Extend QObject to create keyboard filter
Foundations of Qt Development\Chapter06\eventfilter\main.cpp
/*
* Copyright (c) 2006-2007, Johan Thelin
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#include <QApplication>
#include <QLineEdit>
#include <QKeyEvent>
class KeyboardFilter : public QObject
{
public:
KeyboardFilter( QObject *parent = 0 ) : QObject( parent ) {}
protected:
bool eventFilter( QObject *dist, QEvent *event )
{
if( event->type() == QEvent::KeyPress )
{
QKeyEvent *keyEvent = static_cast<QKeyEvent*>( event );
if( QString("1234567890").indexOf( keyEvent->text() ) != -1 )
return true;
}
return false;
}
};
int main( int argc, char **argv )
{
QApplication app( argc, argv );
QLineEdit lineEdit;
KeyboardFilter filter;
lineEdit.installEventFilter( &filter );
lineEdit.show();
return app.exec();
}
| 1. | Subclass QEvent |