Styjun

I have to draw some EA diagrams using only the .eap file without an installed EA on the server. So I am opening it as MDB-File via ODBC.

I know there is the attribute t_diagramlinks.Geometry (with edge=1,2,3,4) and the Attribute t_connector.Start_Edge and the attribute t_connector.End_Edge.

The table t_diagramlinks with the attribute Geometry is diagram-dependent.
The table t_connector with the attributes .Start_Edge and .End_Edge is not diagram-dependent --> there could be connections that haven't been drawn on a diagram.

I know that the SX, SY, EX, EY of t_diagramlinks are coordinates relative to the origin of each node that is drawn on a diagram.

Problem: EX / EY sometimes is zero and isn't painting the end line to the edge of the node. I guess it has something to do with mouse release position.

"My Interpretation" below is what my renderer produces based on my assumptions.

"EA Interpretation" is what EA is actually rendering and which I would like to see in my renderer as well.

Questions

• I am using the csv-Value EDGE in t_diagramlinks.Geometry - but where
  do I find this for the end node?




• For which purpose are the attributes Start_Edge an End_Edge in the
  table t_connector when it is not diagram-dependent?

I am using in t_diagramlinks.Geometry the csv-Value EDGE - but where
do i find this for the end node?

You need to use Euclide. SX,SY/EX,EY are relative shifts from the shortest center connection between start and end element.

For which purpose are the attributes Start_Edge an End_Edge in the
table "t_connector" when it is not diagram-dependend?

They are used for qualified properties.

Edit: To elaborate a bit more on your basic issue. t_diagramlinks.path holds bending points for the connector (if any are specified). So in order to find the point where a connector actually joins an element you have to find the nearest bend to that element. Now between this bend and the middle of the element you will have a natural attachment point. Relative to that the SX-Y (/EX-Y) are added to make the manually shifted rendered attachment point.

The above goes with a grain of salt. I never verified the nitty gritty but used my stomach from seeing the numbers. I might look into that in detail to update my Inside book but can't promise.

2nd Edit: Now that I know that "My Interpretation" is what your renderer produces based on your assumptions, here's the (most likely; see above) story. In order to render a connector EA will use the following information:

• the frame coordinates of the two connected elements


• calculated from the coordinates the middle point of the elements


• the path property of the connector (if not empty)


• the nearest bending point to the relevant elements (if not empty)


• the shift factors SX-Y and EX-Y for the connector

Starting from the start element's middle point you draw a virtual line to either the nearest bending point or the middle of the end element (unless see below). That way you can calculate the virtual attachment point at the element's rectangular frame (even use cases have a rectangular frame). Now you shift that point by SX-Y which will (/should?) always travel along the edge of the element frame. Now you have the virtual attachment point for the start element.

On the other side (the end element; my "unless" from above) you would do a similar thing to calculate the virtual attachment for the end. What I don't know is the real order in which EA is doing that (I have no code insight). So if you have manual offsets on both sides the calculation will give different results depending on the order to draw the virtual connection to the other side (so: is the shift on the other side respected or not). Basically I think you can neglect that for 99.9% of all cases and the rest is just irrelevant noise.

So now you know the virtual end points you either connect them directly or, if a path is give, you connect them via the bending points.

Again: all with a grain of salt. It's just observation from the outside but likely not too far away. There's also the fact that you have different line styles with rounded edges (not taken into account here) and bezier lines (even more dragon land).

Thank you very much. I choosed to calculate the End-Edge mathematically:

My problem was, that i wasn't able to detect the end edge of the target endnode on a link relation. Further more there are 8 different link types, that are determining the layout of the links. So as Thomas mentioned i had to detect the last point before the endpoint. If it is a path, the last node of the path is the point before the endpoint. If there is not a path, the startnodes starting point is the last point before the endpoint. But if there is a path defined and the link mode has been set to 1 i may not process the connection path, because the Conn_Path property is containing a customized line - but after customizing the user has selected to have a direct link (it will not be deleted).

The mathematic behind is used as linear function y=m*x+b and the lines are described by 4 straight lines which are appropriate to the edges of the endnode.

