Added usage of ScreenContext in EulaScreen.

chrome/browser/ui/webui/chromeos/login/base_screen_handler.h

 // 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 "components/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 BaseScreen;
+
 // 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.
@@ skipping 46 matching lines @@
 
   // 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);
 
+  // WebUIMessageHandler implementation:
+  virtual void RegisterMessages() override;
+
   // This method is called when page is ready. It propagates to inherited class
   // via virtual Initialize() method (see below).
   void InitializeBase();
 
   void set_async_assets_load_id(const std::string& async_assets_load_id) {
     async_assets_load_id_ = async_assets_load_id;
   }
   const std::string& async_assets_load_id() const {
     return async_assets_load_id_;
   }
 
  protected:
   // All subclasses should implement this method to provide localized values.
   virtual void DeclareLocalizedValues(LocalizedValuesBuilder* builder) = 0;
 
+  // All subclasses should implement this method to register callbacks for JS
+  // messages.
+  //
+  // TODO (ygorshenin, crbug.com/433797): make this method purely vrtual when
+  // all screens will be switched to use ScreenContext.
+  virtual void DeclareJSCallbacks() {}
+
   // 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) {
@@ skipping 96 matching lines @@
   // 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();
 
+  void set_base_screen(BaseScreen* base_screen) { base_screen_ = base_screen; }
+
  private:
   // Returns full name of JS method based on screen and method
   // names.
   std::string FullMethodPath(const std::string& method) const;
 
+  // Handles situation when screen context is changed.
+  void HandleContextChanged(const base::DictionaryValue* diff);
+
   // Keeps whether page is ready.
   bool page_is_ready_;
 
+  BaseScreen* base_screen_;
+
   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_;
 
   // The string id used in the async asset load in JS. If it is set to a
   // non empty value, the Initialize will be deferred until the underlying load
   // is finished.
   std::string async_assets_load_id_;
 
   DISALLOW_COPY_AND_ASSIGN(BaseScreenHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_BASE_SCREEN_HANDLER_H_