[metacity] theme: redo meta_theme_load function

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 305b0461bc27216b854f54e38e95c56d214db012
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Jan 30 11:57:19 2016 +0200

    theme: redo meta_theme_load function

 src/ui/theme-parser.c |   97 +++++++++++++++++++++++++++++++++++++------------
 src/ui/theme-viewer.c |   19 +++++++---
 src/ui/theme.c        |   11 +++---
 src/ui/theme.h        |    5 ++-
 4 files changed, 96 insertions(+), 36 deletions(-)
---
diff --git a/src/ui/theme-parser.c b/src/ui/theme-parser.c
index 0a8a94f..a16159d 100644
--- a/src/ui/theme-parser.c
+++ b/src/ui/theme-parser.c
@@ -214,9 +214,6 @@ parse_info_free (ParseInfo *info)
   g_slist_free (info->states);
   g_slist_free (info->required_versions);
 
-  if (info->theme)
-    meta_theme_free (info->theme);
-
   if (info->layout)
     meta_frame_layout_unref (info->layout);
 
@@ -3465,7 +3462,6 @@ start_element_handler (GMarkupParseContext *context,
     case STATE_START:
       if (strcmp (element_name, "metacity_theme") == 0)
         {
-          info->theme = meta_theme_new (META_THEME_TYPE_METACITY);
           info->theme->name = g_strdup (info->theme_name);
           info->theme->filename = g_strdup (info->theme_file);
           info->theme->dirname = g_strdup (info->theme_dir);
@@ -3708,11 +3704,7 @@ end_element_handler (GMarkupParseContext *context,
       g_assert (info->theme);
 
       if (!meta_theme_validate (info->theme, error))
-        {
-          add_context_to_error (error, context);
-          meta_theme_free (info->theme);
-          info->theme = NULL;
-        }
+        add_context_to_error (error, context);
 
       pop_state (info);
       g_assert (peek_state (info) == STATE_START);
@@ -4124,8 +4116,62 @@ theme_error_is_fatal (GError *error)
            error->code == META_THEME_ERROR_TOO_OLD));
 }
 
-static MetaTheme *
-load_theme (const char *theme_dir,
+static void
+clear_theme (MetaTheme *theme)
+{
+  gint i;
+
+  g_free (theme->name);
+  theme->name = NULL;
+
+  g_free (theme->dirname);
+  theme->dirname = NULL;
+
+  g_free (theme->filename);
+  theme->filename = NULL;
+
+  g_free (theme->readable_name);
+  theme->readable_name = NULL;
+
+  g_free (theme->date);
+  theme->date = NULL;
+
+  g_free (theme->description);
+  theme->description = NULL;
+
+  g_free (theme->author);
+  theme->author = NULL;
+
+  g_free (theme->copyright);
+  theme->copyright = NULL;
+
+  if (theme->titlebar_font)
+    {
+      pango_font_description_free (theme->titlebar_font);
+      theme->titlebar_font = NULL;
+    }
+
+  g_hash_table_remove_all (theme->images_by_filename);
+  g_hash_table_remove_all (theme->layouts_by_name);
+  g_hash_table_remove_all (theme->styles_by_name);
+  g_hash_table_remove_all (theme->style_sets_by_name);
+
+  for (i = 0; i < META_FRAME_TYPE_LAST; i++)
+    {
+      if (theme->style_sets_by_type[i] == NULL)
+        continue;
+
+      meta_frame_style_set_unref (theme->style_sets_by_type[i]);
+      theme->style_sets_by_type[i] = NULL;
+    }
+
+  g_clear_object (&theme->impl);
+  theme->impl = g_object_new (META_TYPE_THEME_METACITY, NULL);
+}
+
+static gboolean
+load_theme (MetaTheme  *theme,
+            const char *theme_dir,
             const char *theme_name,
             guint       major_version,
             GError    **error)
@@ -4136,14 +4182,16 @@ load_theme (const char *theme_dir,
   gsize length;
   char *theme_filename;
   char *theme_file;
-  MetaTheme *retval;
+  gboolean retval;
 
-  g_return_val_if_fail (error && *error == NULL, NULL);
+  g_return_val_if_fail (error && *error == NULL, FALSE);
 
   text = NULL;
-  retval = NULL;
+  retval = FALSE;
   context = NULL;
 
+  clear_theme (theme);
+
   theme_filename = g_strdup_printf (METACITY_THEME_FILENAME_FORMAT, major_version);
   theme_file = g_build_filename (theme_dir, theme_filename, NULL);
 
@@ -4154,6 +4202,7 @@ load_theme (const char *theme_dir,
 
   parse_info_init (&info);
 
+  info.theme = theme;
   info.theme_name = theme_name;
   info.theme_file = theme_file;
   info.theme_dir = theme_dir;
@@ -4168,8 +4217,7 @@ load_theme (const char *theme_dir,
   if (!g_markup_parse_context_end_parse (context, error))
     goto out;
 
-  retval = info.theme;
-  info.theme = NULL;
+  retval = TRUE;
 
  out:
   if (*error && !theme_error_is_fatal (*error))
@@ -4201,18 +4249,19 @@ keep_trying (GError **error)
   return FALSE;
 }
 
