Changes for page KIML Layout Options

Last modified by Alexander Schulz-Rosengarten on 2023/09/11 16:17

From version 15.1
edited by cds
on 2013/06/03 12:41
Change comment: Migrated to Confluence 5.3
To version 18.1
edited by msp
on 2014/03/07 17:04
Change comment: There is no comment for this version

Summary

Details

Page properties
Author
... ... @@ -1,1 +1,1 @@
1 -XWiki.cds
1 +XWiki.msp
Content
... ... @@ -2,25 +2,29 @@
2 2  This is preliminary and incomplete documentation. You've been warned.
3 3  {{/warning}}
4 4  
5 -KIML defines a whole set of standard layout options that many layout algorithms support. Whether an algorithm supports a layout option depends on the option and on the algorithm. When an option is supported by an algorithm, it may change the option's default value. Algorithms may also provide more specialized documentation for a given layout option.
5 +KIML defines a whole set of standard layout options that many layout algorithms support. Whether an algorithm supports a layout option depends on the option and on the algorithm. When an option is supported by an algorithm, that algorithm may override the option's default value. Algorithms may also provide more specialized documentation for layout options.
6 6  
7 7  **Contents**
8 8  
9 9  
10 10  
11 -{{toc/}}
11 +{{toc maxLevel="2"/}}
12 12  
13 13  = Overview =
14 14  
15 -Beside a human-readable name, layout options are defined by the following properties:
15 +Beside a user-friendly name, layout options are defined by the following properties:
16 16  
17 17  * An ID to identify them.
18 -* A type. One of Boolean, String, Int, Float, Enum, EnumSet (a {{code language="none"}}Set{{/code}} over a given enumeration), or Object. The types Enum and EnumSet have to be further defined by an enumeration class. The Object type can be constricted to a certain class.
19 -* The kinds of graph objects the option applies to. At least one of Parents (nodes that have children, including the diagram root node), Nodes, Edges, Ports, and Labels.
20 -* An optional default value. If an option is not set on an object and if the option does not have a default value, {{code language="none"}}null{{/code}} is returned when it is accessed.
18 +* A type. One of Boolean, String, Int, Float, Enum, EnumSet (a s{{code language="none"}}et{{/code}} over a given enumeration), or Object (a non-primitive Java object). The types Enum and EnumSet have to be further defined by an enumeration class. The Object type can be constricted to a certain Java class.
19 +* The kinds of graph objects the option applies to. At least one of Parents (nodes that have children, including the diagram root node), Nodes, Edges, Ports, or Labels.
20 +* An optional default value. A default value may also be provided by the layout algorithm using the option, or by the modeling application you are using. In these cases the value given here is overridden.
21 21  
22 -KIML defines the following set of layout options:
22 +Layout options can be assigned to two main categories: user options and programmatic options.
23 23  
24 +== User Options ==
25 +
26 +User options are those that you can see in the "//Layout View//" available in Eclipse if the KIML user interface is installed. That view is restricted to layout options that are supported by the currently active layout algorithm. Furthermore, some options are visible only when the //Show Advanced Properties// button is active in the view.
