Normally an application will not need to create its own
QStyle will handle this detail for you. A style writer can optionally use a
QFocusFrame to have a focus area outside of the widget’s paintable geometry. In this way space need not be reserved for the widget to have focus but only set on a
setWidget . It is, however, legal to create your own
QFocusFrame on a custom widget and set its geometry manually via
setGeometry however you will not get auto-placement when the focused widget changes size or placement.
The focus frame will not monitor
parent for updates but rather can be placed manually or by using
setWidget . A
WA_NoChildEventsForParent attribute; as a result the parent will not receive a
ChildAdded event, this will make it possible to manually set the geometry of the
QFocusFrame inside of a
QSplitter or other child event monitoring widget.
QFocusFrame will track changes to
widget and resize itself automatically. If the monitored widget’s parent changes,
QFocusFrame will follow the widget and place itself around the widget automatically. If the monitored widget is deleted,
QFocusFrame will set it to zero.
Returns the currently monitored widget for automatically resize and update.