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How can I get the application QmlEngine ?

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  • J.HilkJ J.Hilk

    @kmarconi
    take a look here:
    https://doc.qt.io/qt-5/qtquick-internationalization.html

    K Offline
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    kmarconi
    wrote on last edited by
    #12

    @J-Hilk Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

    J.HilkJ KroMignonK 2 Replies Last reply
    0
    • K kmarconi

      @J-Hilk Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

      J.HilkJ Offline
      J.HilkJ Offline
      J.Hilk
      Moderators
      wrote on last edited by
      #13

      @kmarconi said in How can I get the application QmlEngine ?:

      Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

      so, you answered your own question

      Refreshes all binding expressions that use strings marked for translation. What is that "marked" thing and how to apply it ? Thanks

      😉


      Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


      Q: What's that?
      A: It's blue light.
      Q: What does it do?
      A: It turns blue.

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      • J.HilkJ J.Hilk

        @kmarconi said in How can I get the application QmlEngine ?:

        Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

        so, you answered your own question

        Refreshes all binding expressions that use strings marked for translation. What is that "marked" thing and how to apply it ? Thanks

        😉

        K Offline
        K Offline
        kmarconi
        wrote on last edited by
        #14

        @J-Hilk Yeah but I thought that maybe there was another thing to do ... I'm stuck now so I'm trying everything I can Haha

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        • K kmarconi

          @J-Hilk Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

          KroMignonK Offline
          KroMignonK Offline
          KroMignon
          wrote on last edited by
          #15

          @kmarconi said in How can I get the application QmlEngine ?:

          Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

          My way to ensure translation is the define a global Object which handle language changes.
          This object is exposed to QML with engine->rootContext()->setContextProperty("translation", &myLocalesHandler).

          This object has a property called emptyString:

              Q_PROPERTY(QString emptyString     READ emptyString     NOTIFY languageChanged)
          ....
              QString emptyString() const
              {
                  return QString();
              }
          

          On language change signal languageChanged() is emitted and in QML I have something like this:

          Label {
              text: qsTr("This is a message") + translation.emptyString
          }
          

          Works great for me, hope this could also helps you.

          It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

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          2
          • fcarneyF Offline
            fcarneyF Offline
            fcarney
            wrote on last edited by
            #16

            When I have objects that live in qml space such as a plain QObject, I will make it based upon QQuickItem in order to get the qml engine. I often do this for image providers that provide QImages to qml. I think any QQuick based object should be able to do this.

            C++ is a perfectly valid school of magic.

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            • KroMignonK KroMignon

              @kmarconi said in How can I get the application QmlEngine ?:

              Yeah I already been there but every string which needs to be translated are already marked as qsTr so ...

              My way to ensure translation is the define a global Object which handle language changes.
              This object is exposed to QML with engine->rootContext()->setContextProperty("translation", &myLocalesHandler).

              This object has a property called emptyString:

                  Q_PROPERTY(QString emptyString     READ emptyString     NOTIFY languageChanged)
              ....
                  QString emptyString() const
                  {
                      return QString();
                  }
              

              On language change signal languageChanged() is emitted and in QML I have something like this:

              Label {
                  text: qsTr("This is a message") + translation.emptyString
              }
              

              Works great for me, hope this could also helps you.

              K Offline
              K Offline
              kmarconi
              wrote on last edited by
              #17

              @KroMignon Thanks for your help, will try it now. I just have question on your translation class. Where do you emit the signal languageChanged and how do you link it to your function which retranslate the app with the engine ? Thanks !

              J.HilkJ 1 Reply Last reply
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              • K kmarconi

                @KroMignon Thanks for your help, will try it now. I just have question on your translation class. Where do you emit the signal languageChanged and how do you link it to your function which retranslate the app with the engine ? Thanks !

