Removing transition causes exception

[Matthias Schoettle]

When trying to remove a transition in a state view an exception occurs.

In my case I have one state with two self-transitions and I tried to remove one of them.

Exception:

org.eclipse.emf.common.util.WrappedException: An exception was ignored during command execution
    at org.eclipse.emf.common.command.BasicCommandStack.handleError(BasicCommandStack.java:281)
    at org.eclipse.emf.common.command.BasicCommandStack.execute(BasicCommandStack.java:112)
    at ca.mcgill.sel.ram.controller.BaseController.doExecute(BaseController.java:105)
    at ca.mcgill.sel.ram.controller.TransitionController.deleteTransition(TransitionController.java:49)
    at ca.mcgill.ram.ui.handler.state.impl.TransitionViewHandler$1.elementSelected(TransitionViewHandler.java:73)
    at ca.mcgill.ram.ui.handler.state.impl.TransitionViewHandler$1.elementSelected(TransitionViewHandler.java:1)
    at ca.mcgill.ram.ui.components.RamSelectorComponent.selectElement(RamSelectorComponent.java:779)
    at ca.mcgill.ram.ui.components.RamSelectorComponent.access$5(RamSelectorComponent.java:777)
    at ca.mcgill.ram.ui.components.RamSelectorComponent$InternalSelectorHandler.processTapEvent(RamSelectorComponent.java:188)
    at ca.mcgill.ram.ui.handler.BaseHandler.processGestureEvent(BaseHandler.java:78)
[...]
Caused by: java.lang.ArrayIndexOutOfBoundsException: -1
    at org.eclipse.emf.common.util.BasicEList.remove(BasicEList.java:605)
    at org.eclipse.emf.common.notify.impl.NotifyingListImpl.doRemove(NotifyingListImpl.java:756)
    at org.eclipse.emf.common.notify.impl.NotifyingListImpl.remove(NotifyingListImpl.java:707)
    at org.eclipse.emf.edit.command.RemoveCommand.doExecute(RemoveCommand.java:321)
    at org.eclipse.emf.edit.command.AbstractOverrideableCommand.execute(AbstractOverrideableCommand.java:125)
    at org.eclipse.emf.common.command.CompoundCommand.execute(CompoundCommand.java:261)
    at org.eclipse.emf.common.command.BasicCommandStack.execute(BasicCommandStack.java:78)
    ... 38 more

This causes two other exceptions:

Exception in thread "Animation Thread" java.lang.NullPointerException
    at ca.mcgill.sel.ram.validator.ValidationManager.commandStackChanged(ValidationManager.java:246)
    at org.eclipse.emf.common.command.BasicCommandStack.notifyListeners(BasicCommandStack.java:270)

org.eclipse.emf.common.util.WrappedException: An exception was ignored during command execution
    at org.eclipse.emf.common.command.CompoundCommand.execute(CompoundCommand.java:290)
[...]
Caused by: java.lang.NullPointerException
    at ca.mcgill.ram.ui.views.RelationshipView.updateLines(RelationshipView.java:606)
    at ca.mcgill.ram.ui.views.state.StateMachineView.buildTransition(StateMachineView.java:156)
    at ca.mcgill.ram.ui.views.state.StateMachineView.notifyChanged(StateMachineView.java:250)

[Matthias Schoettle]

I suspect it is either the order of how commands are executed or the fact that for everything, even for just removing from a reference, RemoveCommands are used, which I think also try to remove from the owner.

[Matthias Schoettle]

Also in StateMachineView.removeTransitionView(Transition) the transition is removed from the state's ingoing and outgoing lists, which should not be done manually in the view.

[Matthias Schoettle]

Also, when undoing the adding of a transition, a dangling reference occurs: The transition is still in the State's incoming/outgoing transitions.

[Matthias Schoettle]

Resolved issue #211: Adding and removing of transitions properly done now through commands, which allows to undo them as well without running into problems in the UI or dangling references.

→ <<cset 8b6f16b3ec06>>

[Matthias Schoettle]

References issue #211: Fixed creation of transition, it was created in the wrong direction.

→ <<cset 924d8ce7ff60>>