[gtk+/parser: 48/74] cssprovider: Keep track of passed in error differently

[Benjamin Otte <otte src gnome org>]

commit 8bf98c5151b3efa7f519e20e0167c520b50f3529
Author: Benjamin Otte <otte redhat com>
Date:   Mon Apr 11 02:32:26 2011 +0200

    cssprovider: Keep track of passed in error differently
    
    Instead of having an error member in the CSS provider's private struct,
    connect a signal handler when an error is passed in. This has two
    advantages:
    1) It makes the code clearer as we don't have to keep track of an error
       member anywhere.
    2) It causes a non-emission of the g_warning() when an error was passed
       in, because it only triggers when no signal handlers are connected.
       So we get identical behavior to GTK 3.0 where warnings where only
       emitted when no error was passed in.

 gtk/gtkcssprovider.c |   56 ++++++++++++++++++++++++++++++++-----------------
 1 files changed, 36 insertions(+), 20 deletions(-)
---
diff --git a/gtk/gtkcssprovider.c b/gtk/gtkcssprovider.c
index 2f04855..8f40c21 100644
--- a/gtk/gtkcssprovider.c
+++ b/gtk/gtkcssprovider.c
@@ -800,9 +800,6 @@ struct _GtkCssProviderPrivate
   GHashTable *symbolic_colors;
 
   GPtrArray *selectors_info;
-
-  /* Current parser state */
-  GError *error;
 };
 
 enum ParserScope {
@@ -869,14 +866,6 @@ gtk_css_provider_parsing_error (GtkCssProvider  *provider,
                                 guint            position,
                                 const GError *   error)
 {
-  GtkCssProviderPrivate *priv = provider->priv;
-
-  if (!priv->error)
-    {
-      priv->error = g_error_copy (error);
-      g_prefix_error (&priv->error, "%s:%u:%u: ", path ? path : "<unknown>", line, position);
-    }
-
   /* Only emit a warning when we have no error handlers. This is our
    * default handlers. And in this case erroneous CSS files are a bug
    * and should be fixed.
@@ -1774,10 +1763,6 @@ css_provider_reset_parser (GtkCssProvider *css_provider)
   priv = css_provider->priv;
 
   gtk_css_scanner_reset (priv->scanner);
-
-  if (priv->error)
-    g_error_free (priv->error);
-  priv->error = NULL;
 }
 
 static void
@@ -2599,18 +2584,37 @@ gtk_css_provider_reset (GtkCssProvider *css_provider)
     g_ptr_array_remove_range (priv->selectors_info, 0, priv->selectors_info->len);
 }
 
+static void
+gtk_css_provider_propagate_error (GtkCssProvider  *provider,
+                                  const gchar     *path,
+                                  guint            line,
+                                  guint            position,
+                                  const GError    *error,
+                                  GError         **propagate_to)
+{
+  /* we already set an error. And we'd like to keep the first one */
+  if (*propagate_to)
+    return;
+
+  *propagate_to = g_error_copy (error);
+  g_prefix_error (propagate_to, "%s:%u:%u: ", path ? path : "<unknown>", line, position);
+}
 
 static gboolean
 parse_stylesheet (GtkCssProvider  *css_provider,
                   GScanner        *scanner,
                   GError         **error)
 {
-  GtkCssProviderPrivate *priv;
-  gboolean result;
+  gulong error_handler;
 
-  result = TRUE;
+  if (error)
+    error_handler = g_signal_connect (css_provider,
+                                      "parsing-error",
+                                      G_CALLBACK (gtk_css_provider_propagate_error),
+                                      error);
+  else
+    error_handler = 0; /* silence gcc */
 
-  priv = css_provider->priv;
   g_scanner_get_next_token (scanner);
 
   while (!g_scanner_eof (scanner))
@@ -2634,7 +2638,19 @@ parse_stylesheet (GtkCssProvider  *css_provider,
       g_scanner_get_next_token (scanner);
     }
 
-  return result;
+  if (error)
+    {
+      g_signal_handler_disconnect (css_provider, error_handler);
+      
+      if (*error)
+        {
+          /* We clear all contents from the provider for backwards compat reasons */
+          gtk_css_provider_reset (css_provider);
+          return FALSE;
+        }
+    }
+
+  return TRUE;
 }
 
 /**