Gantt Performance

[bzbetty]

Large Gantt charts are noticably slow, doing a very quick/basic profile it seems that GanttColumns are rerendered whenever the mouse moves. This seems to be mostly to get the Y position of the mouse to render the GantAddFeatureHelper. As soon as I remove the useMouse line (and anything it breaks) the whole chart is noticably snappier.

Thoughts:

• While the value is throttled the rerender still happens. Is there a better way to throttle?
• The houseEnter/Leave events don't seem to cause the same issue, could use rows or cells with onenter/leave evnets instead of tracking the mouse directly (the pixel perfect Y tracking does seem a bit weird anyway)
• Does the add feature have to be in every column? if you hoisted it up to be a single component at the top level then only that component would need to track the mouse (you'd then have to calculate X and Y position, so I appreciate why you did it the way you did).
• Coudl the mouse tracking only be enabled/disabled when the mouse is in that container? (useMouse doesn't seem to have that feature)