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QStackedWidget (index out of range)

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  • ahsan737A ahsan737

    @mrjj this UI containing QCustomPlot and Graph works fine, but gives an error when I add it to QStackedWidget. How can it possibly be evaluated?

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #10

    @ahsan737
    Are you sure its not empty and you connected signals to some slot so it tried to do something ?
    Try adding a new QCustomPlot instead and see.

    ui->stackedWidget->addWidget(new QCustomPlot (this) );

    to see if that also gives same error.

    1 Reply Last reply
    0
    • ahsan737A ahsan737

      @JonB @sierdzio I have just loaded these widgets, and when I deploy on the device then the app crash at the start even before I do anything.

      Error

      F libFBC3.so: ASSERT failure in QList<T>::at: "index out of range",
      

      Move to next Index

      void MainWindow::_onNext()
      {
          int Index=ui->stackedWidget->currentIndex();
          Index++;
          ui->stackedWidget->setCurrentIndex(Index);
      }
      

      Added Widgets

                              ui->stackedWidget->addWidget(&_screen);
                              ui->stackedWidget->addWidget(&_newMeasure);
                              ui->stackedWidget->addWidget(&_manual1);
                              ui->stackedWidget->addWidget(&_manual2);
                              ui->stackedWidget->addWidget(&_prep_1_1);
                              ui->stackedWidget->addWidget(&_prep_1_2);
                              ui->stackedWidget->addWidget(&_prep_1_3);
                              ui->stackedWidget->addWidget(&_prep_3);
                              ui->stackedWidget->addWidget(&_prep_4);
                              ui->stackedWidget->addWidget(&_prep_5);
                              ui->stackedWidget->addWidget(&_prep_6);
                              ui->stackedWidget->addWidget(&_prep_7);   
                              ui->stackedWidget->addWidget(&_prep_10);
                              ui->stackedWidget->addWidget(&_prep_8);
                              ui->stackedWidget->addWidget(&_prep_9);
                              ui->stackedWidget->addWidget(&_prep_2);
                              ui->stackedWidget->addWidget(&_static_1);
                              ui->stackedWidget->addWidget(&_staticInstruct_1);
                              ui->stackedWidget->addWidget(&_staticInstruct_2);
                              ui->stackedWidget->addWidget(&_staticInstruct_3);
                              ui->stackedWidget->addWidget(&_staticInstruct_4);
                              ui->stackedWidget->addWidget(&_staticInstruct_5);
                              ui->stackedWidget->addWidget(&_staticInstruct_6);
                              ui->stackedWidget->addWidget(&_staticInstruct_7);
                              ui->stackedWidget->addWidget(&_staticInstruct_8);
                              ui->stackedWidget->addWidget(&_staticMeasure);
                              ui->stackedWidget->addWidget(&_dynamicInstruct_1);
                              ui->stackedWidget->addWidget(&_dynamicInstruct_2);
                              ui->stackedWidget->addWidget(&_dynamicInstruct_3);
                              ui->stackedWidget->addWidget(&_dynamicMeasure);
                              ui->stackedWidget->addWidget(&_dynamicPrep);
                              ui->stackedWidget->addWidget(&_saveData);
                              ui->stackedWidget->addWidget(&_secondPrep_1);
                              ui->stackedWidget->addWidget(&_secondPrep_2);
                              ui->stackedWidget->addWidget(&_secondPrep_3);
                              ui->stackedWidget->addWidget(&_secondPrep_4);
                              ui->stackedWidget->addWidget(&_secondPrep_5);
                              ui->stackedWidget->addWidget(&_secondPrep_6);
                              ui->stackedWidget->addWidget(&_settings);
                              ui->stackedWidget->addWidget(&_admin);
                              ui->stackedWidget->addWidget(&_showdata);
                              ui->stackedWidget->addWidget(&_btSettings);
      
      Christian EhrlicherC Offline
      Christian EhrlicherC Offline
      Christian Ehrlicher
      Lifetime Qt Champion
      wrote on last edited by
      #11

      @ahsan737 said in QStackedWidget (index out of range):

      Move to next Index

      Did you actually check what @JonB wrote?
      Can you post the complete backtrace?

