Node Order Barycenter Heuristic

[soerendomroes]

Adds a barycenter heuristic that first takes the node order into account.
Only the order of the dummy nodes is changed. All real nodes remain at the same position relative to the other real nodes.

TODO:

• Wait for layered: Added model order cycle breaker. #759 to be merged
• Solve partial ordering problem (same as model order node comparator)
• Add tests

[soerendomroes]

The test failure is in ForsterConstraintResolverTest with tickets/layered/528_nodeEdgeOverlap.elkt. I cannot reproduce this failure locally.

[soerendomroes]

The Test after my test seems to fail (which is odd)

[soerendomroes]

It has to be the newly introduced option that is tested in the ModelOrderBarycenterHeuristicTest that is somehow responsible for the failure.

[soerendomroes]

Locally, after ModelOrderBarycenterHeuristicTest, LayerSweepCrossingMinimizerTest runs and after that runs ForsterConstraintResolverTest which fails in one case with:

java.lang.AssertionError
	at org.eclipse.elk.alg.layered.p3order.ForsterConstraintResolver.findViolatedConstraint(ForsterConstraintResolver.java:234)
	at org.eclipse.elk.alg.layered.p3order.ForsterConstraintResolver.processConstraints(ForsterConstraintResolver.java:150)
	at org.eclipse.elk.alg.layered.p3order.ForsterConstraintResolver.processConstraints(ForsterConstraintResolver.java:132)
	at org.eclipse.elk.alg.layered.p3order.BarycenterHeuristic.minimizeCrossings(BarycenterHeuristic.java:97)
	at org.eclipse.elk.alg.layered.p3order.BarycenterHeuristic.minimizeCrossings(BarycenterHeuristic.java:345)
	at org.eclipse.elk.alg.layered.p3order.LayerSweepCrossingMinimizer.sweepReducingCrossings(LayerSweepCrossingMinimizer.java:421)
	at org.eclipse.elk.alg.layered.p3order.LayerSweepCrossingMinimizer.minimizeCrossingsWithCounter(LayerSweepCrossingMinimizer.java:256)
	at org.eclipse.elk.alg.layered.p3order.LayerSweepCrossingMinimizer.compareDifferentRandomizedLayouts(LayerSweepCrossingMinimizer.java:215)
	at org.eclipse.elk.alg.layered.p3order.LayerSweepCrossingMinimizer.minimizeCrossings(LayerSweepCrossingMinimizer.java:148)
	at org.eclipse.elk.alg.layered.p3order.LayerSweepCrossingMinimizer.process(LayerSweepCrossingMinimizer.java:126)
	at org.eclipse.elk.alg.layered.p3order.LayerSweepCrossingMinimizer.process(LayerSweepCrossingMinimizer.java:1)
	at org.eclipse.elk.alg.layered.ElkLayered.layout(ElkLayered.java:608)
	at org.eclipse.elk.alg.layered.ElkLayered.doLayout(ElkLayered.java:144)
	at org.eclipse.elk.alg.layered.LayeredLayoutProvider.layout(LayeredLayoutProvider.java:56)
	at org.eclipse.elk.core.RecursiveGraphLayoutEngine.executeAlgorithm(RecursiveGraphLayoutEngine.java:250)
	at org.eclipse.elk.core.RecursiveGraphLayoutEngine.layoutRecursively(RecursiveGraphLayoutEngine.java:218)
	at org.eclipse.elk.core.RecursiveGraphLayoutEngine.layoutRecursively(RecursiveGraphLayoutEngine.java:200)
	at org.eclipse.elk.core.RecursiveGraphLayoutEngine.layout(RecursiveGraphLayoutEngine.java:96)
	at org.eclipse.elk.alg.test.framework.ExperimentStatement.evaluate(ExperimentStatement.java:82)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.eclipse.elk.alg.test.framework.LayoutTestRunner.runChild(LayoutTestRunner.java:353)
	at org.eclipse.elk.alg.test.framework.LayoutTestRunner.runChild(LayoutTestRunner.java:1)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:365)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:273)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:159)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray2(ReflectionUtils.java:206)
	at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:161)
	at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:84)
	at org.eclipse.tycho.surefire.osgibooter.OsgiSurefireBooter.run(OsgiSurefireBooter.java:113)
	at org.eclipse.tycho.surefire.osgibooter.HeadlessTestApplication.run(HeadlessTestApplication.java:21)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.eclipse.equinox.internal.app.EclipseAppContainer.callMethodWithException(EclipseAppContainer.java:593)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:205)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:137)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:107)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:657)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:594)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1465)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1438)

I know that it has something to do with the new option and not the test itself since everything works fine with the new test if it does not specify the new option. Also if I remove the necessary check in the BarycenterHeuristic it does fail as expected.