GdkDrawingContext

GdkDrawingContext — Drawing context for GDK windows

Functions

Properties

CairoRegion * clip Read / Write / Construct Only
GdkDrawContext * paint-context Read / Write / Construct Only
GdkWindow * window Read / Write / Construct Only

Types and Values

Object Hierarchy

    GObject
    ╰── GdkDrawingContext

Includes

#include <gdk/gdkwayland.h>

Description

GdkDrawingContext is an object that represents the current drawing state of a GdkWindow.

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

A GdkDrawingContext can only be created by calling gdk_window_begin_draw_frame() and will be valid until a call to gdk_window_end_draw_frame().

GdkDrawingContext is available since GDK 3.22

Functions

gdk_drawing_context_get_window ()

GdkWindow *
gdk_drawing_context_get_window (GdkDrawingContext *context);

Retrieves the window that created the drawing context .

Parameters

context

a GdkDrawingContext

 

Returns

a GdkWindow.

[transfer none]

Since: 3.22

gdk_drawing_context_get_clip ()

cairo_region_t *
gdk_drawing_context_get_clip (GdkDrawingContext *context);

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

Parameters

context

a GdkDrawingContext

 

Returns

a Cairo region.

[transfer full][nullable]

Since: 3.22

gdk_drawing_context_get_cairo_context ()

cairo_t *
gdk_drawing_context_get_cairo_context (GdkDrawingContext *context);

Retrieves a Cairo context to be used to draw on the GdkWindow that created the GdkDrawingContext. The context must have been created without a GdkDrawContext for this function to work. If gdk_drawing_context_get_paint_context() does not return NULL, then this function will.

The returned context is guaranteed to be valid as long as the GdkDrawingContext is valid, that is between a call to gdk_window_begin_draw_frame() and gdk_window_end_draw_frame().

Parameters

context

a GdkDrawingContext created with a NULL paint context

 

Returns

a Cairo context to be used to draw the contents of the GdkWindow. The context is owned by the GdkDrawingContext and should not be destroyed. NULL is returned when a paint context is in used.

[transfer none]

Since: 3.22

gdk_drawing_context_is_valid ()

gboolean
gdk_drawing_context_is_valid (GdkDrawingContext *context);

Checks whether the given GdkDrawingContext is valid.

Parameters

context

a GdkDrawingContext

 

Returns

TRUE if the context is valid

Since: 3.22

Types and Values

GdkDrawingContext

typedef struct _GdkDrawingContext GdkDrawingContext;

Property Details

The “clip” property

  “clip”                     CairoRegion *

The clip region applied to the drawing context.

Flags: Read / Write / Construct Only

Since: 3.22

The “paint-context” property

  “paint-context”            GdkDrawContext *

The GdkDrawContext used to draw or NULL if Cairo is used.

Flags: Read / Write / Construct Only

Since: 3.90

The “window” property

  “window”                   GdkWindow *

The GdkWindow that created the drawing context.

Flags: Read / Write / Construct Only

Since: 3.22