Another attempt:

MyTable.h:
Qt Code: 
  1. #include <QTableWidget>
  2. #include <QFocusEvent>
  3. #include <QEvent>
  4. #include <QLineEdit>
  5.  
  6. #include <iostream>
  7.  
  8. class MyTable : public QTableWidget
  9. {
  10.     Q_OBJECT
  11.  
  12.   public:
  13.     MyTable( QWidget * parent = 0) : QTableWidget(parent)
  14.     {
  15.         setColumnCount(7);
  16.         setRowCount(1);
  17.  
  18.         for(unsigned int i = 0; i < columnCount(); ++i)
  19.         {
  20.             QWidget * e = new QLineEdit(this);
  21.             setCellWidget(0, i, e);
  22.             e->setFocusPolicy( Qt::ClickFocus );
  23.         }
  24.     }
  25.  
  26.     bool event( QEvent * e )
  27.     {
  28.         switch( e->type() )
  29.         {
  30.             case QEvent::KeyPress:
  31.                 e->accept();
  32.                 QKeyEvent   *ke = (QKeyEvent *) e;
  33.                 QObject     *p  = parent();
  34.                 bool        res = true;
  35.  
  36.                 switch( ke->key() )
  37.                 {
  38.                     case Qt::Key_Backtab:
  39.                         res = focusNextPrevChild(false);
  40.                         break;
  41.                     case Qt::Key_Tab:
  42.                         res = focusNextPrevChild(true);
  43.                         break;
  44.                 }
  45.                 return res;
  46.         }
  47.  
  48.         return QTableWidget::event(e);
  49.     }
  50.  
  51.     void focusInEvent( QFocusEvent *e )
  52.     {
  53.         switch( e->reason() )
  54.         {
  55.             case Qt::BacktabFocusReason:
  56.                 setCurrentCell(0, columnCount()-1);
  57.                 break;
  58.             case Qt::TabFocusReason:
  59.             default:
  60.                 setCurrentCell(0,0);
  61.                 break;
  62.         }
  63.     }
  64.  
  65.     bool focusNextPrevChild( bool next )
  66.     {
  67.         if( next )
  68.         {
  69.             if( currentColumn() < columnCount() - 1 )
  70.             {
  71.                 setCurrentCell( 0, currentColumn() + 1);
  72.                 return true;
  73.             }
  74.         }
  75.         else if( currentColumn() > 0 )
  76.         {
  77.                 setCurrentCell( 0, currentColumn() - 1);
  78.                 return true;
  79.         }
  80.  
  81.         return false;
  82.     }
  83.  
  84. };
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I don't know why this works only one way: when pressing tab it loops as it should. But when I press Shift+Tab ( = Key_Backtab) it loops inside one MyTable. Why does it behave like that?