Create some signals/slots to demonstrate what I mean.

(These are currently not connected, therefore nothing happens yet).
Connect signals from last commit.

ImagePreview::areaCreated -> Dialog::slotNewArea
ListSelect::positionableTagSelected -> Dialog::positionableTagSelected
ListSelect::positionableTagDeselected -> Dialog::positionableTagDeselected
ResizableFrame::tagAssociated -> Dialog::positionableTagDeselected