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Version 21.1 by msp on 2014/03/08 21:51
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2
3 KIML defines a whole set of standard layout options that many layout algorithms support. 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.
4
5 **Contents**
6
7
8
9 {{toc maxLevel="2"/}}
10
11 = Overview =
12
13 Beside a user-friendly name, layout options are defined by the following properties:
14
15 * An ID to identify them.
16 * 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.
17 * The kinds of graph objects the option applies to. At least one of Nodes, Edges, Ports, Labels, or Parents (nodes that have children, including the diagram root node). Parents-applicable options affect whole graphs or subgraphs, while options with other application targets affect only single graph elements.
18 * 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.
19
20 Layout options can be assigned to two main categories: user options and programmatic options.
21
22 == User Options ==
23
24 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.
25
26 |=(((
27 Option
28 )))|=(((
29 ID
30 )))|=(((
31 Type
32 )))|=(((
33 Applies to
34 )))|=(((
35 Default
36 )))
37 |(((
38 Alignment
39 )))|(((
40 de.cau.cs.kieler.alignment
41 )))|(((
42 Enum
43 )))|(((
44 Nodes
45 )))|(((
46 AUTOMATIC
47 )))
48 |(((
49 Aspect Ratio
50 )))|(((
51 de.cau.cs.kieler.aspectRatio
52 )))|(((
53 Float
54 )))|(((
55 Parents
56 )))|(((
57 0.0
58 )))
59 |(((
60 Bend Points
61 )))|(((
62 de.cau.cs.kieler.bendPoints
63 )))|(((
64 Object
65 )))|(((
66 Edges
67 )))|(((
68
69 )))
70 |(((
71 Border Spacing
72 )))|(((
73 de.cau.cs.kieler.borderSpacing
74 )))|(((
75 Float
76 )))|(((
77 Parents
78 )))|(((
79
80 )))
81 |(((
82 Debug Mode
83 )))|(((
84 de.cau.cs.kieler.debugMode
85 )))|(((
86 Boolean
87 )))|(((
88 Parents
89 )))|(((
90 false
91 )))
92 |(((
93 Direction
94 )))|(((
95 de.cau.cs.kieler.direction
96 )))|(((
97 Enum
98 )))|(((
99 Parents
100 )))|(((
101
102 )))
103 |(((
104 [[Edge Routing>>doc:||anchor="edgeRouting"]]
105 )))|(((
106 de.cau.cs.kieler.edgeRouting
107 )))|(((
108 Enum
109 )))|(((
110 Parents
111 )))|(((
112
113 )))
114 |(((
115 Expand Nodes
116 )))|(((
117 de.cau.cs.kieler.expandNodes
118 )))|(((
119 Boolean
120 )))|(((
121 Parents
122 )))|(((
123 false
124 )))
125 |(((
126 Interactive
127 )))|(((
128 de.cau.cs.kieler.interactive
129 )))|(((
130 Boolean
131 )))|(((
132 Parents
133 )))|(((
134 false
135 )))
136 |(((
137 Label Spacing
138 )))|(((
139 de.cau.cs.kieler.labelSpacing
140 )))|(((
141 Float
142 )))|(((
143 Edges
144 Nodes
145 )))|(((
146
147 )))
148 |(((
149 [[Layout Hierarchy>>doc:||anchor="layoutHierarchy"]]
150 )))|(((
151 de.cau.cs.kieler.layoutHierarchy
152 )))|(((
153 Boolean
154 )))|(((
155 Parents
156 )))|(((
157 false
158 )))
159 |(((
160 [[Layout Algorithm>>doc:||anchor="layoutAlgorithm"]]
161 )))|(((
162 de.cau.cs.kieler.algorithm
163 )))|(((
164 String
165 )))|(((
166 Parents
167 )))|(((
168
169 )))
170 |(% colspan="1" %)(% colspan="1" %)
171 (((
172 Node Label Placement
173 )))|(% colspan="1" %)(% colspan="1" %)
174 (((
175 de.cau.cs.kieler.nodeLabelPlacement
176 )))|(% colspan="1" %)(% colspan="1" %)
