modified from Rolias/PropertyHelper.h
These macros are intended to reduce the amount of boilerplate code the user has to write when using the Qt Frameworks's Q_PROPERTY feature. The idea was to provide something similar to C#'s auto property feature.
public double myValue {get;set;}I was after the lack of clutter not the syntax. This file contains two macros.
AUTO_PROPERTY(TYPE, NAME)It will create a standard
Q_PROPERTY (TYPE, NAME READ NAME WRITE Name NOTIFY NAMEChanged) macro of the passed type and name. In addition, it will create a standard getter named NAME, setter named Name and signal named NAMEChanged(TYPE value) It will also create the member data variable. Note it does not use the more standard setName syntax, mostly because I didn't know how to do the capitalization trick. The member var is named with an a_ prefix because it is intended to remind the user to NOT use the member variable name directly. The user should use the property name instead. If you don't like the a_ prefix change the macro.
READONLY_PROPERTY(TYPE, NAME)will create a standard
Q_PROPERTY(TYPE NAME READ NAME CONST)It will create the getter and the member variable name. In this macro, the member variable again uses a_ but the user is expected to initialize this variable directly. All reads of the variable should be done through the property for consistency.
READ_PROPERTY(TYPE, NAME)will create a standard
Q_PROPERTY(TYPE NAME READ NAME NOTIFY NAMEChanged)It like the READONLY_PROPERTY but the variable can be WRITE the new value only in C++ code.
AUTO_PROPERTY(QString, myProperty)
READONLY_PROPERTY(double, myValueProp)
READ_PROPERTY(double, myValueProp)Use these macros in the private: section of your header only. They use both public and private keywords and leave the header in the private section. Putting these macros directly under the Q_OBJECT macro at the top of the class is acceptable. If for some reason you have to use these macros in the public section it is your responsibility to add the public: keyword after the macro.
Note that these macros are only intended to be used as shown. The parameters are NOT intended to be expressions but simply the type and name. The parameters aren't parenthesized in the body of the macro and the entire macro is not parenthesized. Enjoy responsibly.
If you uses these macros at the top of your class then the member variables they create will be the first ones in your class. Therefore, to make tools like lint happy, you should add these variables to your initializer list in the order they are declared; before any variables that come after these macros. If you want to fully initialize variables in the order they are declared then even AUTO_PROPERTY created variables will need to be accessed directly. There is no harm in doing this. In general I was trying to adhere to the philosophy of the member variables being hidden and only the property being used.
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