Enhance AppData file

[scx]

I would like to enhance the AppData file.

This is related to submitting my flatpak package to the Flathub repository.
#396
flathub/flathub#810

You should also consider changing application id, as well as renaming AppData, desktop and icon file.
https://github.com/flathub/flathub/wiki/AppData-Guidelines#id
Although It is not required, it is highly recommended.

See also:
https://github.com/flathub/flathub/wiki/AppData-Guidelines
https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-launchable
https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-releases
https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-provides
https://hughsie.github.io/oars

[manisandro]

Could you use the same indentation as before for the appdata file so that what actually changed is easily recognizable?

[scx]

@manisandro

Could you use the same indentation as before for the appdata file so that what actually changed is easily recognizable?

Sorry. Flathub maintainers tend to block pull requests due to trivialities such as "inappropriate" (in their opinion) indentation.

Convert single-space indent to double-space indent:

sed -i -re 's/^( +)/\1\1/' gimagereader.appdata.xml.in

Convert double-space indent to single-space indent:

sed -i -re 's/^( +)\1/\1/' gimagereader.appdata.xml.in

[manisandro]

Thanks, I'll follow up with a whitespace-change commit to double-space indent then.