Unix: install icons into <prefix>/icons/hicolor

[Felix Krull]

On (non-Apple) Unix, the application icon is currently installed into <prefix>/share/pixmaps. Instead, icons in several sizes should be installed into <prefix>/share/icons/hicolor/<size>/apps/.

I couldn't find any actual reference, but /usr/share/pixmaps seems to be the old way. In particular, Flatpak makes exporting icons in pixmaps more difficult, so this seems relevant in light of #831.

[Helder Correia]

@fk Any update on this?

[Felix Krull]

@heldercorreia ...no. I forgot about this issue and ended up doing it in the packaging for the Flatpak, much like it is in the generic packages.

I think we should just close this: * for the simple use case of building and installing from source, pixmaps still works * I would neither want to bundle the same icon file in different resolutions, nor figure out how to render the SVG in the CMake build without an extra dependency.

I dunno. I'm feeling lazy about this, and doing it as part of the packaging seems to work fine.

[OP]

It's not necessary to render the SVG into fixed sizes for this to work. There is a dedicated subdirectory for this purpose called scalable. The full path would then look like this: <prefix>/share/icons/hicolor/scalable/apps/

[Felix Krull]

@rindeal Yeah, but then you only have the SVG icon. And you might be right, that might work correctly, but it seems... incorrect? Plus, I'm quite sure that's not enough for Flathub, so it doesn't matter anyway.