In the base case -- where nothing is moving -- it'...

# tornadofx

[carlw]

In the base case -- where nothing is moving -- it's set to bogus values. I usually use -1, but if you're feeling Smalltalk-y you could use an object constant like EMPTY_TILE.

The purpose of tracking something like this is to cancel the drag operation. For example, if the users presses the ESC key or drags outside of the app entirely.