In Qt 5.10.1, why do I need to click twice on a QPushButton to get a release event?

[mangoByte]

I recently upgraded to Qt 5.10.1 from 5.2 and found that my QPushButtons required more than a single click for the release signal to be emitted. For a pared down example, consider:

MyButton::MyButton(QWidget *parent) :
        QPushButton(parent)
    {
    }
 
    void MyButton::mousePressEvent(QMouseEvent *event)
    {
        qDebug() << "MOUSE PRESS!";
        QPushButton::mousePressEvent(event);
    }
 
    void MyButton::mouseReleaseEvent(QMouseEvent *event)
    {
        qDebug() << "MOUSE RELEASE!";
        QPushButton::mouseReleaseEvent(event);
    }
 
    void MyButton::mouseMoveEvent(QMouseEvent *event)
    {
        qDebug() << "MOUSE MOVE!";
        QPushButton::mouseMoveEvent(event);
    }

MyButton::MyButton(QWidget *parent) :
        QPushButton(parent)
    {
    }
    
    void MyButton::mousePressEvent(QMouseEvent *event)
    {
        qDebug() << "MOUSE PRESS!";
        QPushButton::mousePressEvent(event);
    }
    
    void MyButton::mouseReleaseEvent(QMouseEvent *event)
    {
        qDebug() << "MOUSE RELEASE!";
        QPushButton::mouseReleaseEvent(event);
    }
    
    void MyButton::mouseMoveEvent(QMouseEvent *event)
    {
        qDebug() << "MOUSE MOVE!";
        QPushButton::mouseMoveEvent(event);
    }

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Which after a single click, output was:

MOUSE PRESS!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!

MOUSE PRESS!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!
MOUSE MOVE!

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... etc, and NO "MOUSE RELEASE!" For that, I had to click a second time!

First, I tried adding in main.cpp on QApplication a:

a.setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents);

a.setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents);

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Secondly, at the widget level I tried:

ui->pushButton->setAttribute(Qt::WA_AcceptTouchEvents);

ui->pushButton->setAttribute(Qt::WA_AcceptTouchEvents);

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Neither of which seemed to help.
Now, in my production code, I found that for a QPushButton which opened a QDialog, I could trigger it on the "pressed" signal and after it's return, add:

QMouseEvent event( QEvent::MouseButtonRelease, ui->pushButton->pos(), Qt::AllButtons, 0, 0 );
QApplication::sendEvent( ui->pushButton, &event );

QMouseEvent event( QEvent::MouseButtonRelease, ui->pushButton->pos(), Qt::AllButtons, 0, 0 );
QApplication::sendEvent( ui->pushButton, &event );

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And that worked fine!
However, for the QPushButtons in my QDialog, I still have the problem of the buttons not providing a "release" after a "click".

Any insight would be greatly appreciated! (This is a cross-compiled Linux application on a device with a touch screen.)

[jimbo]

Does this help:-
https://stackoverflow.com/questions/...ton-is-pressed

[mangoByte]

Thank you for your response. I read that question and the answer to it was very close to the first example code I provided. There was no mention, however, of the release event NOT happening with a single "click".

[jimbo]

What about:-

QAbstractButton Class
Inherited By:
QCheckBox, QPushButton, QRadioButton, and QToolButton

[override virtual protected] void QAbstractButton::keyReleaseEvent(QKeyEvent *e)

---

Added after 1 2 minutes:

What about:-

QAbstractButton Class
Inherited By:
QCheckBox, QPushButton, QRadioButton, and QToolButton

[override virtual protected] void QAbstractButton::keyReleaseEvent(QKeyEvent *e)

Shou;d have said:-
[override virtual protected] void QAbstractButton::mouseReleaseEvent(QMouseEvent *e)
Reimplemented from QWidget::mouseReleaseEvent().

[mangoByte]

I found that installing an eventFilter on the QPushButton where I return false for Mouse Press/Release made it respond as expected!

bool MyEvent::eventFilter(QObject *obj, QEvent *event)
{
    if (event->type() == QEvent::MouseButtonPress)
    {
        qDebug() << "MouseButtonPress";
        return false;
    }
    else if (event->type() == QEvent::MouseMove)
    {
        qDebug() << "MouseMove";
        return false;
    }
    else if (event->type() == QEvent::MouseButtonRelease)
    {
        qDebug() << "MouseButtonRelease";
        return false;
    }
    else
    {
        return QObject::eventFilter(obj, event);
    }
}

bool MyEvent::eventFilter(QObject *obj, QEvent *event)
{
    if (event->type() == QEvent::MouseButtonPress)
    {
        qDebug() << "MouseButtonPress";
        return false;
    }
    else if (event->type() == QEvent::MouseMove)
    {
        qDebug() << "MouseMove";
        return false;
    }
    else if (event->type() == QEvent::MouseButtonRelease)
    {
        qDebug() << "MouseButtonRelease";
        return false;
    }
    else
    {
        return QObject::eventFilter(obj, event);
    }
}

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And added in MainWindow:

auto myEvent = new MyEvent(this);
ui->pushButton->installEventFilter(myEvent);

auto myEvent = new MyEvent(this);
ui->pushButton->installEventFilter(myEvent);

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