1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_UI_WEBUI_SHOWN_SECTIONS_HANDLER_H_ 6 #define CHROME_BROWSER_UI_WEBUI_SHOWN_SECTIONS_HANDLER_H_ 7 #pragma once 8 9 #include "chrome/browser/prefs/pref_change_registrar.h" 10 #include "content/browser/webui/web_ui.h" 11 #include "content/common/notification_observer.h" 12 13 class Extension; 14 class Value; 15 class PrefService; 16 17 // Use for the shown sections bitmask. 18 // Currently, only the THUMB and APPS sections can be toggled by the user. Other 19 // sections are shown automatically if they have data, and hidden otherwise. 20 enum Section { 21 // If one of these is set, the corresponding section shows large thumbnails, 22 // else it shows only a small overview list. 23 THUMB = 1 << 0, 24 APPS = 1 << 6, 25 26 // We use the low 16 bits for sections, the high 16 bits for menu mode. 27 ALL_SECTIONS_MASK = 0x0000FFFF, 28 29 // If one of these is set, then the corresponding section is shown in a menu 30 // at the bottom of the NTP and no data is directly visible on the NTP. 31 MENU_THUMB = 1 << (0 + 16), 32 MENU_RECENT = 1 << (2 + 16), 33 MENU_APPS = 1 << (6 + 16), 34 }; 35 36 class ShownSectionsHandler : public WebUIMessageHandler, 37 public NotificationObserver { 38 public: 39 explicit ShownSectionsHandler(PrefService* pref_service); ~ShownSectionsHandler()40 virtual ~ShownSectionsHandler() {} 41 42 // Helper to get the current shown sections. 43 static int GetShownSections(PrefService* pref_service); 44 45 // Expands |section|, collapsing any previously expanded section. This is the 46 // same thing that happens if a user clicks on |section|. 47 static void SetShownSection(PrefService* prefs, Section section); 48 49 // WebUIMessageHandler implementation. 50 virtual void RegisterMessages(); 51 52 // NotificationObserver implementation. 53 virtual void Observe(NotificationType type, 54 const NotificationSource& source, 55 const NotificationDetails& details); 56 57 // Callback for "getShownSections" message. 58 void HandleGetShownSections(const ListValue* args); 59 60 // Callback for "setShownSections" message. 61 void HandleSetShownSections(const ListValue* args); 62 63 static void RegisterUserPrefs(PrefService* pref_service); 64 65 static void MigrateUserPrefs(PrefService* pref_service, 66 int old_pref_version, 67 int new_pref_version); 68 69 static void OnExtensionInstalled(PrefService* prefs, 70 const Extension* extension); 71 72 private: 73 PrefService* pref_service_; 74 PrefChangeRegistrar pref_registrar_; 75 76 DISALLOW_COPY_AND_ASSIGN(ShownSectionsHandler); 77 }; 78 79 #endif // CHROME_BROWSER_UI_WEBUI_SHOWN_SECTIONS_HANDLER_H_ 80