Detect if a QPushButton is being clicked

Question

I'm trying to find out whether a button is being pressed or not from within the paintEvent(), so that I can draw the "down" state. However, I don't know where to find this information. I tried QStyleOptionButton::state but it doesn't tell whether the button is being clicked or not. The output of the debug statement is always something like "QStyle::State( "Active | Enabled | HasFocus | MouseOver" )" so nothing about a MouseDown state.

void XQPushButton::mousePressEvent(QMouseEvent* event) {
    QPushButton::mousePressEvent(event);

    QStyleOptionButton options;
    options.initFrom(this);
    qDebug() << (options.state);
}


void XQPushButton::paintEvent(QPaintEvent* event) {
    QPushButton::paintEvent(event);

    QStyleOptionButton options;
    options.initFrom(this);
    qDebug() << (options.state);
}

So any idea how I can detect if the button is being clicked?

Answer 1

QPushButton inherits QAbstractButton, which provides the down property:

This property holds whether the button is pressed down.

The documentation of the QStyleOption parent class contains an example that uses this property:

void MyPushButton::paintEvent(QPaintEvent *)
{
    QStyleOptionButton option;
    option.initFrom(this);
    option.state = isDown() ? QStyle::State_Sunken : QStyle::State_Raised;
    //...
}

In other words, the sunken/raised state is not initialized by initFrom(). This makes some sense, since initFrom is inherited from QStyleOption and takes a QWidget:

void initFrom ( const QWidget * widget )

– and a generic QWidget has no notion of "raised" or "sunken".

At least this is how I read the docs.