Qt：enterEvent和leaveEvent不起作用

Question

I have strange problem with mouse events in Qt. I have following code:

#ifndef QSTONEFIELD_HPP_
#define QSTONEFIELD_HPP_

#include <QtGui>
#include <QWidget>

class QStoneField : public QWidget
{
    Q_OBJECT

private:
    // some stuff

public:
    // some methods

protected:
    void paintEvent(QPaintEvent *event);   
    virtual void mousePressEvent(QMouseEvent * event);
    virtual void enterEvent(QMouseEvent * event);
    virtual void leaveEvent(QMouseEvent * event);

signals:

public slots:

};

#endif

And in second file I have:

#include "qstonefield.hpp"
// FIXME temporary include
#include <iostream>
using namespace std;

// some other methods ..

void QStoneField::mousePressEvent(QMouseEvent * event)
{
    cout << "CLICK!" << endl << flush;
}

void QStoneField::enterEvent(QMouseEvent * event)
{
    cout << "ENTER!" << endl << flush;
}

void QStoneField::leaveEvent(QMouseEvent * event)
{
    cout << "LEAVE!" << endl << flush;
}

And now when I compile and run it, I can invoke mousePressEvent because program prints "CLICK!", but when I am crossing the widget by mouse, it prints just nothing. Of course in main.cpp I didnt forget to stone.setMouseTracking(true).

Why enterEvent and leaveEvent doesnt work? It should work according to documentation. Thanks in advance!

Answer 1

The signature of your function should be:

virtual void QStoneField::enterEvent(QEvent * event);
virtual void QStoneField::leaveEvent(QEvent * event);

You are simply using the wrong parameter for the function which means the one from Qwidget are not overwritten.

I recommend you to consider what the default implementation does, for example :

virtual void QStoneField::leaveEvent(QEvent * event){
       //do my own things
       QWidget::leaveEvent(event);
}