clutter_canvas_new ()

ClutterContent *
clutter_canvas_new (void);

Creates a new instance of ClutterCanvas.

You should call clutter_canvas_set_size() to set the size of the canvas.

You should call clutter_content_invalidate() every time you wish to draw the contents of the canvas.

Since: 1.10

clutter_canvas_set_size ()

gboolean
clutter_canvas_set_size (ClutterCanvas *canvas,
                         int width,
                         int height);

Sets the size of the canvas , and invalidates the content.

This function will cause the canvas to be invalidated only if the size of the canvas surface has changed.

If you want to invalidate the contents of the canvas when setting the size, you can use the return value of the function to conditionally call clutter_content_invalidate():

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if (!clutter_canvas_set_size (canvas, width, height))
  clutter_content_invalidate (CLUTTER_CONTENT (canvas));

Since: 1.10

clutter_canvas_set_scale_factor ()

void
clutter_canvas_set_scale_factor (ClutterCanvas *canvas,
                                 int scale);

Sets the scaling factor for the Cairo surface used by canvas .

This function should rarely be used.

The default scaling factor of a ClutterCanvas content uses the “window-scaling-factor” property, which is set by the windowing system. By using this function it is possible to override that setting.

Changing the scale factor will invalidate the canvas .

Since: 1.18

clutter_canvas_get_scale_factor ()

int
clutter_canvas_get_scale_factor (ClutterCanvas *canvas);

Retrieves the scaling factor of canvas , as set using clutter_canvas_set_scale_factor().

Since: 1.18

struct ClutterCanvas

struct ClutterCanvas;

The ClutterCanvas structure contains private data and should only be accessed using the provided API.

Since: 1.10

struct ClutterCanvasClass

struct ClutterCanvasClass {
  gboolean (* draw) (ClutterCanvas *canvas,
                     cairo_t       *cr,
                     int            width,
                     int            height);
};

The ClutterCanvasClass structure contains private data.

Since: 1.10

The “height” property

  “height”                   gint

The height of the canvas.

Flags: Read / Write

Allowed values: >= -1

Default value: -1

Since: 1.10

The “scale-factor” property

  “scale-factor”             gint

The scaling factor to be applied to the Cairo surface used for drawing.

If “scale-factor” is set to a negative value, the value of the “window-scaling-factor” property is used instead.

Use “scale-factor-set” to check if the scale factor is set.

Flags: Read / Write

Allowed values: [-1,1000]

Default value: -1

Since: 1.18

The “scale-factor-set” property

  “scale-factor-set”         gboolean

Whether the “scale-factor” property is set.

If the “scale-factor-set” property is FALSE then ClutterCanvas will use the “window-scaling-factor” property.

Flags: Read

Default value: FALSE

Since: 1.18

The “width” property

  “width”                    gint

The width of the canvas.

Flags: Read / Write

Allowed values: >= -1

Default value: -1

Since: 1.10

The “draw” signal

gboolean
user_function (ClutterCanvas *canvas,
               CairoContext  *cr,
               gint           width,
               gint           height,
               gpointer       user_data)

The “draw” signal is emitted each time a canvas is invalidated.

It is safe to connect multiple handlers to this signal: each handler invocation will be automatically protected by cairo_save() and cairo_restore() pairs.

Flags: No Recursion

Since: 1.10