#include <QLineEdit>

class LineEditClickedButton : public QLineEdit
{
    Q_OBJECT
public:
    explicit LineEditClickedButton(QWidget *parent = nullptr);

protected:
    void keyPressEvent(QKeyEvent *event) Q_DECL_OVERRIDE;

signals:
    void buttonPressed(QString button);
};

#include "lineeditclickedbutton.h"
#include <QKeyEvent>

LineEditClickedButton::LineEditClickedButton(QWidget *parent) :
    QLineEdit(parent)
{}

void LineEditClickedButton::keyPressEvent(QKeyEvent *e)
{
    switch (e->key()) {
    case Qt::Key_Escape:
        emit buttonPressed("esc");
        break;
    case Qt::Key_Tab:
        emit buttonPressed("tab");
        break;
    }
    QLineEdit::keyPressEvent(e);
}