register to handle i.delta.chat links

[adbenitez]

close #2920

[adbenitez]

in one Xiaomi phone it doesn't open in DC but in the browser, in another phone (CalyxOS) it also doesn't open in DC by default but going to system settings of DC I can see a "open supported links" option and there you have to manually enable to open i.delta.chat directly in DC,

it says something about "zero verified links" and an info at the bottom points "An app can verify links to automatically open in the app" so it seems that to open links automatically the i.delta.chat needs to be tweaked in some way to report that DC app is allowed to handle their links instead of opening in browser, makes some sense, ex. then no fake app can open WhatsApp, or Signal links etc. but it makes all more complicated and less useful

[adbenitez]

the link at the bottom is: https://developer.android.com/training/app-links/verify-site-associations

[github-actions]

To test the changes in this pull request, install this apk:
📦 app-preview.apk

[hpk42]

could you provide the contents of the "assetlinks.json" file? we can put it to i.delta.chat and then it should work, i guess? https://developer.android.com/training/app-links/verify-android-applinks#web-assoc

[adbenitez]

could you provide the contents of the "assetlinks.json" file? we can put it to i.delta.chat and then it should work, i guess? https://developer.android.com/training/app-links/verify-android-applinks#web-assoc

yes, but sadly that will not work for fdroid builds, because we don't own the signing key IIRC, but it will work for gplay releases, I guess it is not the end of the world, anyway worse case the page gets opened in the browser and then user can click link/button that then opens in DC, and I expect the fdroid users be much less than gplay

[r10s]

code lgtm, did not test.

for testing, it seems esp. important that existing OPENPGP4FPR links continue working (which one can easily test by open the i.delta.chat in the browser manually, then the page shows the OPENPGP4FPR links)