27 +
24 24  |=(((
25 25  Option
26 26  )))|=(((
... ... @@ -74,24 +74,8 @@
74 74  )))|(((
75 75  Parents
76 76  )))|(((
77 --1.0
81 +
78 78  )))
79 -|(% colspan="1" %)(% colspan="1" %)
80 -(((
81 -Comment Box
82 -)))|(% colspan="1" %)(% colspan="1" %)
83 -(((
84 -de.cau.cs.kieler.commentBox
85 -)))|(% colspan="1" %)(% colspan="1" %)
86 -(((
87 -Boolean
88 -)))|(% colspan="1" %)(% colspan="1" %)
89 -(((
90 -Nodes
91 -)))|(% colspan="1" %)(% colspan="1" %)
92 -(((
93 -false
94 -)))
95 95  |(((
96 96  Debug Mode
97 97  )))|(((
... ... @@ -103,22 +103,6 @@
103 103  )))|(((
104 104  false
105 105  )))
106 -|(% colspan="1" %)(% colspan="1" %)
107 -(((
108 -Diagram Type
109 -)))|(% colspan="1" %)(% colspan="1" %)
110 -(((
111 -de.cau.cs.kieler.diagramType
112 -)))|(% colspan="1" %)(% colspan="1" %)
113 -(((
114 -String
115 -)))|(% colspan="1" %)(% colspan="1" %)
116 -(((
117 -
118 -)))|(% colspan="1" %)(% colspan="1" %)
119 -(((
120 -
121 -)))
122 122  |(((
123 123  Direction
124 124  )))|(((
... ... @@ -128,24 +128,8 @@
128 128  )))|(((
129 129  Parents
130 130  )))|(((
131 -UNDEFINED
103 +
132 132  )))
133 -|(% colspan="1" %)(% colspan="1" %)
134 -(((
135 -Edge Label Placement
136 -)))|(% colspan="1" %)(% colspan="1" %)
137 -(((
138 -de.cau.cs.kieler.edgeLabelPlacement
139 -)))|(% colspan="1" %)(% colspan="1" %)
140 -(((
141 -Enum
142 -)))|(% colspan="1" %)(% colspan="1" %)
143 -(((
144 -Labels
145 -)))|(% colspan="1" %)(% colspan="1" %)
146 -(((
147 -UNDEFINED
148 -)))
149 149  |(((
150 150  [[Edge Routing>>doc:||anchor="edgeRouting"]]
151 151  )))|(((
... ... @@ -155,24 +155,8 @@
155 155  )))|(((
156 156  Parents
157 157  )))|(((
158 -UNDEFINED
114 +
159 159  )))
160 -|(% colspan="1" %)(% colspan="1" %)
161 -(((
162 -Edge Type
163 -)))|(% colspan="1" %)(% colspan="1" %)
164 -(((
165 -de.cau.cs.kieler.edgeType
166 -)))|(% colspan="1" %)(% colspan="1" %)
167 -(((
168 -Enum
169 -)))|(% colspan="1" %)(% colspan="1" %)
170 -(((
171 -Edges
172 -)))|(% colspan="1" %)(% colspan="1" %)
173 -(((
174 -NONE
175 -)))
176 176  |(((
177 177  Expand Nodes
178 178  )))|(((
... ... @@ -184,54 +184,6 @@
184 184  )))|(((
185 185  false
186 186  )))
187 -|(% colspan="1" %)(% colspan="1" %)
188 -(((
189 -Font Name
190 -)))|(% colspan="1" %)(% colspan="1" %)
191 -(((
192 -de.cau.cs.kieler.fontName
193 -)))|(% colspan="1" %)(% colspan="1" %)
194 -(((
195 -String
196 -)))|(% colspan="1" %)(% colspan="1" %)
197 -(((
198 -Labels
199 -)))|(% colspan="1" %)(% colspan="1" %)
200 -(((
201 -
202 -)))
203 -|(% colspan="1" %)(% colspan="1" %)
204 -(((
205 -Font Size
206 -)))|(% colspan="1" %)(% colspan="1" %)
207 -(((
208 -de.cau.cs.kieler.fontSize
209 -)))|(% colspan="1" %)(% colspan="1" %)
210 -(((
211 -Int
212 -)))|(% colspan="1" %)(% colspan="1" %)
213 -(((
214 -Labels
215 -)))|(% colspan="1" %)(% colspan="1" %)
216 -(((
217 -
218 -)))
219 -|(% colspan="1" %)(% colspan="1" %)
220 -(((
221 -Hypernode
222 -)))|(% colspan="1" %)(% colspan="1" %)
223 -(((
224 -de.cau.cs.kieler.hypernode
225 -)))|(% colspan="1" %)(% colspan="1" %)
226 -(((
227 -Boolean
228 -)))|(% colspan="1" %)(% colspan="1" %)
229 -(((
230 -Nodes
231 -)))|(% colspan="1" %)(% colspan="1" %)
232 -(((
233 -false
234 -)))
235 235  |(((
236 236  Interactive
237 237  )))|(((
