Add alternative access to image description, especially for mobile

[cincodenada]

Hello! Been trying out Pinafore and so far I like it a lot, and it's given me some inspiration for what could be accomplished with a PWA for some other projects as well.

One thing I miss in Pinafore is the ability to easily view the image description on my phone - mobile browsers generally don't have great title-text support (since they don't have hover). It would be nice to have an option in the image overlay screen to view the alt text - Tusky, for instance, implements this as a little pull-up drawer that shows the first couple lines of description text, it would alo be reasonable to have another button similar to the zoom button (which is super handy, btw!) that would bring up the image description, perhaps an ℹ️-type icon.

One thing I do like about the technique of showing the first line or two with an option to expand, though, is that it makes (part of) the image description visible by default, which makes folks more aware of image descriptions, more than an easily-ignored i button would do. That visibility in turn I think encourages use of image descriptions, which is good for everyone!

Also if I've missed some way of getting to image descriptions on mobile, then consider this a request to make that more discoverable, ha!

[nolanlawson]

Thanks for reaching out. It depends on the browser, but some mobile browsers let you see the alt text. On Firefox for Android, for instance, you can long-press and it will show a little popup with the alt text. I think it cuts it off, though, and I admit it probably doesn't work cross browser, so this would be a great addition.

[nolanlawson]

The tricky part is finding an affordance that doesn't break the built-in browser behavior – overriding the long-press, for instance, would disable the ability to download or share the image. A pull-up drawer makes sense, but sadly gestures are difficult to implement on the web in an accessible and cross-platform way. (Or at least, I haven't really added gestures anywhere to Pinafore yet.)

[cincodenada]

Okay, I got a bee in my bonnet and drafted up a proof-of-concept in #2103 taking your thoughts on interaction into account - I used the unused button slot on the left-hand side, altho as I mention there if we always show the first line of the description, it could just be expanded by tapping on the text.

I actually use Firefox on Android and noticed the long-press alt-text, but as you note, it does cut it off, which makes it a partial solution at best, as many image descriptions are a paragraph long or more.