State of Observers Redux — 18 August 2011

[thomthom]

aiaiai... sigh

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[thomthom]

Update to include SU 8.0 M1
http://www.thomthom.net/software/sketchup/observers/

[Dan Rathbun]

You have that the AppObserver::onQuit is working...

It's is bugged in v8 (at least. And I did report a bug last beta cycle.)

It does not wait until the callbacks return, before shutting down the application.
Trying to use the callback to save plugin settings, and so forth, often fails for me.

Also, trying to dettach the observer itself from within onQuit causes a GPF (if I remember right.)
In addition coders should NOT open any "owned" windows (like WebDialogs and messageboxes,) during the callback, until they fix the 'non-blocking' issue.

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Can't remember if v7 had any of these problems.

[thomthom]

@dan rathbun said:

You have that the AppObserver::onQuit is working...

It's is bugged in v8 (at least. And I did report a bug last beta cycle.)

Ok - I'll add that. Never used it. All the observers I've not tried and not heard any reports on I assume is working.

@dan rathbun said:

InstanceObserver

@dan rathbun said:

what about Groups?

Groups and Images all are listed in model.definition.

@dan rathbun said:

(Note how I changed the example, from UI.messagebox to puts.

I wish the docs would do that. Messageboxes are double plus ungood - especially in observer events.

[thomthom]

Dan, how do you test AppObserver::onQuit ?

If I had a test case that illustrates the symptoms I could quickly run it on SU 6-8.

[Dan Rathbun]

@thomthom said:

Dan, how do you test AppObserver::onQuit

Tough one... as it DOES fire. (It just doesn't wait for the callback to finish.)
Well I first found it because I wanted to save the pos & size of several windows using Win32API calls.
But it wasn't working.

So I tried putting a debug popup messagebox inside onQuit(), thinking the shutdown process should stop, until I clicked "OK". But it DIDN'T stop, the messagebox came up, but everything else shutdown. And when I closed the messagebox, it's owner (the Sketchup App window,) no longer existed, so Windows poped up the VS Just in Time debugger query box (you know.. "DO want Debug now?")

So next I tried, to open a WebDialog.. and that made things even worse. (I got a post-shutdown BugSplat!) They were either GPF or "Unhandled Win32 Exception".)

I was trying to call a method that saved a whole bunch of data into the Registry, and that method may have called another method as well. Anyway, I even tried "lean" the process way down, putting all statements inside the onQuit(), and removing every extra reference assignment I could. But Sketchup just would not wait. It seemed to be processing all the onQuit callbacks, in the Ruby thread, but at the same time, cleaning up the main App thread, and disposing of all it's child windows.

Perhaps it's a unique thing because I want to save window object data, ...that most other plugins would not encounter.

I plan to try using Ruby define_finalizer, and see if that works for me.

As far as testing.. I'll have to think more on this... perhaps a trace function.

[Dan Rathbun]

@thomthom said:

@dan rathbun said:

InstanceObserver

@dan rathbun said:

what about Groups?

Groups and Images all are listed in model.definition.

I don't have a Mac to test this InstanceObserver workaround.

(And I fixed the example. I don't know why, but every single time I go to write an initialize() method, I forget to put def in front of it!)

[Dan Rathbun]

InstanceObserver

I'm wonding if you can do this

#
class InstSpy < Sketchup;;InstanceObserver

  if RUBY_PLATFORM =~ /(darwin)/
    def onQuit()
      Sketchup.active_model.definitions.instances.each{|i|
        i.remove_observer(self)
      }
      # what about Groups?
    end
  end #if

  def initialize(*args)
    Sketchup.add_observer(self) if RUBY_PLATFORM =~ /(darwin)/
  end

  # define your Instance callbacks;
 
  def onOpen(instance)
    puts("onOpen; " + instance.to_s)
  end

  def onClose(instance)
    puts("onClose; " + instance.to_s)
  end

end # class

(Note how I changed the example, from UI.messagebox to puts.

[thomthom]

In TT_Lib2 I got a function TT.debug that outputs a string to any system debugger, like DebugView. That can probably be used to track onQuit.

[thomthom]

Added public bug tracker to the BitBucket repo:
https://bitbucket.org/thomthom/sketchup-observers/issues?status=new&status=open

People can add reports of broken observer events there.