177 (((
178 EnumSet
179 )))|(% colspan="1" %)(% colspan="1" %)
180 (((
181 Nodes
182 )))|(% colspan="1" %)(% colspan="1" %)
183 (((
184
185 )))
186 |(((
187 Port Constraints
188 )))|(((
189 de.cau.cs.kieler.portConstraints
190 )))|(((
191 Enum
192 )))|(((
193 Nodes
194 )))|(((
195
196 )))
197 |(% colspan="1" %)(% colspan="1" %)
198 (((
199 Port Label Placement
200 )))|(% colspan="1" %)(% colspan="1" %)
201 (((
202 de.cau.cs.kieler.portLabelPlacement
203 )))|(% colspan="1" %)(% colspan="1" %)
204 (((
205 Enum
206 )))|(% colspan="1" %)(% colspan="1" %)
207 (((
208 Nodes
209 )))|(% colspan="1" %)(% colspan="1" %)
210 (((
211 OUTSIDE
212 )))
213 |(% colspan="1" %)(% colspan="1" %)
214 (((
215 Port Spacing
216 )))|(% colspan="1" %)(% colspan="1" %)
217 (((
218 de.cau.cs.kieler.portSpacing
219 )))|(% colspan="1" %)(% colspan="1" %)
220 (((
221 Float
222 )))|(% colspan="1" %)(% colspan="1" %)
223 (((
224 Nodes
225 )))|(% colspan="1" %)(% colspan="1" %)
226 (((
227
228 )))
229 |(((
230 Position
231 )))|(((
232 de.cau.cs.kieler.position
233 )))|(((
234 Object
235 )))|(((
236 Labels
237 Nodes
238 Ports
239 )))|(((
240
241 )))
242 |(((
243 Priority
244 )))|(((
245 de.cau.cs.kieler.priority
246 )))|(((
247 Int
248 )))|(((
249 Edges
250 Nodes
251 )))|(((
252
253 )))
254 |(% colspan="1" %)(% colspan="1" %)
255 (((
256 Randomization Seed
257 )))|(% colspan="1" %)(% colspan="1" %)
258 (((
259 de.cau.cs.kieler.randomSeed
260 )))|(% colspan="1" %)(% colspan="1" %)
261 (((
262 Int
263 )))|(% colspan="1" %)(% colspan="1" %)
264 (((
265 Parents
266 )))|(% colspan="1" %)(% colspan="1" %)
267 (((
268
269 )))
270 |(% colspan="1" %)(% colspan="1" %)
271 (((
272 Separate Connected Components
273 )))|(% colspan="1" %)(% colspan="1" %)
274 (((
275 de.cau.cs.kieler.separateConnComp
276 )))|(% colspan="1" %)(% colspan="1" %)
277 (((
278 Boolean
279 )))|(% colspan="1" %)(% colspan="1" %)
280 (((
281 Parents
282 )))|(% colspan="1" %)(% colspan="1" %)
283 (((
284
285 )))
286 |(% colspan="1" %)(% colspan="1" %)
287 (((
288 Size Constraint
289 )))|(% colspan="1" %)(% colspan="1" %)
290 (((
291 de.cau.cs.kieler.sizeConstraint
292 )))|(% colspan="1" %)(% colspan="1" %)
293 (((
294 EnumSet
295 )))|(% colspan="1" %)(% colspan="1" %)
296 (((
297 Nodes
298 )))|(% colspan="1" %)(% colspan="1" %)
299 (((
300
301 )))
302 |(% colspan="1" %)(% colspan="1" %)
303 (((
304 Size Options
305 )))|(% colspan="1" %)(% colspan="1" %)
306 (((
307 de.cau.cs.kieler.sizeOptions
308 )))|(% colspan="1" %)(% colspan="1" %)
309 (((
310 EnumSet
311 )))|(% colspan="1" %)(% colspan="1" %)
312 (((
313 Nodes
314 )))|(% colspan="1" %)(% colspan="1" %)
315 (((
316 DEFAULT_MINIMUM_SIZE
317 )))
318 |(% colspan="1" %)(% colspan="1" %)
319 (((
320 Spacing
321 )))|(% colspan="1" %)(% colspan="1" %)
322 (((
323 de.cau.cs.kieler.spacing
324 )))|(% colspan="1" %)(% colspan="1" %)
325 (((
326 Float
327 )))|(% colspan="1" %)(% colspan="1" %)
328 (((
329 Parents
330 )))|(% colspan="1" %)(% colspan="1" %)
331 (((
332
333 )))
334
335 == Programmatic Options ==
336
337 Programmatic options are such that are meant to be configured exclusively through the KIML API. They should not be visible in the user interface.
