Remove 'Enable tap-to-click' checkbox for non-touchpad devices.

chrome/browser/ui/webui/options/chromeos/system_options_handler.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/webui/options/chromeos/system_options_handler.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/json/json_value_serializer.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/accessibility_util.h"
 #include "chrome/browser/chromeos/dbus/dbus_thread_manager.h"
 #include "chrome/browser/chromeos/dbus/power_manager_client.h"
 #include "chrome/browser/chromeos/language_preferences.h"
+#include "chrome/browser/chromeos/system/touchpad_settings.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/options/chromeos/system_settings_provider.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/extensions/extension.h"
 #include "grit/browser_resources.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/locale_settings.h"
 #include "grit/theme_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
+namespace {
+
+void TouchpadExistsFileThread(bool* exists) {
+  *exists = chromeos::system::touchpad_settings::TouchpadExists();
+}
+
+}
+
 SystemOptionsHandler::SystemOptionsHandler()
     : chromeos::CrosOptionsPageUIHandler(
         new chromeos::SystemSettingsProvider()) {
 }
 
 SystemOptionsHandler::~SystemOptionsHandler() {
 }
 
 void SystemOptionsHandler::GetLocalizedValues(
     DictionaryValue* localized_strings) {
@@ skipping 51 matching lines @@
           settings_provider_.get())->GetTimezoneList());
 }
 
 void SystemOptionsHandler::Initialize() {
   DCHECK(web_ui_);
   PrefService* pref_service = g_browser_process->local_state();
   bool acc_enabled = pref_service->GetBoolean(prefs::kAccessibilityEnabled);
   base::FundamentalValue checked(acc_enabled);
   web_ui_->CallJavascriptFunction(
       "options.SystemOptions.SetAccessibilityCheckboxState", checked);
+
+  bool* exists = new bool;
+  BrowserThread::PostTaskAndReply(BrowserThread::FILE, FROM_HERE,
+      base::Bind(&TouchpadExistsFileThread, exists),
+      base::Bind(&SystemOptionsHandler::TouchpadExists, AsWeakPtr(), exists));
+}
+
+void SystemOptionsHandler::TouchpadExists(bool* exists) {
+  if (*exists)
+    web_ui_->CallJavascriptFunction("options.SystemOptions.showTapToClick");
+  delete exists;
 }
 
 void SystemOptionsHandler::RegisterMessages() {
   DCHECK(web_ui_);
   web_ui_->RegisterMessageCallback("accessibilityChange",
       base::Bind(&SystemOptionsHandler::AccessibilityChangeCallback,
                  base::Unretained(this)));
 
   web_ui_->RegisterMessageCallback("decreaseScreenBrightness",
       base::Bind(&SystemOptionsHandler::DecreaseScreenBrightnessCallback,
@@ skipping 17 matching lines @@
   // can make it very difficult to see the increase brightness button.
   chromeos::DBusThreadManager::Get()->power_manager_client()->
       DecreaseScreenBrightness(false);
 }
 
 void SystemOptionsHandler::IncreaseScreenBrightnessCallback(
     const ListValue* args) {
   chromeos::DBusThreadManager::Get()->power_manager_client()->
       IncreaseScreenBrightness();
 }