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To Detent Or Not To Detent…

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Sean P. DeNigris

To Detent Or Not To Detent…

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Can anyone explain the purpose of sending #detentBy:atMultiplesOf:snap: in the method below? The problem is that, if you resize programatically below a factor of 0.1, you enter a black hole from which many scale attempts become effectively ignored. If the send is removed, everything works for my use case, but I don't understand its purpose and so don't know if it's a bug or feature!
TransformationMorph>>#extent: newExtent
self adjustAfter:
[ | scaleFactor |scaleFactor := (self scale * newExtent r / self fullBounds extent r) max: 0.1.
self scale: (scaleFactor detentBy: 0.1 atMultiplesOf: 1.0 snap: false)]

Cheers,
Sean

Nicolai Hess

Re: To Detent Or Not To Detent…

2015-09-02 17:42 GMT+02:00 Sean P. DeNigris <[hidden email]>:

Can anyone explain the purpose of sending #detentBy:atMultiplesOf:snap: in
the method below? The problem is that, if you resize programatically below a
factor of 0.1, you enter a black hole from which many scale attempts become
effectively ignored. If the send is removed, everything works for my use
case, but I don't understand its purpose and so don't know if it's a bug or
feature!
TransformationMorph>>#extent: newExtent
self adjustAfter:
[ | scaleFactor |scaleFactor := (self scale * newExtent r / self
fullBounds extent r) max: 0.1.
self scale: (scaleFactor detentBy: 0.1 atMultiplesOf: 1.0 snap: false)]

Maybe it is not needed for the #extent method.

It is used for rotation and scaling with the halos. For example, if you

remove that call in #scaleToMatch:, it may be difficult (or impossible, due to rounding errors)

to scale a Morph back to scale factor 1.0.

But I think it is enough to use this in #scaleToMatch: , no need to have it in #extent: too.

-----
Cheers,
Sean
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