sync/js/js_controller.h

   1 // Copyright 2012 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 SYNC_JS_JS_CONTROLLER_H_
   6 #define SYNC_JS_JS_CONTROLLER_H_
   7
   8 // See README.js for design comments.
   9
  10 #include <string>
  11
  12 #include "sync/base/sync_export.h"
  13
  14 namespace syncer {
  15
  16 class JsArgList;
  17 class JsEventHandler;
  18 class JsReplyHandler;
  19 template <typename T> class WeakHandle;
  20
  21 // An interface for objects that JsEventHandlers directly interact
  22 // with.  JsEventHandlers can add themselves to receive events and
  23 // also send messages which will eventually reach the backend.
  24 class SYNC_EXPORT JsController {
  25  public:
  26   // Adds an event handler which will start receiving JS events (not
  27   // immediately, so this can be called in the handler's constructor).
  28   // Multiple event handlers are supported, but each event handler
  29   // must be added at most once.
  30   //
  31   // Ideally, we'd take WeakPtrs, but we need the raw pointer values
  32   // to be able to look them up for removal.
  33   virtual void AddJsEventHandler(JsEventHandler* event_handler) = 0;
  34
  35   // Removes the given event handler if it has been added.  It will
  36   // immediately stop receiving any JS events.
  37   virtual void RemoveJsEventHandler(JsEventHandler* event_handler) = 0;
  38
  39   // Processes a JS message.  The reply (if any) will be sent to
  40   // |reply_handler| if it is initialized.
  41   virtual void ProcessJsMessage(
  42       const std::string& name, const JsArgList& args,
  43       const WeakHandle<JsReplyHandler>& reply_handler) = 0;
  44
  45  protected:
  46   virtual ~JsController() {}
  47 };
  48
  49 }  // namespace syncer
  50
  51 #endif  // SYNC_JS_JS_CONTROLLER_H_