[Design polish] Add liquid glass bottom tabs to iOS

[shawnborton]

We want to explore what it would take to implement native liquid glass bottom tabs on iOS. We also need to be conscious of what this means for Android, whether we can do some kind of floating tab system over there or just keep what we current have or use a more native approach.

Two points of reference here:

• @AndrewGable wired up a POC that uses liquid glass so we can see it in action
• @shawnborton wired up a pseudo-glass implementation that isn't pure native but tries to mimic the glass effect

@adamgrzybowski is this something you or someone on your team can look into? We are mostly curious what it would take to pull this off before fully committing. cc @Expensify/design @JmillsExpensify

Issue Owner

Current Issue Owner: @huult

[sumo-slonik]

Hi @shawnborton, I worked on the Tab Navigator implementation, and I’d be happy to help prepare some MVP where we can figure out what kind of interaction and overall feel of the bar would be good for us.

[shawnborton]

That sounds like a good plan to me 👍

[sumo-slonik]

I’ll prepare a version with a single tab navbar so we can assess whether the issues and trade-offs that come with it are significant enough to outweigh the benefits of reducing it. I’ll also prepare a version with two tab navbars, so we can compare both approaches and determine which direction makes more sense.

I’ll share an update shortly and then ask you to build the ad hoc.

[JmillsExpensify]

Thanks, assigned you!

[grgia]

@shawnborton happy to help review here, gonna self assign! But also cc @AndrewGable given he was the liquid glass mastermind

[sumo-slonik]

@shawnborton What is the expected behavior on Mobile Web and Android as part of this implementation? Are we aiming to keep the current behavior there unchanged?

[shawnborton]

Hmm good question for mWeb. For Android, it sounds like we can do some kind of rounded bottom tabs - @dubielzyk-expensify can probably share more there.

For mWeb (or even Android too), I would be fine trying some kind of rounded bottom tabs too like so:

Basically the same shape and idea as liquid glass tabs, but without the effect.

[sumo-slonik]

Thanks!

[JmillsExpensify]

Going to also assign myself so I get the product review at the PR stage.