GTK: Look up newer menu symbols with older GTK+ versions.

chrome/browser/ui/gtk/global_bookmark_menu.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/gtk/global_bookmark_menu.h"
 
+#include <dlfcn.h>
 #include <gtk/gtk.h>
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/gtk/global_bookmark_menu.h"
 #include "chrome/browser/ui/gtk/global_menu_bar.h"
 #include "chrome/browser/ui/gtk/gtk_theme_service.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
 #include "content/common/notification_service.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/gtk_util.h"
 
 namespace {
 
 const int kMaxChars = 50;
 
+// We need to know whether we're using a newer GTK at run time because we need
+// to prevent
+typedef void (*gtk_menu_item_set_label_func)(GtkMenuItem*, const gchar*);
+gtk_menu_item_set_label_func gtk_menu_item_set_label_sym =
+#if GTK_CHECK_VERSION(2, 16, 1)
+    gtk_menu_item_set_label;
+#else
+    NULL;
+#endif
+
+void EnsureMenuItemFunctions() {
+#if !GTK_CHECK_VERSION(2, 16, 1)
+  static bool methods_looked_up = false;
+  if (!methods_looked_up) {
+    methods_looked_up = true;
+    gtk_menu_item_set_label_sym =
+        reinterpret_cast<gtk_menu_item_set_label_func>(
+            dlsym(NULL, "gtk_menu_item_set_label"));
+  }
+#endif
+}
+
 }  // namespace
 
 GlobalBookmarkMenu::GlobalBookmarkMenu(Browser* browser)
     : browser_(browser),
       profile_(browser->profile()),
       default_favicon_(NULL),
       ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)) {
   DCHECK(profile_);
 
   default_favicon_ = GtkThemeService::GetDefaultFavicon(true);
   default_folder_ = GtkThemeService::GetFolderIcon(true);
   registrar_.Add(this, NotificationType::BROWSER_THEME_CHANGED,
                  Source<Profile>(profile_));
 }
 
 GlobalBookmarkMenu::~GlobalBookmarkMenu() {
   profile_->GetBookmarkModel()->RemoveObserver(this);
 }
 
 void GlobalBookmarkMenu::Init(GtkWidget* bookmark_menu) {
   bookmark_menu_ = bookmark_menu;
 
-  BookmarkModel* model = profile_->GetBookmarkModel();
-  model->AddObserver(this);
-  if (model->IsLoaded())
-    Loaded(model);
+  EnsureMenuItemFunctions();
+  if (gtk_menu_item_set_label_sym) {
+    BookmarkModel* model = profile_->GetBookmarkModel();
+    model->AddObserver(this);
+    if (model->IsLoaded())
+      Loaded(model);
+  }
 }
 
 void GlobalBookmarkMenu::RebuildMenuInFuture() {
   method_factory_.RevokeAll();
   MessageLoop::current()->PostTask(
       FROM_HERE,
       method_factory_.NewRunnableMethod(&GlobalBookmarkMenu::RebuildMenu));
 }
 
 void GlobalBookmarkMenu::RebuildMenu() {
-#if !GTK_CHECK_VERSION(2, 16, 1)
-  // We can't deal with this case; we need to use dynamic APIs. Thankfully,
-  // this will never visibly do anything on earlier versions of GTK+.
-  return;
-#endif
+
+
   BookmarkModel* model = profile_->GetBookmarkModel();
   DCHECK(model);
   DCHECK(model->IsLoaded());
 
   ClearBookmarkMenu();
 
   const BookmarkNode* bar_node = model->GetBookmarkBarNode();
   if (bar_node->child_count()) {
     AddBookmarkMenuItem(bookmark_menu_, gtk_separator_menu_item_new());
     AddNodeToMenu(bar_node, bookmark_menu_);
@@ skipping 55 matching lines @@
       AddBookmarkMenuItem(menu, item);
     }
   }
 }
 
 void GlobalBookmarkMenu::ConfigureMenuItem(const BookmarkNode* node,
                                            GtkWidget* menu_item) {
   // This check is only to make things compile on Hardy; this code won't
   // display any visible widgets in older systems that don't have a global menu
   // bar.
-#if GTK_CHECK_VERSION(2, 16, 1)
-  string16 elided_name = l10n_util::TruncateString(node->GetTitle(), kMaxChars);
-  gtk_menu_item_set_label(GTK_MENU_ITEM(menu_item),
-                          UTF16ToUTF8(elided_name).c_str());
-#endif
+  if (gtk_menu_item_set_label_sym) {
+    string16 elided_name =
+        l10n_util::TruncateString(node->GetTitle(), kMaxChars);
+    gtk_menu_item_set_label_sym(GTK_MENU_ITEM(menu_item),
+                                UTF16ToUTF8(elided_name).c_str());
+  }
 
   if (node->is_url()) {
     std::string tooltip = gtk_util::BuildTooltipTitleFor(node->GetTitle(),
                                                          node->GetURL());
     gtk_widget_set_tooltip_markup(menu_item, tooltip.c_str());
   }
 
   const SkBitmap& bitmap = profile_->GetBookmarkModel()->GetFavicon(node);
   if (!bitmap.isNull()) {
     GdkPixbuf* pixbuf = gfx::GdkPixbufFromSkBitmap(&bitmap);
@@ skipping 103 matching lines @@
 void GlobalBookmarkMenu::OnBookmarkItemActivated(GtkWidget* menu_item) {
   // The actual mouse event that generated this activated event was in a
   // different process. Go with something default.
   const BookmarkNode* node = static_cast<const BookmarkNode*>(
       g_object_get_data(G_OBJECT(menu_item), "bookmark-node"));
 
   browser_->OpenURL(node->GetURL(), GURL(), NEW_FOREGROUND_TAB,
                     PageTransition::AUTO_BOOKMARK);
 }