electron/native_mate/wrappable_base.h

68 lines
2 KiB
C++

#ifndef NATIVE_MATE_WRAPPABLE_BASE_H_
#define NATIVE_MATE_WRAPPABLE_BASE_H_
#include "native_mate/compat.h"
namespace mate {
namespace internal {
struct Destroyable;
}
// Wrappable is a base class for C++ objects that have corresponding v8 wrapper
// objects. To retain a Wrappable object on the stack, use a gin::Handle.
//
// USAGE:
// // my_class.h
// class MyClass : Wrappable<MyClass> {
// public:
// ...
// };
//
// Subclasses should also typically have private constructors and expose a
// static Create function that returns a mate::Handle. Forcing creators through
// this static Create function will enforce that clients actually create a
// wrapper for the object. If clients fail to create a wrapper for a wrappable
// object, the object will leak because we use the weak callback from the
// wrapper as the signal to delete the wrapped object.
class WrappableBase {
public:
WrappableBase();
virtual ~WrappableBase();
// Retrieve the v8 wrapper object cooresponding to this object.
v8::Local<v8::Object> GetWrapper();
// Returns the Isolate this object is created in.
v8::Isolate* isolate() const { return isolate_; }
protected:
// Called after the "_init" method gets called in JavaScript.
virtual void AfterInit(v8::Isolate* isolate) {}
// Bind the C++ class to the JS wrapper.
// This method should only be called by classes using Constructor.
virtual void InitWith(v8::Isolate* isolate, v8::Local<v8::Object> wrapper);
// Marks wrapped object as high memory usage
// Deletes the wrapped object on the first round of GC callbacks
void MarkHighMemoryUsage() { high_memory_ = true; }
private:
friend struct internal::Destroyable;
static void FirstWeakCallback(
const v8::WeakCallbackInfo<WrappableBase>& data);
static void SecondWeakCallback(
const v8::WeakCallbackInfo<WrappableBase>& data);
v8::Isolate* isolate_;
v8::Global<v8::Object> wrapper_; // Weak
bool high_memory_;
DISALLOW_COPY_AND_ASSIGN(WrappableBase);
};
} // namespace mate
#endif // NATIVE_MATE_WRAPPABLE_BASE_H_