Notification in VAB

[mhoram]

I am writing a mod that displays information about the vessel while it is in the VAB.

Is there a way to get a notification whenever a part is added to or removed from the vessel or the resources or staging of a part have changed?

Testing the entries in EditorLogic.SortedShipList for changes is possible, but not very elegant.

[DiEvAl]

Have you looked how other mods do this?

[mhoram]

Yes and they had their own method for looking at EditorLogic.SortedShipList. Simply wanted to know, if such a trigger-mechanism exists - although I don't think that it is likely.

[Airblader]

There definitely are events for attaching/detaching. I believe they were GameEvents.OnPartAttach and GameEvents.OnPartRemove. Beware that most other events do not work in the VAB/SPH and that there is no active vessel in the editors. I'm also not sure if OnPartAttach will fire for the root part (even though I just played around with these events a few days ago…).

I would also recommend wrapping access to SortedShipList in a try/catch as I experienced a bug with it (in case you're still working with it): http://bugs.kerbalspaceprogram.com/issues/2021

Edited January 12, 2014 by Airblader

[mhoram]

There definitely are events for attaching/detaching. I believe they were GameEvents.OnPartAttach and GameEvents.OnPartRemove. Beware that most other events do not work in the VAB/SPH and that there is no active vessel in the editors. I'm also not sure if OnPartAttach will fire for the root part (even though I just played around with these events a few days ago…).

I would also recommend wrapping access to SortedShipList in a try/catch as I experienced a bug with it (in case you're still working with it): http://bugs.kerbalspaceprogram.com/issues/2021

The perfect answer to my question ... did not know about GameEvents.

onPartAttach and onPartRemove take care about parts, with onInputLocksModified I can test if the mouse left the staging-configuration-area and onPartActionUIDismiss fires whenever the ActionGUI of a part gets closed.

That is good enough for my application.

        public void start_triggers()
        {
            GameEvents.onPartAttach.Add(myfun);
            GameEvents.onPartRemove.Add(myfun);
            GameEvents.onInputLocksModified.Add(myfun2);
            GameEvents.onPartActionUIDismiss.Add(myfun3);
        }

        public void end_triggers()
        {
            GameEvents.onPartAttach.Remove(myfun);
            GameEvents.onPartRemove.Remove(myfun);
            GameEvents.onInputLocksModified.Remove(myfun2);
            GameEvents.onPartActionUIDismiss.Remove(myfun3);
        }

Thanks also for the hint about the exception. Since this is only called from an attached part, I did not experience any problems yet.

[Magion]

I would also recommend wrapping access to SortedShipList in a try/catch as I experienced a bug with it (in case you're still working with it): http://bugs.kerbalspaceprogram.com/issues/2021

It's not bug. I don't know why you wrote it into KSP bugtracker. It's normal, that in C# you can't work with empty list. Just write this before your code.

if (EditorLogic.startPod != null)
{
    [Your Code]
}

[Airblader]

I'm not trying to work with the list. Granted, I am new to C# itself (coming from Java), but so much as assigning a property to a local variable should not throw an exception. If it's null, that's alright. But accessing any property should never throw.

See http://msdn.microsoft.com/en-us/library/ms229006.aspx:

X AVOID throwing exceptions from property getters.

Property getters should be simple operations and should not have any preconditions. If a getter can throw an exception, it should probably be redesigned to be a method. Notice that this rule does not apply to indexers, where we do expect exceptions as a result of validating the arguments.

Edited January 13, 2014 by Airblader