Morphic equivalent of 'display: none'?

Hi all,

does Morphic has an equivalent of JavaScript's 'display: none'?

#show/#hide/#visible: reserve space for the hidden morph. However, there are other scenarios where you do not want to reserve space. (A simple example would be a list that should only appear iff it has items.)

In JS, you can use 'display: none' instead of 'visibility: hidden' to give the space back to the element's remaining siblings.

But in Morphic, is there currently any better option than #delete (and #addMorph:) later?

(IMO, delete'n'add is not always the best pattern to do this. You need to remember the index and owner of the relevant morph for adding it later.)

Provided that I did not overlook any existing features, would you consider this a useful extension for Morphic?

I was thinking of a property (#skipLayout, if you do not have any better idea) and a convenience method (#nonSkippedSubmorphs) that rejects suppressed submorphs. TableLayout would need to use this selector instead of regular #submorphs.

Or would this break too many existing things that rely on #submorphs?

Another approach would be a selector in the TableLayoutProperties to have all submorphs skipped that are hidden via classical #visible. But this would be less powerful as you couldn't combine both kinds of hiding in the same morph. But maybe this would be even better in terms of avoiding complexity?

I'm looking forward to your opinions.

Best,

Christoph

Am 03.04.2020 17:48:29 schrieb Stéphane Rollandin <[hidden email]>:

> #show/#hide/#visible: reserve space for the hidden morph. However, there
> are other scenarios where you do not want to reserve space. (A simple
> example would be a list that should only appear iff it has items.)

You could have such a "removed morph" temporarily #become: a collapsed
representation (like a flat invisible morph for a list item), and then
swap it back when you need it. I have used that pattern; #become: is fast.

>
> In JS, you can use 'display: none' instead of 'visibility: hidden' to
> give the space back to the element's remaining siblings.
>
> But in Morphic, is there currently any better option than #delete (and
> #addMorph:) later?
>
>
> (IMO, delete'n'add is not always the best pattern to do this. You
> need to remember the index and owner of the relevant morph for adding it
> later.)
>
>
> Provided that I did not overlook any existing features, would you
> consider this a useful extension for Morphic?

No. I think this should be implemented either via specific mophs or via
specific layout (probably yet to be invented).

>
> I was thinking of a property (#skipLayout, if you do not have any better
> idea) and a convenience method (#nonSkippedSubmorphs) that
> rejects suppressed submorphs. TableLayout would need to use this
> selector instead of regular #submorphs.
>
> Or would this break too many existing things that rely on #submorphs?

Oh, yes, please do not add any logic to #submorphs. It is a plain array
and a lot of things rely on this. You can implement a wrapper Morph with
all that logic, instead.

>
>
> Another approach would be a selector in the TableLayoutProperties
> to have all submorphs skipped that are hidden via classical #visible.
> But this would be less powerful as you couldn't combine both kinds of
> hiding in the same morph. But maybe this would be even better in terms
> of avoiding complexity?

Not a good idea IMO to use a property tag to represent another property.
#visible should just be about visibility.

Best,

Stef

Perfect! Thanks, Marcel! :-)

Best,

Christoph