[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/api_event_handler.h

-// Copyright 2016 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 EXTENSIONS_RENDERER_API_EVENT_HANDLER_H_
-#define EXTENSIONS_RENDERER_API_EVENT_HANDLER_H_
-
-#include <string>
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "extensions/common/event_filter.h"
-#include "extensions/renderer/api_binding_types.h"
-#include "extensions/renderer/event_emitter.h"
-#include "v8/include/v8.h"
-
-namespace base {
-class ListValue;
-}
-
-namespace extensions {
-struct EventFilteringInfo;
-
-// The object to handle API events. This includes vending v8::Objects for the
-// event; handling adding, removing, and querying listeners; and firing events
-// to subscribed listeners. Designed to be used across JS contexts, but on a
-// single thread.
-class APIEventHandler {
- public:
-  // The callback to be called when event listeners change. |was_manual|
-  // indicates that the change was due to an extension calling addListener or
-  // removeListener, rather than through something like context destruction.
-  // See also APIEventListeners.
-  using EventListenersChangedMethod =
-      base::Callback<void(const std::string& event_name,
-                          binding::EventListenersChanged,
-                          const base::DictionaryValue* filter,
-                          bool was_manual,
-                          v8::Local<v8::Context>)>;
-
-  APIEventHandler(const binding::RunJSFunction& call_js,
-                  const binding::RunJSFunctionSync& call_js_sync,
-                  const EventListenersChangedMethod& listeners_changed);
-  ~APIEventHandler();
-
-  // Returns a new v8::Object for an event with the given |event_name|. If
-  // |notify_on_change| is true, notifies whenever listeners state is changed.
-  v8::Local<v8::Object> CreateEventInstance(const std::string& event_name,
-                                            bool supports_filters,
-                                            int max_listeners,
-                                            bool notify_on_change,
-                                            v8::Local<v8::Context> context);
-
-  // Creates a new event without any name. This is used by custom bindings when
-  // the entirety of the logic for the event is contained in the renderer. These
-  // events do not notify of new/removed listeners or allow for dispatching
-  // through FireEventInContext().
-  v8::Local<v8::Object> CreateAnonymousEventInstance(
-      v8::Local<v8::Context> context);
-
-  // Invalidates the given |event|.
-  void InvalidateCustomEvent(v8::Local<v8::Context> context,
-                             v8::Local<v8::Object> event);
-
-  // Notifies all listeners of the event with the given |event_name| in the
-  // specified |context|, sending the included |arguments|.
-  void FireEventInContext(const std::string& event_name,
-                          v8::Local<v8::Context> context,
-                          const base::ListValue& arguments,
-                          const EventFilteringInfo& filter);
-
-  // Registers a |function| to serve as an "argument massager" for the given
-  // |event_name|, mutating the original arguments.
-  // The function is called with two arguments: the array of original arguments
-  // being dispatched to the event, and the function to dispatch the event to
-  // listeners.
-  void RegisterArgumentMassager(v8::Local<v8::Context> context,
-                                const std::string& event_name,
-                                v8::Local<v8::Function> function);
-
-  // Returns true if there is a listener for the given |event_name| in the
-  // given |context|.
-  bool HasListenerForEvent(const std::string& event_name,
-                           v8::Local<v8::Context> context);
-
-  // Invalidates listeners for the given |context|. It's a shame we have to
-  // have this separately (as opposed to hooking into e.g. a PerContextData
-  // destructor), but we need to do this before the context is fully removed
-  // (because the associated extension ScriptContext needs to be valid).
-  void InvalidateContext(v8::Local<v8::Context> context);
-
-  // Returns the number of event listeners for a given |event_name| and
-  // |context|.
-  size_t GetNumEventListenersForTesting(const std::string& event_name,
-                                        v8::Local<v8::Context> context);
-
- private:
-  // Method to run a given v8::Function. Curried in for testing.
-  binding::RunJSFunction call_js_;
-  binding::RunJSFunctionSync call_js_sync_;
-
-  EventListenersChangedMethod listeners_changed_;
-
-  // The associated EventFilter; shared across all contexts and events.
-  EventFilter event_filter_;
-
-  DISALLOW_COPY_AND_ASSIGN(APIEventHandler);
-};
-
-}  // namespace extensions
-
-#endif  // EXTENSIONS_RENDERER_API_EVENT_HANDLER_H_