If you have two nested containers and a shape inside the inner container a wrong connector will be activated if you try to create connection (target) to the shape. This can be reproduced with the MVVM SDK example. Try to connect the "Polo" shape to the "Bugatti" shape. The auto connector of the "Bugatti" shape will not be activated when the endpoint of the connection is inside the shape. It will be activated only if you directly hover over the connector.

Implemented functionality that detects a connection creation being cancelled through the Esc key and notifies the user

In order to take advantage of this functionality you should inherit the ConnectionTool of RadDiagram and override the KeyDown method - if it returns true the tool action has been canceled.
More about how to customize RadDiagram tools you can find in our help topic " Tools Customization": http://www.telerik.com/help/wpf/raddiagram-tools-customization.html

Available in LIB version: 2014.3.1103

We use a RadDiagram for what is essentially graphic-art layout.  At times, subpixel positioning and extents really are correct for this use case.  We have shapes correctly positioned and displaying at subpixel accuracy; however, the selection outline always snaps to a pixel.

This is particularly relevant when zoomed in on a piece of art, e.g., aligning semi-transparent edges.  It looks odd to have the selection outline lie outside of the visible extents of the art.  Furthermore, when moving the art by mouse, the interaction is odd in that the art appears to move smoothly while the selection outline pops from pixel to pixel.  This confused our users as to what was really happening as they positioned things.

The relevant code for this is in RadDiagram.UpdateManipulationAdorner, which uses Math.Floor and Math.Ceiling to snap the line to pixel borders.  This was apparently put in to solve issues of blurriness from having a, say, 1-pixel selection outline lie at a sub-pixel position.  Perhaps a dependency property to control whether this snapping happens?

Implement automatic-layout of Polytree (http://en.wikipedia.org/wiki/Polytree) graphs.
Layout with multiple roots in single graph component.

We added an SDK sample showing how you can layout such tree hierarchies in RadDiagram:
https://github.com/telerik/xaml-sdk/tree/master/Diagram/MultipleRootsInSingleTreeLayout 

The middle point in this context is a point that is located on the line segment that is positioned after the middle length of the line. Add a property on the RadDiagramConnection class that returns the middle point. The property should be DependencyProperty so it can be bound with OneWayToSource mode in order to be able to notify the bound view model (if such is presented).

Currently, you can get this information by combining the CalculateMiddlePointOfLine and AllPoints methods of the ConnectionUtilities class.

var allConnectionPoints = Telerik.Windows.Diagrams.Core.ConnectionUtilities.ConnectionUtilities.AllPoints(radDiagramConnection);
var startAndEndPoints = new Tuple<Point, Point>(radDiagramConnection.StartPoint, radDiagramConnection.EndPoint);
Point middlePoint = Telerik.Windows.Diagrams.Core.ConnectionUtilities.CalculateMiddlePointOfLine(startAndEndPoints, allConnectionPoints);

When you start resize operation on a grouped ContainerShape and Shape in it the Container shape size can not be shrink-ed more than the previous BottomRight position of the shape in it (despite that the shape size is changed and there is space for the collapsing).


Available in LIB version: 2016.1.21

When you paste a big image (bigger than 1024px) it gets blurry

A small glitch appears when the pencil tool is used. The glitch is demonstrated in the attached image.

To reproduce this use the following code snippet:

Steps to reproduce:

1. Start a new connection from Shape 1, by dragging one of its connectors.
2. Drag the connection over Shape 2. 

Expected: The connector closest to the mouse should get highlighted and when you drop the connection it should get attached to the shape.
Actual: The closest connector is not highlighted. Also, when you drop the connection over the target shape it doesn't get attached.

Add an option to modify the StartPoint and EndPoint properties of RadDiagramConnection instances via the SettingsPane.

This functionality can be achieved by modifying the default ControlTemplate of the SettingsPaneView element to include an additional RadTabItem instance in the RadTabControl element. In the additional RadTabItem, input controls can be used, such as the RadNumericUpDown element. These elements should modify properties that will be present in a custom LinkViewModelBase<NodeViewModelBase>> class. More specifically, the X and Y properties of the StartPoint and EndPoint properties of the RadDiagramConnection element.

The attached sample project shows the implementation of the above approach for achieving this requirement.

Add an option to customize the available colors in the SettingsPane control:

Use Bezier Connection.

Change Start / End Handles with Mouse or with SetBezierHandles method in code.

Rotate/ Drag the connection and notice it is being shifted / its geometry changes unexpectedly.

Possible workaround override the RadDiagramConnection like so:

  public class CustomConnection : RadDiagramConnection
    {
        protected override void OnStartPointChanged(System.Windows.Point newValue, System.Windows.Point oldValue)
        {
            this.ConnectionPoints[0] = new Point(
                    this.ConnectionPoints[0].X - newValue.X + oldValue.X,
                    this.ConnectionPoints[0].Y - newValue.Y + oldValue.Y);         
               
            
            base.OnStartPointChanged(newValue, oldValue);           
        }

        protected override void OnEndPointChanged(Point newValue, Point oldValue)
        {
            this.ConnectionPoints[1] = new Point(
                    this.ConnectionPoints[1].X - newValue.X + oldValue.X,
                    this.ConnectionPoints[1].Y - newValue.Y + oldValue.Y);         
              
            
            base.OnEndPointChanged(newValue, oldValue);           
        }
    }


Available in R3 2016 SP

I looked at the RadDiagram options, but it doesn't have anything that compares to a circular relationship chart.  Here's an example:

https://www.codeproject.com/KB/silverlight/342715/screenshot2.png

Part of this article:

https://www.codeproject.com/Articles/342715/Plotting-Circular-Relationship-Graphs-with-Silverl

I gave some thought at trying to rewrite the code into WPF, but I've got too many other irons in the fire.  Figured I'd ask as this sort of visualization control doesn't appear in your current collection.  I have a project that could benefit from displaying weighted relationships in such a manner, but my choices are either do something sub-par with the RadDiagram option, write one myself, find another controls collection and port everything, or leave the feature out for now.  I'm going for the leave it out option for the moment, and see if your UI wizards can come up with something...

Just as a use case, one of the reasons for wanting this is to diagram conversations between individuals in email messages.  Being able to show who's talking to whom and how frequently using one of these charts for visualization allows you to quickly find patterns...

StackOverflowException is thrown when the Layout() method of RadDiagram is called and the diagram's router is OrgTreeRouter. To reproduce this  use TreeLayoutSettings.

To work this around, add bigger HorizontalSeparation and VerticalSeparation for the TreeLayoutSettings. Or disable the connections routing using the RouteConnections property of RadDiagram.