IliPointerTypeClass Class Reference

User interface class. More...

#include <ilviews/dataccess/datatype.h>

Inheritance diagram for IliPointerTypeClass:

Protected Member Functions
	IliPointerTypeClass (const char *name)
	Constructs an IliPointerTypeClass data type. More...
virtual IlAny	lockAny (IlAny any) const
	Increments a reference count related to an object. More...
virtual void	unLockAny (IlAny any) const
	Decrements a reference count related to an object. More...
Protected Member Functions inherited from IliDatatype
void	doRegister ()
	This protected member function can be called in the constructor of subclasses of IliDatatype to make the object visible to the GetDatatypeByName() and GetDatatypeByPrettyName() static member functions. More...
Protected Member Functions inherited from IliRefCounted
virtual	~IliRefCounted ()
	This is the virtual destructor of the IliRefCounted class. More...

Additional Inherited Members
Public Member Functions inherited from IliDatatype
const char *	getName () const
	Returns the name of a data type object. More...
virtual IliSchema *	getNestedSchema () const
	Returns the schema of the manager IliTable objects if this is a structured data type. More...
const char *	getPrettyName (IlvDisplay *display) const
	Returns pretty name. More...
virtual IlBoolean	isAnonymous () const
	Returns IlTrue if the name of the data type is not an identifier. More...
virtual IlBoolean	isBinaryType () const
	Returns IlTrue if the native format of the data type is binary. More...
virtual IlBoolean	isDateTimeType () const
	Returns IlTrue if the native format of the data type is a date or a time. More...
virtual IlBoolean	isDecimalType () const
	Returns IlTrue if the native format of the data type is IliDecimal. More...
virtual IlBoolean	isFractionalType () const
	Returns IlTrue if the native format of the data type is a real (for example, float, double, or IliDecimal). More...
virtual IlBoolean	isIntegralType () const
	Returns IlTrue if the native format of the data type is not a real (for example, Boolean, byte, or integer). More...
virtual IlBoolean	isLargeObjectType () const
	Returns IlTrue if the native format of the data type corresponds to a large type in the database (for example, long string). More...
virtual IlBoolean	isNumericType () const
	Returns IlTrue if the native format of the data type is numeric (for example, Boolean, byte, integer, float, double, or IliDecimal). More...
virtual IlBoolean	isObjectType () const
	Returns IlTrue if the the data type is an object. More...
IlBoolean	isRegistered () const
	Returns IlTrue if the data type is registered. More...
virtual IlBoolean	isStringType () const
	Returns IlTrue if the native format of the data type is a character string (for example, string or long string). More...
virtual IlBoolean	isStructuredType () const
	Returns IlTrue if the data type is a structured type (for example, table or object). More...
virtual IlBoolean	isTableType () const
	Returns IlTrue if the the data type is a table. More...
virtual IliTable *	makeTable () const
	Returns a created IliMemoryTable having the same schema as the data type if this is a structured data type. More...
void	writeType (std::ostream &output) const
	Writes the name of the data type to an output stream. More...
Public Member Functions inherited from IliRefCounted
IlInt	getRefCount () const
	Returns the reference count of the object. Initially, this property is set to 0. More...
void	lock () const
	Increments the reference count of the object.
void	unLock () const
	Decrements the reference count of the object. More...
Static Public Member Functions inherited from IliDatatype
static const IliDatatype *	GetDatatypeByName (const char *name)
	Returns the data type from a name. More...
static const IliDatatype *	GetDatatypeByPrettyName (IlvDisplay *disp, const char *name)
	Returns a data type whose localized name is prettyName or 0 if no such data type exists. More...
static const IliDatatype *	ReadType (std::istream &input)
	Reads a data type name from an input stream. More...

Detailed Description

User interface class.

Library: dataccess

The IliPointerTypeClass class can serve as a base class to implement custom data types. It works in conjunction with the IliValue::asAny() and IliValue::importAny() member functions. A custom data type manages objects of a given C++ type through IliValue objects. Internally, the managed objects are represented as void pointers by way of IlAny. The lockAny() and unLockAny() member functions provide the conversion between IlAny and the appropriate type and manage the object lifetime. A data type can specify what happens when an IliValue object is copied into another object. One of the following can occur:

• The managed can be shared between both IliValue objects.
• The managed object can be copied along with the IliValue object.

The following example shows how the sharing policy can be implemented:

class BitmapTypeClass
: public IliPointerTypeClass
{
public:
    BitmapTypeClass() : IliPointerTypeClass("MyBitmapType") {
        doRegister();
    }
    virtual IlAny lockAny(IlAny any) const {
        IlvBitmap* bmp = (IlvBitmap*)any;
        if (bmp) {
            bmp->lock();
        |
        return bmp;
    }
    virtual void unLockAny(IlAny any) const {
        IlvBitmap* bmp = (IlvBitmap*)any;
        if (bmp) {
            bmp->unLock();
        }
    }
};
BitmapTypeClass* BitmapType = new BitmapTypeClass();
IliValue toIliValue(IlvBitmap* bmp)
{
    IliValue value(BitmapType);
    value.importAny(bmp);
}
IlvBitmap* toIlvBitmap(const IliValue& value)
{
    if (value.getType() == BitmapType) {
        return (IlvBitmap*)value.asAny();
    }
    return 0;
}

The following example shows how the copy policy can be implemented:

class RectTypeClass
: public IliPointerTypeClass
{
public:
    RectTypeClass() : IliPointerTypeClass("MyRectType") {
        doRegister();
    }
    virtual IlAny lockAny(IlAny any) const {
        IlvRect* pRect = (IlvRect*)any;
        if (pRect) {
            return new IlvRect(*pRect);
        }
        return 0;
    }
    virtual void unLockAny(IlAny any) const {
        IlvRect* pRect = (IlvRect*)any;
    }
};
RectTypeClass* RectType = new RectTypeClass();
IliValue toIliValue(const IlvRect& rect)
{
    IliValue value(RectType);
    value.importAny(&rect);
    return value;
}
IlvRect toIlvRect(const IliValue& value)
{
    if (value.getType() == RectType) {
        return (IlvRect*)value.asAny();
    }
    return 0;
}

Constructor & Destructor Documentation

IliPointerTypeClass()

IliPointerTypeClass::IliPointerTypeClass ( const char *  name )

protected

Constructs an IliPointerTypeClass data type.

Parameters

name	If the name is unique among all registered data types, it is possible to call IliDatatype::doRegister() during construction to make the data type instance visible through IliDatatype::GetDatatypeByName() and IliDatatype::GetDatatypeByPrettyName().

Member Function Documentation

lockAny()

virtual IlAny IliPointerTypeClass::lockAny ( IlAny  any ) const

protectedvirtual

Increments a reference count related to an object.

Depending on the sharing policy of the data type, this virtual member function should do one of the following:

• Increment a reference count related to the object and return any itself.
• Return a copy of any.

If the object is 0, this member function should return 0.

Parameters

any	A pointer to an object managed by this data type or 0.

Returns

The object or 0.

unLockAny()

virtual void IliPointerTypeClass::unLockAny ( IlAny  any ) const

protectedvirtual

Decrements a reference count related to an object.

Depending on the sharing policy of this data type, this virtual member function should do one of the following:

• Decrement a reference count related to the object.
• Delete the object.

Parameters

any	A pointer to an object managed by this data type.