electron/shell/browser/event_emitter_mixin.h
2020-07-30 09:17:57 -07:00

95 lines
3.5 KiB
C++

// Copyright (c) 2019 Slack Technologies, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#ifndef SHELL_BROWSER_EVENT_EMITTER_MIXIN_H_
#define SHELL_BROWSER_EVENT_EMITTER_MIXIN_H_
#include <utility>
#include "gin/object_template_builder.h"
#include "shell/browser/javascript_environment.h"
#include "shell/common/gin_helper/event_emitter.h"
namespace gin_helper {
namespace internal {
v8::Local<v8::FunctionTemplate> GetEventEmitterTemplate(v8::Isolate* isolate);
} // namespace internal
template <typename T>
class EventEmitterMixin {
public:
// this.emit(name, new Event(), args...);
template <typename... Args>
bool Emit(base::StringPiece name, Args&&... args) {
v8::Isolate* isolate = electron::JavascriptEnvironment::GetIsolate();
v8::Locker locker(isolate);
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Object> wrapper;
if (!static_cast<T*>(this)->GetWrapper(isolate).ToLocal(&wrapper))
return false;
v8::Local<v8::Object> event = internal::CreateEvent(isolate, wrapper);
return EmitWithEvent(isolate, wrapper, name, event,
std::forward<Args>(args)...);
}
// this.emit(name, event, args...);
template <typename... Args>
bool EmitCustomEvent(base::StringPiece name,
v8::Local<v8::Object> custom_event,
Args&&... args) {
v8::Isolate* isolate = electron::JavascriptEnvironment::GetIsolate();
v8::HandleScope scope(isolate);
v8::Local<v8::Object> wrapper;
if (!static_cast<T*>(this)->GetWrapper(isolate).ToLocal(&wrapper))
return false;
return EmitWithEvent(isolate, wrapper, name, custom_event,
std::forward<Args>(args)...);
}
protected:
EventEmitterMixin() = default;
gin::ObjectTemplateBuilder GetObjectTemplateBuilder(v8::Isolate* isolate) {
gin::PerIsolateData* data = gin::PerIsolateData::From(isolate);
auto* wrapper_info = &(static_cast<T*>(this)->kWrapperInfo);
v8::Local<v8::FunctionTemplate> constructor =
data->GetFunctionTemplate(wrapper_info);
if (constructor.IsEmpty()) {
constructor = v8::FunctionTemplate::New(isolate);
constructor->SetClassName(
gin::StringToV8(isolate, static_cast<T*>(this)->GetTypeName()));
constructor->Inherit(internal::GetEventEmitterTemplate(isolate));
data->SetFunctionTemplate(wrapper_info, constructor);
}
return gin::ObjectTemplateBuilder(isolate,
static_cast<T*>(this)->GetTypeName(),
constructor->InstanceTemplate());
}
private:
// this.emit(name, event, args...);
template <typename... Args>
static bool EmitWithEvent(v8::Isolate* isolate,
v8::Local<v8::Object> wrapper,
base::StringPiece name,
v8::Local<v8::Object> event,
Args&&... args) {
auto context = isolate->GetCurrentContext();
gin_helper::EmitEvent(isolate, wrapper, 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(EventEmitterMixin);
};
} // namespace gin_helper
#endif // SHELL_BROWSER_EVENT_EMITTER_MIXIN_H_