C++ (Qt)
class TextEdit : public QTextEdit
{
Q_OBJECT
public:
    TextEdit( QWidget* parent = 0 )
    : QTextEdit( parent )
    {
          resize_timer_.setInterval( 50 );
          resize_timer_.setSingleShot( true );
          connect( resize_timer_, SIGNAL( timeout() ), this, SLOT( delayed_resize() ) );
    }
    virtual ~TextEdit() {}
 
protected slots:
    void delayed_resize()
    {
          QTextEdit::resizeEvent( &QResizeEvent( size(), old_size_ ) );
    }
 
protected:
     void resizeEvent( QResizeEvent* e )
     {
          if( !resize_timer_.isActive() )
            old_size_ = e->oldSize();
          resize_timer_.start();
     }
 
private:
    QTimer   resize_timer_;
    QSize    old_size_;
};

C++ (Qt)
QSize QWidget::size() const