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/* Copyright (C) 2004 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/**
* @file myx_gc_variant.h
* @brief Implementation of a general purpose variant data type.
*
*/
#ifndef __GC_VARIANT_H__
#define __GC_VARIANT_H__
#include "myx_gc.h"
//----------------------------------------------------------------------------------------------------------------------
class CGCBase;
/**
* Implementation of a variant data type that can carry values of different type.
*/
typedef enum tagGCVariantType
{
GC_VAR_UNKNOWN, // The value type is unknown (e.g. because a property does not exist).
GC_VAR_BOOL, // The value is a boolean.
GC_VAR_INT, // The value is an integer number.
GC_VAR_FLOAT, // The value is a floating point number.
GC_VAR_STRING, // The value is a sequence of characters.
GC_VAR_OBJECT // The value is an object with subproperties (e.g. a figure instance).
} TGCVariantType;
typedef struct GENERIC_CANVAS_API tagGCVariant
{
private:
TGCVariantType type;
bool b;
int i; // Values are not in a union because of the string entry.
float f;
string s;
CGCBase* reference;
public:
tagGCVariant()
{
type = GC_VAR_UNKNOWN;
b = false;
i = 0;
f = 0;
reference = NULL;
};
tagGCVariant& operator = (const tagGCVariant& other);
tagGCVariant& operator = (const bool& b);
operator bool();
tagGCVariant& operator = (const int& i);
operator int();
tagGCVariant& operator = (const float& f);
operator float();
tagGCVariant& operator = (const string& s);
operator string();
tagGCVariant& operator = (const char* s);
tagGCVariant& operator = (CGCBase* object);
operator CGCBase*();
template <class T> T* cast(void)
{
if (type == GC_VAR_OBJECT)
return (T*) reference;
else
return NULL;
};
CGCBase* operator -> ();
tagGCVariant& operator += (const string& s);
tagGCVariant& operator += (const char* s);
bool isNonNullReference(void) { return type == GC_VAR_OBJECT && reference != NULL; };
bool isReference(void) { return type == GC_VAR_OBJECT; };
bool isString(void) { return type == GC_VAR_STRING; };
bool isValid(void) { return type != GC_VAR_UNKNOWN; };
} TGCVariant;
//----------------------------------------------------------------------------------------------------------------------
#endif // __GC_VARIANT_H__
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