Item Reorder

[Nubeat7]

I once saw a clamp solution that was so elegant and readable, that I want to share it here:
CODE: SELECT ALL
newId = [0, @id + @move, @order.length - 1].sort[1]


EDIT: You should never use a capital letter to start a variable!

thats a very beautiful solution, need to remember this the next time , also about the capitals

Once it reaches the end it wraps around to the beginning.

but it doesn't, it also rotates the whole array

Your example throws an error right away when I load it. I'm using 3.0.4; not sure if that's relevant.

which error? its working here with 3.06 maybe you need to init @select?

[RJHollins]

Would someone describe/explain what a 'clamp solution' means/does or what the purpose/need ?

Something 'elegant' and 'readable' are always of great interest

thx

[Perfect Human Interface]

Once it reaches the end it wraps around to the beginning.

but it doesn't, it also rotates the whole array

You're misunderstanding the logic. When you shift the item all the way around back to the beginning the array won't return to the original order, it will be rotated. It's correct; a natural consequence of reordering items in this manner.

which error? its working here with 3.06 maybe you need to init @select?

Yeah, clicking the @select input seemed to take care of it.

[tulamide]

Would someone describe/explain what a 'clamp solution' means/does or what the purpose/need ?

It means exactly what the term indicates: A clamp function takes care that a value is always between a minimum and a maximum value (including both). For example, if you clamp 3 between 2 and 4, the result is 3, but clamping 3 between 4 and 6 returns 4.

The beauty of this solution lies in the clever use of the sort-method, that come with Ruby arrays. The value, min and max build an array that is then sorted. And from the resulting array the second index is returned. As an example, clamping 3 between 4 and 6 with sort:
[6, 3, 4).sort -> returns [3, 4, 6] -> from that array the second entry is taken -> 4

but it doesn't, it also rotates the whole array

That's why I said in my other post, that it's not really shifting nor swapping.

[Nubeat7]

You're misunderstanding the logic. When you shift the item all the way around back to the beginning the array won't return to the original order, it will be rotated. It's correct; a natural consequence of reordering items in this manner.

you are are right i don't see some logic in this behaviour, why should the array rotate when the item is moved from the beginning to the end? i don't see any "natural" logic there...
you also said:

Well, semantics... I think "shifting individual items up and down" is straightforward enough. It's not meant to shift the whole array, of course.

but if you intended it like this, sure, it will be a feature then, not a bug

maybe you should explain this in the description then, that people don't get confused what it really should do.

if you want to wrap the item when moving it beyond the array borders, the insert methode would be the better soultion, this is how i understand it

[Nubeat7]

The beauty of this solution lies in the clever use of the sort-method, that come with Ruby arrays. The value, min and max build an array that is then sorted. And from the resulting array the second index is returned. As an example, clamping 3 between 4 and 6 with sort:
[6, 3, 4).sort -> returns [3, 4, 6] -> from that array the second entry is taken -> 4

thanks for the explaining tulamide, you can find this methode also inside the stock knobs, don't know how often i saw it and never thought about how fancy this methode is or how it works

[Perfect Human Interface]

you are are right i don't see some logic in this behaviour, why should the array rotate when the item is moved from the beginning to the end? i don't see any "natural" logic there...

It's just what happens when you apply this kind of swap/displacement logic circularly. Just like when you move one item down, the items below it shift up; this is that happening but wrapped across the borders. So whether or not that's "desired" that's what this logic gets you. (I have a major-brand synth plugin that has this behavior, for what it's worth.)

if you want to wrap the item when moving it beyond the array borders, the insert methode would be the better soultion, this is how i understand it

This is a really good solution though, maybe better. I'll have to see if I can wrap my brain around this to apply it to the other method (list of positions) and maybe add it to the original post.