4 ms·

> I always wonder why Qt5+/Qml/QtQuick have not taken the XP desktop development by storm. If I had to guess, it's because people are misinformed about the pri

by dx87 7y ago

> I always wonder why Qt5+/Qml/QtQuick have not taken the XP desktop development by storm. If I had to guess, it's because people are misinformed about the pricing and features. I regularly see people who assume that you either have to pay a large per-developer fee, or completely open source your application, even though Qt is licensed under the LGPL, so you're fine as long as you don't statically link it or depend on secret modifications to Qt for your application. A lot of people also assume it only supports C++ and dismiss it outright.

jacobush 7y ago
LGPL is problematic for App Store, since the user should be able to relink the app with a newer version [of QT] if they wanted to.
- de_watcher 7y ago
  They can relink. The object files for relinking aren't required to go through App Store. Static/dynamic linking isn't a problem.
  - jacobush 7y ago
    Interesting. If I install this [0] app, how can I relink it against my patched QT5? 0: https://apps.apple.com/us/app/qt-5-showcases-by-v-play-apps/id1040477271 https://apps.apple.com/us/app/qt-5-showcases-by-v-play-apps/...
    - jcelerier 7y ago
      Felgo most certainly uses Qt through the commercial license so nothing is LGPL here.
      - jacobush 7y ago
        Right. Now imagine it didn't. What then?
        jcelerier 7y ago
        you ask them for the LGPL package, they send it to you, you compile ? The onus is on the person making the app that links against the LGPL library to provide you with the build instruction. At worse they would give you their main static library and Qt LGPL source code and you just have to relink them and open Xcode to upload it to your iDevice ? Here is for instance the source code for the telegram app for iOS which is under GPL : https://github.com/TelegramMessenger/Telegram-iOS https://github.com/TelegramMessenger/Telegram-iOS there is no difference with... basically every other open source project ? Open the .xcodeproj, build, run.
        jacobush 7y ago
        I am not talking primarily about open source projects, but about closed source projects with LGPL components on app stores. You’d need the proprietary main object from them. Also, requiring that your users have an Apple dev account before they can execute their rights is problematic at best. I am not alone in rejecting Qt on these grounds, in favour of some MIT or similarly licensed alternative.
        jcelerier 7y ago
        > I am not talking primarily about open source projects, but about closed source projects with LGPL components on app stores. You’d need the proprietary main object from them. yes, and as I said if they are not providing them to you they are breaking the LGPL plain and simple. If they break their contract you're in undefined-behaviour land anyways :-) > Also, requiring that your users have an Apple dev account before they can execute their rights is problematic at best. I am not alone in rejecting Qt on these grounds, in favour of some MIT or similarly licensed alternative. You don't need a dev account to upload something to your phone since Xcode 7 or 8. Only to put it on the appstore. Prior to that, sure, it was hard to comply with the LGPL.
    - de_watcher 7y ago
      Normally you ask them for the object files, but those specific guys are middleware developers so they provide QtCreator configured to build with their library (to get a different Qt version, select a different Qt Kit in QtCreator settings). Additionally, the nature of the library is that it's probably a plugin that's loaded by a regular Qt application, as a result you've got their classes available in the QML scripts. It isn't very intrusive on the practical level. They don't say what license they use though.

by dx87 7y ago

jacobush 7y ago

LGPL is problematic for App Store, since the user should be able to relink the app with a newer version [of QT] if they wanted to.

de_watcher 7y ago
They can relink. The object files for relinking aren't required to go through App Store. Static/dynamic linking isn't a problem.
- jacobush 7y ago
  Interesting. If I install this [0] app, how can I relink it against my patched QT5? 0: https://apps.apple.com/us/app/qt-5-showcases-by-v-play-apps/id1040477271 https://apps.apple.com/us/app/qt-5-showcases-by-v-play-apps/...
  - jcelerier 7y ago
    Felgo most certainly uses Qt through the commercial license so nothing is LGPL here.
    - jacobush 7y ago
      Right. Now imagine it didn't. What then?
      - jcelerier 7y ago
        you ask them for the LGPL package, they send it to you, you compile ? The onus is on the person making the app that links against the LGPL library to provide you with the build instruction. At worse they would give you their main static library and Qt LGPL source code and you just have to relink them and open Xcode to upload it to your iDevice ? Here is for instance the source code for the telegram app for iOS which is under GPL : https://github.com/TelegramMessenger/Telegram-iOS https://github.com/TelegramMessenger/Telegram-iOS there is no difference with... basically every other open source project ? Open the .xcodeproj, build, run.
        jacobush 7y ago
        I am not talking primarily about open source projects, but about closed source projects with LGPL components on app stores. You’d need the proprietary main object from them. Also, requiring that your users have an Apple dev account before they can execute their rights is problematic at best. I am not alone in rejecting Qt on these grounds, in favour of some MIT or similarly licensed alternative.
        jcelerier 7y ago
        > I am not talking primarily about open source projects, but about closed source projects with LGPL components on app stores. You’d need the proprietary main object from them. yes, and as I said if they are not providing them to you they are breaking the LGPL plain and simple. If they break their contract you're in undefined-behaviour land anyways :-) > Also, requiring that your users have an Apple dev account before they can execute their rights is problematic at best. I am not alone in rejecting Qt on these grounds, in favour of some MIT or similarly licensed alternative. You don't need a dev account to upload something to your phone since Xcode 7 or 8. Only to put it on the appstore. Prior to that, sure, it was hard to comply with the LGPL.
  - de_watcher 7y ago
    Normally you ask them for the object files, but those specific guys are middleware developers so they provide QtCreator configured to build with their library (to get a different Qt version, select a different Qt Kit in QtCreator settings). Additionally, the nature of the library is that it's probably a plugin that's loaded by a regular Qt application, as a result you've got their classes available in the QML scripts. It isn't very intrusive on the practical level. They don't say what license they use though.