338
339 |=(((
340 Option
341 )))|=(((
342 ID
343 )))|=(((
344 Type
345 )))|=(((
346 Applies to
347 )))|=(((
348 Default
349 )))
350 |(% colspan="1" %)(% colspan="1" %)
351 (((
352 Animate
353 )))|(% colspan="1" %)(% colspan="1" %)
354 (((
355 de.cau.cs.kieler.animate
356 )))|(% colspan="1" %)(% colspan="1" %)
357 (((
358 Boolean
359 )))|(% colspan="1" %)(% colspan="1" %)
360 (((
361 Parents
362 )))|(% colspan="1" %)(% colspan="1" %)
363 (((
364 true
365 )))
366 |(% colspan="1" %)(% colspan="1" %)
367 (((
368 Animation Time Factor
369 )))|(% colspan="1" %)(% colspan="1" %)
370 (((
371 de.cau.cs.kieler.animTimeFactor
372 )))|(% colspan="1" %)(% colspan="1" %)
373 (((
374 Int
375 )))|(% colspan="1" %)(% colspan="1" %)
376 (((
377 Parents
378 )))|(% colspan="1" %)(% colspan="1" %)
379 (((
380 100
381 )))
382 |(% colspan="1" %)(% colspan="1" %)
383 (((
384 [[Comment Box>>doc:||anchor="commentBox"]]
385 )))|(% colspan="1" %)(% colspan="1" %)
386 (((
387 de.cau.cs.kieler.commentBox
388 )))|(% colspan="1" %)(% colspan="1" %)
389 (((
390 Boolean
391 )))|(% colspan="1" %)(% colspan="1" %)
392 (((
393 Nodes
394 )))|(% colspan="1" %)(% colspan="1" %)
395 (((
396 false
397 )))
398 |(((
399 [[Diagram Type>>doc:||anchor="diagramType"]]
400 )))|(((
401 de.cau.cs.kieler.diagramType
402 )))|(((
403 String
404 )))|(((
405 Parents
406 )))|(((
407
408 )))
409 |(((
410 Edge Label Placement
411 )))|(((
412 de.cau.cs.kieler.edgeLabelPlacement
413 )))|(((
414 Enum
415 )))|(((
416 Labels
417 )))|(((
418
419 )))
420 |(% colspan="1" %)(% colspan="1" %)
421 (((
422 Edge Type
423 )))|(% colspan="1" %)(% colspan="1" %)
424 (((
425 de.cau.cs.kieler.edgeType
426 )))|(% colspan="1" %)(% colspan="1" %)
427 (((
428 Enum
429 )))|(% colspan="1" %)(% colspan="1" %)
430 (((
431 Edges
432 )))|(% colspan="1" %)(% colspan="1" %)
433 (((
434 NONE
435 )))
436 |(% colspan="1" %)(% colspan="1" %)
437 (((
438 Font Name
439 )))|(% colspan="1" %)(% colspan="1" %)
440 (((
441 de.cau.cs.kieler.fontName
442 )))|(% colspan="1" %)(% colspan="1" %)
443 (((
444 String
445 )))|(% colspan="1" %)(% colspan="1" %)
446 (((
447 Labels
448 )))|(% colspan="1" %)(% colspan="1" %)
449 (((
450
451 )))
452 |(% colspan="1" %)(% colspan="1" %)
453 (((
454 Font Size
455 )))|(% colspan="1" %)(% colspan="1" %)
456 (((
457 de.cau.cs.kieler.fontSize
458 )))|(% colspan="1" %)(% colspan="1" %)
459 (((
460 Int
461 )))|(% colspan="1" %)(% colspan="1" %)
462 (((
463 Labels
464 )))|(% colspan="1" %)(% colspan="1" %)
465 (((
466
467 )))
468 |(% colspan="1" %)(% colspan="1" %)
469 (((
470 [[Hypernode>>doc:||anchor="hypernode"]]
471 )))|(% colspan="1" %)(% colspan="1" %)
472 (((
473 de.cau.cs.kieler.hypernode
474 )))|(% colspan="1" %)(% colspan="1" %)
475 (((
476 Boolean
477 )))|(% colspan="1" %)(% colspan="1" %)
478 (((
479 Nodes
480 )))|(% colspan="1" %)(% colspan="1" %)
481 (((
482 false
483 )))
