Custom connection serialization?

Segments saved like this:

For Each connection As CustomConnection In Me.Dg.Connections
  For Each segment As DiagramConnectionSegment In connection.Segments
    diagram.Segments.Add(New SegmentData() With { .X = segment.EndPoint.X, .Y = segment.EndPoint.Y })
  Next
Next

Cannot load the segments back to the diagram like this:

For Each data As SegmentData In savedSegments
  segments.Add(New DiagramConnectionSegment(data.X, data.Y) )            
Next

and parsing them to the Connection constructor:

Dim connection As New CustomConnection(connectionPointA, connectionPointB, segments)
Dg.Connections.Add(connection)

does not load any of previous lines. It is not an option to load them from the default serializer provided by Mindscape. It seems like I draw the lines using the pathfinder again.

Regards, Michael

Hello Michael

For connections that you want to specify the segment list, you can set IsUserModified to true. This is a signal for the pathfinders to only re-find a path if absolutely necessary.

Jason Fauchelle

Hi' Jason

The IsUserModified helped, but........

Skipping the first segment, cause the line to be rendered correct with the movable segment as before. However the position of the line is not restored accordingly. Rendering all segments again cause the position of lines to be as before, but no movable segment is rendered.

Saving:

For Each connection As CustomConnection In Me.Dg.Connections
  For Each segment As DiagramConnectionSegment In connection.Segments
    diagram.Segments.Add(New SegmentData() With { .X = segment.EndPoint.X, .Y = segment.EndPoint.Y, .IsMoveable = TypeOf segment Is MovableDiagramConnectionSegment })
  Next
Next

Loading:

For Each data As SegmentData In savedSegments.Skip(1)
  segments.Add(If(data.IsMoveable, New MovableDiagramConnectionSegment(data.X, data.Y), New DiagramConnectionSegment(data.X, data.Y)))
Next

Regards, Michael

Hello Michael

That sounds bizarre. Your code looks correct (except for skipping the first segment). I have not been able to reproduce this at my end. Could you please send a repro project, then I'll be able to find the problem for you.

Jason Fauchelle

Sorry for the late reply, I've been very busy....... Please have a look in the attached repro project, there is a pdf file with a little description included as well.

Regards, Michael

No worries Michael

Thanks for the repro project. The reason why the segments are not movable is because of one small piece of missing logic. In your DoLoadCustom method, while creating the segments, you need to manually set the PreviousSegment property of each segment to reference the previous segment. (I've made a note for the foundation to automatically handle this in a future version). Here is one possible modification of your code that will achieve this:

Dim previousSeg As DiagramConnectionSegment = Nothing
For i As Integer = 0 To savedSegmentData.Count - 1
    Dim d As SegmentData = savedSegmentData(i)
    Dim isMovable As Boolean = i > 1 AndAlso i < savedSegmentData.Count - 1
    Dim seg As DiagramConnectionSegment = If(isMovable, New MovableDiagramConnectionSegment(d.X, d.Y), New DiagramConnectionSegment(d.X, d.Y))
    seg.PreviousSegment = previousSeg
    previousSeg = seg
    segments.Add(seg)
Next

Your custom loading and saving logic does not seem to currently use the IsUserModified flag that I previously mentioned. If you implement the support for this flag, then your custom load and save implementations will correctly maintain the users segments positions. After you implement this, if the positions are still lost, you'll need to get the latest nightly build of WPF Diagramming as I noticed the version you are using has a bug related to this. Nightly builds can be downloaded from your account page.

Let me know if there are further problems.

-Jason Fauchelle

Hi' Jason

Once again, you saved my day........ Thanks :-)

The PreviousSegment "thing" did the trick.

Regards, Michael