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 JsEventHandler;
  17 template <typename T> class WeakHandle;
  18
  19 // An interface for objects that JsEventHandlers directly interact
  20 // with.  JsEventHandlers can add themselves to receive events and
  21 // also send messages which will eventually reach the backend.
  22 class SYNC_EXPORT JsController {
  23  public:
  24   // Adds an event handler which will start receiving JS events (not
  25   // immediately, so this can be called in the handler's constructor).
  26   // Multiple event handlers are supported, but each event handler
  27   // must be added at most once.
  28   //
  29   // Ideally, we'd take WeakPtrs, but we need the raw pointer values
  30   // to be able to look them up for removal.
  31   virtual void AddJsEventHandler(JsEventHandler* event_handler) = 0;
  32
  33   // Removes the given event handler if it has been added.  It will
  34   // immediately stop receiving any JS events.
  35   virtual void RemoveJsEventHandler(JsEventHandler* event_handler) = 0;
  36
  37  protected:
  38   virtual ~JsController() {}
  39 };
  40
  41 }  // namespace syncer
  42
  43 #endif  // SYNC_JS_JS_CONTROLLER_H_