Autoscroll diagram on node outside viewport

GoXam
1

The aim is to let user moving node outside the actual viewport (using drag tool) without stop dragging, scroll the diagram, restart dragging but performing a clever auto-scroll.

I use this code, but it is not really good…

[Code]
public void MovePanel(Node node)
{
if (node == null) return;
DiagramPanel panel = node.Panel;
if (panel == null) return;

        // get the bounds of the Node, in model coordinates
        Rect r = node.Bounds;
        // get the bounds of the visible extent of the view, in model coordinates
        Rect v = panel.ViewportBounds;

        // scroll the panel in the right direction
        double dX = v.X;
        double dY = v.Y;
        double dDelta = 20.0;
        double dMore = 30.0;

        if (r.Y + r.Height >= v.Y + v.Height + dMore) dY += dDelta;
        else if (r.Y <= v.Y + dMore) dY -= dDelta;

        if (r.X + r.Width >= v.X + v.Width + dMore) dX += dDelta;
        else if (r.X <= v.X + dMore) dX -= dDelta;

        if (dX != v.X || dY != v.Y)
            panel.Position = new Point(dX, dY);
    }

[\code]