StDrawingArea: St Reference Manual

StDrawingArea

StDrawingArea — A dynamically-sized Cairo drawing area

Functions

void	st_drawing_area_queue_repaint ()
cairo_t *	st_drawing_area_get_context ()
void	st_drawing_area_get_surface_size ()

Types and Values

#define	ST_TYPE_DRAWING_AREA
struct	StDrawingAreaClass
	StDrawingArea

Description

StDrawingArea is similar to ClutterCairoTexture in that it allows drawing via Cairo; the primary difference is that it is dynamically sized. To use, connect to the “repaint” signal, and inside the signal handler, call st_drawing_area_get_context() to get the Cairo context to draw to. The “repaint” signal will be emitted by default when the area is resized or the CSS style changes; you can use the st_drawing_area_queue_repaint() as well.

Functions

st_drawing_area_queue_repaint ()

void
st_drawing_area_queue_repaint (StDrawingArea *area);

Will cause the actor to emit a ::repaint signal before it is next drawn to the scene. Useful if some parameters for the area being drawn other than the size or style have changed. Note that clutter_actor_queue_redraw() will simply result in the same contents being drawn to the scene again.

Parameters

area

the StDrawingArea

st_drawing_area_get_context ()

cairo_t *
st_drawing_area_get_context (StDrawingArea *area);

Gets the Cairo context to paint to. This function must only be called from a signal hander for the ::repaint signal.

Parameters

area

the StDrawingArea

Returns

the Cairo context for the paint operation.

[transfer none]

st_drawing_area_get_surface_size ()

void
st_drawing_area_get_surface_size (StDrawingArea *area,
                                  guint *width,
                                  guint *height);

Gets the size of the cairo surface being painted to, which is equal to the size of the content area of the widget. This function must only be called from a signal hander for the ::repaint signal.

Parameters

area	the StDrawingArea
width	location to store the width of the painted area.	[out]
height	location to store the height of the painted area.	[out]

Types and Values

ST_TYPE_DRAWING_AREA

#define ST_TYPE_DRAWING_AREA (st_drawing_area_get_type ())

struct StDrawingAreaClass

struct StDrawingAreaClass {
    StWidgetClass parent_class;

    void (*repaint) (StDrawingArea *area);
};

StDrawingArea

typedef struct _StDrawingArea StDrawingArea;