484 |(% colspan="1" %)(% colspan="1" %)
485 (((
486 Layout Ancestors
487 )))|(% colspan="1" %)(% colspan="1" %)
488 (((
489 de.cau.cs.kieler.layoutAncestors
490 )))|(% colspan="1" %)(% colspan="1" %)
491 (((
492 Boolean
493 )))|(% colspan="1" %)(% colspan="1" %)
494 (((
495 Parents
496 )))|(% colspan="1" %)(% colspan="1" %)
497 (((
498 false
499 )))
500 |(% colspan="1" %)(% colspan="1" %)
501 (((
502 Maximal Animation Time
503 )))|(% colspan="1" %)(% colspan="1" %)
504 (((
505 de.cau.cs.kieler.maxAnimTim
506 )))|(% colspan="1" %)(% colspan="1" %)
507 (((
508 Int
509 )))|(% colspan="1" %)(% colspan="1" %)
510 (((
511 Parents
512 )))|(% colspan="1" %)(% colspan="1" %)
513 (((
514 4000
515 )))
516 |(% colspan="1" %)(% colspan="1" %)
517 (((
518 Minimal Animation Time
519 )))|(% colspan="1" %)(% colspan="1" %)
520 (((
521 de.cau.cs.kieler.minAnimTim
522 )))|(% colspan="1" %)(% colspan="1" %)
523 (((
524 Int
525 )))|(% colspan="1" %)(% colspan="1" %)
526 (((
527 Parents
528 )))|(% colspan="1" %)(% colspan="1" %)
529 (((
530 400
531 )))
532 |(% colspan="1" %)(% colspan="1" %)
533 (((
534 Minimal Height
535 )))|(% colspan="1" %)(% colspan="1" %)
536 (((
537 de.cau.cs.kieler.minHeight
538 )))|(% colspan="1" %)(% colspan="1" %)
539 (((
540 Float
541 )))|(% colspan="1" %)(% colspan="1" %)
542 (((
543 Nodes
544 Parents
545 )))|(% colspan="1" %)(% colspan="1" %)
546 (((
547 0.0
548 )))
549 |(% colspan="1" %)(% colspan="1" %)
550 (((
551 Minimal Width
552 )))|(% colspan="1" %)(% colspan="1" %)
553 (((
554 de.cau.cs.kieler.minWidth
555 )))|(% colspan="1" %)(% colspan="1" %)
556 (((
557 Float
558 )))|(% colspan="1" %)(% colspan="1" %)
559 (((
560 Nodes
561 Parents
562 )))|(% colspan="1" %)(% colspan="1" %)
563 (((
564 0.0
565 )))
566 |(% colspan="1" %)(% colspan="1" %)
567 (((
568 [[No Layout>>doc:||anchor="noLayout"]]
569 )))|(% colspan="1" %)(% colspan="1" %)
570 (((
571 de.cau.cs.kieler.noLayout
572 )))|(% colspan="1" %)(% colspan="1" %)
573 (((
574 Boolean
575 )))|(% colspan="1" %)(% colspan="1" %)
576 (((
577
578 )))|(% colspan="1" %)(% colspan="1" %)
579 (((
580 false
581 )))
582 |(% colspan="1" %)(% colspan="1" %)
583 (((
584 Port Index
585 )))|(% colspan="1" %)(% colspan="1" %)
586 (((
587 de.cau.cs.kieler.portIndex
588 )))|(% colspan="1" %)(% colspan="1" %)
589 (((
590 Int
591 )))|(% colspan="1" %)(% colspan="1" %)
592 (((
593 Ports
594 )))|(% colspan="1" %)(% colspan="1" %)
595 (((
596
597 )))
598 |(% colspan="1" %)(% colspan="1" %)
599 (((
600 [[Port Offset>>doc:||anchor="portOffset"]]
601 )))|(% colspan="1" %)(% colspan="1" %)
602 (((
603 de.cau.cs.kieler.offset
604 )))|(% colspan="1" %)(% colspan="1" %)
605 (((
606 Float
607 )))|(% colspan="1" %)(% colspan="1" %)
608 (((
609 Ports
610 )))|(% colspan="1" %)(% colspan="1" %)
611 (((
612
613 )))
614 |(% colspan="1" %)(% colspan="1" %)
615 (((
616 Port Side
617 )))|(% colspan="1" %)(% colspan="1" %)
