Why open a class ?

2013/1/4 Ken G. Brown <kbrown at mac.com>:
>
> On 2013-01-04, at 1:57 AM, Edgar J. De Cleene wrote:
>
>>
>>
>>
>> On 1/3/13 11:50 PM, "Ralph Boland" <rpboland at gmail.com> wrote:
>>
>>> I would like to create a small TextMorph that continuously displays the
>>> position
>>> of the cursor.  To do this I need to write something of the form:
>>>
>>> true whileTrue: [
>>>    x := self getCursorPosition.
>>>    textMorph display: x.
>>>    self sleep:  10   "milliseconds"]
>>>
>>> I plan to use this when investigating some morph that is not displaying the
>>> way
>>> I expect it to.
>>>
>>> Can someone provide me with hints as how to properly do this or point
>>> me to a package that already does this or something similar?
>>>
>>> I have searched the code and the Internet.  I found that "getCursorPosition"
>>> can be implemented as:
>>>
>>>     "World activeHand position"
>>>
>>> I can also figure out how to build the Morph I need to display the
>>> Cursor position.
>>>
>>> I don't know how to implement "sleep:"
>>> I am not sure if I should use an infinite loop as I have.
>>>
>>> An alternative to the TextMorph I want is to construct a cursor that
>>> continuously displays its
>>> position but I prefer my original plan.
>>>
>>> Any help much appreciated.
>>>
>>> Ralph Boland
>>>
>>
>> See the attached, I use daily
>>
>> Evaluate InfoMorph openInWorld or InfoMorph openInHand
>>
>> Cheers
>>
>> Edgar
>
> Have you been able to run this in the latest Squeak4.4-12327 on Cog 2640?
> On my Mac, InfoMorph openInWorld fails:
>
> InfoMorph class(Object)>>doesNotUnderstand: #openInWorld
>         Receiver: InfoMorph
>         Arguments and temporary variables:
>                 aMessage:       openInWorld
>                 exception:      MessageNotUnderstood: InfoMorph class>>openInWorld
>                 resumeValue:    nil
>         Receiver's instance variables:
>                 superclass:     StringMorph
>                 methodDict:     a MethodDictionary(#cambio:->(InfoMorph>>#cambio: "a CompiledMethod...etc...
>                 format:         150
>                 instanceVariables:      nil
>                 organization:   ('step' step stepTime)
> ('as yet unclassified' cambio:)
>
>                 subclasses:     nil
>                 name:   #InfoMorph
>                 classPool:      nil
>                 sharedPools:    nil
>                 environment:    Smalltalk globals "a SystemDictionary with lots of globals"
>                 category:       #SqueakRos
>
> Ken G. Brown
>
>
>>
> [see attached file: InfoMorph.st]
>
>
>