millimeters.

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

screenListVisuals Source

Arguments

:: Screen
-> IO [Visual]	returns a list of visuals

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.

screenGetToplevelWindows Source

Arguments

:: Screen
-> IO [DrawWindow]	returns list of toplevel windows

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).

screenMakeDisplayName Source

Arguments

:: GlibString string
=> Screen
-> IO string	returns a newly allocated string

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

screenGetNMonitors Source

Arguments

:: Screen
-> IO Int	returns number of monitors which `screen` consists of.

Returns the number of monitors which screen consists of.

screenGetMonitorGeometry Source

Arguments

:: Screen
-> Int	`monitorNum` - the monitor number.
-> IO Rectangle

Retrieves the Rectangle representing the size and position of the individual monitor within the entire screen area.

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

screenGetMonitorAtPoint Source

Arguments

:: Screen
-> Int	`x` - the x coordinate in the virtual screen.
-> Int	`y` - the y coordinate in the virtual screen.
-> IO Int	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.

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

screenGetMonitorAtWindow Source

Arguments

:: Screen
-> DrawWindow	`window` - a `DrawWindow`
-> IO Int	returns the monitor number in which most of `window` is located, or if `window` does not intersect any monitors, a monitor, close to `window`.

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

screenGetMonitorHeightMm Source

Arguments

:: Screen
-> Int	`monitorNum` - number of the monitor
-> IO Int	returns the height of the monitor, or -1 if not available

Gets the height in millimeters of the specified monitor.

Available since Gdk version 2.14

screenGetMonitorWidthMm Source

Arguments

:: Screen
-> Int	`monitorNum` - number of the monitor
-> IO Int	returns the width of the monitor, or -1 if not available

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

Available since Gdk version 2.14

screenGetMonitorPlugName Source

Arguments

:: GlibString string
=> Screen
-> Int	`monitorNum` - number of the monitor
-> IO (Maybe string)	returns a newly-allocated string containing the name of the monitor, or `Nothing` if the name cannot be determined

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

Available since Gdk version 2.14

screenGetActiveWindow Source

Arguments

:: Screen
-> IO (Maybe DrawWindow)	returns the currently active window, or `Nothing`.

Returns the currently active window of this screen.

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.

Available since Gdk version 2.10

screenGetWindowStack Source

Arguments

:: Screen
-> IO (Maybe [DrawWindow])	returns a list of `DrawWindow`s for the current window stack, or `Nothing`.

Returns a list of DrawWindows 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.

Available since Gdk version 2.10

Attributes

screenFontOptions :: Attr Screen (Maybe FontOptions) Source

The default font options for the screen.

screenResolution :: Attr Screen Double Source

The resolution for fonts on the screen.

Default value: -1

screenDefaultColormap :: Attr Screen Colormap Source

Sets the default colormap for screen.

Gets the default colormap for screen.

Removed in Gtk3.

Signals

screenSizeChanged :: ScreenClass self => Signal self (IO ()) Source

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

screenCompositedChanged :: ScreenClass self => Signal self (IO ()) Source

The screenCompositedChanged signal is emitted when the composited status of the screen changes

Available since Gdk version 2.10

screenMonitorsChanged :: ScreenClass self => Signal self (IO ()) Source

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

Only for X for now. Future implementations for Win32 and OS X may be a possibility.

Available since Gdk version 2.14