text: // 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.
  
  #ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_BASE_SCREEN_HANDLER_H_
  #define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_BASE_SCREEN_HANDLER_H_
  
  #include <string>
  
  #include "base/bind.h"
  #include "base/bind_helpers.h"
  #include "base/callback.h"
  #include "base/strings/string16.h"
  #include "chrome/browser/ui/webui/chromeos/login/base_screen_handler_utils.h"
  #include "content/public/browser/web_ui.h"
  #include "content/public/browser/web_ui_message_handler.h"
  #include "ui/gfx/native_widget_types.h"
  
  namespace base {
  class DictionaryValue;
  class ListValue;
  class Value;
  }
  
  namespace chromeos {
  
  // Class that collects Localized Values for translation.
  class LocalizedValuesBuilder {
   public:
    explicit LocalizedValuesBuilder(base::DictionaryValue* dict);
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message| is text of the message.
    void Add(const std::string& key, const std::string& message);
  
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message| is text of the message.
    void Add(const std::string& key, const string16& message);
  
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message_id| is a resource id of message.
    void Add(const std::string& key, int message_id);
  
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message_id| is a resource id of message. Message is expected to have
    // one format parameter subsituted by |a|.
    void AddF(const std::string& key,
              int message_id,
              const string16& a);
  
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message_id| is a resource id of message. Message is expected to have
    // two format parameters subsituted by |a| and |b| respectively.
    void AddF(const std::string& key,
              int message_id,
              const string16& a,
              const string16& b);
  
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message_id| is a resource id of message. Message is expected to have
    // one format parameter subsituted by resource identified by |message_id_a|.
    void AddF(const std::string& key,
              int message_id,
              int message_id_a);
  
    // Method to declare localized value. |key| is the i18n key used in html.
    // |message_id| is a resource id of message. Message is expected to have
    // two format parameters subsituted by resource identified by |message_id_a|
    // and |message_id_b| respectively.
    void AddF(const std::string& key,
              int message_id,
              int message_id_a,
              int message_id_b);
   private:
    // Not owned.
    base::DictionaryValue* dict_;
  };
  
  // Base class for the OOBE/Login WebUI handlers.
  class BaseScreenHandler : public content::WebUIMessageHandler {
   public:
    // C-tor used when JS screen prefix is not needed.
    BaseScreenHandler();
  
    // C-tor used when JS screen prefix is needed.
    explicit BaseScreenHandler(const std::string& js_screen_path);
  
    virtual ~BaseScreenHandler();
  
    // Gets localized strings to be used on the page.
    void GetLocalizedStrings(
        base::DictionaryValue* localized_strings);
  
    // This method is called when page is ready. It propagates to inherited class
    // via virtual Initialize() method (see below).
    void InitializeBase();
  
   protected:
    // All subclasses should implement this method to provide localized values.
    virtual void DeclareLocalizedValues(LocalizedValuesBuilder* builder) = 0;
  
    // Subclasses can override these methods to pass additional parameters
    // to loadTimeData. Generally, it is a bad approach, and it should be replaced
    // with Context at some point.
    virtual void GetAdditionalParameters(base::DictionaryValue* parameters);
  
    // Shortcut for calling JS methods on WebUI side.
    void CallJS(const std::string& method);
  
    template<typename A1>
    void CallJS(const std::string& method, const A1& arg1) {
      web_ui()->CallJavascriptFunction(FullMethodPath(method), MakeValue(arg1));
    }
  
    template<typename A1, typename A2>
    void CallJS(const std::string& method, const A1& arg1, const A2& arg2) {
      web_ui()->CallJavascriptFunction(FullMethodPath(method), MakeValue(arg1),
                                       MakeValue(arg2));
    }
  
    template<typename A1, typename A2, typename A3>
    void CallJS(const std::string& method,
                const A1& arg1,
                const A2& arg2,
                const A3& arg3) {
      web_ui()->CallJavascriptFunction(FullMethodPath(method),
                                       MakeValue(arg1),
                                       MakeValue(arg2),
                                       MakeValue(arg3));
    }
  
    template<typename A1, typename A2, typename A3, typename A4>
    void CallJS(const std::string& method,
                const A1& arg1,
                const A2& arg2,
                const A3& arg3,
                const A4& arg4) {
      web_ui()->CallJavascriptFunction(FullMethodPath(method),
                                       MakeValue(arg1),
                                       MakeValue(arg2),
                                       MakeValue(arg3),
                                       MakeValue(arg4));
    }
  
