MetaType class reference
[Base module]
Declaration
#include <QtLua/Value>
namespace QtLua {
template <typename X> class MetaType;
};
This class is a member of the QtLua namespace.
This abstract template class is declared in QtLua/qtluametatype.hh source file, line 82.
This abstract template class contains pure virtuals.
Description
This class can be used to register conversion functions used by QtLua to convert between Lua values and C++ types registered as Qt meta types. It enables use of user defined types for QObject properties and slot parameters.
Consider the following user defined struct and QObject properties:
// code from examples/cpp/types/myobject.hh:32
struct Mystruct
{
int a;
int b;
};
class MyQObject : public QObject
{
Q_OBJECT;
Q_PROPERTY(Mystruct mystruct READ mystruct WRITE setMystruct);
Q_PROPERTY(QMainWindow* mainwindow READ mainwindow WRITE setMainwindow);
The following code shows how to write conversion handler class to handle the Mystruct C++ type as a table value on the lua side:
// code from examples/cpp/types/myobject.hh:41
QTLUA_METATYPE(MyStructConvert, Mystruct);
QtLua::Value MyStructConvert::qt2lua(QtLua::State *ls, const Mystruct *qtvalue)
{
QtLua::Value luavalue(QtLua::Value::new_table(ls));
luavalue[1] = qtvalue->a;
luavalue[2] = qtvalue->b;
return luavalue;
}
bool MyStructConvert::lua2qt(Mystruct *qtvalue, const QtLua::Value &luavalue)
{
qtvalue->a = luavalue.at(1);
qtvalue->b = luavalue.at(2);
return true;
}
The conversion handler and the Qt meta type will be registered on class instantiation:
// code from examples/cpp/types/meta.cc:30
MyStructConvert mystruct_converter;
Moreover, a template class with builtin conversion functions is available to readily handle QObject pointer cases:
// code from examples/cpp/types/myobject.hh:60
QTLUA_METATYPE_QOBJECT(MyQMainwindowConvert, QMainWindow);
// code from examples/cpp/types/meta.cc:33
MyQMainwindowConvert qmainwindow_converter;
See also qRegisterMetaType, QTLUA_METATYPE macro, QTLUA_METATYPE_ID macro and QTLUA_METATYPE_QOBJECT macro.
Members
Protected functions
Private function
- MetaType()
Private fields
Macros
Members detail
This constructor is declared in QtLua/qtluametatype.hh source file, line 88.
This member access is protected.
Register a conversion handler for an already registered Qt meta type.
This constructor is declared in QtLua/qtluametatype.hh source file, line 92.
This member access is protected.
Register a conversion handler and qt meta type (using the qRegisterMetaType function).
This constructor is declared in QtLua/qtluametatype.hh source file, line 146.
This member access is private.
This destructor is declared in QtLua/qtluametatype.hh source file, line 95.
This member access is protected.
Unregister conversion handler
This macro is declared in QtLua/qtluametatype.hh source file, line 107.
This macro defines a type conversion handler class. Class instantiation will also take care of registering the meta type to Qt.
This macro expands to:
struct name
: public QtLua::MetaType<typename_>
{
name()
: QtLua::MetaType<typename_>(#typename_) {}
inline QtLua::Value qt2lua(QtLua::State *ls,
typename_ const * qtvalue);
inline bool lua2qt(typename_ *qtvalue,
const QtLua::Value &luavalue);
};See also MetaType class.
This macro is declared in QtLua/qtluametatype.hh source file, line 122.
This macro defines a type conversion handler class for an existing Qt meta type id.
This macro expands to:
struct name
: public QtLua::MetaType<typename_>
{
name()
: QtLua::MetaType<typename_>((int)typeid_) {}
inline QtLua::Value qt2lua(QtLua::State *ls,
typename_ const * qtvalue);
inline bool lua2qt(typename_ *qtvalue,
const QtLua::Value &luavalue);
};See also MetaType class.
This macro is declared in QtLua/qtluametatype.hh source file, line 139.
This macro defines a type conversion class along with its handler functions able to convert QObject pointers values. The class_ parameter is the bare class name without star.
This macro expands to:
typedef QtLua::MetaTypeQObjectStar<class_> name;See also MetaType class.
This variable is declared in QtLua/qtluametatype.hh source file, line 147.
This member access is private.
This variable is declared in QtLua/qtluametatype.hh source file, line 148.
This member access is private.
virtual bool lua2qt(X *qtvalue, const Value &luavalue) = 0;
This pure virtual function is declared in QtLua/qtluametatype.hh source file, line 103.
This member access is protected.
This function must be implemented to converts a lua value to a C++ value.
The return value is true on success.
This pure virtual function is declared in QtLua/qtluametatype.hh source file, line 99.
This member access is protected.
This function must be implemented to converts a C++ value to a lua value.