GooCanvasStyle

GooCanvasStyle — support for cascading style properties for canvas items.

Synopsis

                    GooCanvasStyle;
                    GooCanvasStyleProperty;

GooCanvasStyle*     goo_canvas_style_new                (void);
GooCanvasStyle*     goo_canvas_style_copy               (GooCanvasStyle *style);

GooCanvasStyle*     goo_canvas_style_get_parent         (GooCanvasStyle *style);
void                goo_canvas_style_set_parent         (GooCanvasStyle *style,
                                                         GooCanvasStyle *parent);

GValue*             goo_canvas_style_get_property       (GooCanvasStyle *style,
                                                         GQuark property_id);
void                goo_canvas_style_set_property       (GooCanvasStyle *style,
                                                         GQuark property_id,
                                                         const GValue *value);

gboolean            goo_canvas_style_set_fill_options   (GooCanvasStyle *style,
                                                         cairo_t *cr);
gboolean            goo_canvas_style_set_stroke_options (GooCanvasStyle *style,
                                                         cairo_t *cr);

extern              GQuark goo_canvas_style_antialias_id;
extern              GQuark goo_canvas_style_fill_pattern_id;
extern              GQuark goo_canvas_style_fill_rule_id;
extern              GQuark goo_canvas_style_font_desc_id;
extern              GQuark goo_canvas_style_hint_metrics_id;
extern              GQuark goo_canvas_style_line_cap_id;
extern              GQuark goo_canvas_style_line_dash_id;
extern              GQuark goo_canvas_style_line_join_id;
extern              GQuark goo_canvas_style_line_join_miter_limit_id;
extern              GQuark goo_canvas_style_line_width_id;
extern              GQuark goo_canvas_style_operator_id;
extern              GQuark goo_canvas_style_stroke_pattern_id;

Object Hierarchy

  GObject
   +----GooCanvasStyle

Description

GooCanvasStyle provides support for cascading style properties for canvas items. It is intended to be used when implementing new canvas items.

Style properties are identified by a unique GQuark, and contain arbitrary data stored in a GValue.

GooCanvasStyle also provides a few convenience functions such as goo_canvas_style_set_stroke_options() and goo_canvas_style_set_fill_options() which efficiently apply an item's standard style properties to the given cairo_t.

Details

GooCanvasStyle

typedef struct {
  GooCanvasStyle *parent;
  GArray *properties;
} GooCanvasStyle;

GooCanvasStyle holds the style properties of a canvas item, as well as a pointer to the parent style.

GooCanvasStyle *`parent`;	the parent style.
GArray *`properties`;	an array of GooCanvasStyleProperty property settings.

GooCanvasStyleProperty

typedef struct {
  GQuark id;
  GValue value;
} GooCanvasStyleProperty;

GooCanvasStyleProperty represents a property setting.

GQuark `id`;	the unique property identifier.
GValue `value`;	the value of the property.

goo_canvas_style_new ()

GooCanvasStyle*     goo_canvas_style_new                (void);

Creates a new GooCanvasStyle.

Returns :

a new GooCanvasStyle.

goo_canvas_style_copy ()

GooCanvasStyle*     goo_canvas_style_copy               (GooCanvasStyle *style);

Copies the given GooCanvasStyle, by copying all of its properties. Though the parent of the new style is left unset.

`style` :	a GooCanvasStyle.
Returns :	a copy of the given GooCanvasStyle.

goo_canvas_style_get_parent ()

GooCanvasStyle*     goo_canvas_style_get_parent         (GooCanvasStyle *style);

Gets the parent of the style.

`style` :	a style.
Returns :	the parent of the given style, or `NULL`.

goo_canvas_style_set_parent ()

void                goo_canvas_style_set_parent         (GooCanvasStyle *style,
                                                         GooCanvasStyle *parent);

Sets the parent of the style.

`style` :	a style.
`parent` :	the new parent.

goo_canvas_style_get_property ()

GValue*             goo_canvas_style_get_property       (GooCanvasStyle *style,
                                                         GQuark property_id);

Gets the value of a property.

This searches though all the GooCanvasStyle's own list of property settings and also all ancestor GooCanvasStyle objects.

Note that it returns a pointer to the internal GValue setting, which should not be changed.

`style` :	a style.
`property_id` :	the property identifier.
Returns :	the property value, or `NULL` if it isn't set.

goo_canvas_style_set_property ()

void                goo_canvas_style_set_property       (GooCanvasStyle *style,
                                                         GQuark property_id,
                                                         const GValue *value);

Sets a property in the style, replacing any current setting.

Note that this will override the property setting in ancestor GooCanvasStyle objects.

`style` :	a style.
`property_id` :	the property identifier.
`value` :	the value of the property.

goo_canvas_style_set_fill_options ()

gboolean            goo_canvas_style_set_fill_options   (GooCanvasStyle *style,
                                                         cairo_t *cr);

Sets the standard cairo fill options using the given style.

`style` :	a style.
`cr` :	a cairo context.
Returns :	`TRUE` if a paint source is set, or `FALSE` if the fill should be skipped.

goo_canvas_style_set_stroke_options ()

gboolean            goo_canvas_style_set_stroke_options (GooCanvasStyle *style,
                                                         cairo_t *cr);

Sets the standard cairo stroke options using the given style.

`style` :	a style.
`cr` :	a cairo context.
Returns :	`TRUE` if a paint source is set, or `FALSE` if the stroke should be skipped.

goo_canvas_style_antialias_id

extern GQuark goo_canvas_style_antialias_id;

Unique GQuark identifier used for the standard antialias property.

goo_canvas_style_fill_pattern_id

extern GQuark goo_canvas_style_fill_pattern_id;

Unique GQuark identifier used for the standard fill pattern property.

goo_canvas_style_fill_rule_id

extern GQuark goo_canvas_style_fill_rule_id;

Unique GQuark identifier used for the standard fill rule property.

goo_canvas_style_font_desc_id

extern GQuark goo_canvas_style_font_desc_id;

Unique GQuark identifier used for the standard font description property.

goo_canvas_style_hint_metrics_id

extern GQuark goo_canvas_style_hint_metrics_id;

Unique GQuark identifier used for the standard hint metrics property.

goo_canvas_style_line_cap_id

extern GQuark goo_canvas_style_line_cap_id;

Unique GQuark identifier used for the standard line cap property.

goo_canvas_style_line_dash_id

extern GQuark goo_canvas_style_line_dash_id;

Unique GQuark identifier used for the standard line dash property.

goo_canvas_style_line_join_id

extern GQuark goo_canvas_style_line_join_id;

Unique GQuark identifier used for the standard line join property.

goo_canvas_style_line_join_miter_limit_id

extern GQuark goo_canvas_style_line_join_miter_limit_id;

Unique GQuark identifier used for the standard miter limit property.

goo_canvas_style_line_width_id

extern GQuark goo_canvas_style_line_width_id;

Unique GQuark identifier used for the standard line width property.

goo_canvas_style_operator_id

extern GQuark goo_canvas_style_operator_id;

Unique GQuark identifier used for the standard operator property.

goo_canvas_style_stroke_pattern_id

extern GQuark goo_canvas_style_stroke_pattern_id;

Unique GQuark identifier used for the standard stroke pattern property.

			GooCanvas Reference Manual
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