rendernodeparser: Add support for reusing textures

We extend the syntax for textures from just:
  <url>
to
  [<string>] <url>
  <string>
where the first defines a named texture while the second references a
texture.
Or to give an example:
  texture {
    bounds: 0 0 10 10;
    texture: "foo" url("foo.png");
  }
  texture {
    bounds: 20 0 10 10;
    texture: "foo";
  }
This will draw the texture "foo.png" twice, once at (0,0) and once at
(20,0).

The intended use for this is both shortening generated node files as
well as allowing to write tests that reuse textures, in particular when
mixing them in texture and texture-scale nodes.

1 files changed, 42 insertions, 1 deletions

diff --git a/gsk/gskrendernodeparser.c b/gsk/gskrendernodeparser.c
index c67ab81148..c74d16660a 100644
--- a/gsk/gskrendernodeparser.c
+++ b/gsk/gskrendernodeparser.c
@@ -115,8 +115,41 @@ parse_texture (GtkCssParser *parser,
 {
   GdkTexture *texture;
   GError *error = NULL;
+  const GtkCssToken *token;
   GtkCssLocation start_location;
-  char *url, *scheme;
+  char *url, *scheme, *texture_name;
+
+  token = gtk_css_parser_get_token (parser);
+  if (gtk_css_token_is (token, GTK_CSS_TOKEN_STRING))
+    {
+      texture_name = gtk_css_parser_consume_string (parser);
+
+      if (context->named_textures)
+        texture = g_hash_table_lookup (context->named_textures, texture_name);
+      else
+        texture = NULL;
+
+      if (texture)
+        {
+          *(GdkTexture **) out_data = g_object_ref (texture);
+          g_free (texture_name);
+          return TRUE;
+        }
+      else if (gtk_css_parser_has_token (parser, GTK_CSS_TOKEN_EOF))
+        {
+          gtk_css_parser_error_value (parser, "No texture named \"%s\"", texture_name);
+          g_free (texture_name);
+          return FALSE;
+        }
+
+      if (context->named_textures && g_hash_table_lookup (context->named_textures, texture_name))
+        {
+          gtk_css_parser_error_value (parser, "A texture named \"%s\" already exists.", texture_name);
+          g_clear_pointer (&texture_name, g_free);
+        }
+    }
+  else
+    texture_name = NULL;
 
   start_location = *gtk_css_parser_get_start_location (parser);
   url = gtk_css_parser_consume_url (parser);
@@ -176,6 +209,14 @@ parse_texture (GtkCssParser *parser,
       return FALSE;
     }
 
+  if (texture_name)
+    {
+      if (context->named_textures == NULL)
+        context->named_textures = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                                         g_free, g_object_unref);
+      g_hash_table_insert (context->named_textures, texture_name, g_object_ref (texture));
+    }
+
   *(GdkTexture **) out_data = texture;
   return TRUE;
 }