electron/shell/common/gin_helper/event_emitter.h
Cheng Zhao eb0e55c514
chore: remove native_mate (Part 9) (#20645)
* refactor: remove a few uses of native_mate/gfx_converter.h

* refactor: deprecate mate::EventEmitter

* refactor: add gin_helper::EventEmitter

* refactor: convert a few classes to use gin_helper::EventEmitter

* refactor: get rid of native_mate_converters/gfx_converter.h

* fix: follow native_mate on reporting errors

* fix: gin is weak at guessing parameter types

* fix: incorrect full class name

* fix: gin::Handle does not accept null
2019-10-21 16:05:40 +09:00

107 lines
3.6 KiB
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// Copyright (c) 2019 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#ifndef SHELL_COMMON_GIN_HELPER_EVENT_EMITTER_H_
#define SHELL_COMMON_GIN_HELPER_EVENT_EMITTER_H_
#include <utility>
#include <vector>
#include "base/optional.h"
#include "electron/shell/common/api/api.mojom.h"
#include "shell/common/gin_helper/event_emitter_caller.h"
namespace gin_helper {
namespace internal {
v8::Local<v8::Object> CreateEventObject(v8::Isolate* isolate);
v8::Local<v8::Object> CreateCustomEvent(v8::Isolate* isolate,
v8::Local<v8::Object> object,
v8::Local<v8::Object> event);
v8::Local<v8::Object> CreateEventFromFlags(v8::Isolate* isolate, int flags);
} // namespace internal
// Provide helperers to emit event in JavaScript.
//
// TODO(zcbenz): Inherit from Wrappable directly after removing native_mate.
template <typename Base>
class EventEmitter : public Base {
public:
typedef std::vector<v8::Local<v8::Value>> ValueArray;
// Make the convinient methods visible:
// https://isocpp.org/wiki/faq/templates#nondependent-name-lookup-members
v8::Isolate* isolate() const { return Base::isolate(); }
v8::Local<v8::Object> GetWrapper() const { return Base::GetWrapper(); }
v8::MaybeLocal<v8::Object> GetWrapper(v8::Isolate* isolate) const {
return Base::GetWrapper(isolate);
}
// this.emit(name, event, args...);
template <typename... Args>
bool EmitCustomEvent(base::StringPiece name,
v8::Local<v8::Object> event,
Args&&... args) {
return EmitWithEvent(
name, internal::CreateCustomEvent(isolate(), GetWrapper(), event),
std::forward<Args>(args)...);
}
// this.emit(name, new Event(flags), args...);
template <typename... Args>
bool EmitWithFlags(base::StringPiece name, int flags, Args&&... args) {
return EmitCustomEvent(name,
internal::CreateEventFromFlags(isolate(), flags),
std::forward<Args>(args)...);
}
// this.emit(name, new Event(), args...);
template <typename... Args>
bool Emit(base::StringPiece name, Args&&... args) {
v8::Locker locker(isolate());
v8::HandleScope handle_scope(isolate());
v8::Local<v8::Object> wrapper = GetWrapper();
if (wrapper.IsEmpty()) {
return false;
}
v8::Local<v8::Object> event = internal::CreateEventObject(isolate());
event
->Set(isolate()->GetCurrentContext(),
gin::StringToV8(isolate(), "sender"), wrapper)
.IsJust();
return EmitWithEvent(name, event, std::forward<Args>(args)...);
}
protected:
EventEmitter() {}
private:
// this.emit(name, event, args...);
template <typename... Args>
bool EmitWithEvent(base::StringPiece name,
v8::Local<v8::Object> event,
Args&&... args) {
// It's possible that |this| will be deleted by EmitEvent, so save anything
// we need from |this| before calling EmitEvent.
auto* isolate = this->isolate();
v8::Locker locker(isolate);
v8::HandleScope handle_scope(isolate);
auto context = isolate->GetCurrentContext();
EmitEvent(isolate, GetWrapper(), name, event, std::forward<Args>(args)...);
v8::Local<v8::Value> defaultPrevented;
if (event->Get(context, gin::StringToV8(isolate, "defaultPrevented"))
.ToLocal(&defaultPrevented)) {
return defaultPrevented->BooleanValue(isolate);
}
return false;
}
DISALLOW_COPY_AND_ASSIGN(EventEmitter);
};
} // namespace gin_helper
#endif // SHELL_COMMON_GIN_HELPER_EVENT_EMITTER_H_