GTK: Support Ambiance/Radiance and Dust button ordering.

chrome/browser/gtk/gconf_titlebar_listener.cc

Index: chrome/browser/gtk/gconf_titlebar_listener.cc
diff --git a/chrome/browser/gtk/gconf_titlebar_listener.cc b/chrome/browser/gtk/gconf_titlebar_listener.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d1ba5cd2c67815bad6674d4ab6a73b5142d8d36e
--- /dev/null
+++ b/chrome/browser/gtk/gconf_titlebar_listener.cc
@@ -0,0 +1,117 @@
+// Copyright (c) 2009 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/gtk/gconf_titlebar_listener.h"
+
+#include <gtk/gtk.h>
+
+#include "base/scoped_ptr.h"
+#include "base/env_var.h"
+#include "base/xdg_util.h"
+#include "chrome/browser/gtk/browser_titlebar.h"
+
+namespace {
+
+// A default button order string for when we aren't asking gconf for the
+// metacity configuration.
+const char* kDefaultButtonPlacement = ":minimize,maximize,close";
+
+// The GConf key we read for the button placement string. Even through the key
+// has "metacity" in it, it's shared between metacity and compiz.
+const char* kButtonLayoutKey = "/apps/metacity/general/button_layout";
+
+// GConf requires us to subscribe to a parent directory before we can subscribe
+// to changes in an individual key in that directory.
+const char* kMetacityGeneral = "/apps/metacity/general";
+
+}  // namespace
+
+// Public interface:
+
+void GConfTitlebarListener::SetTitlebarButtons(BrowserTitlebar* titlebar) {
+  if (client_) {
+    titlebar->BuildButtons(current_value_);
+    titlebars_.insert(titlebar);
+  } else {
+    titlebar->BuildButtons(kDefaultButtonPlacement);
+  }
+}
+
+void GConfTitlebarListener::RemoveObserver(BrowserTitlebar* titlebar) {
+  titlebars_.erase(titlebar);
+}
+
+// Private:
+
+GConfTitlebarListener::GConfTitlebarListener() : client_(NULL) {
+  scoped_ptr<base::EnvVarGetter> env_getter(base::EnvVarGetter::Create());
+  if (base::GetDesktopEnvironment(env_getter.get()) ==
+      base::DESKTOP_ENVIRONMENT_GNOME) {
+    client_ = gconf_client_get_default();
+    // If we fail to get a context, that's OK, since we'll just fallback on
+    // not receiving gconf keys.
+    if (client_) {
+      // Get the initial value of the key.
+      GError* error = NULL;
+      GConfValue* gconf_value = gconf_client_get(client_, kButtonLayoutKey,
+                                                 &error);
+      if (HandleGError(error, kButtonLayoutKey))
+        return;
+      ParseAndStoreValue(gconf_value);
+
+      // Register that we're interested in the values of this directory.
+      gconf_client_add_dir(client_, kMetacityGeneral,
+                           GCONF_CLIENT_PRELOAD_ONELEVEL, &error);
+      if (HandleGError(error, kMetacityGeneral))
+        return;
+
+      // Register to get notifies about changes to this key.
+      gconf_client_notify_add(
+          client_, kButtonLayoutKey,
+          reinterpret_cast<void (*)(GConfClient*, guint, GConfEntry*, void*)>(
+              OnChangeNotificationThunk),
+          this, NULL, &error);
+      if (HandleGError(error, kButtonLayoutKey))
+        return;

[tony, 2010/05/14 01:02:56]

Nit: This early return seems pointless.

+    }
+  }
+}
+
+void GConfTitlebarListener::OnChangeNotification(GConfClient* client,
+                                                 guint cnxn_id,
+                                                 GConfEntry* entry) {
+  if (strcmp(gconf_entry_get_key(entry), kButtonLayoutKey) == 0) {
+    GConfValue* gconf_value = gconf_entry_get_value(entry);
+    ParseAndStoreValue(gconf_value);
+
+    // Broadcast the new configuration to all windows:
+    for (std::set<BrowserTitlebar*>::const_iterator it = titlebars_.begin();
+         it != titlebars_.end(); ++it) {
+      (*it)->BuildButtons(current_value_);
+    }
+  }
+}
+
+bool GConfTitlebarListener::HandleGError(GError* error, const char* key) {
+  if (error != NULL) {
+    LOG(ERROR) << "Error with gconf key '" << key << "': " << error->message;
+    g_error_free(error);
+    g_object_unref(client_);
+    client_ = NULL;
+    return true;
+  }
+  return false;
+}
+
+void GConfTitlebarListener::ParseAndStoreValue(GConfValue* gconf_value) {
+  if (gconf_value) {
+    const char* value = gconf_value_get_string(gconf_value);
+    if (value)

[Evan Stade, 2010/05/13 20:30:16]

nit: consider

current_value_ = value ? value : kDefaultButtonPlacement;

+      current_value_ = value;
+    else
+      current_value_ = kDefaultButtonPlacement;
+  } else {
+    current_value_ = kDefaultButtonPlacement;
+  }
+}