The auto snapping to nearest ConnectionPoint mechanism

Hi,

I am having a problem here where the auto snapping to the nearest ConnectionPoint doesn't work anymore. I tried using the sample and it seems to be working. So, there must be something in my node style / connection template that preventing that from happen? Could you point me to a specific area which I can root cause it?

Thanks.

Hello

It may be something to do with hit testing on your node style(s). When you say that it is not working, do you mean that when you drop a connection on the node (not on an exact connection point) the connection is not made at all? or do you mean the connection is added to the diagram, but not connecting to the closest connection point? Is this behaviour happening to all the different type of nodes you have? Also, does it work if you drop the connection exactly on a connection point? Would you be able to send us a simple repro of this issue?

-Jason

Hi, here is the repo that you can look into.

1. Snapping is not available for my custom style, you'll need to click "Add Node", then try creating connection by dragging to the edge, the connection will only be created if you drop it EXACTLY on the > spot. ( > is an inbound)

2. I might want to disable the behaviour of the OutboundConnectionPoints keep disappearing whenever I drag a connection to the node. You can notice it here as well.

3. It's regarding how I setup the PositionCalculator in the ConnectionPoint. I read your reply just now regarding the OnPositionChanged event. I am still a bit confused about the OffsetPositionCalculator that being set whenever I create a new ConnectionPoint using the factory. (Specifically in line: 87, FlowDiagramConnectionModel). I'll need TotalConnectionPoints on the particular edge in order to re-calculate the position of the connectionPoint. Should I simplify the implementation by moving all the calculation to the OnPositionChanged event, just set the position on the fly? without setting the calculator?

Thanks

Hello

Thanks for the repro, it helps a lot. There seems to be some issue with using the "new" keyword to override the ConnectionPoints property. Is there any particular reason why you need to do this? If possible, I recommend just using the ConnectionPoints property implemented in the DiagramNode class which your FlowDiagramNodeModelBase class extends. Note that the DiagramNode implements this property using an ObservableCollection, but exposes it as an IList. In your repro, you can comment out the connectionPoint field and the ConnectionPoints property in the FlowDiagramNodeModelBase. Then cast the ConnectionPoints property into an INotifyCollectionChanged in the constructor to attach the event handler. When you run the repro now, you'll see some of the connection points are placed incorrectly, but the auto snapping feature will be working now. Let me know what you think of this approach.

-Jason

wow, didn't expect to be the 'new' keyword issue, as it works previously in version1.0. I changed the code accordingly and now it works, just as you said, the positions are a bit off, need to fine tune again. :/

Anyway, that solve my first problem, 2 to go. :)

Thanks.