So you can do the following algorithm:

The complete algorithm is using the following approach:

1.) Determine straight line between start- and endnode (there are 2 special cases if the line is completely horizontal or vertically parallel to the coordinate system)

2.) Create a rectangle which consists of four straight lines (2 vertical / 2 horizontal lines)

3.) Determine the intersection of the first straight line with the rectangles lines

4.) Exclude point that are not consisting to the rectangle

5.) Determine the point on the rectangle with the shortest distance => this is the searched end edge point

The written javascript code i have used to do the routing is the following:

 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Erzeuge eine eigene Link-Klasse für das Routing der Pfeile, die von Hand gezogen wurden
// und über spezielle Attribute in der EAP-Datei definiert werden
// Ruft die Superklasse von go.Link im Konstruktor auf
function MultiNodePathLink() 
 go.Link.call(this);

go.Diagram.inherit(MultiNodePathLink, go.Link); // Erben von go.Link

// ignores this.routing, this.adjusting, this.corner, this.smoothness, this.curviness
/** @override */
MultiNodePathLink.prototype.computePoints = function () 

 // Die this Referenz ist hier ist ein geerbter ein go.Link. der bei Links
 var startNode = this.fromNode;
 var startNodeX = startNode.location.M; // X-Koordinate vom Startknoten
 var startNodeY = startNode.location.N; // Y-Koordinate vom Startknoten

 var endNode = this.toNode;
 var endNodeX = endNode.location.M; // X-Koordinate vom Startknoten
 var endNodeY = endNode.location.N; // Y-Koordinate vom Startknoten

 var startNodeData = startNode.data; // Das sind die Daten
 var endNodeData = endNode.data; // Das sind die Daten

 // Die Link-Daten
 var linkProperties = this.data;
 //** Das Feld Style in [t_diagramlink] bestimmt die Connector-Darstellung **/
 // http://www.capri-soft.de/blog/?p=2904
 /*
 * 1 = Direct Mode=1
 * 2 = Auto Routing Mode=2
 * 3 = Custom Line Mode=3
 * 4 = Tree Vertical Mode=3;TREE=V
 * 5 = Tree Horizontal Mode=3;TREE=H
 * 6 = Lateral Vertical Mode=3;TREE=LV
 * 7 = Lateral Horizontal Mode=3;TREE=LH
 * 8 = Orthogonal Square Mode=3;TREE=OS
 * 9 = Orthogonal Rounded Mode=3;TREE=OR
 */
 var styleStringArray = linkProperties.style.split(";");
 var mode = -1;
 var tree = '';
 for (var i = 0; i < styleStringArray.length; i++) 
 if (styleStringArray[i].trim().indexOf('Mode=') > -1) 
 mode = styleStringArray[i].replace('Mode=', '');
 

 if (styleStringArray[i].trim().indexOf('TREE=') > -1) 
 tree = styleStringArray[i].replace('TREE=', '');
 
 



 // In der Tabelle t_diagramlinks in der Freitextspalte "Geometry" wird in einem CSV-String
 // gespeichert, wie der Link letztendlich auf dem Diagram gezogen wurde
 var geometryString = linkProperties.geometry.split(";");
 // SX and SY are relative to the centre of the start object
 var sx = geometryString[0].replace("SX=", "");
 var sy = geometryString[1].replace("SY=", "");
 // EX and EY are relative to the centre of the end object
 var ex = geometryString[2].replace("EX=", "");
 var ey = geometryString[3].replace("EY=", "");

 // SX=-67;SY=-43;EX=-12;EY=-40;EDGE=3;$LLB=;
 // LLT=;LMT=;LMB=CX=30:CY=13:OX=11:OY=-2:HDN=0:BLD=0:ITA=0:UND=0:CLR=-1:ALN=1:DIR=0:ROT=0;
 // LRT=;LRB=;IRHS=;ILHS=;

 // EDGE ranges in value from 1-4, with 1=Top, 2=Right, 3=Bottom, 4=Left (Outgoing Point of the Start Object)
 var edge = geometryString[4].replace("EDGE=", "");

 // Hier beginnt das Custom-Routing
 this.clearPoints();
 if (linkProperties.start_object_name == 'System Verification Test Reports' && linkProperties.end_object_name == 'System test specifications') 
 var test = 'irrsinn';
 
