Image Occlusion: Add an error message if no masks are set

[david-allison]

• Share an image to AnkiDroid as 'Image Occlusion'
• Click 'save'

Expected

• A user is informed that masks must be added before an IO note is saved

Actual

• No error occurs, screen stays open

Code:

https://github.com/ankitects/anki/blob/dac26ce67147b261d79a56092320cc2f5af0d990/ts/routes/image-occlusion/%5B...imagePathOrNoteId%5D/%2Bpage.ts#L11-L13

[david-allison]

• There appears to be no way to listen to the state changes of the screen
  • (whether there are any valid masks)
• The JS does not inform us that the method failed

Therefore it's best to wait for upstream to determine how to provide us with this information

[david-allison]

https://github.com/ankidroid/Anki-Android/labels/Good%20First%20Issue%21

• View the upstream code, and confirm my findings in Image Occlusion: Add an error message if no masks are set #19443 (comment) are correct
• Summarize the issue, and our requirements from a code change in https://github.com/ankitects/anki/blob/dac26ce67147b261d79a56092320cc2f5af0d990/ts/routes/image-occlusion/%5B...imagePathOrNoteId%5D/%2Bpage.ts#L25-L28

We will then be able to post an issue upstream, and block this issue until upstream Anki provides functionality to cleanly solve this

[tarone-saloni]

i can solve this issue please assign me!