Adds a new highlighting effect to the actively selected row in
ComboBox ListView. ComboBoxEditor can now be controlled with
page up, page down, and the up and down arrow keys. ESC and loss
of focus now cause comboboxes to close. Now activates on mouseup
as well as return.
This implements the following optimizations:
* Rather than clearing a HashTable of selected items and re-populating
it every time the selection rectangle changes, determine the delta
by only examining the items that might be in the area where the
selection may have changed compared to the previous area. Then
only add/remove selection items as needed.
* When painting, only query and paint the items actually visible.
Also, keep a local cache of item information such as calculated
rectangles and selection state, so it doesn't have to be calculated
over and over again.
This is really just a workaround to keep SystemMonitor's process table
working right wrt selection retention during resorts (while also doing
full index invalidation on things like ProfileViewer inversion.)
It's starting to feel like the model abstraction is not super great
and we'll need a better approach if we want to actually build some more
dynamic functionality into our views.
AbstractView does not know which column it's displaying which makes it
impossible to implement the select_all functionality up there. Now
descendants override the pure virtual select_all method and implement
it themselves.
You can now drop things on an AbstractView, which will ask its model if
the drag is acceptable to drop at the index where it's dropped.
If it's accepted by the model, the view will fire the on_drop hook.
