[Potlatch-dev] Development note - selections, ControllerStates and event listeners
richard at systemeD.net
Wed Nov 3 15:10:23 GMT 2010
This is here partly for Andy and Dave and anyone else who hacks on the
P2 source, and partly for me as an aide-memoire. :)
I've refactored a bunch of the selection code in preparation for
allowing multiple selection one day. (See
The ControllerStates now have a _selection property. This is an array
containing all the selected objects. It replaces the previous
selectedWay and selectedNode.
There are various setters and getters in ControllerState.as. In
particular, for single object ControllerStates (which are all that
exist right now), you will want to use the firstSelected getter, and
cast it as a Node or Way if required.
So where previously you'd have used
node = selectedNode
you now use
node = firstSelected as Node
node = Node(firstSelected)
There may be regressions as a result so let me know if you spot any.
Secondly, while working on this, I think I figured out a big P2 bug.
There have been several reports of shift-click to insert a node
stopping working, and of course we have the long-standing issue where
WayUIs occasionally hang around between zoom levels.
This appears to be because WayUIs weren't being destroyed when they
should be; and that's partly because event listeners need to be
expressly removed, otherwise they prevent an object from being garbage
collected. (You can also use setWeakReference when you do
addEventListener, but it's neater to remove them manually.)
There were some other bugs that showed up too. But (and like I say,
this is here as an aide-memoire for me as much as anything) make sure
you remove any event listeners you've added!
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