Adding class to MainWindow - using QHBoxLayout ?

[anneranch]

In so many words and with usual way to make me feel like an idiot for asking I now have BETTER understanding of widgets.
Thanks.
Especially the structure of QMainWindow.
Simple - it contains three QWidgets and the one I want to work with is the "centralwidget".
I have NO issues adding to "centralwidget" using QtDesigner GUI, i will be looking into HOW to add generic QWidget in code.
By generic I mean simple "button" or entire class - such as QDock.
I'll ask for more help IF I NEED IT.

[d_stranz]

In so many words and with usual way to make me feel like an idiot for asking I now have BETTER understanding of widgets.

Sorry, I don't mean to make you feel like an idiot, but so many times I give you example code, and then you seem to decide you want to do something different that doesn't work. Follow my examples, follow the many, many Qt examples that use QMainWindow, and you won't spend so much time trying to get your UI to work.

If you are using Qt Creator, look on the Welcome page. You'll see 100 or more projects under Examples, and a bunch of video and other tutorials on the Tutorials page. Many of the QWidget-based examples use QMainWindow as a start and add their UI to the central widget.