Extend QObject to create keyboard filter : QEvent « Qt « C++






  1. C++
  2. Qt
  3. QEvent

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();
}








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1.Subclass QEvent