Search code examples
c++qtqstyle

How to know header text width in QStyle?

I have a QTreeView and use ProxyStyle for that.

enter image description here

The pic above is just the header. Now I need to draw the up/down arrow (for sorting items) beside header label as in figure. In order to put the arrow in the correct postion I need to know:

  • the left margin = distance between the text and left border
  • the text width
  • the right margin = distance between the text and the arrow

How can I calculate the text width in this case? I thought about QFontMetrics but dont know how to receive the text to calculate.

In my style I use only drawPrimitive function

void MyStyle::drawPrimitive( PrimitiveElement p_pe, const QStyleOption *p_option, QPainter *p_painter, const QWidget *p_widget ) const
{
  int leftmargin = 10;
  int rightmargin = 10;
  if ( p_pe == PE_IndicatorHeaderArrow )
  {
     if ( const QStyleOptionHeader *header = qstyleoption_cast<const QStyleOptionHeader *>( p_option ) )
     {
        QPixmap pix;
        if ( header->sortIndicator & QStyleOptionHeader::SortUp )
        {
           pix = QPixmap( ":/sortUp.png" );
        }
        else if ( header->sortIndicator & QStyleOptionHeader::SortDown )
        {
           pix = QPixmap( ":/sortDown.png" );
        }
        p_painter->drawPixmap( header->rect.left() + leftmargin+ subElementRect( SE_HeaderLabel, p_option, p_widget ).width() + rightmargin, header->rect.top() + pix.height(), pix );
     }
  }
  else
  {
     QProxyStyle::drawPrimitive( p_pe, p_option, p_painter, p_widget );
  }
}

I use subElementRect( SE_HeaderLabel, p_option, p_widget ).width() in this case but it is wrong. How can I calculate the width of the text?

Solution

  • It is all contained in the QStyleOptionHeader. The text width could be obtained by calling:

    int textWidth = header->fontMetrics.boundingRect(header->text).width();