Android and LGPL



  • Hi,

    Trying to figure out what is possible/required for using Qt LGPL for a closed source Android app to be published on Play Store.

    I see a few options/issues:

    • Using Ministro: this allows updating of the lib, but how about having user substitute his own modified version of Qt (as required by LGPL)? Also IMO Ministro is a pretty bad UX for end users.
    • Using bundled Qt libs: how can end-user substitute these? Would require re-packing apk with changed libs, which would void signing and break app updates

    Is Qt essentially not that attractive for Android development unless you get the commercial Qt fro Mobile license?

    -pjoe



  • Also TBH $149/month Qt Mobile license is rather steep price for me for a lib to do Android/iOS development. Especially since I don't need enginio or paid support, I just want to be able to use the lib legally :)


  • Moderators

    [quote author="pjoe" date="1387311732"]

    • Using bundled Qt libs: how can end-user substitute these? Would require re-packing apk with changed libs, which would void signing and break app updates[/quote]

    IMHO it's ok that repacking the apk breaks the signing, since after it it's not your work anymore. And the same for updates. I don't think that the LGPL requires this.
    On Android it's quite easy to install unsigned apks, so this shouldn't be problem for users in general.
    So all you have todo is give the user the chance to substitude the LGPL part (Qt) of your work. Your actual app can still be closed source.

    But also note that i am not a lawyer. ;)



  • Yeah I think the tricky part is for user to get hold of apk. Though I suppose I could always publish the apk somewhere other than Play Store for users to get hold of if they want to replace LGPL libs.

    It would be great with an authoritative answer from Digia on this :)


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.