A facility to replay a 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 renderReplaySetNodeFilter to filter each individual node and then run renderReplayFilterNode on the nodes you want to filter.

If you want to just walk the node tree and extract information without any modifications, you can also use renderNodeGetChildren.

Here is a little example application that redacts text in a node file:

#include <gtk/gtk.h>

static GskRenderNode *
redact_nodes (GskRenderReplay *replay,
              GskRenderNode   *node,
              gpointer         user_data)
{
  GskRenderNode *result;

  if (gsk_render_node_get_node_type (node) == GSK_TEXT_NODE)
    {
      graphene_rect_t bounds;
      const GdkRGBA *color;

      gsk_render_node_get_bounds (node, &bounds);
      color = gsk_text_node_get_color (node);

      result = gsk_color_node_new (color, &bounds);
    }
  else
    {
      result = gsk_render_replay_default (replay, node);
    }

  return result;
}

int
main (int argc, char *argv[])
{
  GFile *file;
  GBytes *bytes;
  GskRenderNode *result, *node;
  GskRenderReplay *replay;

  gtk_init ();

  if (argc != 3)
    {
      g_print ("usage: %s INFILE OUTFILE\n", argv[0]);
      return 0;
    }

  file = g_file_new_for_commandline_arg (argv[1]);
  bytes = g_file_load_bytes (file, NULL, NULL, NULL);
  g_object_unref (file);
  if (bytes == NULL)
    return 1;

  node = gsk_render_node_deserialize (bytes, NULL, NULL);
  g_bytes_unref (bytes);
  if (node == NULL)
    return 1;

  replay = gsk_render_replay_new ();
  gsk_render_replay_set_node_filter (replay, redact_nodes, NULL, NULL);
  result = gsk_render_replay_filter_node (replay, node);
  gsk_render_replay_free (replay);

  if (!gsk_render_node_write_to_file (result, argv[2], NULL))
    return 1;

  gsk_render_node_unref (result);
  gsk_render_node_unref (node);

  return 0;
}

Since: 4.22

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