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Link lineEdit to a progressbar



  • Hi everyone
    I have three lineEdits(lineEdit_1, lineEdit_2 and lineEdit_3 ) in Dialog window. When lineEdit_2 and lineEdit_3 are empty, as the user types something in the lineEdit_1, an arc is supposed to be drawn from 0 to 120 degree.
    I have written the following code. My problem is that when I type something in the lineEdit_1, the arc is drawn even if the lineEdit_2 and lineEdit_3 are not empty.
    I don't know how to define the situation that just when the lineEdit_2 and lineEdit_3 are empty and the user types something in lineEdit_1, the arc is drawn.
    I would appreciate if someone could help me

    Here is the code:

    dialog.h:

    #ifndef DIALOG_H
    #define DIALOG_H
    
    #include <QDialog>
    #include <QPainter>
    #include <QPen>
    #include <QRectF>
    #include <QSlider>
    #include <QLineEdit>
    
    namespace Ui {
    class Dialog;
    }
    
    class Dialog : public QDialog
    {
      Q_OBJECT
    
    public:
      explicit Dialog(QWidget *parent = 0);
      ~Dialog();
      double progress;
      QLineEdit *lineEdit_1;
      QLineEdit *lineEdit_2 ;
      QLineEdit *lineEdit_3;
    
    
    public slots:
      void setProgress();
    
    
    protected:
      void paintEvent(QPaintEvent *);
    
    private:
      Ui::Dialog *ui;
    
    };
    
    #endif // DIALOG_H
    
    

    dialog.cpp:

    #include "dialog.h"
    #include "ui_dialog.h"
    
    Dialog::Dialog(QWidget *parent) :
        QDialog(parent),
        ui(new Ui::Dialog)
    {
        ui->setupUi(this);
    
        lineEdit_1 = new QLineEdit(this);
        lineEdit_1->setGeometry(500,50,100,50);
        lineEdit_1->show();
    
    
        lineEdit_2 = new QLineEdit(this);
        lineEdit_2->setGeometry(500,150,100,50);
        lineEdit_2->show();
    
    
        lineEdit_3 = new QLineEdit(this);
        lineEdit_3->setGeometry(500,250,100,50);
        lineEdit_3->show();
    
    
        if(lineEdit_2->text().isEmpty() && lineEdit_3->text().isEmpty())
        {
         connect(lineEdit_1, SIGNAL(textChanged(const QString &)), this, SLOT(setProgress()));
        }
    
    
    }
    
    Dialog::~Dialog()
    {
        delete ui;
    }
    
    void Dialog::setProgress()
    {
        progress = 120;
        this->update();
    }
    
    
    
    
    void Dialog::paintEvent(QPaintEvent *)
    {
        QPainter p(this);
    
        QPen pen;
        pen.setWidth(7);
        pen.setColor(Qt::red);
        p.setPen(pen);
    
        p.setRenderHint(QPainter::Antialiasing);
    
        QRectF rectangle(30.0, 20.0, 200.0, 200.0);
    
    
        int startAngle = 0 * 16;
        int spanAngle = progress * 16;
    
    
    
        p.drawArc(rectangle, startAngle, spanAngle);
    
    
        //the number texted in the circle center
        p.drawText(rectangle,Qt::AlignCenter,QString::number(progress)+" %");
    }
    
    

    main.cpp:

    #include "dialog.h"
    #include <QApplication>
    #include <QSlider>
    
    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
    
        Dialog w;
        w.show();
    
    
        return a.exec();
    }
    
    

    The output:
    The Output.png


  • Lifetime Qt Champion

    Hi,

    Check the status of all your line edits in the slot and set the value accordingly.



  • @SGaist Hi. Thank you so much.


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