scopedbitmapaccess.hxx

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#ifndef INCLUDED_VCL_SCOPEDBITMAPACCESS_HXX
#define INCLUDED_VCL_SCOPEDBITMAPACCESS_HXX

namespace vcl
{

template < class Access, class Bitmap, Access* (Bitmap::* Acquire)() > class ScopedBitmapAccess
{
public:
    explicit ScopedBitmapAccess( Bitmap& rBitmap ) :
        mpAccess( nullptr ),
        mpBitmap( &rBitmap )
    {
        mpAccess = (mpBitmap->*Acquire)();
    }

    ScopedBitmapAccess( Access* pAccess, Bitmap& rBitmap ) :
        mpAccess( pAccess ),
        mpBitmap( &rBitmap )
    {
    }

    ScopedBitmapAccess( ) :
        mpAccess( nullptr ),
        mpBitmap( nullptr )
    {
    }

    // Move semantics
    ScopedBitmapAccess &operator=(ScopedBitmapAccess&&other)
    {
        mpAccess=other.mpAccess;
        mpBitmap=other.mpBitmap;
        other.mpAccess = nullptr;
        other.mpBitmap = nullptr;
        return *this;
     }

    // Disable copy from lvalue.
    ScopedBitmapAccess(const ScopedBitmapAccess&) = delete;
    ScopedBitmapAccess &operator=(const ScopedBitmapAccess&) = delete;

    ~ScopedBitmapAccess() COVERITY_NOEXCEPT_FALSE
    {
        if (mpAccess)
           mpBitmap->ReleaseAccess( mpAccess );
    }

    void reset()
    {
        if (mpAccess)
        {
           mpBitmap->ReleaseAccess( mpAccess );
           mpAccess = nullptr;
        }
    }

    bool operator!() const { return !mpAccess; }
    explicit operator bool() const
    {
        return mpAccess;
    }

    Access*         get() { return mpAccess; }
    const Access*   get() const { return mpAccess; }

    Access*         operator->() { return mpAccess; }
    const Access*   operator->() const { return mpAccess; }

    Access&         operator*() { return *mpAccess; }
    const Access&   operator*() const { return *mpAccess; }

private:
    Access*     mpAccess;
    Bitmap*     mpBitmap;
};

}

#endif // INCLUDED_VCL_SCOPEDBITMAPACCESS_HXX

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