class Gsk::RenderNode

Overview

GskRenderNode is the basic block in a scene graph to be rendered using Gsk#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 Gsk#Renderer it's safe to release any reference you have on them. All Gsk#RenderNodes are immutable, you can only specify their properties during construction.

Direct Known Subclasses

Defined in:

lib/gi-crystal/src/auto/gsk-4.0/render_node.cr
lib/gtk4/src/bindings/gsk/render_node.cr

Class Method Summary

Instance Method Summary

Class Method Detail

def self.deserialize(bytes : GLib::Bytes, error_func : Gsk::ParseErrorFunc?, user_data : Pointer(Void)?) : Gsk::RenderNode? #

Loads data previously created via Gsk::RenderNode#serialize.

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


def self.g_type : UInt64 #

Returns the type id (GType) registered in GLib type system.


Instance Method Detail

def bounds : Graphene::Rect #

Retrieves the boundaries of the @node.

The node will not draw outside of its boundaries.


def draw(cr : Cairo::Context) : 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 Gdk#Surface's rendering buffer.

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


def finalize #

Called by the garbage collector. Decreases the reference count of object. (i.e. its memory is freed).


def node_type : Gsk::RenderNodeType #

Returns the type of the @node.


def 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.


def to_unsafe : Pointer(Void) #

Returns a pointer to the C object.


def write_to_file(filename : String) : Bool #

This function is equivalent to calling Gsk::RenderNode#serialize followed by GLib#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.