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<p><font size="+1">Hi Mark,<br>
</font></p>
<p><font size="+1">You should delete all the instances of LineMorph
before changing its definition.</font></p>
<p><font size="+1">In general, while it is ok to change the class
definition of existing Object, you have some risks with
uninitialized attributes declared and initialized in the
ancestors hierarchy.</font></p>
<p><font size="+1">This the problem you encounter.</font></p>
<p><font size="+1">Hilaire</font><br>
</p>
<div class="moz-cite-prefix">Le 13/11/2021 à 23:17, Mark via
Cuis-dev a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:4F0725DF-4D49-49AE-89E4-477B16397AB2@virtualmdj.com">
<div class="">ISSUE #2</div>
<div class="">After restarting Cuis, I re-added the
LineExampleMorph (section 7.1.1 - <a
href="https://cuis-smalltalk.github.io/TheCuisBook/Going-Vector.html"
class="" moz-do-not-send="true">https://cuis-smalltalk.github.io/TheCuisBook/Going-Vector.html</a>)</div>
<div class="">And instantiated it.</div>
<div class="">It drew a green line.</div>
<div class=""><br class="">
</div>
<div class="">Then, I went to the class definition and changed its
superclass from Morph to MovableMorph and saved.</div>
<div class=""><br class="">
</div>
<div class="">Everything seems fine … but, when I clicked on the
existing green line, the debugger popped up</div>
<div class=""><br class="">
</div>
<div class="">So, I closed the debug window and went to the
Workspace window and executed “LineExampleMorph allInstancesDo:
[:x | x delete. ]”</div>
</blockquote>
<pre class="moz-signature" cols="72">GNU Dr. Geo
<a class="moz-txt-link-freetext" href="http://drgeo.eu">http://drgeo.eu</a>
<a class="moz-txt-link-freetext" href="http://blog.drgeo.eu">http://blog.drgeo.eu</a></pre>
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