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Dynamic Handling of Hundreds of UI elements

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  • kshegunovK kshegunov

    @mrsurge
    No, the problem is with my code, it happens sometimes when I don't double-check my examples. The proper function to use would be QObject::findChildren. I usually use it similarly to this:

    QList<QLineEdit *> list = ui->doubleSpinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
    

    This should compile fine.

    Kind regards.

    M Offline
    M Offline
    mrsurge
    wrote on last edited by mrsurge
    #7

    @kshegunov
    your right that did compile just fine, but it only works for doubleSpinBox not doubleSpinBox_2 - doubleSpinBox_312

    kshegunovK 1 Reply Last reply
    0
    • M mrsurge

      @kshegunov
      your right that did compile just fine, but it only works for doubleSpinBox not doubleSpinBox_2 - doubleSpinBox_312

      kshegunovK Offline
      kshegunovK Offline
      kshegunov
      Moderators
      wrote on last edited by kshegunov
      #8

      @mrsurge

      Just apply the same principle:

      MainWindow::MainWindow(QWidget *parent)
          : QMainWindow(parent), ui(new Ui::MainWindow)
      {
          ui->setupUi(this);
      
          QList<QSpinBox *> sbList = findChildren<QSpinBox *>(QString(), Qt::FindDirectChildrenOnly);
          foreach (QSpinBox * spinBox, sbList)  {
                  spinBox->installEventFilter(this);  //< Do you need this??
      
                  QList<QLineEdit *> leList = spinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
                  foreach (QLineEdit * lineEdit, leList)
                      lineEdit->installEventFilter(this);
          }
      }
      

      Read and abide by the Qt Code of Conduct

      M 1 Reply Last reply
      1
      • kshegunovK kshegunov

        @mrsurge

        Just apply the same principle:

        MainWindow::MainWindow(QWidget *parent)
            : QMainWindow(parent), ui(new Ui::MainWindow)
        {
            ui->setupUi(this);
        
            QList<QSpinBox *> sbList = findChildren<QSpinBox *>(QString(), Qt::FindDirectChildrenOnly);
            foreach (QSpinBox * spinBox, sbList)  {
                    spinBox->installEventFilter(this);  //< Do you need this??
        
                    QList<QLineEdit *> leList = spinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
                    foreach (QLineEdit * lineEdit, leList)
                        lineEdit->installEventFilter(this);
            }
        }
        
        M Offline
        M Offline
        mrsurge
        wrote on last edited by mrsurge
        #9

        @kshegunov
        This worked :

        QList<QDoubleSpinBox *> sbList = ui->centralWidget->findChildren<QDoubleSpinBox *>(QString());
        foreach (QDoubleSpinBox * spinBox, sbList)  {
                    //spinBox->installEventFilter(this);  //< Do you need this??//<-no I don't
        
           QList<QLineEdit *> leList = spinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
           foreach (QLineEdit * lineEdit, leList)
                        lineEdit->installEventFilter(this);
        }
        

        many thanks for steering me in the right direction.

        now on to saving the item to the specific line item

        kshegunovK 1 Reply Last reply
        0
        • M mrsurge

          @kshegunov
          This worked :

          QList<QDoubleSpinBox *> sbList = ui->centralWidget->findChildren<QDoubleSpinBox *>(QString());
          foreach (QDoubleSpinBox * spinBox, sbList)  {
                      //spinBox->installEventFilter(this);  //< Do you need this??//<-no I don't
          
             QList<QLineEdit *> leList = spinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
             foreach (QLineEdit * lineEdit, leList)
                          lineEdit->installEventFilter(this);
          }
          

          many thanks for steering me in the right direction.

          now on to saving the item to the specific line item

          kshegunovK Offline
          kshegunovK Offline
          kshegunov
          Moderators
          wrote on last edited by
          #10

          @mrsurge
          Yes, of course, I forgot we're in a main window. Anyway, I'm glad it worked. One note, though, if possible use the QObject::findChildren with Qt::FindDirectChildrenOnly so Qt will not go about recursively looking for all. If your spin boxes are in layouts, but not inside other widgets, this should also work:

          QList<QDoubleSpinBox *> sbList = ui->centralWidget->findChildren<QDoubleSpinBox *>(QString(), Qt::FindDirectChildrenOnly);
          

          Kind regards.

          Read and abide by the Qt Code of Conduct

          M 1 Reply Last reply
          0
          • kshegunovK kshegunov

            @mrsurge
            Yes, of course, I forgot we're in a main window. Anyway, I'm glad it worked. One note, though, if possible use the QObject::findChildren with Qt::FindDirectChildrenOnly so Qt will not go about recursively looking for all. If your spin boxes are in layouts, but not inside other widgets, this should also work:

            QList<QDoubleSpinBox *> sbList = ui->centralWidget->findChildren<QDoubleSpinBox *>(QString(), Qt::FindDirectChildrenOnly);
            

            Kind regards.

