Error using ScheduledControllers - debug show it's an UndefinedObject !!!

Boris.Gaertner Boris.Gaertner at
Tue Nov 13 10:07:55 UTC 2007

Hi Theo,
a few days ago you asked the same question and received
some answers that should help you getting started.

To resume:
1. For a first experiment with MVC, you should download
and use Squeak 3.7. In newer versions, MVC is seriously
damaged by recent additions to the Morphic GUI.
(In 3.10, the debugger does not come up in MVC and
the generic text edit menus of class ParagraphEditor do
not pop up.)

2. To use MVC, you have to enter a MVC project.
To do that, you bring up the World menu and select the
option 'open'. You get a new menu, where you select the
second last option: 'mvc project'. When you select this
option, a very small window is placed on the screen.
Double click on this window: The window opens itself
and now you are in a MVC project.

3. You may wish to download this tutorial:
It is quite incomplete, but it may give you some hints.


----- Original Message ----- 
From: "theo" <theo at>
To: <squeak-dev at>
Sent: Tuesday, November 13, 2007 6:22 AM
Subject: Error using ScheduledControllers - debug show it's an 
UndefinedObject !!!

>> Hi,
>> I'm new to Squeak ST and am trying to create some views using MVC.
>> I found a sample and I've tried to run the following in a workspace and 
>> get and error see below test/error...
>> Do I need to initialize ScheduledControllers  and if so how?
>> Thanks, Theo
>> PS I'm not new to Smalltalk, I've been using Dolphin ST Pro for a few 
>> years.
>> ====== test code ==============
>> "from: "
>> | form pen view topView |
>> form := Form extent: 300 at 300 depth: Display depth.
>> form fillColor: Color green.
>> pen := Pen newOnForm: form.
>> pen defaultNib: 4.
>> 1 to: 50 do: [:i | pen go: i*4. pen turn: 89].
>> view := FormView new.
>> view model: form.
>> view borderWidth: 2.
>> topView := ColorSystemView new.
>> topView model: form. "to set the correct window size"
>> topView addSubView: view.
>> topView controller open.
>> =========== end of test code ==============
>> It fails on the last line of the above,
>> the error is generated by:    StandardSystemController >> open
>> statement:        ScheduledControllers scheduleAvtive: self
>> error:   MessageNotUnderstood:    UndefinedObject .. scheduleActive:
>> ==================================

More information about the Squeak-dev mailing list