                J.HilkJ Offline
                J.HilkJ Offline
                J.Hilk
                Moderators
                wrote on last edited by
                #18

                @kmarconi what @KroMignon described was the way you had to go before Qt 5.10

                you can take a look at this blog post, I think its rather good:

                https://retifrav.github.io/blog/2017/01/04/translating-qml-app/


                Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                Q: What's that?
                A: It's blue light.
                Q: What does it do?
                A: It turns blue.

                K 1 Reply Last reply
                1
                • J.HilkJ J.Hilk

                  @kmarconi what @KroMignon described was the way you had to go before Qt 5.10

                  you can take a look at this blog post, I think its rather good:

                  https://retifrav.github.io/blog/2017/01/04/translating-qml-app/

                  K Offline
                  K Offline
                  kmarconi
                  wrote on last edited by
                  #19

                  @J-Hilk Yeah I've seen this post but it's kinda dirty way to retranslate the whole app I think ... I still will try it but I hope to find a way to use the retranslate function properly.

                  J.HilkJ 1 Reply Last reply
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                  • K kmarconi

                    @J-Hilk Yeah I've seen this post but it's kinda dirty way to retranslate the whole app I think ... I still will try it but I hope to find a way to use the retranslate function properly.

                    J.HilkJ Offline
                    J.HilkJ Offline
                    J.Hilk
                    Moderators
                    wrote on last edited by
                    #20

                    @kmarconi
                    what would you consider a proper retranslate functionality ?

                    You can either,

                    • call retranslate() on the QQmlEngine,
                    • update the strings via the empty string property workaround
                    • reload the qml file entirely

                    there are not other ways, at least that I know of


                    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                    Q: What's that?
                    A: It's blue light.
                    Q: What does it do?
                    A: It turns blue.

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                    • J.HilkJ J.Hilk

                      @kmarconi
                      what would you consider a proper retranslate functionality ?

                      You can either,

                      • call retranslate() on the QQmlEngine,
                      • update the strings via the empty string property workaround
                      • reload the qml file entirely

                      there are not other ways, at least that I know of

                      K Offline
                      K Offline
                      kmarconi
                      wrote on last edited by kmarconi
                      #21

                      @J-Hilk Calling retranslate for me is the cleanest way. No need to add "+trans.emptyString" on each of my qsTr object and I have a lot. I need to figure out how to solve this infinite binding loop. Is reloading the whole qml a heavy task for the system ?

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                      • KroMignonK Offline
                        KroMignonK Offline
                        KroMignon
                        wrote on last edited by KroMignon
                        #22

                        @kmarconi said in How can I get the application QmlEngine ?:

                        I still will try it but I hope to find a way to use the retranslate function properly.

                        I can not figure out what your problem is.
                        @J-Hilk have give you all information you need to do it.

                        If you are using Qt 5.10 and upper (which is not my case) simply follow documentation
                        That's not so complicated to follow, you could create a class which handle the locales, for example let it call LocalHandler, when you have install the new translator with QCoreApplication::installTranslator() then emit a signal for example called translationUpated().
                        Then in your main.cpp:

                        LocalHandler loc;
                        
                        QObject::connect(&loc, &LocalHandler::translationUpated, engine, &QQmlEngine::retranslate);
                        

                        Alternatively you can use a app->installEventFilter() to catch QEvent::LanguageChange and then trigger QQmlEngine::retranslate().

                        For prior version, you have to do more work ==> https://retifrav.github.io/blog/2017/01/04/translating-qml-app/

                        It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                        K 1 Reply Last reply
                        1
                        • KroMignonK KroMignon

                          @kmarconi said in How can I get the application QmlEngine ?:

                          I still will try it but I hope to find a way to use the retranslate function properly.

                          I can not figure out what your problem is.
                          @J-Hilk have give you all information you need to do it.

