Nothing happens if num reads the same as the current label. If the label has a buddy, the accelerator is disabled since the pixmap doesn't contain any suitable character. The label resizes itself if auto-resizing is enabled. Nothing happens if pixmap is the same as the current label. The label resizes itself if auto-resizing is enabled.
Nothing happens if text is the same as the current label.
The default setting is AutoText, i.e. the label autodetects the format from text . If the format is RichText, the label uses the default mime source factory to resolve references to images. Note that a label is only useful for rather small documents with one or maximal two lines of text. If you need to display larger documents, a QTextView is the widget of choice. It will flicker less on resize and can also provide a scrollbar if necessary.