            M Offline
            M Offline
            mrsurge
            wrote on last edited by
            #11

            @kshegunov

            ok now how do I return a value from the dialog box to the doubleSpinBox that was clicked?

            kshegunovK 1 Reply Last reply
            0
            • M mrsurge

              @kshegunov

              ok now how do I return a value from the dialog box to the doubleSpinBox that was clicked?

              kshegunovK Offline
              kshegunovK Offline
              kshegunov
              Moderators
              wrote on last edited by
              #12

              @mrsurge
              I've provided some guidelines here.
              If this is working,

              QList<QLineEdit *> leList = spinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
              

              then the line edit has a QSpinBox for a parent. You have the line edit that'd been clicked here:

              void MainWindow::saveDataToLineEdit(QWidget * widget)
              {
                  QLineEdit * lineEdit = qobject_cast<QLineEdit *>(widget);
                  // ... Then the line edit parent is ...
                  QSpinBox * spinBox = qobject_cast<QSpinBox *>(lineEdit->parent());
                  // ... and so on ...
              }
              

              Read and abide by the Qt Code of Conduct

              M 1 Reply Last reply
              0
              • kshegunovK kshegunov

                @mrsurge
                I've provided some guidelines here.
                If this is working,

                QList<QLineEdit *> leList = spinBox->findChildren<QLineEdit *>(QString(), Qt::FindDirectChildrenOnly);
                

                then the line edit has a QSpinBox for a parent. You have the line edit that'd been clicked here:

                void MainWindow::saveDataToLineEdit(QWidget * widget)
                {
                    QLineEdit * lineEdit = qobject_cast<QLineEdit *>(widget);
                    // ... Then the line edit parent is ...
                    QSpinBox * spinBox = qobject_cast<QSpinBox *>(lineEdit->parent());
                    // ... and so on ...
                }
                
                M Offline
                M Offline
                mrsurge
                wrote on last edited by mrsurge
                #13

                @kshegunov said:

                bool MainWindow::eventFilter(QObject * obj, QEvent * event)
                {
                if(event->type() == QEvent::MouseButtonPress)
                {
                Dialog mdialog;

                    QSignalMapper mapper(&mdialog);
                    mapper.setMapping(qobject_cast<QWidget *>(obj));
                    QObject::connect(&mdialog, SIGNAL(accepted()), &mapper, SLOT(map()));
                    QObject::connect(&mapper, SIGNAL(mapped(QWidget *)), this, SLOT(saveDataToLineEdit(QWidget *)));
                
                    mdialog.exec();
                }
                return false;
                

                }

                my compiler says

                mapper.setMapping(qobject_cast<QWidget *>(obj));
                

                requires a second argument

                mapper.setMapping(qobject_cast<QWidget *>(obj),0);
                

                works but i have no idea what thats doing

                kshegunovK 1 Reply Last reply
                0
                • M mrsurge

                  @kshegunov said:

                  bool MainWindow::eventFilter(QObject * obj, QEvent * event)
                  {
                  if(event->type() == QEvent::MouseButtonPress)
                  {
                  Dialog mdialog;

                      QSignalMapper mapper(&mdialog);
                      mapper.setMapping(qobject_cast<QWidget *>(obj));
                      QObject::connect(&mdialog, SIGNAL(accepted()), &mapper, SLOT(map()));
                      QObject::connect(&mapper, SIGNAL(mapped(QWidget *)), this, SLOT(saveDataToLineEdit(QWidget *)));
                  
                      mdialog.exec();
                  }
                  return false;
                  

                  }

                  my compiler says

                  mapper.setMapping(qobject_cast<QWidget *>(obj));
                  

                  requires a second argument

                  mapper.setMapping(qobject_cast<QWidget *>(obj),0);
                  

                  works but i have no idea what thats doing

                  kshegunovK Offline
                  kshegunovK Offline
                  kshegunov
                  Moderators
                  wrote on last edited by
                  #14

                  @mrsurge
                  Yes, I forgot the sender. That should be:

                  mapper.setMapping(&mdialog, qobject_cast<QWidget *>(obj));
                  

                  QSignalMapper is a simple utility class to provide mapping of signals without parameters to signals/slots with a single parameter. This is done, because QDialog::accepted has no notion of the QLineEdit that triggers the event filter, so what the line does is simply to remap the signal to a slot that accepts the QLineEdit object as a parameter.

                  Kind regards.

                  Read and abide by the Qt Code of Conduct

                  M 1 Reply Last reply
                  0
                  • kshegunovK kshegunov

                    @mrsurge
                    Yes, I forgot the sender. That should be:

                    mapper.setMapping(&mdialog, qobject_cast<QWidget *>(obj));
                    

                    QSignalMapper is a simple utility class to provide mapping of signals without parameters to signals/slots with a single parameter. This is done, because QDialog::accepted has no notion of the QLineEdit that triggers the event filter, so what the line does is simply to remap the signal to a slot that accepts the QLineEdit object as a parameter.

                    Kind regards.

                    M Offline
                    M Offline
                    mrsurge
                    wrote on last edited by
                    #15

                    @kshegunov

                    Ok I have a separate form, cpp, and .h for my dialog, does all this still apply? do i need to add anything to my dialog.cpp or .h?

                    kshegunovK 1 Reply Last reply
                    0
                    • M mrsurge

                      @kshegunov

                      Ok I have a separate form, cpp, and .h for my dialog, does all this still apply? do i need to add anything to my dialog.cpp or .h?

                      kshegunovK Offline
                      kshegunovK Offline
                      kshegunov
                      Moderators
                      wrote on last edited by
                      #16

                      @mrsurge
                      Hello,

                      Ok I have a separate form, cpp, and .h for my dialog, does all this still apply? do i need to add anything to my dialog.cpp or .h?

                      It shouldn't matter how you initialize the dialog, provided you call QDialog::accept() at the appropriate place, i.e. when a save/ok button is clicked.

                      Kind regards.

                      Read and abide by the Qt Code of Conduct

                      1 Reply Last reply
                      0

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