                          If you are using Qt 5.10 and upper (which is not my case) simply follow documentation
                          That's not so complicated to follow, you could create a class which handle the locales, for example let it call LocalHandler, when you have install the new translator with QCoreApplication::installTranslator() then emit a signal for example called translationUpated().
                          Then in your main.cpp:

                          LocalHandler loc;
                          
                          QObject::connect(&loc, &LocalHandler::translationUpated, engine, &QQmlEngine::retranslate);
                          

                          Alternatively you can use a app->installEventFilter() to catch QEvent::LanguageChange and then trigger QQmlEngine::retranslate().

                          For prior version, you have to do more work ==> https://retifrav.github.io/blog/2017/01/04/translating-qml-app/

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                          kmarconi
                          wrote on last edited by
                          #23

                          @KroMignon I already done everything you told me but thank you ;) I was just saying that if I could not use the emptyString trick it could be interesting for me. Why I'm saying this is because with the trick , I have the error " ListElement: cannot use script for property value" . Is is because I cannot use the trick in a ListElement object ?

                          KroMignonK 1 Reply Last reply
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                          • K kmarconi

                            @KroMignon I already done everything you told me but thank you ;) I was just saying that if I could not use the emptyString trick it could be interesting for me. Why I'm saying this is because with the trick , I have the error " ListElement: cannot use script for property value" . Is is because I cannot use the trick in a ListElement object ?

                            KroMignonK Offline
                            KroMignonK Offline
                            KroMignon
                            wrote on last edited by KroMignon
                            #24

                            @kmarconi said in How can I get the application QmlEngine ?:

                            I have the error "ListElement: cannot use script for property value"

                            AFAIK, ListElement cannot be changed dynamically ==> cf QTBUG-16289

                            edit

                            You have to use QT_TR_NOOP() and qsTr() on the delegate, like this (extract from QTBUG-16289):

                            ListModel {
                                id: myModel
                            
                                ListElement {
                                    desc: QT_TR_NOOP("Example")
                                }
                            }
                            
                            ListView {
                                model: myModel
                            
                                delegate: Text {
                                    text: qsTr(desc)
                                }
                            }
                            

                            It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                            K 1 Reply Last reply
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                            • KroMignonK KroMignon

                              @kmarconi said in How can I get the application QmlEngine ?:

                              I have the error "ListElement: cannot use script for property value"

                              AFAIK, ListElement cannot be changed dynamically ==> cf QTBUG-16289

                              edit

                              You have to use QT_TR_NOOP() and qsTr() on the delegate, like this (extract from QTBUG-16289):

                              ListModel {
                                  id: myModel
                              
                                  ListElement {
                                      desc: QT_TR_NOOP("Example")
                                  }
                              }
                              
                              ListView {
                                  model: myModel
                              
                                  delegate: Text {
                                      text: qsTr(desc)
                                  }
                              }
                              
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                              K Offline
                              kmarconi
                              wrote on last edited by kmarconi
                              #25

                              @KroMignon Yeah just seen it on a stackoverflow post (https://stackoverflow.com/questions/7659442/listelement-fields-as-properties) but I canno't change my qml part because the way it is designed is fixed so I need to find a way to use the retranslate function without having this binding loop.

                              KroMignonK 1 Reply Last reply
                              0
                              • K kmarconi

                                @KroMignon Yeah just seen it on a stackoverflow post (https://stackoverflow.com/questions/7659442/listelement-fields-as-properties) but I canno't change my qml part because the way it is designed is fixed so I need to find a way to use the retranslate function without having this binding loop.

                                KroMignonK Offline
                                KroMignonK Offline
                                KroMignon
                                wrote on last edited by KroMignon
                                #26

                                @kmarconi said in How can I get the application QmlEngine ?:

                                I need to find a way to use the retranslate function without having this binding loop.

                                Take a look at the QTBUG-16289, the way they propose is to use QT_TR_NOOP() on ListElement to add string in translation file, and to use qsTr() in the delegate to do translation.

                                It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                                K 1 Reply Last reply
                                2
                                • KroMignonK KroMignon

                                  @kmarconi said in How can I get the application QmlEngine ?:

                                  I need to find a way to use the retranslate function without having this binding loop.

