Fixed stroke width

GoJS
#1

Hi,

I have a node that is basically a simply rectangle with a stroke width of 2 px.
I’d like the stroke width to be ‘always’ of 2px width, whichever the zoom level is. By that i mean that the width should always looks the same to the user.
Is there a simple way to achieve this ?

Thanks

#2

Perhaps like this sample does?

http://gojs.net/latest/samples/constantSize.html

  // This code keeps all nodes at a constant size in the viewport,
  // by adjusting for any scaling done by zooming in or out.
  // This code ignores simple Parts;
  // Links will automatically be rerouted as Nodes change size.
  var origscale = NaN;
  var oldscale = NaN;
  myDiagram.addDiagramListener("InitialLayoutCompleted", function(e) { origscale = oldscale = myDiagram.scale; });
  myDiagram.addDiagramListener("ViewportBoundsChanged", function(e) {
    if (isNaN(origscale)) return;
    var newscale = myDiagram.scale;
    if (oldscale === newscale) return;  // optimization: don't scale Nodes when just scrolling/panning
    oldscale = newscale; 
    myDiagram.skipsUndoManager = true;
    myDiagram.startTransaction("scale Nodes");
    myDiagram.nodes.each(function(node) {
        node.scale = origscale / newscale;
      });
    myDiagram.commitTransaction("scale Nodes");
    myDiagram.skipsUndoManager = false;
  });
#3

Thank Simon

I have looked at this example… it makes me realize that i have not stated my question correctly.

The user will not be able to zoom/unzoom in my diagram, but the dimension of the diagram can vary. I’d like my node to always have a stroke of ‘2px’ whichever the dimensions of the diagram are.

I think i can use the initialLayoutCompleted and do some maths here to adjust the stroke width of my node according to the current scaling.

#4

Hmm. Ok. Doing some work in initialLayoutCompleted is probably the right thing to do then.

#5

Thanks Simon, I find a good solution :

overviewDiagram.addDiagramListener("InitialLayoutCompleted", function(e) {
        var node = overviewDiagram.findNodeForKey('VIEWPORT');
        var drawedViewport = node.findObject('VIEWPORTRECTANGLE');
        drawedViewport.strokeWidth = 2 / overviewDiagram.scale;
    });