Class: Gsk::RenderNode

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Overview

GskRenderNode is the basic block in a scene graph to be rendered using [classGsk.Renderer].

Each node has a parent, except the top-level node; each node may have children nodes.

Each node has an associated drawing surface, which has the size of the rectangle set when creating it.

Render nodes are meant to be transient; once they have been associated to a [classGsk.Renderer] it's safe to release any reference you have on them. All [classGsk.RenderNode]s are immutable, you can only specify their properties during construction.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.deserialize(bytes, error_func, user_data) ⇒ Gsk::RenderNode

Loads data previously created via [methodGsk.RenderNode.serialize].

For a discussion of the supported format, see that function.

Parameters:

  • bytes (GLib::Bytes) —

    the bytes containing the data

  • error_func (Gsk::ParseErrorFunc) —

    Callback on parsing errors

  • user_data (GObject) —

    user_data for error_func

Returns:

Instance Method Details

#draw(cr) ⇒ nil

Draw the contents of node to the given cairo context.

Typically, you'll use this function to implement fallback rendering of GskRenderNodes on an intermediate Cairo context, instead of using the drawing context associated to a [classGdk.Surface]'s rendering buffer.

For advanced nodes that cannot be supported using Cairo, in particular for nodes doing 3D operations, this function may fail.

Parameters:

  • cr (cairo::Context) —

    cairo context to draw to

Returns:

  • (nil)

#get_bounds(bounds) ⇒ nil

Retrieves the boundaries of the node.

The node will not draw outside of its boundaries.

Parameters:

  • bounds (Graphene::Rect) —

    return location for the boundaries

Returns:

  • (nil)

#node_type ⇒ Gsk::RenderNodeType

Returns the type of the node.

Returns:

#ref ⇒ Gsk::RenderNode

Acquires a reference on the given GskRenderNode.

Returns:

#serialize ⇒ GLib::Bytes

Serializes the node for later deserialization via gsk_render_node_deserialize(). No guarantees are made about the format used other than that the same version of GTK will be able to deserialize the result of a call to gsk_render_node_serialize() and gsk_render_node_deserialize() will correctly reject files it cannot open that were created with previous versions of GTK.

The intended use of this functions is testing, benchmarking and debugging. The format is not meant as a permanent storage format.

Returns:

  • (GLib::Bytes) —

    a GBytes representing the node.

#unref ⇒ nil

Releases a reference on the given GskRenderNode.

If the reference was the last, the resources associated to the node are freed.

Returns:

  • (nil)

#write_to_file(filename) ⇒ Boolean

This function is equivalent to calling [methodGsk.RenderNode.serialize] followed by [funcGLib.file_set_contents].

See those two functions for details on the arguments.

It is mostly intended for use inside a debugger to quickly dump a render node to a file for later inspection.

Parameters:

  • filename (Gsk::filename) —

    the file to save it to.

Returns:

  • (Boolean) —

    true if saving was successful