618 (((
619 de.cau.cs.kieler.portSide
620 )))|(% colspan="1" %)(% colspan="1" %)
621 (((
622 Enum
623 )))|(% colspan="1" %)(% colspan="1" %)
624 (((
625 Ports
626 )))|(% colspan="1" %)(% colspan="1" %)
627 (((
628
629 )))
630 |(% colspan="1" %)(% colspan="1" %)
631 (((
632 Progress Bar
633 )))|(% colspan="1" %)(% colspan="1" %)
634 (((
635 de.cau.cs.kieler.progressBar
636 )))|(% colspan="1" %)(% colspan="1" %)
637 (((
638 Boolean
639 )))|(% colspan="1" %)(% colspan="1" %)
640 (((
641 Parents
642 )))|(% colspan="1" %)(% colspan="1" %)
643 (((
644 false
645 )))
646 |(% colspan="1" %)(% colspan="1" %)
647 (((
648 Scale Factor
649 )))|(% colspan="1" %)(% colspan="1" %)
650 (((
651 de.cau.cs.kieler.scaleFactor
652 )))|(% colspan="1" %)(% colspan="1" %)
653 (((
654 Float
655 )))|(% colspan="1" %)(% colspan="1" %)
656 (((
657 Nodes
658 )))|(% colspan="1" %)(% colspan="1" %)
659 (((
660 1.0
661 )))
662 |(% colspan="1" %)(% colspan="1" %)
663 (((
664 Zoom to Fit
665 )))|(% colspan="1" %)(% colspan="1" %)
666 (((
667 de.cau.cs.kieler.zoomToFit
668 )))|(% colspan="1" %)(% colspan="1" %)
669 (((
670 Boolean
671 )))|(% colspan="1" %)(% colspan="1" %)
672 (((
673 Parents
674 )))|(% colspan="1" %)(% colspan="1" %)
675 (((
676 false
677 )))
678
679 === Layout Output Properties ===
680
681 A few properties are used as additional information in the output of a layout algorithm. This information should be considered when the layout is applied to the original diagram
682
683 |=(((
684 Property
685 )))|=(((
686 ID
687 )))|=(((
688 Type
689 )))|=(((
690 Applies to
691 )))
692 |(((
693 [[Edge Routing>>doc:||anchor="edgeRouting"]]
694 )))|(((
695 de.cau.cs.kieler.edgeRouting
696 )))|(((
697 Enum
698 )))|(((
699 Edges
700 )))
701 |(((
702 Junction Points
703 )))|(((
704 de.cau.cs.kieler.junctionPoints
705 )))|(((
706 Object
707 )))|(((
708 Edges
709 )))
710
711
712
713 = Detailed Documentation =
714
715 This section explains every layout option in more detail.
716
717 == The Most Important Options ==
718
719 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.
720
721 === Layout Algorithm ===
722
723 {{id name="layoutAlgorithm"/}}
724
725 The option with identifier {{code language="none"}}de.cau.cs.kieler.algorithm{{/code}} specifies which layout algorithm to use for a graph or subgraph. 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. It is possible to set different values for this option on subgraphs of a hierarchical graph, where a subgraph is identified by a parent node. A layout algorithm is responsible to process only the direct content of a given parent node. An exception from this rule is made when the [[Layout Hierarchy>>doc:||anchor="layoutHierarchy"]] option is active.
726
727 The following layout has been created by setting a force-based layout algorithm on the inner hierarchy level and a layer-based layout algorithm on the top level.
