* If there would be no tooltip otherwise, it just shows the thumbnail. Otherwise
any tooltip text (like view parameters or image layout) is displayed below the
thumbnail
* This prevents SH_ItemView_ArrowKeysNavigateIntoChildren from causing left-move
from an expanded node to jump immediately to its parent instead of collapsing
it when the scrollbar is not leftmost
* This allows us to add rich text support much more easily into other itemviews
like RDTableView.
* We set it up for debug messages so that resource links in debug messages can
be linked.
* This is supported currently in the API inspector, constant buffer previewer, and resource inspector.
* The saved expansions are only saved while the capture is open, and will be reset each time.
* This item delegate will forward on either to a specified other
delegate or to the base implementation. This allows chaining delegates
(i.e. having one built-in to the widget, which forwards to a user-set
delegate).
* There's a messy order-of-operations thing to deal with various
different themes, as well as a couple of minor problems, but at least
the highlight and selection bars draw fairly consistently and don't
leave an ugly gap over the branches.
baldurk