ios/public/provider/web/web_ui_ios_message_handler.h

   1 // Copyright 2014 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 IOS_PUBLIC_PROVIDER_WEB_WEB_UI_IOS_MESSAGE_HANDLER_H_
   6 #define IOS_PUBLIC_PROVIDER_WEB_WEB_UI_IOS_MESSAGE_HANDLER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/strings/string16.h"
  10
  11 class GURL;
  12
  13 namespace base {
  14 class DictionaryValue;
  15 class ListValue;
  16 }
  17
  18 namespace web {
  19
  20 class WebUIIOS;
  21 class WebUIIOSImpl;
  22
  23 // Messages sent from the DOM are forwarded via the WebUIIOS to handler
  24 // classes. These objects are owned by WebUIIOS and destroyed when the
  25 // host is destroyed.
  26 class WebUIIOSMessageHandler {
  27  public:
  28   WebUIIOSMessageHandler() : web_ui_(NULL) {}
  29   virtual ~WebUIIOSMessageHandler() {}
  30
  31  protected:
  32   // Helper methods:
  33
  34   // Extract an integer value from a list Value.
  35   static bool ExtractIntegerValue(const base::ListValue* value, int* out_int);
  36
  37   // Extract a floating point (double) value from a list Value.
  38   static bool ExtractDoubleValue(const base::ListValue* value,
  39                                  double* out_value);
  40
  41   // Extract a string value from a list Value.
  42   static base::string16 ExtractStringValue(const base::ListValue* value);
  43
  44   // This is where subclasses specify which messages they'd like to handle and
  45   // perform any additional initialization. At this point web_ui() will return
  46   // the associated WebUIIOS object.
  47   virtual void RegisterMessages() = 0;
  48
  49   // Returns the attached WebUIIOS for this handler.
  50   WebUIIOS* web_ui() const { return web_ui_; }
  51
  52   // Sets the attached WebUIIOS - exposed to subclasses for testing purposes.
  53   void set_web_ui(WebUIIOS* web_ui) { web_ui_ = web_ui; }
  54
  55  private:
  56   // Provide external classes access to web_ui() and set_web_ui().
  57   friend class WebUIIOSImpl;
  58
  59   WebUIIOS* web_ui_;
  60 };
  61
  62 }  // namespace web
  63
  64 #endif  // IOS_PUBLIC_PROVIDER_WEB_WEB_UI_IOS_MESSAGE_HANDLER_H_