It is common practice in many UI situations to preselect the text displayed in a text editing field in such a way that if the user starts typing it immediately replaces the displayed text.
This can be useful for example in search field to show the previously searched text (for reuse or editing) while making it easy to search for a new text string simply by start typing.
I've searched for how to do this in TextField, but not found a way yet - is it possible?