Qt Auto Property Macros

PropertyHelper.h

#pragma once
#include <QObject>
//See Gist Comment for description, usage, warnings and license information
#define AUTO_PROPERTY(TYPE, NAME) \
    Q_PROPERTY(TYPE NAME READ NAME WRITE NAME NOTIFY NAME ## Changed ) \
    public: \
       TYPE NAME() const { return a_ ## NAME ; } \
       void NAME(TYPE value) { \
          if (a_ ## NAME == value)  return; \
          a_ ## NAME = value; \
          emit NAME ## Changed(value); \
        } \
       Q_SIGNAL void NAME ## Changed(TYPE value);\
    private: \
       TYPE a_ ## NAME;

#define READONLY_PROPERTY(TYPE, NAME) \
    Q_PROPERTY(TYPE NAME READ NAME CONSTANT ) \
    public: \
       TYPE NAME() const { return a_ ## NAME ; } \
    private: \
       void NAME(TYPE value) {a_ ## NAME = value; } \
       TYPE a_ ## NAME;

12/4/2014 Fixed wayward pair of {} after private type declaration.

This is a great idea, but unfortunately, setProperty does not work with this. The reason is that moc does not create the property because it doesn't understand the AUTO_PROPERTY macro. Do you know a solution for this?

Update: Aha! Moc does expand macros, since Qt5. I only have to take care that moc has the same include path as the C++ compiler, or otherwise make sure that moc actually finds PropertyHelper.h.

Hi, thanks for your great working

I have some ideas for updating the file.

• Use reference in function WRITE in AUTO_PROPERTY
void NAME(const TYPE& value)

• Remove function WRITE in READONLY_PROPERTY
void NAME(TYPE value) {a_ ## NAME = value; }

• Add define READ_PROPERTY with the Q_SIGNAL for qml can get the notify when property changed in C++.
  QML can not change the property.

You can see details in https://gist.github.com/tackelua/bcae0e346fc98184ba7a044315fd0a4c/revisions#diff-b6a69a742adff907546e80f3703e301a