cef/libcef_dll/cpptoc/cpptoc.h

166 lines
5.0 KiB
C++

// Copyright (c) 2009 The Chromium Embedded Framework Authors. All rights
// reserved. Use of this source code is governed by a BSD-style license that
// can be found in the LICENSE file.
#ifndef CEF_LIBCEF_DLL_CPPTOC_CPPTOC_H_
#define CEF_LIBCEF_DLL_CPPTOC_CPPTOC_H_
#pragma once
#include "include/base/cef_logging.h"
#include "include/base/cef_macros.h"
#include "include/cef_base.h"
#include "include/capi/cef_base_capi.h"
// Wrap a C++ class with a C structure. This is used when the class
// implementation exists on this side of the DLL boundary but will have methods
// called from the other side of the DLL boundary.
template <class ClassName, class BaseName, class StructName>
class CefCppToC : public CefBase {
public:
// Structure representation with pointer to the C++ class.
struct Struct {
StructName struct_;
CefCppToC<ClassName, BaseName, StructName>* class_;
};
// Use this method to retrieve the underlying class instance from our
// own structure when the structure is passed as the required first
// parameter of a C API function call. No explicit reference counting
// is done in this case.
static CefRefPtr<BaseName> Get(StructName* s) {
DCHECK(s);
// Cast our structure to the wrapper structure type.
Struct* wrapperStruct = reinterpret_cast<Struct*>(s);
// Return the underlying object instance.
return wrapperStruct->class_->GetClass();
}
// Use this method to create a wrapper structure for passing our class
// instance to the other side.
static StructName* Wrap(CefRefPtr<BaseName> c) {
if (!c.get())
return NULL;
// Wrap our object with the CefCppToC class.
ClassName* wrapper = new ClassName(c.get());
// Add a reference to our wrapper object that will be released once our
// structure arrives on the other side.
wrapper->AddRef();
// Return the structure pointer that can now be passed to the other side.
return wrapper->GetStruct();
}
// Use this method to retrieve the underlying class instance when receiving
// our wrapper structure back from the other side.
static CefRefPtr<BaseName> Unwrap(StructName* s) {
if (!s)
return NULL;
// Cast our structure to the wrapper structure type.
Struct* wrapperStruct = reinterpret_cast<Struct*>(s);
// Add the underlying object instance to a smart pointer.
CefRefPtr<BaseName> objectPtr(wrapperStruct->class_->GetClass());
// Release the reference to our wrapper object that was added before the
// structure was passed back to us.
wrapperStruct->class_->Release();
// Return the underlying object instance.
return objectPtr;
}
explicit CefCppToC(BaseName* cls)
: class_(cls) {
DCHECK(cls);
struct_.class_ = this;
// zero the underlying structure and set base members
memset(&struct_.struct_, 0, sizeof(StructName));
struct_.struct_.base.size = sizeof(StructName);
struct_.struct_.base.add_ref = struct_add_ref;
struct_.struct_.base.release = struct_release;
struct_.struct_.base.has_one_ref = struct_has_one_ref;
#ifndef NDEBUG
base::AtomicRefCountInc(&DebugObjCt);
#endif
}
virtual ~CefCppToC() {
#ifndef NDEBUG
base::AtomicRefCountDec(&DebugObjCt);
#endif
}
BaseName* GetClass() { return class_; }
// If returning the structure across the DLL boundary you should call
// AddRef() on this CefCppToC object. On the other side of the DLL boundary,
// call UnderlyingRelease() on the wrapping CefCToCpp object.
StructName* GetStruct() { return &struct_.struct_; }
// CefBase methods increment/decrement reference counts on both this object
// and the underlying wrapper class.
void AddRef() const {
UnderlyingAddRef();
ref_count_.AddRef();
}
bool Release() const {
UnderlyingRelease();
if (ref_count_.Release()) {
delete this;
return true;
}
return false;
}
bool HasOneRef() const { return ref_count_.HasOneRef(); }
// Increment/decrement reference counts on only the underlying class.
void UnderlyingAddRef() const { class_->AddRef(); }
bool UnderlyingRelease() const { return class_->Release(); }
bool UnderlyingHasOneRef() const { return class_->HasOneRef(); }
#ifndef NDEBUG
// Simple tracking of allocated objects.
static base::AtomicRefCount DebugObjCt; // NOLINT(runtime/int)
#endif
protected:
Struct struct_;
BaseName* class_;
private:
static void CEF_CALLBACK struct_add_ref(struct _cef_base_t* base) {
DCHECK(base);
if (!base)
return;
Struct* impl = reinterpret_cast<Struct*>(base);
impl->class_->AddRef();
}
static int CEF_CALLBACK struct_release(struct _cef_base_t* base) {
DCHECK(base);
if (!base)
return 0;
Struct* impl = reinterpret_cast<Struct*>(base);
return impl->class_->Release();
}
static int CEF_CALLBACK struct_has_one_ref(struct _cef_base_t* base) {
DCHECK(base);
if (!base)
return 0;
Struct* impl = reinterpret_cast<Struct*>(base);
return impl->class_->HasOneRef();
}
CefRefCount ref_count_;
DISALLOW_COPY_AND_ASSIGN(CefCppToC);
};
#endif // CEF_LIBCEF_DLL_CPPTOC_CPPTOC_H_