Hello,

I'm overloading the QStyledItemDelegate::paint() function to enable the display of text and/or icons (depending on user preference) in a table column. I have the feature working exactly as I intended. However, getting the text and icons to align with the other data in the row required me to add / subtract pixels from the rect position (denoted by the "Offset" variables in the code below).

I suppose this will work, but it makes me nervous, as I fear I may have implemented a device-dependent solution, thus different video cards or platforms may render everything differently, making my adjustments worthless. Is there a device independent way to match the alignment of painted text / graphics to the alignemnt of values of the adjacent cells? Or can anyone assuage my fears that my approach is going to be ok, regardless of platform / video hardware?

Obligatory code:

Qt Code: 
  1. void CSVWorld::RecordStatusDelegate::paint (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
  2. {
  3.    painter->save();
  4.  
  5.    QFont font = QApplication::font();
  6.    font.setPointSize(10);
  7.  
  8.    QFontMetrics fm(font);
  9.  
  10.    QString text = "";
  11.    QIcon *icon = 0;
  12.  
  13.    switch (index.data().toInt())
  14.    {
  15.         //ICON SELECTION LOGIC HERE
  16.    }
  17.  
  18.    QRect textRect = option.rect;
  19.    QRect iconRect = option.rect;
  20.     int displayables = 0;
  21.  
  22.    //for icon-only (1), default option.rect centers icon left-to-right
  23.    //otherwise, size option.rect to fit the icon, forcing left-alignment with text
  24.  
  25.     iconRect.setTop (iconRect.top() + mIconTopOffset);   //device-dependent?
  26.     iconRect.setBottom (iconRect.top() + mIconSize);
  27.  
  28.     if (displayables == 0 && (icon) )
  29.     {
  30.         iconRect.setRight (iconRect.left() + mIconSize);
  31.         textRect.setLeft (iconRect.right() + (mIconSize/4) * 3);
  32.         textRect.setRight (textRect.left() + fm.width(text));
  33.     }
  34.     else
  35.         textRect.setLeft (textRect.left() + mTextLeftOffset );   //device-dependent?
  36.  
  37.     textRect.setTop (textRect.top() + ((option.rect.height() - fm.height()) / 2) + mTextTopOffset);   //device-dependent?
  38.  
  39.    if (displayables == 0 || displayables == 1)
  40.    {
  41.         if (icon)
  42.            painter->drawPixmap(iconRect.center(),icon->pixmap(mIconSize, mIconSize));
  43.    }
  44.  
  45.    // icon + text or text only, or force text if no icon exists for status
  46.    if (displayables == 0 || displayables == 2 || !(icon) )
  47.    {
  48.         painter->setFont(font);
  49.         painter->drawText(textRect,text);
  50.    }
  51.  
  52.    painter->restore();
  53.  
  54. }
To copy to clipboard, switch view to plain text mode