How do I use promote to in Qt Designer in pyqt4?

Question

In the designer when I right click a widget, and I click promote to I get this window. See the screenshot below.

I have never used this feature. Basically, the header file is confusing me. What is it for? Does that mean I can create a new class in this case, inheriting QLineEdit and add more methods to it? What is the promoted class name?

Answer 1

This allows you to use custom widgets defined elsewhere, which designer otherwise wouldn't know about.

For example, if you've defined a widget MyLabel derived from QLabel, then you can define it here and then just insert a QLabel as placeholder in your ui and promote it to MyLabel.

The uic compiler will then include the necessary imports/includes, for example if you specified mypackage/mycomponent.h as header file and MyLabel as class name, then pyuic will add

from mypackage.mycomponent import MyLabel

(note how the .h is ignored, and slashes are converted to . by pyuic to keep compatibility with python)

Global include is ignored by pyuic, it only affects uic (generate #include "mypackage/mycomponent.h" or #include <mypackage/mycomponent.h> for c++)