if(event->type() == QEvent::KeyRelease) gives error

[schooner]

Hi

This is driving me nuts, so hopefully someone has the answer.

I am re-implementing QApplication to filter all mouse and keyboard events to a widget which is embedded into a tk application.
tk does not pass on focus properly and the tk app needs some crucial keystrokes forwarded, so I have to check everything
including checking which child widget is the receiver and forcing focus in some instances.

I just finished dealing with mouse clicks and went to add keystrokes

bool FilterApplication::notify( QObject *receiver, QEvent *event )
{
    if(event->type() == QEvent::MouseButtonPress)
        qDebug() << "Button Pressed";
    if(event->type() == QEvent::KeyRelease)
        qDebug() << "Key Released";
 
.......
 
}

bool FilterApplication::notify( QObject *receiver, QEvent *event )
{
    if(event->type() == QEvent::MouseButtonPress)
        qDebug() << "Button Pressed";
    if(event->type() == QEvent::KeyRelease)
        qDebug() << "Key Released";

.......

}

To copy to clipboard, switch view to plain text mode 

The test for mouse events is fine, but when I try to do the same for key press / release events I get

FilterApplication.cpp: In member function ‘virtual bool FilterApplication::notify(QObject*, QEvent*)’:
FilterApplication.cpp:33:29: error: expected unqualified-id before numeric constant
FilterApplication.cpp:33:29: error: expected ‘)’ before numeric constant
make: *** [FilterApplication.o] Error 1

I can cast the event eg.

QKeyEvent *K = (QKeyEvent*)event;
if (K->key() == Qt::Key_Escape)
     qDebug() << "Escape Pressed";

QKeyEvent *K = (QKeyEvent*)event;
if (K->key() == Qt::Key_Escape)
     qDebug() << "Escape Pressed";

To copy to clipboard, switch view to plain text mode 

That works fine, except that I get 3 key codes instead of 1 for release and I am casting and testing stuff that isn't key events

Hopefully something simple, but my head is scrambled trying to find it.

Qt 4.8 on Linux

regards

[anda_skoa]

Maybe a typo or something similar?

A quick test:

#include <QApplication>
#include <QDebug>
#include <QKeyEvent>
#include <QLineEdit>
 
class Filter : public QObject
{
public:
    bool eventFilter(QObject *watched, QEvent *event)
    {
        switch (event->type()) {
        case QEvent::KeyPress:
            qDebug() << "Key Press Event for" << watched << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        case QEvent::KeyRelease:
            qDebug() << "Key Release Event for" << watched << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        default:
            break;
        }
 
        return false; // do not filter
    }
};
 
int main(int argc, char **argv)
{
    QApplication app(argc, argv);
 
    app.installEventFilter(new Filter);
 
    QLineEdit lineEdit;
    lineEdit.show();
 
    return app.exec();
}

#include <QApplication>
#include <QDebug>
#include <QKeyEvent>
#include <QLineEdit>

class Filter : public QObject
{
public:
    bool eventFilter(QObject *watched, QEvent *event)
    {
        switch (event->type()) {
        case QEvent::KeyPress:
            qDebug() << "Key Press Event for" << watched << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        case QEvent::KeyRelease:
            qDebug() << "Key Release Event for" << watched << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        default:
            break;
        }
    
        return false; // do not filter
    }
};

int main(int argc, char **argv)
{
    QApplication app(argc, argv);
    
    app.installEventFilter(new Filter);
    
    QLineEdit lineEdit;
    lineEdit.show();
    
    return app.exec();
}

To copy to clipboard, switch view to plain text mode 

Cheers,
_

[schooner]

Hi

Maybe a typo or something similar?

You would think so wouldn't you?

This gives the same error for the KeyEvent tests but not the MouseEvent test

switch (event->type()) 
        {
        case QEvent::KeyPress:
            qDebug() << "Key Press Event for" << receiver << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        case QEvent::KeyRelease:
            qDebug() << "Key Release Event for" << receiver << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        case QEvent::MouseButtonDblClick:
            qDebug() << "Mouse button doubleclick event for" << receiver << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        default:
            break;
        }

switch (event->type()) 
        {
        case QEvent::KeyPress:
            qDebug() << "Key Press Event for" << receiver << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        case QEvent::KeyRelease:
            qDebug() << "Key Release Event for" << receiver << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        case QEvent::MouseButtonDblClick:
            qDebug() << "Mouse button doubleclick event for" << receiver << ":" << static_cast<QKeyEvent*>(event)->text();
            break;
        default:
            break;
        }

To copy to clipboard, switch view to plain text mode 

Error

-o FilterApplication.o FilterApplication.cpp
FilterApplication.cpp: In member function ‘virtual bool FilterApplication::notify(QObject*, QEvent*)’:
FilterApplication.cpp:52:22: error: expected unqualified-id before numeric constant
FilterApplication.cpp:52:22: error: expected ‘:’ before numeric constant
FilterApplication.cpp:52:30: error: expected ‘;’ before ‘:’ token
FilterApplication.cpp:55:22: error: expected unqualified-id before numeric constant
FilterApplication.cpp:55:22: error: expected ‘:’ before numeric constant
FilterApplication.cpp:55:32: error: expected ‘;’ before ‘:’ token
make: *** [FilterApplication.o] Error 1


I have now found the cause of the error

In a global header, the Xlib headers required for X forwarding through XSendEvent are included
#include <X11/Xlib.h>
#include <X11/keysym.h>

I suspect there is a #define clash between keysym.h and the Qt KeyEvent headers
Have not tracked it down yet, but commenting out the includes allows compilation, so I am off again

regards