Show me where I am zoomed within an image

[akhenry]

Is your feature request related to a problem? Please describe.
When zoomed in an image, it would be useful to know where in the full image I am zoomed. This is particularly useful when locking zoom state and moving between images.

Describe the solution you'd like
When zoomed within an image, show a rectangle within a thumbnail of the full image indicating where I am zoomed. This could be overlaid on the existing image thumbnail, since we're already showing a thumbnail there.

Example

[akhenry]

@charlesh88 Thoughts?

[LuciNyan]

I'd love to work on this issue! Could you please assign this to me if not been assigned to anybody yet? Thanks! <3

[ozyx]

Verified, Testathon 12/5/22:

Zoom indicator displays correctly when zoomed in and panned. It also applies to adjacent images if the zoom if locked. On window resize, the zoom area adjusts correctly. Awesome stuff.

[davetsay]

verified

[davetsay]

this is great @LuciNyan , thanks!