... ... @@ -253,7 +253,7 @@
253 253  Edges
254 254  Nodes
255 255  )))|(((
256 --1.0
148 +
257 257  )))
258 258  |(((
259 259  Layout Hierarchy
... ... @@ -267,7 +267,7 @@
267 267  false
268 268  )))
269 269  |(((
270 -Layout Algorithm
162 +[[Layout Algorithm>>doc:||anchor="layoutAlgorithm"]]
271 271  )))|(((
272 272  de.cau.cs.kieler.algorithm
273 273  )))|(((
... ... @@ -279,56 +279,6 @@
279 279  )))
280 280  |(% colspan="1" %)(% colspan="1" %)
281 281  (((
282 -Minimal Height
283 -)))|(% colspan="1" %)(% colspan="1" %)
284 -(((
285 -de.cau.cs.kieler.minHeight
286 -)))|(% colspan="1" %)(% colspan="1" %)
287 -(((
288 -Float
289 -)))|(% colspan="1" %)(% colspan="1" %)
290 -(((
291 -Nodes
292 -Parents
293 -)))|(% colspan="1" %)(% colspan="1" %)
294 -(((
295 -0.0
296 -)))
297 -|(% colspan="1" %)(% colspan="1" %)
298 -(((
299 -Minimal Width
300 -)))|(% colspan="1" %)(% colspan="1" %)
301 -(((
302 -de.cau.cs.kieler.minWidth
303 -)))|(% colspan="1" %)(% colspan="1" %)
304 -(((
305 -Float
306 -)))|(% colspan="1" %)(% colspan="1" %)
307 -(((
308 -Nodes
309 -Parents
310 -)))|(% colspan="1" %)(% colspan="1" %)
311 -(((
312 -0.0
313 -)))
314 -|(% colspan="1" %)(% colspan="1" %)
315 -(((
316 -No Layout
317 -)))|(% colspan="1" %)(% colspan="1" %)
318 -(((
319 -de.cau.cs.kieler.noLayout
320 -)))|(% colspan="1" %)(% colspan="1" %)
321 -(((
322 -Boolean
323 -)))|(% colspan="1" %)(% colspan="1" %)
324 -(((
325 -
326 -)))|(% colspan="1" %)(% colspan="1" %)
327 -(((
328 -false
329 -)))
330 -|(% colspan="1" %)(% colspan="1" %)
331 -(((
332 332  Node Label Placement
333 333  )))|(% colspan="1" %)(% colspan="1" %)
334 334  (((
... ... @@ -352,7 +352,7 @@
352 352  )))|(((
353 353  Nodes
354 354  )))|(((
355 -UNDEFINED
197 +
356 356  )))
357 357  |(% colspan="1" %)(% colspan="1" %)
358 358  (((
... ... @@ -372,36 +372,20 @@
372 372  )))
373 373  |(% colspan="1" %)(% colspan="1" %)
374 374  (((
375 -[[Port Offset>>doc:||anchor="portOffset"]]
217 +Port Spacing
376 376  )))|(% colspan="1" %)(% colspan="1" %)
377 377  (((
378 -de.cau.cs.kieler.offset
220 +de.cau.cs.kieler.portSpacing
379 379  )))|(% colspan="1" %)(% colspan="1" %)
380 380  (((
381 381  Float
382 382  )))|(% colspan="1" %)(% colspan="1" %)
383 383  (((
384 -Ports
226 +Nodes
385 385  )))|(% colspan="1" %)(% colspan="1" %)
386 386  (((
387 387  
388 388  )))
389 -|(% colspan="1" %)(% colspan="1" %)
390 -(((
391 -Port Side
392 -)))|(% colspan="1" %)(% colspan="1" %)
393 -(((
394 -de.cau.cs.kieler.portSide
395 -)))|(% colspan="1" %)(% colspan="1" %)
396 -(((
397 -Enum
398 -)))|(% colspan="1" %)(% colspan="1" %)
399 -(((
400 -Ports
401 -)))|(% colspan="1" %)(% colspan="1" %)
402 -(((
403 -UNDEFINED
404 -)))
405 405  |(((
406 406  Position
407 407  )))|(((
... ... @@ -505,21 +505,250 @@
505 505  Parents
506 506  )))|(% colspan="1" %)(% colspan="1" %)
507 507  (((
508 --1.0
334 +
509 509  )))
510 510  
511 -= The Most Important Options =
337 +== Programmatic Options ==
512 512  
513 -**TODO:** Write a bit of documentation about the most important layout options and how to use them, possibly with a simple example or something.
339 +Programmatic options are such that are meant to be configured exclusively through the KIML API. They should not be visible in the user interface.
