electron/shell/browser/event_emitter_mixin.h

76 lines
2.8 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 ELECTRON_SHELL_BROWSER_EVENT_EMITTER_MIXIN_H_
#define ELECTRON_SHELL_BROWSER_EVENT_EMITTER_MIXIN_H_
#include <string_view>
#include <utility>
#include "gin/handle.h"
#include "gin/object_template_builder.h"
#include "shell/browser/javascript_environment.h"
#include "shell/common/gin_helper/event.h"
#include "shell/common/gin_helper/event_emitter.h"
namespace gin_helper {
template <typename T>
class EventEmitterMixin {
public:
// disable copy
EventEmitterMixin(const EventEmitterMixin&) = delete;
EventEmitterMixin& operator=(const EventEmitterMixin&) = delete;
// this.emit(name, new Event(), args...);
// Returns true if event.preventDefault() was called during processing.
template <typename... Args>
bool Emit(const std::string_view name, Args&&... args) {
v8::Isolate* isolate = electron::JavascriptEnvironment::GetIsolate();
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Object> wrapper;
if (!static_cast<T*>(this)->GetWrapper(isolate).ToLocal(&wrapper))
return false;
gin::Handle<internal::Event> event = internal::Event::New(isolate);
gin_helper::EmitEvent(isolate, wrapper, name, event,
std::forward<Args>(args)...);
return event->GetDefaultPrevented();
}
// this.emit(name, args...);
template <typename... Args>
void EmitWithoutEvent(const std::string_view name, Args&&... args) {
v8::Isolate* isolate = electron::JavascriptEnvironment::GetIsolate();
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Object> wrapper;
if (!static_cast<T*>(this)->GetWrapper(isolate).ToLocal(&wrapper))
return;
gin_helper::EmitEvent(isolate, wrapper, name, 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());
}
};
} // namespace gin_helper
#endif // ELECTRON_SHELL_BROWSER_EVENT_EMITTER_MIXIN_H_