electron/atom/common/native_mate_converters/callback.cc

138 строки
4.1 KiB
C++

// Copyright (c) 2015 GitHub, Inc. All rights reserved.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "atom/common/native_mate_converters/callback.h"
#include "content/public/browser/browser_thread.h"
using content::BrowserThread;
namespace mate {
namespace internal {
namespace {
struct TranslaterHolder {
Translater translater;
};
// Cached JavaScript version of |CallTranslater|.
v8::Persistent<v8::FunctionTemplate> g_call_translater;
void CallTranslater(v8::Local<v8::External> external,
v8::Local<v8::Object> state,
mate::Arguments* args) {
v8::Isolate* isolate = args->isolate();
// Check if the callback has already been called.
v8::Local<v8::String> called_symbol = mate::StringToSymbol(isolate, "called");
if (state->Has(called_symbol)) {
args->ThrowError("callback can only be called for once");
return;
} else {
state->Set(called_symbol, v8::Boolean::New(isolate, true));
}
TranslaterHolder* holder = static_cast<TranslaterHolder*>(external->Value());
holder->translater.Run(args);
delete holder;
}
// func.bind(func, arg1).
// NB(zcbenz): Using C++11 version crashes VS.
v8::Local<v8::Value> BindFunctionWith(v8::Isolate* isolate,
v8::Local<v8::Context> context,
v8::Local<v8::Function> func,
v8::Local<v8::Value> arg1,
v8::Local<v8::Value> arg2) {
v8::MaybeLocal<v8::Value> bind = func->Get(mate::StringToV8(isolate, "bind"));
CHECK(!bind.IsEmpty());
v8::Local<v8::Function> bind_func =
v8::Local<v8::Function>::Cast(bind.ToLocalChecked());
v8::Local<v8::Value> converted[] = { func, arg1, arg2 };
return bind_func->Call(
context, func, arraysize(converted), converted).ToLocalChecked();
}
} // namespace
// Destroy the class on UI thread when possible.
struct DeleteOnUIThread {
template<typename T>
static void Destruct(const T* x) {
if (Locker::IsBrowserProcess() &&
!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
BrowserThread::DeleteSoon(BrowserThread::UI, FROM_HERE, x);
} else {
delete x;
}
}
};
// Like v8::Global, but ref-counted.
template<typename T>
class RefCountedGlobal : public base::RefCountedThreadSafe<RefCountedGlobal<T>,
DeleteOnUIThread> {
public:
RefCountedGlobal(v8::Isolate* isolate, v8::Local<v8::Value> value)
: handle_(isolate, v8::Local<T>::Cast(value)) {
}
bool IsAlive() const {
return !handle_.IsEmpty();
}
v8::Local<T> NewHandle(v8::Isolate* isolate) const {
return v8::Local<T>::New(isolate, handle_);
}
private:
v8::Global<T> handle_;
DISALLOW_COPY_AND_ASSIGN(RefCountedGlobal);
};
SafeV8Function::SafeV8Function(v8::Isolate* isolate, v8::Local<v8::Value> value)
: v8_function_(new RefCountedGlobal<v8::Function>(isolate, value)) {
}
SafeV8Function::SafeV8Function(const SafeV8Function& other)
: v8_function_(other.v8_function_) {
}
SafeV8Function::~SafeV8Function() {
}
bool SafeV8Function::IsAlive() const {
return v8_function_.get() && v8_function_->IsAlive();
}
v8::Local<v8::Function> SafeV8Function::NewHandle(v8::Isolate* isolate) const {
return v8_function_->NewHandle(isolate);
}
v8::Local<v8::Value> CreateFunctionFromTranslater(
v8::Isolate* isolate, const Translater& translater) {
// The FunctionTemplate is cached.
if (g_call_translater.IsEmpty())
g_call_translater.Reset(
isolate,
mate::CreateFunctionTemplate(isolate, base::Bind(&CallTranslater)));
v8::Local<v8::FunctionTemplate> call_translater =
v8::Local<v8::FunctionTemplate>::New(isolate, g_call_translater);
TranslaterHolder* holder = new TranslaterHolder;
holder->translater = translater;
return BindFunctionWith(isolate,
isolate->GetCurrentContext(),
call_translater->GetFunction(),
v8::External::New(isolate, holder),
v8::Object::New(isolate));
}
} // namespace internal
} // namespace mate