<![CDATA[reuse of custom C++ class]]>I use the same C++ chart class multiple times in a QML desktop application. I currently use multiple copies of the class with slightly different names and register them as follows:

ret = qmlRegisterType<MyClass0>("QwtQuick2", 1, 0, "MyClass0");

ret = qmlRegisterType<MyClass1>("QwtQuick2", 1, 0, "MyClass1");

ret = qmlRegisterType<MyClass2>("QwtQuick2", 1, 0, "MyClass2");

MyClass0 myclass0;
MyClass1 myclass1;
MyClass2 myclass2;

Here I connect the signals and slots to the classes for each chart.

This method functions as needed but I would prefer to not maintain many copies of the same class. Is there an alternative method?

Thanks,
Aaron

]]>https://forum.qt.io/topic/126876/reuse-of-custom-c-classRSS for NodeMon, 13 Apr 2026 04:31:53 GMTFri, 21 May 2021 21:10:55 GMT60<![CDATA[Reply to reuse of custom C++ class on Fri, 21 May 2021 22:14:59 GMT]]>Are you using these in QML?
Just do this in C++:

qmlRegisterType<MyClass>("QwtQuick2", 1, 0, "MyClass");

Then in qml:

import QwtQuick2 1.0
...
MyClass {
  id: myclass0
}
MyClass {
  id: myclass1
}
MyClass {
  id: myclass2
}

You can connect signals in qml via Connections, through on<signal name> callbacks, or actual connect calls to attach to functions in qml.

What are you connecting to these objects?

]]>https://forum.qt.io/post/660955https://forum.qt.io/post/660955Fri, 21 May 2021 22:14:59 GMT<![CDATA[Reply to reuse of custom C++ class on Fri, 21 May 2021 22:24:22 GMT]]>Thank you, I will look into what you suggest.
The signals to the instances contain different QVector arrays of data to be displayed.

Aaron

]]>https://forum.qt.io/post/660956https://forum.qt.io/post/660956Fri, 21 May 2021 22:24:22 GMT<![CDATA[Reply to reuse of custom C++ class on Fri, 21 May 2021 22:14:59 GMT]]>Are you using these in QML?
Just do this in C++:

qmlRegisterType<MyClass>("QwtQuick2", 1, 0, "MyClass");

Then in qml:

import QwtQuick2 1.0
...
MyClass {
  id: myclass0
}
MyClass {
  id: myclass1
}
MyClass {
  id: myclass2
}

You can connect signals in qml via Connections, through on<signal name> callbacks, or actual connect calls to attach to functions in qml.

What are you connecting to these objects?

]]>https://forum.qt.io/post/660955https://forum.qt.io/post/660955Fri, 21 May 2021 22:14:59 GMT<![CDATA[Reply to reuse of custom C++ class on Fri, 21 May 2021 21:21:36 GMT]]>The classes are identical except for the name. I change the name so that I can connect different signals to each instance.

]]>https://forum.qt.io/post/660949https://forum.qt.io/post/660949Fri, 21 May 2021 21:21:36 GMT<![CDATA[Reply to reuse of custom C++ class on Fri, 21 May 2021 21:12:40 GMT]]>Hi,

What are the differences between these classes ?

]]>https://forum.qt.io/post/660948https://forum.qt.io/post/660948Fri, 21 May 2021 21:12:40 GMT