GI.Gdk.Objects.DrawingContext

DrawingContext is an object that represents the current drawing state of a Window.

It's possible to use a DrawingContext to draw on a Window via rendering API like Cairo or OpenGL.

A DrawingContext can only be created by calling windowBeginDrawFrame and will be valid until a call to windowEndDrawFrame.

DrawingContext is available since GDK 3.22

Exported types

newtype DrawingContext

Memory-managed wrapper type.

Constructors

DrawingContext (ManagedPtr DrawingContext)

Instances

GObject DrawingContext

Defined in GI.Gdk.Objects.DrawingContext

Methods

gobjectType :: IO GType

HasParentTypes DrawingContext

Defined in GI.Gdk.Objects.DrawingContext

type ParentTypes DrawingContext

Defined in GI.Gdk.Objects.DrawingContext

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

class (GObject o, IsDescendantOf DrawingContext o) => IsDrawingContext o

Type class for types which can be safely cast to DrawingContext, for instance with toDrawingContext.

Instances

(GObject o, IsDescendantOf DrawingContext o) => IsDrawingContext o

Defined in GI.Gdk.Objects.DrawingContext

toDrawingContext :: (MonadIO m, IsDrawingContext o) => o -> m DrawingContext

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

noDrawingContext :: Maybe DrawingContext

A convenience alias for Nothing :: Maybe DrawingContext.

Methods

getCairoContext

drawingContextGetCairoContext

Arguments

:: (HasCallStack, MonadIO m, IsDrawingContext a)

=> a

-> m Context

Returns: a Cairo context to be used to draw the contents of the Window. The context is owned by the DrawingContext and should not be destroyed

Retrieves a Cairo context to be used to draw on the Window that created the DrawingContext.

The returned context is guaranteed to be valid as long as the DrawingContext is valid, that is between a call to windowBeginDrawFrame and windowEndDrawFrame.

Since: 3.22

getClip

drawingContextGetClip

Arguments

:: (HasCallStack, MonadIO m, IsDrawingContext a)

=> a

context: a DrawingContext

-> m (Maybe Region)

Returns: a Cairo region

Retrieves a copy of the clip region used when creating the context.

Since: 3.22

getWindow

drawingContextGetWindow

Arguments

:: (HasCallStack, MonadIO m, IsDrawingContext a)

=> a

context: a DrawingContext

-> m Window

Returns: a Window

Retrieves the window that created the drawing context.

Since: 3.22

isValid

drawingContextIsValid

Arguments

:: (HasCallStack, MonadIO m, IsDrawingContext a)

=> a

context: a DrawingContext

-> m Bool

Returns: True if the context is valid

Checks whether the given DrawingContext is valid.

Since: 3.22

Properties

clip

The clip region applied to the drawing context.

Since: 3.22

constructDrawingContextClip :: IsDrawingContext o => Region -> IO (GValueConstruct o)

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

getDrawingContextClip :: (MonadIO m, IsDrawingContext o) => o -> m (Maybe Region)

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

get drawingContext #clip

window

The Window that created the drawing context.

Since: 3.22

constructDrawingContextWindow :: (IsDrawingContext o, IsWindow a) => a -> IO (GValueConstruct o)

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

getDrawingContextWindow :: (MonadIO m, IsDrawingContext o) => o -> m Window

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

get drawingContext #window