UX: Enable long-touch menu in photo viewer on iOS

[jkgeyti]

With the recent release, and the improved touch support, photoprism is finally usable on iOS! Loving all the good work and fantastic additions 🎉 There's still a handful of issues wrt downloading and sharing, but in the interim, it'd be good to be able to copy the JPEG shown in the photo viewer, so images can be quickly shared with other apps.

In desktop browsers, you can right click images to get a context menu that includes a "Copy image" context menu, but on iOS, -webkit-touch-callout: none is set on images shown in the popup full-screen image viewer, which disables the long-press context menu.

As a quick hack, adding the following css and long-clicking images produces the context menu shown in the screenshot below. I'm not sure if there's any good justification for disabling the context menu on mobile devices, but if not, it'd be really convenient if it could be enabled 🙏 .

.pswp__img {
    -webkit-touch-callout: default !important;
}

[graciousgrey]

We use photoswipe for the fullscreen viewer, so we did not implement it on our own. There might be a reason why it is implemented this way. Changing this would require testing on all kinds of devices and browsers which we cannot afford at the moment. Opening images in other apps is planned see: #25 or #658

[jkgeyti]

Makes sense. I've raised it as a request on the photoswipe repo.

[jkgeyti]

This is targeted to be solved in photoswipe v5 (unreleased)

dimsemenov/PhotoSwipe#1748 (comment)

[Soulplayer]

I see that version 5 is released yet it does not work on photoprism. This would be a great addition 😇?

[lastzero]

After testing it locally, I added this bit of CSS as a workaround until we have a new viewer. It's available for testing in our development preview and demo in about one hour.