728
729 [[image:attach:layout_algorithm.png]]
730
731 ==== Available Algorithms and Libraries ====
732
733 * **The [[KLay Project>>doc:Layout Algorithms (KLay)]]** - Java implementations of standard layout approaches, augmented with special processing of graph features such as ports and labels.
734 * **Randomizer** - Distributes the nodes randomly; not very useful, but it can show how important a good layout is for understanding a graph.
735 * (((
736 **Box Layout** - Ignores edges, places all nodes in rows. Can be used to layout collections of unconnected boxes, such as Statechart regions.
737 )))
738 * **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.
739 * **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.
740 * **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.
741
742 ==== Predefined Layout Types ====
743
744 * **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.
745 * **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.
746 * **Force** - Layout algorithms that follow physical analogies by simulating a system of attractive and repulsive forces.
747 * **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.
748 * **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.
749
750 === Diagram Type ===
751
752 {{id name="diagramType"/}}
753
754 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.
755
756 The following diagram types are predefined:
757
758 * **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.
759 * **State Machine** - All kinds of state machines, automata, and activity diagrams. Examples: [[doc:SCCharts SyncCharts]], UML Activity diagrams.
760 * **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)]].
761 * **Class Diagram** - Class diagrams such as Ecore diagrams for the [[EMF>>url:http://www.eclipse.org/modeling/emf/||shape="rect"]] or UML Class diagrams.
762 * **Use Case Diagram** - Use case diagrams as defined by the UML.
763 * **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]].
764
765 === Edge Routing ===
766
767 {{id name="edgeRouting"/}}
768
769 This option influences the way in which edges are routed between the nodes they connect. The following settings are available:
770
771 * POLYLINE
772 Edges consist of one or more segments defined by a list of bend points.
773 * ORTHOGONAL
774 Edges are routed orthogonally, meaning that each segment of an edge runs either horizontally or vertically.
775 * SPLINES
776 Edges are routed as splines (smooth curves).
777 * UNDEFINED
778 No particular edge routing style is selected. Usually this value points to the default setting of the selected layout algorithm.
779
780 [[image:attach:edge_routing.png]]
781
782 When used as layout option, the edge routing is set for a whole graph or subgraph, i.e. on a parent node. However, the property is additionally used for the output of the layout algorithm in order to mark individual edges. If the edge routing assigned to an edge is anything other than SPLINES, the bend points of that edge are interpreted with their normal meaning, i.e. straight lines are drawn between consecutive bend points. If, on the other hand, a layout algorithm marks an edge with the value SPLINES, the bend points have to be interpreted as control points for a series of cubic splines following this procedure:
783
784 1. Start at the source point of the edge.
785 1. As long as there are at least three bend points left:
786 11. Draw a cubic spline segment to the third bend point with the other two bend points as control points.
787 11. Use the third bend point as start point for the next segment.
788 11. Consume the three bend points and proceed to the next segment.
789 1. Check the number of remaining bend points:
790 11. Two bend points – draw a cubic spline segment to the target point of the edge.
791 11. One bend point – draw a quadratic spline segment to the target point of the edge.
792 11. No bend point – draw a straight line to the target point of the edge.
793
794 == Other Options ==
795
796 === Comment Box ===
797
798 {{id name="commentBox"/}}
799
800 A node that is marked as comment box is treated as a label that needs to be placed somewhere. In contrast to normal node labels (modeled with a KLabel instance), comment boxes may have connections to other nodes, as in the following example.
801
802 [[image:attach:comment_box.png]]
803
804 === (% style="line-height: 1.5625;" %)Hypernode(%%) ===
805
806 {{id name="hypernode"/}}
807
808 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.
809
810 === Layout Hierarchy ===
811
812 {{id name="layoutHierarchy"/}}
813
814 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.
815
816 === No Layout ===
817
818 {{id name="noLayout"/}}
819
820 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.
821
822 === Port Offset ===
823
824 {{id name="portOffset"/}}
825
826 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.
827
828 Set this property if one of the following cases applies:
829
830 * The port constraints on a node are set to FREE, FIXED_SIDES or FIXED_ORDER.
831 * The port constraints on a node are set to FIXED_RATIO or FIXED_POS, and the size of the node is not fixed. (Note that this is especially true for ports of compound nodes.)