113.0a1 (2023-03-19) (64-bit), Win10

Just a nit to polish, but I kept noticing this when firing up Daily.

Folder pane header buttons are currently evenly distributed with several gaps:

• + New Message button centered above folder pane
• ↓ (Get messages) button centered in the gap between + New Message button and left side of folder pane
• ⋯ (Folder pane options) centered in the gap on the right side of folder pane header.

That's kind of nice for the eye, but not very practical imho tbh.

For wider folder panes, I think the alignment is a bit weird, even though it's evenly balanced. Buttons look disconnected. Whenever user changes the folder pane width, the location of these important buttons will change, somewhat breaking muscle memory.
Perhaps we can explore a more stable, consistent, and ergonomic alignment for these buttons?

Proposal for improvement

• Make ↓ (Get messages) button properly left-aligned (always).
• Make + New Message button directly right-adjacent to the ↓ (Get messages) button (always), so the position of the first two buttons will always be the same - good for muscle memory and visual recognition!
• Make ⋯ (Folder pane options) properly right-aligned to the end of the folder pane header - far end is clearly the expected position for such meatball menus, not some random centered position.

(In reply to Anje from comment #1)

Why would composing a new message have anything to do with the Folder Pane? It's in the wrong place.

Hi Anje, there will be a couple of changes to the UI in the Thunderbird Supernova release (mostly available for preview in Beta and Daily), but afasics, no fundamental changes from the existing UI that you couldn't reverse (but you might have to live with some amount of minor changes). This bug isn't the right place to discuss the new UI. I'll send you an email with a few hints.

I'm finding the logic and lack of generic continuity in design confusing. I cannot find any other location where this has been discussed, so if there is a link could you post it.

Get involved section of Thunderbird homepage has all of our communication channels.
UX List, Beta List, and Daily List (in order of relevance/preference) can be used for UX discussions I believe.

There's also a dedicated and detailed Thunderbird blog post on the new Supernova Folder Pane.

Depends on D176292

I'm not sure I agree with the suggested solution.

Having the first 2 buttons left aligned and the meatball menu right aligned looks extremely out of balance.
I think if we want to have a more consistent positioning of those buttons a simple space-between would be better, considering that users now can also hide those initial buttons if they want to.

When both initial buttons are hidden, the meatball menu should appear to the right of the first item, but that's something for another bug.

Pushed by alessandro@thunderbird.net:
https://hg.mozilla.org/comm-central/rev/3de6b2ff9690
Fix the folderPaneMoreButton at the end of the folderPaneHeaderBar. r=aleca

Comment on attachment 9329952 [details]
Bug 1823378 - Fix the folderPaneMoreButton at the end of the folderPaneHeaderBar. r=#thunderbird-front-end-reviewers

[Triage Comment]
Approved for beta

It does look better on daily.

Thunderbird 113.0b5:
https://hg.mozilla.org/releases/comm-beta/rev/9b95931c9d72