 // Hier werden die Wege definiert für das gecustomizte Link Routing
 // Geht der Link nach oben oder unten wird die Y-Koordinate des Startknotens genutzt (Weil Orthogonales Routing)
 var startConnX = null;
 var startConnY = null;
 if (edge == 1) // Ecke oben
 startConnX = Math.abs(startNodeX) + Math.abs((startNode.actualBounds.width / 2) + new Number(sx));
 startConnY = Math.abs(startNodeY);
 
 else if (edge == 3) // Ecke unten
 startConnX = Math.abs(startNodeX) + Math.abs((startNode.actualBounds.width / 2) + new Number(sx));
 startConnY = Math.abs(startNodeY) + new Number(startNode.actualBounds.height);
 
 else if (edge == 2) // Ecke rechts
 startConnX = Math.abs(startNodeX) + startNode.actualBounds.width;
 startConnY = Math.abs(startNodeY) + Math.abs((startNode.actualBounds.height / 2) - new Number(sy));
 
 else if (edge == 4) // Ecke links
 startConnX = new Number(Math.abs(startNodeX));
 startConnY = Math.round(startNodeY) + Math.round((startNode.actualBounds.height / 2) - new Number(sy));
 
 else 
 alert('Die Edge konnte nicht entdeckt werden! Ist der Geometry String in der EAP Datei richtig?');
 

 this.addPoint(new go.Point(Math.round(startConnX), Math.round(startConnY)));

 // Abfrage: Gibt es einen letzten Path Punkt?
 var lastPathPunkt=false;
 var lastPathPunktX, lastPathPunktY;

 if (mode != 1)
 
 // Routing über die Zwischenwege
 if (typeof linkProperties.conn_path !== "undefined" && linkProperties.conn_path !== "") 
 var splittedArray = linkProperties.conn_path.split(";");
 if (splittedArray.length > 1) 
 // Hier ist mindestens ein Wert vorhanden da auch der erste mit Semikolon abgeschlossen wird im Path vom EA
 for (var i = 0; i < splittedArray.length - 1; i++) 
 var einMittelPunkt = splittedArray[i];
 var mittelPunktArray = einMittelPunkt.split(":");
 this.addPoint(new go.Point(Math.abs(new Number(mittelPunktArray[0])), Math.abs(new Number(mittelPunktArray[1]))))
 lastPathPunktX = Math.abs(new Number(mittelPunktArray[0]));
 lastPathPunktY = Math.abs(new Number(mittelPunktArray[1]));
 lastPathPunkt = true;
 
 
 
 

 // Wenn es keinen Pfad gab,muss der letzte Punkt mit dem Startknoten identisch sein
 if (lastPathPunkt == false) 
 lastPathPunktX = Math.abs(Math.round(startConnX));
 lastPathPunktY = Math.abs(Math.round(startConnY));
 

 // End-Routing
 // Der Endpunkt in EA in Document Coordinates
 var endConnX = Math.abs(endNodeX) + Math.abs((endNode.actualBounds.width / 2) + new Number(ex));
 var endConnY = Math.abs(endNodeY) + Math.abs((endNode.actualBounds.height / 2) - new Number(ey));

 // Spezialfälle bei horizontalen und vertikalen Linien:
 if (endConnX == lastPathPunktX) 
 // Es liegt eine vertikale Gerade (z.B. von oben nach unten) vor
 this.addPoint(new go.Point(Math.round(lastPathPunktX), Math.round(lastPathPunktY)));
 this.addPoint(new go.Point(Math.round(endConnX), Math.round(endConnY)));

 else if (endConnY == lastPathPunktY) 
 // Es liegt eine horizontale Gerade (z.B. von rechts nach links) vor
 this.addPoint(new go.Point(Math.round(lastPathPunktX), Math.round(lastPathPunktY)));
 this.addPoint(new go.Point(Math.round(endConnX), Math.round(endConnY)));
 else sY1)
 if (sY1 >= rY1 && sY1 <= rY2) 
 // Der Schnittpunkt sY1 ist am Rechteck
 // Distanz: d=SQRT((y2-y1)^2+(x2-x1)^2)
 var dS3 = Math.sqrt(Math.pow(sY1 - lastPathPunktY, 2) + Math.pow(rX1 - lastPathPunktX, 2));

 lengthToPoint.push(
 "distanz": dS3,
 "x": rX1,
 "y": sY1
 );
 

 var sY2 = m * rX2 + b; // S4(rX2

 return true;
;
// end MultiNodePathLink class