cef/libcef_dll/cpptoc/cpptoc.h

161 lines
4.9 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 _CPPTOC_H
#define _CPPTOC_H
#include "include/cef.h"
#include "include/cef_capi.h"
#include "libcef_dll/cef_logging.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 CefThreadSafeBase<CefBase>
{
public:
// 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)
{
// Cast our structure to the wrapper structure type.
ClassName::Struct* wrapperStruct =
reinterpret_cast<ClassName::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)
{
// Wrap our object with the CefCppToC class.
ClassName* wrapper = new ClassName(c);
// 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)
{
// Cast our structure to the wrapper structure type.
ClassName::Struct* wrapperStruct =
reinterpret_cast<ClassName::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;
}
// Structure representation with pointer to the C++ class.
struct Struct
{
StructName struct_;
CefCppToC<ClassName,BaseName,StructName>* class_;
};
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.get_refct = struct_get_refct;
#ifdef _DEBUG
CefAtomicIncrement(&DebugObjCt);
#endif
}
virtual ~CefCppToC()
{
#ifdef _DEBUG
CefAtomicDecrement(&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.
virtual int AddRef()
{
UnderlyingAddRef();
return CefThreadSafeBase<CefBase>::AddRef();
}
virtual int Release()
{
UnderlyingRelease();
return CefThreadSafeBase<CefBase>::Release();
}
// Increment/decrement reference counts on only the underlying class.
int UnderlyingAddRef() { return class_->AddRef(); }
int UnderlyingRelease() { return class_->Release(); }
int UnderlyingGetRefCt() { return class_->GetRefCt(); }
#ifdef _DEBUG
// Simple tracking of allocated objects.
static long DebugObjCt;
#endif
private:
static int CEF_CALLBACK struct_add_ref(struct _cef_base_t* base)
{
DCHECK(base);
if(!base)
return 0;
Struct* impl = reinterpret_cast<Struct*>(base);
return 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_get_refct(struct _cef_base_t* base)
{
DCHECK(base);
if(!base)
return 0;
Struct* impl = reinterpret_cast<Struct*>(base);
return impl->class_->GetRefCt();
}
protected:
Struct struct_;
BaseName* class_;
};
#endif // _CPPTOC_H