DrawContextProtocol

public protocol DrawContextProtocol : ObjectProtocol

The DrawContextProtocol protocol exposes the methods and properties of an underlying GdkDrawContext instance. The default implementation of these can be found in the protocol extension below. For a concrete class that implements these methods and properties, see DrawContext. Alternatively, use DrawContextRef as a lighweight, unowned reference if you already have an instance you just want to use.

Base class for objects implementing different rendering methods.

GdkDrawContext is the base object used by contexts implementing different rendering methods, such as [classGdk.CairoContext] or [classGdk.GLContext]. It provides shared functionality between those contexts.

You will always interact with one of those subclasses.

A GdkDrawContext is always associated with a single toplevel surface.

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  • ptr

    Untyped pointer to the underlying GdkDrawContext instance.

    Declaration

    Swift

    var ptr: UnsafeMutableRawPointer! { get }
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  • draw_context_ptr Default implementation

    Typed pointer to the underlying GdkDrawContext instance.

    Default Implementation

    Return the stored, untyped pointer as a typed pointer to the GdkDrawContext instance.

    Declaration

    Swift

    var draw_context_ptr: UnsafeMutablePointer<GdkDrawContext>! { get }
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  • Required Initialiser for types conforming to DrawContextProtocol

    Declaration

    Swift

    init(raw: UnsafeMutableRawPointer)
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DrawContext Class

  • Bind a DrawContextPropertyName source property to a given target object.

    Declaration

    Swift

    @discardableResult
@inlinable
func bind<Q, T>(property source_property: DrawContextPropertyName, to target: T, _ target_property: Q, flags f: BindingFlags = .default, transformFrom transform_from: @escaping GLibObject.ValueTransformer = { $0.transform(destValue: $1) }, transformTo transform_to: @escaping GLibObject.ValueTransformer = { $0.transform(destValue: $1) }) -> BindingRef! where Q : PropertyNameProtocol, T : ObjectProtocol

    Parameters

    source_property

    the source property to bind
    target

    the target object to bind to
    target_property

    the target property to bind to
    flags

    the flags to pass to the Binding
    transform_from

    ValueTransformer to use for forward transformation
    transform_to

    ValueTransformer to use for backwards transformation

    Return Value

    binding reference or nil in case of an error

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  • get(property:) Extension method

    Get the value of a DrawContext property

    Declaration

    Swift

    @inlinable
func get(property: DrawContextPropertyName) -> GLibObject.Value

    Parameters

    property

    the property to get the value for

    Return Value

    the value of the named property

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  • set(property:value:) Extension method

    Set the value of a DrawContext property. Note that this will only have an effect on properties that are writable and not construct-only!

    Declaration

    Swift

    @inlinable
func set(property: DrawContextPropertyName, value v: GLibObject.Value)

    Parameters

    property

    the property to get the value for

    Return Value

    the value of the named property

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DrawContext Class: DrawContextProtocol extension (methods and fields)

  • beginFrame(region:) Extension method

    Indicates that you are beginning the process of redrawing region on the context‘s surface.

    Calling this function begins a drawing operation using context on the surface that context was created from. The actual requirements and guarantees for the drawing operation vary for different implementations of drawing, so a [classGdk.CairoContext] and a [classGdk.GLContext] need to be treated differently.

    A call to this function is a requirement for drawing and must be followed by a call to [methodGdk.DrawContext.end_frame], which will complete the drawing operation and ensure the contents become visible on screen.

    Note that the region passed to this function is the minimum region that needs to be drawn and depending on implementation, windowing system and hardware in use, it might be necessary to draw a larger region. Drawing implementation must use [methodGdk.DrawContext.get_frame_region() to query the region that must be drawn.

    When using GTK, the widget system automatically places calls to gdk_draw_context_begin_frame() and gdk_draw_context_end_frame() via the use of [classGsk.Renderer]s, so application code does not need to call these functions explicitly.

    Declaration

    Swift

    @inlinable
func beginFrame<RegionT>(region: RegionT) where RegionT : RegionProtocol
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  • endFrame() Extension method

    Ends a drawing operation started with gdk_draw_context_begin_frame().

    This makes the drawing available on screen. See [methodGdk.DrawContext.begin_frame] for more details about drawing.

    When using a [classGdk.GLContext], this function may call glFlush() implicitly before returning; it is not recommended to call glFlush() explicitly before calling this function.

    Declaration

    Swift

    @inlinable
func endFrame()
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  • getDisplay() Extension method

    Retrieves the GdkDisplay the context is created for

    Declaration

    Swift

    @inlinable
func getDisplay() -> DisplayRef!
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  • getFrameRegion() Extension method

    Retrieves the region that is currently being repainted.

    After a call to [methodGdk.DrawContext.begin_frame] this function will return a union of the region passed to that function and the area of the surface that the context determined needs to be repainted.

    If context is not in between calls to [methodGdk.DrawContext.begin_frame] and [methodGdk.DrawContext.end_frame], nil will be returned.

    Declaration

    Swift

    @inlinable
func getFrameRegion() -> Cairo.RegionRef!
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  • getSurface() Extension method

    Retrieves the surface that context is bound to.

    Declaration

    Swift

    @inlinable
func getSurface() -> SurfaceRef!
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  • display Extension method

    The GdkDisplay used to create the GdkDrawContext.

    Declaration

    Swift

    @inlinable
var display: DisplayRef! { get }
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  • frameRegion Extension method

    Retrieves the region that is currently being repainted.

    After a call to [methodGdk.DrawContext.begin_frame] this function will return a union of the region passed to that function and the area of the surface that the context determined needs to be repainted.

    If context is not in between calls to [methodGdk.DrawContext.begin_frame] and [methodGdk.DrawContext.end_frame], nil will be returned.

    Declaration

    Swift

    @inlinable
var frameRegion: Cairo.RegionRef! { get }
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  • isInFrame Extension method

    Returns true if context is in the process of drawing to its surface.

    This is the case between calls to [methodGdk.DrawContext.begin_frame] and [methodGdk.DrawContext.end_frame]. In this situation, drawing commands may be effecting the contents of the context‘s surface.

    Declaration

    Swift

    @inlinable
var isInFrame: Bool { get }
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  • surface Extension method

    The GdkSurface the context is bound to.

    Declaration

    Swift

    @inlinable
var surface: SurfaceRef! { get }
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