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      1 Reply Last reply
      1
      • SGaistS Offline
        SGaistS Offline
        SGaist
        Lifetime Qt Champion
        wrote on last edited by
        #12

        Hi,

        void MainWindow::_onNext()
        {
        int Index=ui->stackedWidget->currentIndex();
        Index++;
        ui->stackedWidget->setCurrentIndex(Index);
        }

        You are missing the boundary check so suggested by @JonB.

        Interested in AI ? www.idiap.ch
        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

        1 Reply Last reply
        2
        • mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by
          #13

          Hi
          I'm not sure the stackedwidget in itself is to blame for the index out of range.
          If i do this
          ui->stackedWidget->setCurrentIndex(1000);
          in a blank GUI project. Nothing is shown and app just starts.
          Also in the inner code, the index is checked.

          QWidget *QStackedLayout::widget(int index) const
          {
              Q_D(const QStackedLayout);
               if (index < 0 || index >= d->list.size())
                  return nullptr;
              return d->list.at(index)->widget();
          }
          
          
          SGaistS 1 Reply Last reply
          2
          • mrjjM mrjj

            Hi
            I'm not sure the stackedwidget in itself is to blame for the index out of range.
            If i do this
            ui->stackedWidget->setCurrentIndex(1000);
            in a blank GUI project. Nothing is shown and app just starts.
            Also in the inner code, the index is checked.

            QWidget *QStackedLayout::widget(int index) const
            {
                Q_D(const QStackedLayout);
                 if (index < 0 || index >= d->list.size())
                    return nullptr;
                return d->list.at(index)->widget();
            }
            
            
            SGaistS Offline
            SGaistS Offline
            SGaist
            Lifetime Qt Champion
            wrote on last edited by
            #14

            @mrjj Exactly what I was double checking :-)

            Interested in AI ? www.idiap.ch
            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

            mrjjM 1 Reply Last reply
            1
            • SGaistS SGaist

              @mrjj Exactly what I was double checking :-)

              mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by
              #15

              @SGaist
              Hi
              I recalled having a off by one error with a stackedwidget and it seemed to just ignore it - back then so felt the urge to use the source.

              To Make it more interesting, QCustomPlot seems to be using a QVector but
              the actual error is
              ASSERT failure in QList<T>

              So I guess this calls for a back trace as Christian is after :)

              1 Reply Last reply
              2
              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #16

                @mrjj said in QStackedWidget (index out of range):

                So I guess this calls for a back trace as Christian is after :)

                Agreed

                Interested in AI ? www.idiap.ch
                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                1 Reply Last reply
                0
                • ahsan737A Offline
                  ahsan737A Offline
                  ahsan737
                  wrote on last edited by
                  #17

                  Thanks a lot, for your dedicated and kind response, the issue is resolved. It was being caused because the application was failing to read the initial configuration file as I mistakenly forgot calling a class in the startup. Silly yet frustrating mistake,

                  mrjjM 1 Reply Last reply
                  3
                  • ahsan737A ahsan737

                    Thanks a lot, for your dedicated and kind response, the issue is resolved. It was being caused because the application was failing to read the initial configuration file as I mistakenly forgot calling a class in the startup. Silly yet frustrating mistake,

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #18

                    @ahsan737
                    Good you found it.
                    So the QList it had the error about was one of the widget that you inserted into the stacked so it seemed it was related to that ?

                    ahsan737A 1 Reply Last reply
                    0
                    • mrjjM mrjj

                      @ahsan737
                      Good you found it.
                      So the QList it had the error about was one of the widget that you inserted into the stacked so it seemed it was related to that ?

                      ahsan737A Offline
                      ahsan737A Offline
                      ahsan737
                      wrote on last edited by
                      #19

                      @mrjj yes, error was related to QList which was a part of the widget. and when I try to add that widget to stack then it makes the app crash.

                      1 Reply Last reply
                      1

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