514 514  
341 +|=(((
342 +Option
343 +)))|=(((
344 +ID
345 +)))|=(((
346 +Type
347 +)))|=(((
348 +Applies to
349 +)))|=(((
350 +Default
351 +)))
352 +|(((
353 +[[Diagram Type>>doc:||anchor="diagramType"]]
354 +)))|(((
355 +de.cau.cs.kieler.diagramType
356 +)))|(((
357 +String
358 +)))|(((
359 +Parents
360 +)))|(((
361 +
362 +)))
363 +|(((
364 +Edge Label Placement
365 +)))|(((
366 +de.cau.cs.kieler.edgeLabelPlacement
367 +)))|(((
368 +Enum
369 +)))|(((
370 +Labels
371 +)))|(((
372 +
373 +)))
374 +|(% colspan="1" %)(% colspan="1" %)
375 +(((
376 +Edge Type
377 +)))|(% colspan="1" %)(% colspan="1" %)
378 +(((
379 +de.cau.cs.kieler.edgeType
380 +)))|(% colspan="1" %)(% colspan="1" %)
381 +(((
382 +Enum
383 +)))|(% colspan="1" %)(% colspan="1" %)
384 +(((
385 +Edges
386 +)))|(% colspan="1" %)(% colspan="1" %)
387 +(((
388 +NONE
389 +)))
390 +|(% colspan="1" %)(% colspan="1" %)
391 +(((
392 +Font Name
393 +)))|(% colspan="1" %)(% colspan="1" %)
394 +(((
395 +de.cau.cs.kieler.fontName
396 +)))|(% colspan="1" %)(% colspan="1" %)
397 +(((
398 +String
399 +)))|(% colspan="1" %)(% colspan="1" %)
400 +(((
401 +Labels
402 +)))|(% colspan="1" %)(% colspan="1" %)
403 +(((
404 +
405 +)))
406 +|(% colspan="1" %)(% colspan="1" %)
407 +(((
408 +Font Size
409 +)))|(% colspan="1" %)(% colspan="1" %)
410 +(((
411 +de.cau.cs.kieler.fontSize
412 +)))|(% colspan="1" %)(% colspan="1" %)
413 +(((
414 +Int
415 +)))|(% colspan="1" %)(% colspan="1" %)
416 +(((
417 +Labels
418 +)))|(% colspan="1" %)(% colspan="1" %)
419 +(((
420 +
421 +)))
422 +|(% colspan="1" %)(% colspan="1" %)
423 +(((
424 +Hypernode
425 +)))|(% colspan="1" %)(% colspan="1" %)
426 +(((
427 +de.cau.cs.kieler.hypernode
428 +)))|(% colspan="1" %)(% colspan="1" %)
429 +(((
430 +Boolean
431 +)))|(% colspan="1" %)(% colspan="1" %)
432 +(((
433 +Nodes
434 +)))|(% colspan="1" %)(% colspan="1" %)
435 +(((
436 +false
437 +)))
438 +|(% colspan="1" %)(% colspan="1" %)
439 +(((
440 +Minimal Height
441 +)))|(% colspan="1" %)(% colspan="1" %)
442 +(((
443 +de.cau.cs.kieler.minHeight
444 +)))|(% colspan="1" %)(% colspan="1" %)
445 +(((
446 +Float
447 +)))|(% colspan="1" %)(% colspan="1" %)
448 +(((
449 +Nodes
450 +Parents
451 +)))|(% colspan="1" %)(% colspan="1" %)
452 +(((
453 +0.0
454 +)))
455 +|(% colspan="1" %)(% colspan="1" %)
456 +(((
457 +Minimal Width
458 +)))|(% colspan="1" %)(% colspan="1" %)
459 +(((
460 +de.cau.cs.kieler.minWidth
461 +)))|(% colspan="1" %)(% colspan="1" %)
462 +(((
463 +Float
464 +)))|(% colspan="1" %)(% colspan="1" %)
465 +(((
466 +Nodes
467 +Parents
468 +)))|(% colspan="1" %)(% colspan="1" %)
469 +(((
470 +0.0
471 +)))
472 +|(% colspan="1" %)(% colspan="1" %)
473 +(((
474 +No Layout
475 +)))|(% colspan="1" %)(% colspan="1" %)
476 +(((
477 +de.cau.cs.kieler.noLayout
478 +)))|(% colspan="1" %)(% colspan="1" %)
479 +(((
480 +Boolean
481 +)))|(% colspan="1" %)(% colspan="1" %)
482 +(((
483 +
484 +)))|(% colspan="1" %)(% colspan="1" %)
485 +(((
486 +false
487 +)))
488 +|(% colspan="1" %)(% colspan="1" %)
489 +(((
490 +[[Port Offset>>doc:||anchor="portOffset"]]
491 +)))|(% colspan="1" %)(% colspan="1" %)
492 +(((
493 +de.cau.cs.kieler.offset
494 +)))|(% colspan="1" %)(% colspan="1" %)
495 +(((
496 +Float
497 +)))|(% colspan="1" %)(% colspan="1" %)
498 +(((
499 +Ports
500 +)))|(% colspan="1" %)(% colspan="1" %)
501 +(((
502 +
503 +)))
504 +|(% colspan="1" %)(% colspan="1" %)
505 +(((
506 +Port Side
507 +)))|(% colspan="1" %)(% colspan="1" %)
508 +(((
509 +de.cau.cs.kieler.portSide
510 +)))|(% colspan="1" %)(% colspan="1" %)
511 +(((
512 +Enum
513 +)))|(% colspan="1" %)(% colspan="1" %)
514 +(((
515 +Ports
516 +)))|(% colspan="1" %)(% colspan="1" %)
517 +(((
518 +
519 +)))
520 +
515 515  = Detailed Documentation =
516 516  
517 -This section explains every layout option in more detail.