-MetaTheme*
-meta_theme_load (const char  *theme_name,
-                 GError     **err)
+gboolean
+meta_theme_load (MetaTheme    *theme,
+                 const gchar  *theme_name,
+                 GError      **err)
 {
   GError *error = NULL;
   char *theme_dir;
-  MetaTheme *retval;
+  gboolean retval;
   const gchar* const* xdg_data_dirs;
   int major_version;
   int i;
 
-  retval = NULL;
+  retval = FALSE;
 
   /* We try all supported major versions from current to oldest */
   for (major_version = THEME_MAJOR_VERSION; (major_version > 0); major_version--)
@@ -4226,7 +4275,7 @@ meta_theme_load (const char  *theme_name,
                                     THEME_SUBDIR,
                                     NULL);
 
-      retval = load_theme (theme_dir, theme_name, major_version, &error);
+      retval = load_theme (theme, theme_dir, theme_name, major_version, &error);
       g_free (theme_dir);
       if (!keep_trying (&error))
         goto out;
@@ -4241,7 +4290,7 @@ meta_theme_load (const char  *theme_name,
                                         THEME_SUBDIR,
                                         NULL);
 
-          retval = load_theme (theme_dir, theme_name, major_version, &error);
+          retval = load_theme (theme, theme_dir, theme_name, major_version, &error);
           g_free (theme_dir);
           if (!keep_trying (&error))
             goto out;
@@ -4253,7 +4302,7 @@ meta_theme_load (const char  *theme_name,
                                     theme_name,
                                     THEME_SUBDIR,
                                     NULL);
-      retval = load_theme (theme_dir, theme_name, major_version, &error);
+      retval = load_theme (theme, theme_dir, theme_name, major_version, &error);
       g_free (theme_dir);
       if (!keep_trying (&error))
         goto out;
diff --git a/src/ui/theme-viewer.c b/src/ui/theme-viewer.c
index 723121c..0716be5 100644
--- a/src/ui/theme-viewer.c
+++ b/src/ui/theme-viewer.c
@@ -842,6 +842,7 @@ benchmark_summary (void)
 int
 main (int argc, char **argv)
 {
+  gboolean loaded;
   GtkWidget *window;
   GtkWidget *collection;
   MetaStyleInfo *style_info;
@@ -864,23 +865,31 @@ main (int argc, char **argv)
     }
 
   start = clock ();
+  global_theme = meta_theme_new (META_THEME_TYPE_METACITY);
+
   err = NULL;
+  loaded = FALSE;
+
   if (argc == 1)
-    global_theme = meta_theme_load ("Atlanta", &err);
+    loaded = meta_theme_load (global_theme, "Atlanta", &err);
   else if (argc == 2)
-    global_theme = meta_theme_load (argv[1], &err);
+    loaded = meta_theme_load (global_theme, argv[1], &err);
   else
     {
       g_printerr (_("Usage: metacity-theme-viewer [THEMENAME]\n"));
+
+      meta_theme_free (global_theme);
       exit (1);
     }
+
   end = clock ();
 
-  if (global_theme == NULL)
+  if (loaded == FALSE)
     {
-      g_printerr (_("Error loading theme: %s\n"),
-                  err->message);
+      g_printerr (_("Error loading theme: %s\n"), err->message);
       g_error_free (err);
+
+      meta_theme_free (global_theme);
       exit (1);
     }
 
diff --git a/src/ui/theme.c b/src/ui/theme.c
index 6fac26a..f2ab4b4 100644
--- a/src/ui/theme.c
+++ b/src/ui/theme.c
@@ -2211,14 +2211,15 @@ theme_set_current_metacity (const gchar                *name,
       g_strcmp0 (name, meta_current_theme->name) == 0)
     return;
 
-  err = NULL;
-  new_theme = meta_theme_load (name, &err);
+  new_theme = meta_theme_new (META_THEME_TYPE_METACITY);
 
-  if (new_theme == NULL)
+  err = NULL;
+  if (!meta_theme_load (new_theme, name, &err))
     {
-      meta_warning (_("Failed to load theme \"%s\": %s\n"),
-                    name, err->message);
+      g_warning (_("Failed to load theme '%s': %s"), name, err->message);
       g_error_free (err);
+
+      meta_theme_free (new_theme);
     }
   else
     {
diff --git a/src/ui/theme.h b/src/ui/theme.h
index 7fb8e54..2587c9f 100644
--- a/src/ui/theme.h
+++ b/src/ui/theme.h
@@ -148,8 +148,9 @@ void       meta_theme_set_current (const char                 *name,
 MetaTheme* meta_theme_new      (MetaThemeType type);
 void       meta_theme_free     (MetaTheme *theme);
 
-MetaTheme* meta_theme_load (const char *theme_name,
-                            GError    **err);
+gboolean   meta_theme_load (MetaTheme    *theme,
+                            const gchar  *theme_name,
+                            GError      **err);
 
 void meta_theme_set_composited (MetaTheme  *theme,
                                 gboolean    composited);