I am afraid there is no such event, neither there is a possible built-in approach to handle this case. You can request such an improvement here: http://kendoui-feedback.telerik.com/forums/127393-kendo-ui-feedback
Possible solution is to use an internal property that serves as a flag during Diagram processing the layout and an interval that fires your animation. Like so:
diagram = $(
interval = setInterval(
// start animation
With the Diagram I used I was unable to experience so long delay for the layout to redraw itself. But I guess that you have great amount of shapes and connections that might cause a longer delay.
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