I needed to change a QTextEdit to QTextBrowser (to easily support links) in a dialog created with Designer. Apparently this is impossible to do with Qt Creator, because I had to open the .ui file in external editor and change the type of the widget.

This is especially bad, since it's possible to morph QTextBrowser to QTextEdit or QPlainTextEdit, but morphing back isn't possible (except with undo, as long as it remains in undo buffer).

Related, Qt Creator should have option to edit .ui file as text without using external editor, especially now that it has quite nice XML highlighting, and because editing with external editor can't be prevented anyway.