css: Add gtk_css_change_to_string()

Nobody is able to look up those hex values.

gtk/gtkcssprovider.c

@@ -1654,11 +1654,20 @@ verify_tree_get_change_results (GtkCssProvider *provider,
 	GString *s;
 
 	s = g_string_new ("");
-	g_string_append_printf (s, "expected change 0x%x, but it was 0x%x", verify_change, change);
+	g_string_append (s, "expected change ");
+        gtk_css_change_print (verify_change, s);
+        g_string_append (s, ", but it was ");
+        gtk_css_change_print (change, s);
 	if ((change & ~verify_change) != 0)
-	  g_string_append_printf (s, ", unexpectedly set: 0x%x", change & ~verify_change);
+          {
+	    g_string_append (s, ", unexpectedly set: ");
+            gtk_css_change_print (change & ~verify_change, s);
+          }
 	if ((~change & verify_change) != 0)
-	  g_string_append_printf (s, ", unexpectedly no set: 0x%x",  ~change & verify_change);
+          {
+	    g_string_append_printf (s, ", unexpectedly not set: ");
+            gtk_css_change_print (~change & verify_change, s);
+          }
 	g_warning (s->str);
 	g_string_free (s, TRUE);
       }

gtk/gtkcsstypes.c

@@ -94,3 +94,76 @@ _gtk_css_change_for_child (GtkCssChange match)
   return gtk_css_change_translate (match, table, G_N_ELEMENTS (table)); 
 }
 
+void
+gtk_css_change_print (GtkCssChange  change,
+                      GString      *string)
+{
+  const struct {
+    GtkCssChange flags;
+    const char *name;
+  } names[] = {
+    { GTK_CSS_CHANGE_CLASS, "class" },
+    { GTK_CSS_CHANGE_NAME, "name" },
+    { GTK_CSS_CHANGE_ID, "id" },
+    { GTK_CSS_CHANGE_FIRST_CHILD, "first-child" },
+    { GTK_CSS_CHANGE_LAST_CHILD, "last-child" },
+    { GTK_CSS_CHANGE_NTH_CHILD, "nth-child" },
+    { GTK_CSS_CHANGE_NTH_LAST_CHILD, "nth-last-child" },
+    { GTK_CSS_CHANGE_STATE, "state" },
+    { GTK_CSS_CHANGE_SIBLING_CLASS, "sibling-class" },
+    { GTK_CSS_CHANGE_SIBLING_NAME, "sibling-name" },
+    { GTK_CSS_CHANGE_SIBLING_ID, "sibling-id" },
+    { GTK_CSS_CHANGE_SIBLING_FIRST_CHILD, "sibling-first-child" },
+    { GTK_CSS_CHANGE_SIBLING_LAST_CHILD, "sibling-last-child" },
+    { GTK_CSS_CHANGE_SIBLING_NTH_CHILD, "sibling-nth-child" },
+    { GTK_CSS_CHANGE_SIBLING_NTH_LAST_CHILD, "sibling-nth-last-child" },
+    { GTK_CSS_CHANGE_SIBLING_STATE, "sibling-state" },
+    { GTK_CSS_CHANGE_PARENT_CLASS, "parent-class" },
+    { GTK_CSS_CHANGE_PARENT_NAME, "parent-name" },
+    { GTK_CSS_CHANGE_PARENT_ID, "parent-id" },
+    { GTK_CSS_CHANGE_PARENT_FIRST_CHILD, "parent-first-child" },
+    { GTK_CSS_CHANGE_PARENT_LAST_CHILD, "parent-last-child" },
+    { GTK_CSS_CHANGE_PARENT_NTH_CHILD, "parent-nth-child" },
+    { GTK_CSS_CHANGE_PARENT_NTH_LAST_CHILD, "parent-nth-last-child" },
+    { GTK_CSS_CHANGE_PARENT_STATE, "parent-state" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_CLASS, "parent-sibling-" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_NAME, "parent-sibling-name" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_ID, "parent-sibling-id" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_FIRST_CHILD, "parent-sibling-first-child" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_LAST_CHILD, "parent-sibling-last-child" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_NTH_CHILD, "parent-sibling-nth-child" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_NTH_LAST_CHILD, "parent-sibling-nth-last-child" },
+    { GTK_CSS_CHANGE_PARENT_SIBLING_STATE, "parent-sibling-state" },
+    { GTK_CSS_CHANGE_SOURCE, "source" },
+    { GTK_CSS_CHANGE_PARENT_STYLE, "parent-style" },
+    { GTK_CSS_CHANGE_TIMESTAMP, "timestamp" },
+    { GTK_CSS_CHANGE_ANIMATIONS, "animations" },
+  };
+  guint i;
+  gboolean first;
+
+  first = TRUE;
+
+  for (i = 0; i < G_N_ELEMENTS (names); i++)
+    {
+      if (change & names[i].flags)
+        {
+          if (first)
+            first = FALSE;
+          else
+            g_string_append (string, "|");
+          g_string_append (string, names[i].name);
+        }
+    }
+}
+
+char *
+gtk_css_change_to_string (GtkCssChange change)
+{
+  GString *string = g_string_new (NULL);
+
+  gtk_css_change_print (change, string);
+
+  return g_string_free (string, FALSE);
+}
+

gtk/gtkcsstypesprivate.h

@@ -330,6 +330,10 @@ typedef enum /*< skip >*/ {
 GtkCssChange            _gtk_css_change_for_sibling              (GtkCssChange       match);
 GtkCssChange            _gtk_css_change_for_child                (GtkCssChange       match);
 
+char *                  gtk_css_change_to_string                 (GtkCssChange       change);
+void                    gtk_css_change_print                     (GtkCssChange       change,
+                                                                  GString           *string);
+
 /* for lack of better place to put it */
 /* mirror what cairo does */
 #define gtk_rgba_is_clear(rgba) ((rgba)->alpha < ((double)0x00ff / (double)0xffff))