Hi,

Set KeyDownScript="onKeyDown" for the DiagramView, and add a handler that checks the KeyCode argument:

function onKeyDown(sender, args)
{
	if (args.getKeyCode() == 37)
	{
		// move left
	}
} 

The codes for left, up, right and down keys are 37, 38, 39 and 40 respectively. Moving selected nodes can be done by calling their getBounds() method, adding some offset to the coordinates of the returned rectangle and passing the modifiect rect to setBounds.

I hope that helps,
Stoyan