How to mark the whole text by double clicking for QDoubleSpinBox?

Question

I have a class which inherit from QDoubleSpinBox.

 class NumericEdit : public QDoubleSpinBox
 {      
 public:
   NumericEdit( QWidget *p_parent = nullptr );

 protected:
   bool event( QEvent *p_event ) override;
   void keyPressEvent( QKeyEvent *p_event ) override;
   void keyReleaseEvent( QKeyEvent *p_event ) override;
   void focusInEvent( QFocusEvent *p_event ) override;
   void focusOutEvent( QFocusEvent *p_event ) override;
   ............
 };

 NumericEdit::NumericEdit( QWidget *p_parent ) : QDoubleSpinBox( p_parent )
 {
   initStyleSheet();
   setButtonSymbols( QAbstractSpinBox::NoButtons );
   setGroupSeparatorShown( true );
   ..........
 }

The result when I double click into the editing field is like this, only the part in between group separators is marked. If I triple click, the whole text is then marked.

How should I change, sothat when I double click into the editing field (no matter in integer part or decimal part), the whole text is marked?

Answer 1

Solution is reimplementing of QLineEdit::mouseDoubleClickEvent method (not QDoubleSpinBox::mouseDoubleClickEvent).

Custom line edit:

class ExtendedLineEdit : public QLineEdit
{
    Q_OBJECT
public:
    explicit ExtendedLineEdit(QWidget *parent = nullptr);
protected:
    void mouseDoubleClickEvent(QMouseEvent *event);
}

void ExtendedLineEdit::mouseDoubleClickEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton)
    {
        selectAll();
        event->accept();
        return;
    }

    QLineEdit::mouseDoubleClickEvent(event);
}

And then set it to your custom spin box

NumericEdit::NumericEdit(QWidget *p_parent) : QDoubleSpinBox(p_parent)
{
    //...
    ExtendedLineEdit* lineEdit = new ExtendedLineEdit(this);
    setLineEdit(lineEdit);
}