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Hi Christoph --<div><br></div><div>It might help if you remember a preciseExtent in TransformationMorph to then be used during its updates.</div><div><br></div><div>This is not a bug in TableLayout.</div><div>This is not a specific bug in Morphic.</div><div>It is a design issue; a<span style="font-size: 10pt">ll coordinates (or bounds) in Morphic are integer at the moment.</span></div><div><br></div><div>You can observe similar issues when changing the scale factor back and forth.</div><div><br></div><div>Best,</div><div>Marcel</div><div class="mb_sig"></div>
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<p style="color: #AAAAAA; margin-top: 10px;">Am 24.08.2022 20:12:46 schrieb christoph.thiede@student.hpi.uni-potsdam.de <christoph.thiede@student.hpi.uni-potsdam.de>:</p><div style="font-family:Arial,Helvetica,sans-serif">
Hi all,<br>
<br>
I've observed and reproduced a case of "volatile table layout" in Morphic:<br>
<br>
<span style="color: #000000">inner </span><b>:=</b><span style="color: #000000"> Morph </span><span style="color: #000080">new</span><span style="color: #000000"> </span><span style="color: #000080">color:</span><span style="color: #000000"> Color </span><span style="color: #000080">red</span><span style="color: #000000">.<br>
f </span><b>:=</b><span style="color: #000000"> inner </span><span style="color: #000080">addFlexShell</span><span style="color: #000000"><br>
</span><span style="color: #000080">scale:</span><span style="color: #000000"> </span><span style="color: #800000">0.4</span><span style="color: #000000">;<br>
</span><span style="color: #000080">yourself</span><span style="color: #000000">.<br>
<br>
outer </span><b>:=</b><span style="color: #000000"> Morph </span><span style="color: #000080">new</span><span style="color: #000000"> </span><span style="color: #000080">color:</span><span style="color: #000000"> Color </span><span style="color: #000080">yellow</span><span style="color: #000000">.<br>
outer </span><span style="color: #000080">changeTableLayout</span><span style="color: #000000">.<br>
outer </span><span style="color: #000080">addMorph:</span><span style="color: #000000"> f.<br>
outer </span><span style="color: #000080">addMorph:</span><span style="color: #000000"> (Morph </span><span style="color: #000080">new</span><span style="color: #000000"> </span><span style="color: #000080">extent:</span><span style="color: #000000"> </span><span style="color: #800000">30</span><span style="color: #000000"> </span><span style="color: #000080">@</span><span style="color: #000000"> </span><span style="color: #800000">10</span><span style="color: #000000">).<br>
<br>
f </span><span style="color: #000080">layoutChanged</span><span style="color: #000000">. outer </span><span style="color: #000080">fullBounds</span><span style="color: #000000">. f </span><span style="color: #000080">scale</span><span style="color: #000000">. </span><span style="color: #008080"><i>"0.38888888888888895"</i></span><span style="color: #000000"><br>
f </span><span style="color: #000080">layoutChanged</span><span style="color: #000000">. outer </span><span style="color: #000080">fullBounds</span><span style="color: #000000">. f </span><span style="color: #000080">scale</span><span style="color: #000000">. </span><span style="color: #008080"><i>"0.37654320987654327"</i></span><span style="color: #000000"><br>
f </span><span style="color: #000080">layoutChanged</span><span style="color: #000000">. outer </span><span style="color: #000080">fullBounds</span><span style="color: #000000">. f </span><span style="color: #000080">scale</span><span style="color: #000000">. </span><span style="color: #008080"><i>"0.36282578875171484"<br>
"..."</i></span><br>
<br>
The incremental shrinkage of #scale takes place in TransformationMorph>>extent: (see screenshot). I suppose this is the cause of a rounding error (scale is exact, but bounds/fullBounds are rounded), but I'm not sure. The following stabilizes my concrete case, but I'm not sure whether this is the actual solution or just a workaround:<br>
<br>
TransformationMorph >> <b>extent:</b><span style="color: #000000"> </span><span style="color: #000080">newExtent</span><span style="color: #000000"><br>
<br>
