I tested the approach suggested by Zarko and as far as I understand your requirements, it covers them. From the communication so far I can understand that you need to update the size of the custom BackgroundShape so that it stretches all over the available space of the diagraming surface. With the bindings suggested in Zarko's last reply I achieved the behavior that can be seen in this screencast
. Could you please take a look at it and see if you receive the same behavior?
If you can reproduce the exact same behavior on your side, but it is not what you require, I will kindly ask you to provide us with more information about your requirements. We will need you to send over images demonstrating the required behavior.
For example you can make a picture showing the initially loaded diagram. Then you can explain in details what steps you perform and last you can make another picture showing the required sizing and positioning of the custom shape.
By doing so, together, we will ensure that we understand each other and that the communication continues on a positive path leading to resolving any issues that you encounter.
Thank you for your kind cooperation.
Pavel R. Pavlov
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