chxavcleanupstack.h

来自「symbian 下的helix player源代码」· C头文件 代码 · 共 146 行

/************************************************************************
 * chxavcleanupstack.h
 * -------------------
 *
 * Synopsis:
 * Helpers for simplifying use of Symbian cleanup stack. Uses automatic objects
 * to facilitate push/pop/destroy of cleanup stack objects. Use macros only.
 *
 * Target:
 * Symbian OS
 *
 *
 * (c) 1995-2003 RealNetworks, Inc. Patents pending. All rights reserved.
 *
 ************************************************************************/

#ifndef _chxavcleanupstack_h_
#define _chxavcleanupstack_h_

// Symbian includes...
#include <e32std.h>
#include <eikenv.h>

// Forward declarations...
class CSPushPopDelL;
class CSPushPopL;
class CSPopDelL;
class CSPopL;


// make variable name something like "csvar1424"
#define makevar_(var, line) csvar ## line
#define makevar__(line) makevar_(var, line)

//
// AUTO_PUSH_POP_DEL
//
// Use when an object needs to be pushed, then later popped and deleted on exit from a given scope.
//
#define AUTO_PUSH_POP_DEL(p) CSPushPopDelL makevar__(__LINE__) (p);

//
// AUTO_PUSH_POP
//
// Use when an object needs to be pushed, then later popped on exit from a given scope. Typical
// use case is when you are you intend to transfer ownership of a pointer (e.g., return value 
// from function), in which case you do not want to delete the pointer.
//
#define AUTO_PUSH_POP(p)     CSPushPopL makevar__(__LINE__) (p);

//
// AUTO_POP_DEL
//
// Use when an object needs to be popped and deleted on exit from a given scope. Typical use case
// is when you get a pointer that has already been pushed on the cleanup stack for you (e.g., after
// receiving a pointer from a function ending in LC()).
//
#define AUTO_POP_DEL(p)      CSPopDelL makevar__(__LINE__) (p);

//
// AUTO_POP
//
// Use when an object needs to be popped from the cleanup stack on exit from a given scope.
//
#define AUTO_POP(p)          CSPopL makevar__(__LINE__) (p);

//
// AUTO_PUSH_POP_CLOSE_DEL
//
// Use when an object needs to be auto-closed on exit from a given scope (typically use with R objects).
//
#define AUTO_PUSH_POP_CLOSE(item)  CSPushPopCloseL makevar__(__LINE__) (item);


#include <stdlib.h>


// CSPushPopDelL, Use the macro only.
class CSPushPopDelL
{
public:
    explicit CSPushPopDelL(CBase* p) { CleanupStack::PushL(p); }
    CSPushPopDelL(TAny* p){ CleanupStack::PushL(p); };
   
     ~CSPushPopDelL() { CleanupStack::PopAndDestroy(); }
private:
    
    void * operator new(size_t size);
};

// CSPushPopL, Use the macro only.
class CSPushPopL
{
public:
    explicit CSPushPopL(CBase* p) { CleanupStack::PushL(p); }
    CSPushPopL(TAny* p){ CleanupStack::PushL(p); }; 

    ~CSPushPopL() { CleanupStack::Pop(); }
private:
    void * operator new(size_t size);
};




// class CSPopDelL - use macro
class CSPopDelL
{
public:
    CSPopDelL(CBase* /*p*/) {/*no push*/}
    CSPopDelL(TAny* /*p*/) {/*no push*/}
    ~CSPopDelL() { CleanupStack::PopAndDestroy();}
private:
    void * operator new(size_t size); // stack only
};

// class CSPopL - use macro
class CSPopL
{
public:
    CSPopL(CBase* /*p*/) {/*no push*/}
    CSPopL(TAny* /*p*/) {/*no push*/}
    ~CSPopL() { CleanupStack::Pop(); /*no destroy*/}
private:
    void * operator new(size_t size); // stack only
};


// CSPushPopCloseL, Use the macro only.
class CSPushPopCloseL
{
public:
    explicit CSPushPopCloseL(RHandleBase& handle) { CleanupClosePushL(handle); }
    
     ~CSPushPopCloseL() { CleanupStack::PopAndDestroy(); /*calls Close()*/}
private:
    
    void * operator new(size_t size);
};


#endif // _chxavcleanupstack_h_