Question

I have multiple QLineEdit widgets on a configuration widget.

When the configuration text is changed I want to store the updated value (there are a few of them so I don’t want to pass them in one function call at the end).

I was thinking to connect them to one slot or go through QSignalMapper to one slot.

However I’m having trouble finding an elegant way to tell the QLineEdits apart, I want to know which QLineEdit emitted the signal – since I’m in handler object that implements the logic I can’t compare the sender() with the original object.

I can hook them up through QSignalMapper so that my handler gets either int id or QObject* or QWidget* reference to the actual widget that emitted the signal so I can get easily the new text, but I would like to be able to switch on some id to update the correct setting internally.

Is there any elegant way to tag or label Qt objects or widgets?

Answer 1

Dynamic properties allow you to ‘tag’ extra data at run-time onto any QObject derived class. See the QObject::setProperty documentation.

I personally don’t like using dynamic properties as they aren’t documented in the header of the class. I prefer to inherit from the class and add a standard property.