[NTP4] Make TilePage and CardSlider evented to simplify code and fix page switcher bug

chrome/browser/ui/webui/ntp/app_launcher_handler.cc

 // Copyright (c) 2012 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/ntp/app_launcher_handler.h"
 
 #include <string>
 #include <vector>
 
 #include "base/auto_reset.h"
@@ skipping 287 matching lines @@
           content::Details<UnloadedExtensionInfo>(details)->extension;
       if (!extension->is_app())
         return;
 
       scoped_ptr<DictionaryValue> app_info(GetAppInfo(extension));
       scoped_ptr<base::FundamentalValue> uninstall_value(
           Value::CreateBooleanValue(
               content::Details<UnloadedExtensionInfo>(details)->reason ==
               extension_misc::UNLOAD_REASON_UNINSTALL));
       if (app_info.get()) {
+        scoped_ptr<base::FundamentalValue> from_page(
+            Value::CreateBooleanValue(!extension_id_prompting_.empty()));
         web_ui()->CallJavascriptFunction(
-            "ntp4.appRemoved", *app_info, *uninstall_value);
+            "ntp4.appRemoved", *app_info, *uninstall_value, *from_page);
       }
       break;
     }
     case chrome::NOTIFICATION_EXTENSION_LAUNCHER_REORDERED:
     // The promo may not load until a couple seconds after the first NTP view,
     // so we listen for the load notification and notify the NTP when ready.
     case chrome::NOTIFICATION_WEB_STORE_PROMO_LOADED:
-      // TODO(estade): try to get rid of this inefficient operation.
+      // TODO(estade): Try to get rid of this inefficient operation.
       HandleGetApps(NULL);
       break;
     case chrome::NOTIFICATION_PREF_CHANGED: {
       DictionaryValue dictionary;
       FillAppDictionary(&dictionary);
       web_ui()->CallJavascriptFunction("appsPrefChangeCallback", dictionary);
       break;
     }
     case chrome::NOTIFICATION_EXTENSION_INSTALL_ERROR: {
       CrxInstaller* crx_installer = content::Source<CrxInstaller>(source).ptr();
       if (!Profile::FromWebUI(web_ui())->IsSameProfile(
               crx_installer->profile())) {
         return;
       }
-      // Fall Through.
+      // Fall through.
     }
     case chrome::NOTIFICATION_EXTENSION_LOAD_ERROR: {
       attempted_bookmark_app_install_ = false;
       break;
     }
     default:
       NOTREACHED();
   }
 }
 
@@ skipping 492 matching lines @@
   highlight_app_id_.clear();
 }
 
 // static
 void AppLauncherHandler::RegisterUserPrefs(PrefService* pref_service) {
   // TODO(csharp): We will want this to be a syncable preference instead.
   pref_service->RegisterListPref(prefs::kNTPAppPageNames,
                                  PrefService::UNSYNCABLE_PREF);
 }
 
+void AppLauncherHandler::CleanupAfterUninstall() {
+  extension_id_prompting_.clear();
+}
+
 // static
 void AppLauncherHandler::RecordWebStoreLaunch(bool promo_active) {
   UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppLaunchHistogram,
                             extension_misc::APP_LAUNCH_NTP_WEBSTORE,
                             extension_misc::APP_LAUNCH_BUCKET_BOUNDARY);
 
   if (!promo_active) return;
 
   UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppsPromoHistogram,
                             extension_misc::PROMO_LAUNCH_WEB_STORE,
@@ skipping 65 matching lines @@
 
   // The extension can be uninstalled in another window while the UI was
   // showing. Do nothing in that case.
   const Extension* extension =
       extension_service_->GetExtensionById(extension_id_prompting_, true);
   if (!extension)
     return;
 
   extension_service_->UninstallExtension(extension_id_prompting_,
                                          false /* external_uninstall */, NULL);
-
-  extension_id_prompting_ = "";
+  CleanupAfterUninstall();
 }
 
 void AppLauncherHandler::ExtensionUninstallCanceled() {
-  extension_id_prompting_ = "";
+  CleanupAfterUninstall();
 }
 
 void AppLauncherHandler::InstallUIProceed() {
   // Do the re-enable work here.
   DCHECK(!extension_id_prompting_.empty());
 
   // The extension can be uninstalled in another window while the UI was
   // showing. Do nothing in that case.
   const Extension* extension =
       extension_service_->GetExtensionById(extension_id_prompting_, true);
@@ skipping 16 matching lines @@
   // We record the histograms here because ExtensionUninstallCanceled is also
   // called when the extension uninstall dialog is canceled.
   const Extension* extension =
       extension_service_->GetExtensionById(extension_id_prompting_, true);
   std::string histogram_name = user_initiated ?
       "Extensions.Permissions_ReEnableCancel" :
       "Extensions.Permissions_ReEnableAbort";
   ExtensionService::RecordPermissionMessagesHistogram(
       extension, histogram_name.c_str());
 
-  ExtensionUninstallCanceled();
+  CleanupAfterUninstall();
 }
 
 ExtensionUninstallDialog* AppLauncherHandler::GetExtensionUninstallDialog() {
   if (!extension_uninstall_dialog_.get()) {
     extension_uninstall_dialog_.reset(
         ExtensionUninstallDialog::Create(Profile::FromWebUI(web_ui()), this));
   }
   return extension_uninstall_dialog_.get();
 }
 
 ExtensionInstallUI* AppLauncherHandler::GetExtensionInstallUI() {
   if (!extension_install_ui_.get()) {
     extension_install_ui_.reset(
         new ExtensionInstallUI(Profile::FromWebUI(web_ui())));
   }
   return extension_install_ui_.get();
 }
 
 void AppLauncherHandler::UninstallDefaultApps() {
   AppsPromo* apps_promo = extension_service_->apps_promo();
   const ExtensionIdSet& app_ids = apps_promo->old_default_apps();
   for (ExtensionIdSet::const_iterator iter = app_ids.begin();
        iter != app_ids.end(); ++iter) {
     if (extension_service_->GetExtensionById(*iter, true))
       extension_service_->UninstallExtension(*iter, false, NULL);
   }
 }