overhaul the app icon delivery and display
Starting with android-21, it is possible to use vector graphics files (e.g. ic_launcher.xml) for the app icon. With android-26, Google is further pushing that format with its "adaptive icons". fdroidclient should support the XML files as the first choice of icons to download.
This is then also a good opportunity to overhaul App.icon
, App.iconUrl
, and App.iconUrlLarge
. These are inconsistently available and used. Then there is the 512x512 icon.png that in the localized
block that comes from the app's source repo. I think we should first try to use icon.png if its available for the current locale (unless that's the default en-US). Otherwise, it should try to use the vector XML icon, then last resort, use the old per-DPI PNG icons.
This is related to fdroidserver#322 (closed)