Hi All,

I have created a diagram programmatically that looks like example_001.png. There are two table nodes. Each table has an AnchorPattern with two anchor points, one on either side of the caption. Each table consists of multiple rows with AnchorPoints on either side. There are three links, all attached to anchor points. The first one is connected between the two nodes. The second is connected from the first node to the 3rd row in the second node. The third is connected from the 3rd row in the first node to the 3rd row in the second node.

I've attached an xml output of the diagram (example.txt).

When i apply any layout to the graph it seems to either reassign the anchor points (even tho i always set Anchoring = Keep) or ignore the Cascading style and make the links diagonal.

(see the zip for some examples).

Am I doing something wrong? Is there a type of layout that will respect the anchoring for table nodes?

Thanks for any help,

Chris

Hi,

Most layouts (FlowChartLayout included) modify the style of the links in the diagram. This is intentional and is done to accommodate the links to the layout logic. We have made some adjustments to the FlowChartLayout class to force him to preserve the cascading style of the links when possible as well as honor the Anchoring property (which was previously ignored to avoid breaking orthogonality). The adjustments are already available in the 5.8 Beta, which can be downloaded from here.

I hope this helps.

Regards,
Meppy

It appears that the current implementation of Layout.Anchoring does not take into consideration whether a link was attached to a table or an individual table row. However (as you have suggested) it is possible to control the anchoring of a link during layout by handling the Diagram.ValidateAnchorPoint event. The following code illustrates how:

void diagram1_ValidateAnchorPoint(object sender, LinkValidationEventArgs e)
{
	if (!layouting)
		return;

	if (e.ChangingOrigin)
	{
		if (e.Link.OriginIndex == -1)
		{
			// Attached to the table, we want to keep it this way
			if (e.TableRow != -1)
			{
				e.Cancel = true;
				return;
			}
		}
		else
		{
			// Attached to a row, ensure that the link preserves its row
			if (e.Link.OriginIndex != e.TableRow)
			{
				e.Cancel = true;
				return;
			}
		}
	}
	else if (e.ChangingDestination)
	{
		if (e.Link.DestinationIndex == -1)
		{
			// Attached to the table, we want to keep it this way
			if (e.TableRow != -1)
			{
				e.Cancel = true;
				return;
			}
		}
		else
		{
			// Attached to a row, ensure that the link preserves its row
			if (e.Link.DestinationIndex != e.TableRow)
			{
				e.Cancel = true;
				return;
			}
		}
	}
} 

The check at the start of the event handler ensures that this logic will execute only during layouts and it will not affect common interactions with the control. The layouting field is set to true immediately before the Arrange call and set back to false right after.

I hope this helps.

Regards,
Meppy