    // Shortcut methods for adding WebUI callbacks.
    template<typename T>
    void AddRawCallback(const std::string& name,
                        void (T::*method)(const base::ListValue* args)) {
      web_ui()->RegisterMessageCallback(
          name,
          base::Bind(method, base::Unretained(static_cast<T*>(this))));
    }
  
    template<typename T>
    void AddCallback(const std::string& name, void (T::*method)()) {
      base::Callback<void()> callback =
          base::Bind(method, base::Unretained(static_cast<T*>(this)));
      web_ui()->RegisterMessageCallback(
          name, base::Bind(&CallbackWrapper0, callback));
    }
  
    template<typename T, typename A1>
    void AddCallback(const std::string& name, void (T::*method)(A1 arg1)) {
      base::Callback<void(A1)> callback =
          base::Bind(method, base::Unretained(static_cast<T*>(this)));
      web_ui()->RegisterMessageCallback(
          name, base::Bind(&CallbackWrapper1<A1>, callback));
    }
  
    template<typename T, typename A1, typename A2>
    void AddCallback(const std::string& name,
                     void (T::*method)(A1 arg1, A2 arg2)) {
      base::Callback<void(A1, A2)> callback =
          base::Bind(method, base::Unretained(static_cast<T*>(this)));
      web_ui()->RegisterMessageCallback(
          name, base::Bind(&CallbackWrapper2<A1, A2>, callback));
    }
  
    template<typename T, typename A1, typename A2, typename A3>
    void AddCallback(const std::string& name,
                     void (T::*method)(A1 arg1, A2 arg2, A3 arg3)) {
      base::Callback<void(A1, A2, A3)> callback =
          base::Bind(method, base::Unretained(static_cast<T*>(this)));
      web_ui()->RegisterMessageCallback(
          name, base::Bind(&CallbackWrapper3<A1, A2, A3>, callback));
    }
  
    template<typename T, typename A1, typename A2, typename A3, typename A4>
    void AddCallback(const std::string& name,
                     void (T::*method)(A1 arg1, A2 arg2, A3 arg3, A4 arg4)) {
      base::Callback<void(A1, A2, A3, A4)> callback =
          base::Bind(method, base::Unretained(static_cast<T*>(this)));
      web_ui()->RegisterMessageCallback(
          name, base::Bind(&CallbackWrapper4<A1, A2, A3, A4>, callback));
    }
  
    // Called when the page is ready and handler can do initialization.
    virtual void Initialize() = 0;
  
    // Show selected WebUI |screen|. Optionally it can pass screen initialization
    // data via |data| parameter.
    void ShowScreen(const char* screen, const base::DictionaryValue* data);
  
    // Whether page is ready.
    bool page_is_ready() const { return page_is_ready_; }
  
    // Returns the window which shows us.
    virtual gfx::NativeWindow GetNativeWindow();
  
   private:
    // Returns full name of JS method based on screen and method
    // names.
    std::string FullMethodPath(const std::string& method) const;
  
    // Keeps whether page is ready.
    bool page_is_ready_;
  
    base::DictionaryValue* localized_values_;
  
    // Full name of the corresponding JS screen object. Can be empty, if
    // there are no corresponding screen object or several different
    // objects.
    std::string js_screen_path_prefix_;
  
    DISALLOW_COPY_AND_ASSIGN(BaseScreenHandler);
  };
  
  }  // namespace chromeos
  
  #endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_BASE_SCREEN_HANDLER_H_
  