Gsk.RenderReplay

Fields

None

Methods

class

new ()

default (node)

filter_font (font)

filter_node (node)

filter_texture (texture)

foreach_node (node)

free ()

set_font_filter (filter, *user_data)

set_node_filter (filter, *user_data)

set_node_foreach (foreach, *user_data)

set_texture_filter (filter, *user_data)

Details

class Gsk.RenderReplay

A facility to replay a [class`Gsk`.RenderNode] and its children, potentially modifying them.

This is a utility tool to walk a rendernode tree. The most powerful way is to provide a function via [method`Gsk`.RenderReplay.set_node_filter] to filter each individual node and then run [method`Gsk`.RenderReplay.filter_node] on the nodes you want to filter.

An easier method exists to just walk the node tree and extract information without any modifications. If you want to do that, the functions [method`Gsk`.RenderReplay.set_node_foreach] exists. You can also call [method`Gsk`.RenderReplay.foreach_node] to run that function. Note that the previously mentioned complex functionality will still be invoked if you have set up a function for it, but its result will not be returned.

Here is an example that combines both approaches to print the whole tree:

```c #include <gtk/gtk.h>

static Gsk.RenderNode * print_nodes (Gsk.RenderReplay *replay, Gsk.RenderNode *node, object user_data) { int *depth = user_data; Gsk.RenderNode *result;

g_print (“%*s%s\n”, 2 * *depth, “”, GObject.type_name_from_instance ((GObject.TypeInstance *) node));

*depth += 1; result = Gsk.RenderReplay.default (replay, node); *depth -= 1;

return result; }

int main (int argc, str *argv[]) { Gio.File *file; GLib.Bytes *bytes; Gsk.RenderNode *node; Gsk.RenderReplay *replay; int depth = 0;

gtk_init ();

if (argc < 2) { g_print (“usage: %s NODEFILE\n”, argv[0]); return 0; }

file = Gio.File.new_for_commandline_arg (argv[1]); bytes = Gio.File.load_bytes (file, None, None, None); GObject.Object.unref (file); if (bytes == None) return 1;

node = Gsk.RenderNode.deserialize (bytes, None, None); GLib.Bytes.unref (bytes); if (node == None) return 1;

replay = Gsk.RenderReplay.new (); Gsk.RenderReplay.set_node_filter (replay, print_nodes, &depth, None); gsk_render_node_foreach_node (replay, node); Gsk.RenderNode.unref (node);

return 0; } ```

New in version 4.22.

classmethod new()
Returns:

A new replay object to replay nodes

Return type:

Gsk.RenderReplay

Creates a new replay object to replay nodes.

New in version 4.22.

default(node)
Parameters:

node (Gsk.RenderNode) – the node to replay

Returns:

The replayed node

Return type:

Gsk.RenderNode or None

Replays the node using the default method.

The default method calls [method`Gsk`.RenderReplay.filter_node] on all its child nodes and the filter functions for all its properties. If none of them are changed, it returns the passed in node. Otherwise it constructs a new node with the changed children and properties.

It may not be possible to construct a new node when any of the callbacks return None. In that case, this function will return None, too.

New in version 4.22.

filter_font(font)
Parameters:

font (Pango.Font) – The font to filter

Returns:

the filtered font

Return type:

Pango.Font

Filters a font using the current filter function.

New in version 4.22.

filter_node(node)
Parameters:

node (Gsk.RenderNode) – the node to replay

Returns:

The replayed node

Return type:

Gsk.RenderNode or None

Replays a node using the replay’s filter function.

After the replay the node may be unchanged, or it may be removed, which will result in None being returned.

This function calls the registered callback in the following order:

If a foreach function is set, it is called first. If it returns false, this function immediately exits and returns the passed in node.

If a node filter is set, it is called and its result is returned.

[method`Gsk`.RenderReplay.default] is called and its result is returned.

New in version 4.22.

filter_texture(texture)
Parameters:

texture (Gdk.Texture) – The texture to filter

Returns:

the filtered texture

Return type:

Gdk.Texture

Filters a texture using the current filter function.

New in version 4.22.

foreach_node(node)
Parameters:

node (Gsk.RenderNode) – the node to replay

Calls the filter and foreach functions for each node.

This function calls [method`Gsk`.RenderReplay.filter_node] internally, but discards the result assuming no changes were made.

New in version 4.22.

free()

Frees a GskRenderReplay.

New in version 4.22.

set_font_filter(filter, *user_data)
Parameters:

Sets a filter function to be called by [method`Gsk`.RenderReplay.default] for nodes that contain fonts.

You can call [method`GskRenderReplay`.filter_font] to filter a font yourself.

New in version 4.22.

set_node_filter(filter, *user_data)
Parameters:

Sets the function to use as a node filter.

This is the most complex function to use for replaying nodes. It can either:

  • keep the node and just return it unchanged

  • create a replacement node and return that

  • discard the node by returning NULL

  • call [method`Gsk`.RenderReplay.default] to have the default handler run for this node, which calls your function on its children

New in version 4.22.

set_node_foreach(foreach, *user_data)
Parameters:

Sets the function to call for every node.

This function is called before the node filter, so if it returns false, the node filter will never be called.

New in version 4.22.

set_texture_filter(filter, *user_data)
Parameters:

Sets a filter function to be called by [method`Gsk`.RenderReplay.default] for nodes that contain textures.

You can call [method`GskRenderReplay`.filter_texture] to filter a texture yourself.

New in version 4.22.