</span><span style="color: #000000"><u> + </u></span><span style="color: #800000"><u>self</u></span><span style="color: #000000"><u> </u></span><span style="color: #000080"><u>extent</u></span><span style="color: #000000"><u> </u></span><span style="color: #000080"><u>=</u></span><span style="color: #000000"><u> </u></span><span style="color: #000080"><u>newExtent</u></span><span style="color: #000000"><u> </u></span><span style="color: #000080"><u>ifTrue:</u></span><span style="color: #000000"><u> [</u></span><span style="color: #800000"><u>^</u></span><span style="color: #000000"><u> </u></span><span style="color: #800000"><u>self</u></span><span style="color: #000000"><u>].<br>
</u></span> <span style="color: #000000"> </span><span style="color: #800000">self</span><span style="color: #000000"> </span><span style="color: #000080">renderedMorph</span><span style="color: #000000"> </span><span style="color: #000080">==</span><span style="color: #000000"> </span><span style="color: #800000">self</span><span style="color: #000000"><br>
</span> <span style="color: #000000"> </span><span style="color: #000080">ifTrue:</span><span style="color: #000000"> </span><span style="color: #000000">[</span><span style="color: #800000">super</span><span style="color: #000000"> </span><span style="color: #000080">extent:</span><span style="color: #000000"> </span><span style="color: #000080">newExtent</span><span style="color: #000000">]</span><span style="color: #000000"><br>
</span> <span style="color: #000000"> </span><span style="color: #000080">ifFalse:</span><span style="color: #000000"> </span><span style="color: #000000">[</span><span style="color: #000000"><br>
</span> <span style="color: #000000"> </span><span style="color: #800000">self</span><span style="color: #000000"> </span><span style="color: #000080">adjustAfter:</span><span style="color: #000000"> </span><span style="color: #008000">[</span><span style="color: #000000"><br>
</span> <span style="color: #000000"> </span><span style="color: #808080">|</span><span style="color: #000000"> </span><span style="color: #808080">scaleFactor</span><span style="color: #000000"> </span><span style="color: #808080">|</span><span style="color: #000000"><br>
</span> <span style="color: #000000"> </span><span style="color: #808080">scaleFactor</span><span style="color: #000000"> </span><b>:=</b><span style="color: #000000"> </span><span style="color: #800080">(</span><span style="color: #800000">self</span><span style="color: #000000"> </span><span style="color: #000080">scale</span><span style="color: #000000"> </span><span style="color: #000080">*</span><span style="color: #000000"> </span><span style="color: #000080">newExtent</span><span style="color: #000000"> </span><span style="color: #000080">r</span><span style="color: #000000"> </span><span style="color: #000080">/</span><span style="color: #000000"> </span><span style="color: #800000">self</span><span style="color: #000000"> </span><span style="color: #000080">fullBounds</span><span style="color: #000000"> </span><span style="color: #000080">extent</span><span style="color: #000000"> </span><span style="color: #000080">r</span><span style="color: #800080">)</span><span style="color: #000000"> </span><span style="color: #000080">max:</span><span style="color: #000000"> </span><span style="color: #800000">0.1</span><span style="color: #000000">.</span><span style="color: #000000"><br>
</span> <span style="color: #000000"> </span><span style="color: #800000">self</span><span style="color: #000000"> </span><span style="color: #000080">scale:</span><span style="color: #000000"> </span><span style="color: #800080">(</span><span style="color: #808080">scaleFactor</span><span style="color: #000000"> </span><span style="color: #000080">detentBy:</span><span style="color: #000000"> </span><span style="color: #800000">0.1</span><span style="color: #000000"> </span><span style="color: #000080">atMultiplesOf:</span><span style="color: #000000"> </span><span style="color: #800000">1.0</span><span style="color: #000000"> </span><span style="color: #000080">snap:</span><span style="color: #000000"> </span><span style="color: #800000">false</span><span style="color: #800080">)</span><span style="color: #008000">]</span><span style="color: #000000">]</span><span style="color: #000000">.</span><br>
<br>
Looking forward to your feedback!<br>
<br>
Best,<br>
Christoph<br>
<br>
<span style="color: #808080">---<br>
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["volatileTableLayoutStack.png"]</div></blockquote></div>