QLineEdit

gabor53

Hi,
I'm trying to read and validate the entry in QLineEdit when it loses focus either by pressing TAB, ENTER or the user clicks on an other widget.
I have the following code so far (which is not working):

    while((ui->lineEdit->hasFocus ()== (true) ))
    {
    	QString string;
        if(string.length ()<2)
          {
              ui->label_2->setText ("The name is too short!");
              ui->label_2->setStyleSheet ("color: red");

              QPixmap pix
      ("C:/Programming/Projects/FolkFriends/icons/angry.png");
              ui->label_3->setScaledContents (true);
              ui->label_3->setPixmap (pix);
          }
          else
          {
              ui->label_2->setText ("");
              QPixmap pix2("C:/Programming/Projects/FolkFriends/icons/Check-icon.png");
              ui->label_3->setScaledContents (true);
              ui->label_3->setPixmap (pix2);
          }
      }
	  QString Name;
      Name = ui->lineEdit->text ();
      qDebug() << "Name: " << Name;

Please help me to figure out how to do it correctly.
Thank you.

michelson

This post is deleted!

mrjj

Hi
A while loop is not the way :)

as @Charby suggest might be the fastest!

Alternatively You can use
http://doc.qt.io/qt-5.5/qwidget.html#focusOutEvent
Using a subclass

class LineEdit : public QLineEdit
{
    virtual void focusOutEvent( QFocusEvent* )
    {
     /// focus is lost. do stuff
     }
};

Charby

@gabor53 you should connect the editingFinished signal of your lineedit to your custom slot.

gabor53

I came up with the following (not working) code:

	setFocusPolicy (Qt::StrongFocus);

    if((ui->lineEdit->QFocusEvent::lostFocus())==true )

	{
    		QString string;
           string = ui->lineEdit->text ();
                      if(string.length ()<2)
                        {
                            ui->label_4->setText ("The name is too short!");
                            ui->label_4->setStyleSheet ("color: red");

                            QPixmap pix
                    ("C:/Programming/Projects/FolkFriends/icons/angry.png");
                            ui->label_3->setScaledContents (true);
                            ui->label_3->setPixmap (pix);
                        }
                        else
                        {
                            ui->label_4->setText ("");
                            QPixmap pix2("C:/Programming/Projects/FolkFriends/icons/Check-icon.png");
                            ui->label_3->setScaledContents (true);
                            ui->label_3->setPixmap (pix2);
                        }

                    QString Name;
                    Name = ui->lineEdit->text ();
                    qDebug() << "Name: " << Name;

	}

When I run it I get the following error message:
C:\Programming\Projects\Folkfriends\additem.cpp:-1: In constructor 'Additem::Additem(QWidget*)':
C:\Programming\Projects\Folkfriends\additem.cpp:51: error: 'QFocusEvent' is not a base of 'QLineEdit'
if((ui->lineEdit->QFocusEvent::lostFocus())==true )
^
What am I doing wrong?
Thank you for all your help.

ValentinMichelet

This is a C++ error, not an issue with Qt, and the compiler is pretty explicit.
There is no lostFocus() method in QLineEdit class. And adding QFocusEvent is not the solution. Instead, consider implementing what @Charby suggested: connect your ui->lineEdit editingFinished() signal to your custom slot:

connect(ui->lineEdit, SIGNAL(editingFinished()), this, SLOT(readAndValidate()));

Add this connect in your the constructor of the widget that contains the ui.

gabor53

Do I need to create a separate class and object to receive this signal?

ValentinMichelet

connect(ui->lineEdit, SIGNAL(editingFinished()), this, SLOT(readAndValidate()));

The 'this' means that readAndValidate() is a slot that belongs to 'this'.

gabor53

Thank you it worked.

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QLineEdit