Qt stylesheet : set a specific QMenuBar::item background color

Question

I have a QMenuBar with for example two QMenu items.

How can I only make the "Floors" item be blue, for example? I know how to change it for ALL the items with:

QMenuBar::item {
     background: ...;
}

But I can't find a way to color a specific item. I tried to use setProperty on Qmenu, I tried with setPalette,... I just find nothing working. Is there a way to set a specific QMenuBar::item property in C++ code?

Answer 1

I finally found something.

1. Create your own object, for example WidgetMenuBar, inherited from QMenuBar.

2. Add a property to identify wich item should be colored differently:

   for (int i = 0; i < this->actions().size(); i++){
       actions().at(i)->setProperty("selection",false);
   }
   // Only the first item colored
   actions().at(0)->setProperty("selection",true);
   

3. Reimplement void paintEvent(QPaintEvent *e) function of your widget:

   void WidgetMenuBarMapEditor::paintEvent(QPaintEvent *e){
       QPainter p(this);
       QRegion emptyArea(rect());
   
       // Draw the items
       for (int i = 0; i < actions().size(); ++i) {
           QAction *action = actions().at(i);
           QRect adjustedActionRect = this->actionGeometry(action);
   
           // Fill by the magic color the selected item
           if (action->property("selection") == true)
               p.fillRect(adjustedActionRect, QColor(255,0,0));
   
           // Draw all the other stuff (text, special background..)
           if (adjustedActionRect.isEmpty() || !action->isVisible())
               continue;
           if(!e->rect().intersects(adjustedActionRect))
               continue;
           emptyArea -= adjustedActionRect;
           QStyleOptionMenuItem opt;
           initStyleOption(&opt, action);
           opt.rect = adjustedActionRect;
           style()->drawControl(QStyle::CE_MenuBarItem, &opt, &p, this);
       }
   }
   

You can see here how to implement paintEvent function.