523 +== The Most Important Options ==
518 518  
519 -== Edge Routing ==
525 +While most layout options are used to affect how the active layout algorithm computes concrete coordinates for the graph elements, there are some layout options that have a special role in KIML.
520 520  
527 +=== Layout Algorithm ===
521 521  
529 +{{id name="layoutAlgorithm"/}}
522 522  
531 +The option with identifier {{code language="none"}}de.cau.cs.kieler.algorithm{{/code}} specifies which layout algorithm to use for the content of a composite node. The value can be either the identifier of a layout algorithm or the identifier of a layout type. In the latter case the algorithm with highest priority of that type is applied.
532 +
533 +The following layout types are predefined:
534 +
535 +* **Layered** - The layer-based method emphasizes the direction of edges by pointing as many edges as possible into the same direction. The nodes are arranged in layers and then reordered such that the number of edge crossings is minimized. Afterwards, concrete coordinates are computed for the nodes and edge bend points.
536 +* **Orthogonal** - Orthogonal methods follow the "topology-shape-metrics" approach, which first applies a planarization technique, resulting in a planar representation of the graph, then compute an orthogonal shape, and finally determine concrete coordinates for nodes and edge bend points by applying a compaction method.
537 +* **Force** - Layout algorithms that follow physical analogies by simulating a system of attractive and repulsive forces.
538 +* **Circular** - Circular layout algorithms emphasize biconnected components of a graph by arranging them in circles. This is useful if a drawing is desired where such components are clearly grouped, or where cycles are shown as prominent properties of the graph.
539 +* **Tree** - Specialized layout methods for trees, i.e. acyclic graphs. The regular structure of graphs that have no undirected cycles can be emphasized using an algorithm of this type.
540 +
541 +=== Available Algorithms and Libraries ===
542 +
543 +* **The [[KLay Project>>doc:Layout Algorithms (KLay)]]** - Java implementations of standard layout approaches, augmented with special processing of graph features such as ports and edge labels.
544 +* **Randomizer** - Distributes the nodes randomly; not very useful, but it can show how important a good layout is for understanding a graph.
545 +* (((
546 +**Box Layout** - Ignores edges, places all nodes in rows. Can be used to layout collections of unconnected boxes, such as Statechart regions.
547 +)))
548 +* **Fixed Layout** - Does not compute a new layout, but leaves all nodes and edges where they are. If the Position and Bend Points options are set for the elements of the graph, the pre-defined layout is applied.
549 +* **OGDF** ((% style="color: rgb(0,0,0);" %)[[www.ogdf.net>>url:http://www.ogdf.net/||shape="rect"]](%%)) - A self-contained C++ class library for the automatic layout of diagrams. The version that is shipped with KIELER is compiled as an executable that reads files in OGML format and outputs the computed concrete layout.
550 +* **Graphviz** ([[www.graphviz.org>>url:http://www.graphviz.org/||shape="rect"]]) - An open source graph visualization tool with several graph layout programs, web and interactive graphical interfaces, auxiliary tools, libraries, and language bindings. Graphviz needs to be installed separately in order to be used within KIELER, since it is called in a separate process using the DOT language for communication.
