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Launch a second view on a pushed button

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  • L Lucian

    Something is wrong.
    It say : "status sig: false"
    So the signal is not generated.

    Also say:
    QObject::connect: No such signal QQuickView::statusChanged()

    jsulmJ Offline
    jsulmJ Offline
    jsulm
    Lifetime Qt Champion
    wrote on last edited by
    #17

    @Lucian
    Please check documentation: http://doc.qt.io/qt-5/qquickview.html#statusChanged
    The signal has a parameter, so it should be:

    qDebug() << "status sig:" << QObject::connect(view,SIGNAL(statusChanged(QQuickView::Status) ),this, SLOT(startProcess() ) );
    

    https://forum.qt.io/topic/113070/qt-code-of-conduct

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    • L Offline
      L Offline
      Lucian
      wrote on last edited by Lucian
      #18

      Thanks @mrjj , @jsulm
      Now it's better.
      "status sig: true"

      But the startProcess() still isn't call yet.
      The message from slot is not printed and the calc.exe doesn't show up, but at lest the status from QQuickView is changed.

      jsulmJ 1 Reply Last reply
      0
      • L Lucian

        Thanks @mrjj , @jsulm
        Now it's better.
        "status sig: true"

        But the startProcess() still isn't call yet.
        The message from slot is not printed and the calc.exe doesn't show up, but at lest the status from QQuickView is changed.

        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #19

        @Lucian Try to connect first:

        void Process::run() {
            QObject::connect(view,SIGNAL(view::statusChanged),this, SLOT(Process::startProcess()));
            view->setSource(QUrl("qrc:/loading.qml"));
            view->setResizeMode(QQuickView::SizeRootObjectToView);
            view->show();
        }

        https://forum.qt.io/topic/113070/qt-code-of-conduct

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        • L Offline
          L Offline
          Lucian
          wrote on last edited by
          #20

          Yes @jsulm .
          It work but this doesn't solve my problem.
          I try to connect status change with startProcess because the progress bar (loading.qml) was block by waitForFinish(-1).
          Now is happening the same.
          The signal and the slot are called in the right order but also loading.qml doesn't popup until i close the calc.exe.

          jsulmJ 1 Reply Last reply
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          • L Lucian

            Yes @jsulm .
            It work but this doesn't solve my problem.
            I try to connect status change with startProcess because the progress bar (loading.qml) was block by waitForFinish(-1).
            Now is happening the same.
            The signal and the slot are called in the right order but also loading.qml doesn't popup until i close the calc.exe.

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #21

            @Lucian Why do you wait for the process to finish?

            this->proc->waitForFinished(-1);
            

            Are you aware that this call blocks the event loop (so your app is blocked)?

            https://forum.qt.io/topic/113070/qt-code-of-conduct

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            • L Offline
              L Offline
              Lucian
              wrote on last edited by Lucian
              #22

              Yes @jsulm .
              I need to do that because the process what will be launch will create a txt file. This file will be use farder so i need to be sore the process has finished his job and has created the txt.

              jsulmJ 1 Reply Last reply
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              • L Lucian

                Yes @jsulm .
                I need to do that because the process what will be launch will create a txt file. This file will be use farder so i need to be sore the process has finished his job and has created the txt.

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by jsulm
                #23

                @Lucian No need to wait for this! Just connect to http://doc.qt.io/qt-5/qprocess.html#finished signal - when it is called the process has finished...
                Qt is an asynchronous framework - you should adapt to asynchronous programming.

                https://forum.qt.io/topic/113070/qt-code-of-conduct

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                • L Offline
                  L Offline
                  Lucian
                  wrote on last edited by
                  #24

                  But how will wait my application to create the txt file ? Because after the process is finished i want to read from that .txt file created by him and if i read before creation the application will fail.
                  So i need to connect the finish signal from QProcess with a slot that make the read from .txt file? :D

                  jsulmJ 1 Reply Last reply
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                  • L Lucian

                    But how will wait my application to create the txt file ? Because after the process is finished i want to read from that .txt file created by him and if i read before creation the application will fail.
                    So i need to connect the finish signal from QProcess with a slot that make the read from .txt file? :D

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #25

                    @Lucian Yes, you simply connect a slot to that signal and do what you want with that file in this slot.

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

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                    • L Offline
                      L Offline
                      Lucian
                      wrote on last edited by
                      #26

                      I have made some changes and now look like this:

                      void Process::startProcess()
                      {
                          qDebug() << "startProcess called";
                          this->proc->start("C:\\Windows\\System32\\calc.exe", QIODevice::ReadWrite);
                          qDebug() << "connect status :" << QObject::connect(proc,SIGNAL(QProcess::finished()),this, SLOT(addData()));
                      }
                      

                      And the slot:

                      void Process::addData()
                      {
                          qDebug() << "addData call:";
                          SomeClasss c;    
                          c.read();
                      }
                      

                      The problem is again with type of the signal:
                      *QObject::connect: No such signal QProcess::QProcess::finished()

                      From documentation (Qt doc) doesn't seems to be something wrong.

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                      • L Offline
                        L Offline
                        Lucian
                        wrote on last edited by Lucian
                        #27

                        I have solved the problem like this:

                            qDebug() << "connect status :" << QObject::connect(proc,SIGNAL(finished(int, QProcess::ExitStatus)),this, SLOT(addData()));
                        

                        I will mark this as Solved.
                        Thank you for your help @jsulm , @mrjj .

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