                                  Take a look at the QTBUG-16289, the way they propose is to use QT_TR_NOOP() on ListElement to add string in translation file, and to use qsTr() in the delegate to do translation.

                                  K Offline
                                  K Offline
                                  kmarconi
                                  wrote on last edited by
                                  #27

                                  @KroMignon Damn it is so hard to debug a binding loop with QT. Will keep you updated if I finally found out what's going on with my program.

                                  KroMignonK 1 Reply Last reply
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                                  • K kmarconi

                                    @KroMignon Damn it is so hard to debug a binding loop with QT. Will keep you updated if I finally found out what's going on with my program.

                                    KroMignonK Offline
                                    KroMignonK Offline
                                    KroMignon
                                    wrote on last edited by
                                    #28

                                    @kmarconi said in How can I get the application QmlEngine ?:

                                    Damn it is so hard to debug a binding loop with QT.

                                    Yes, binding loops are the hell!
                                    Which Qt Version are you using? For Qt 5.10 and upper you can enable tracing to help you to find bindings problems with QT_LOGGING_RULES.
                                    For example in your main.cpp:

                                        qputenv("QT_LOGGING_RULES", "qt.qml.binding.removal.info=true");
                                    

                                    Take look at this https://www.kdab.com/new-qt-5-10-diagnostics-breaking-qml-bindings/ for more details.

                                    It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

                                    K 2 Replies Last reply
                                    1
                                    • KroMignonK KroMignon

                                      @kmarconi said in How can I get the application QmlEngine ?:

                                      Damn it is so hard to debug a binding loop with QT.

                                      Yes, binding loops are the hell!
                                      Which Qt Version are you using? For Qt 5.10 and upper you can enable tracing to help you to find bindings problems with QT_LOGGING_RULES.
                                      For example in your main.cpp:

                                          qputenv("QT_LOGGING_RULES", "qt.qml.binding.removal.info=true");
                                      

                                      Take look at this https://www.kdab.com/new-qt-5-10-diagnostics-breaking-qml-bindings/ for more details.

                                      K Offline
                                      K Offline
                                      kmarconi
                                      wrote on last edited by
                                      #29

                                      @KroMignon I'm on QT 5.12.3 so that could save me. Will tell you, thanks !

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                                      • KroMignonK KroMignon

                                        @kmarconi said in How can I get the application QmlEngine ?:

                                        Damn it is so hard to debug a binding loop with QT.

                                        Yes, binding loops are the hell!
                                        Which Qt Version are you using? For Qt 5.10 and upper you can enable tracing to help you to find bindings problems with QT_LOGGING_RULES.
                                        For example in your main.cpp:

                                            qputenv("QT_LOGGING_RULES", "qt.qml.binding.removal.info=true");
                                        

                                        Take look at this https://www.kdab.com/new-qt-5-10-diagnostics-breaking-qml-bindings/ for more details.

                                        K Offline
                                        K Offline
                                        kmarconi
                                        wrote on last edited by
                                        #30

                                        @KroMignon My binding loop error hasn't changed at all even with "qputenv("QT_LOGGING_RULES", "qt.qml.binding.removal.info=true");" in my main.cpp file .. Am I condemned to live in this infinite binding loop ? haha

                                        KroMignonK 1 Reply Last reply
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                                        • K kmarconi

                                          @KroMignon My binding loop error hasn't changed at all even with "qputenv("QT_LOGGING_RULES", "qt.qml.binding.removal.info=true");" in my main.cpp file .. Am I condemned to live in this infinite binding loop ? haha

                                          KroMignonK Offline
                                          KroMignonK Offline
                                          KroMignon
                                          wrote on last edited by
                                          #31

                                          @kmarconi said in How can I get the application QmlEngine ?:

                                          Am I condemned to live in this infinite binding loop ?

                                          Can you show the QML code which is not working well?

                                          It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. (Sherlock Holmes)

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