551 +
552 +=== Diagram Type ===
553 +
554 +{{id name="diagramType"/}}
555 +
556 +Diagram types are used to classify graphical diagrams for setting default layout option values for a set of similar diagrams. The diagram type of an element is specified with the layout option {{code language="none"}}de.cau.cs.kieler.diagramType{{/code}}. Layout algorithms can declare which diagram types they support well, and give a priority value for each supported type. KIML decides at runtime which layout algorithm has the highest priority for a given diagram, so that the most suitable algorithm is always used. Usual values for such priorities are between 1 and 10, where the highest value should only be assigned if the algorithm is especially designed for diagrams of the respective type, or if it has proven to be very adequate for them. Lower values should be given if the algorithm is able to draw the diagrams correctly, but with lower quality of the resulting layout.
557 +
558 +The following diagram types are predefined:
559 +
560 +* **General** - This type is automatically assigned to all diagrams for which no specific type is declared. A layout algorithm that has the highest priority on the //General// diagram type is taken as the default algorithm when no further information on a diagram is available to KIML.
561 +* **State Machine** - All kinds of state machines, automata, and activity diagrams. Examples: [[doc:SCCharts SyncCharts]], UML Activity diagrams.
562 +* **Data Flow Diagram** - Actor-oriented diagrams, where connections are mostly done between //ports// of nodes. These diagrams can only be handled properly by very special layout algorithms, such as those developed in the [[KLay project>>doc:Layout Algorithms (KLay)]].
563 +* **Class Diagram** - Class diagrams such as Ecore diagrams for the [[EMF>>url:http://www.eclipse.org/modeling/emf/||shape="rect"]] or UML Class diagrams.
564 +* **Use Case Diagram** - Use case diagrams as defined by the UML.
565 +* **Unconnected Boxes** - Sets of nodes that have no connections and are treated as resizable boxes. This is related to mathematical [[packing problems>>url:http://en.wikipedia.org/wiki/Packing_problem||shape="rect"]]. Example: Regions in [[doc:SCCharts SyncCharts]].
566 +
567 +== Other Options ==
568 +
569 +* **Layout Hierarchy** ({{code language="none"}}de.cau.cs.kieler.layoutHierarchy{{/code}}) - If this option is supported and active, the layout algorithm is requested to process the full hierarchy contained in the input node. This means that instead of executing another algorithm on each hierarchy level, all levels are arranged in a single algorithm execution.
570 +* **Hypernode** ({{code language="none"}}de.cau.cs.kieler.hypernode{{/code}}) - A node that is marked as hypernode has a special role in the graph structure, since all its incident edges are treated as parts of the same [[hyperedge>>url:http://en.wikipedia.org/wiki/Hypergraph||shape="rect"]]. Example: relation vertices in [[Ptolemy>>url:http://ptolemy.eecs.berkeley.edu/||shape="rect"]] models.
571 +* **Comment Box** ({{code language="none"}}de.cau.cs.kieler.commentBox{{/code}}) - A node that is marked as comment box is treated as a label that needs to be placed somewhere. This is different to normal node labels, which are usually regarded as fixed.
572 +* **No Layout** ({{code language="none"}}de.cau.cs.kieler.noLayout{{/code}}) - Elements that are marked with this option are excluded from layout. This is used to identify diagram objects that should not be regarded as graph elements.
573 +
574 +This section explains every layout option in more detail.
575 +
576 +=== Edge Routing ===
577 +
523 523  {{id name="edgeRouting"/}}
524 524  
525 525  This option influences the way in which edges are routed between the nodes they connect. The following settings are available:
... ... @@ -535,10 +535,8 @@
535 535  
536 536  (% style="color: rgb(153,51,0);" %)**TODO:** Add an image illustrating the different routing styles.
537 537  
538 -== Port Offset ==
593 +=== Port Offset ===
539 539  
540 -
541 -
542 542  {{id name="portOffset"/}}
543 543  
544 544  The port offset is used to specify how much space a layout algorithm should leave between a port and the border of its node. This is usually zero, but doesn't have to be. If the offset is not defined for a given port, a layout algorithm can try to infer the offset from the port's coordinates and its node's size in the input graph. This of course requires both properties to be set to sensible values.
Confluence.Code.ConfluencePageClass[0]
Id
... ... @@ -1,1 +1,1 @@
1 -9469964
1 +9470010
URL
... ... @@ -1,1 +1,1 @@
1 -https://rtsys.informatik.uni-kiel.de/confluence//wiki/spaces/KIELER/pages/9469964/KIML Layout Options
1 +https://rtsys.informatik.uni-kiel.de/confluence//wiki/spaces/KIELER/pages/9470010/KIML Layout Options