[Qt-interest] How associate slot sender with my data object?

[Ed Sutton]

I am getting started using signals and slots. I use QSignalMapper with QGroupBox collection of QRadioButtons that select video channels.  

In the received slot, how can I both retrieve the sender's checked state and associate the sender with it's related channel data object?  Do QT widgets support a pointer to a void* "tag object"?  Some way to associate my data object with the signal sender?  I tried to make my own but cannot seem to derive from QRadioButton.

In order to determine the QRadioButton checked state in the slot, the best choice seems to use the SLOT(channelChanged(QWidget*)) signature.  In order to associate the sender with my data object, must I make my own associative map collection?  Is this typical or is there a better approach?

Thanks in advance for sharing your experience,

-Ed