How to show progess in a QTreeView item ?

[THRESHE]

The QStyleOptionViewItem parameter contains all required information.

if (opt.state & QStyle::State_Selected)
   ...
 
if (opt.state & QStyle::State_HasFocus)
   ...

if (opt.state & QStyle::State_Selected)
   ...

if (opt.state & QStyle::State_HasFocus)
   ...

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etc.

And what after ???
I've tried like

if (opt.state & QStyle::State_Selected)
	{
		painter->setBrush(QBrush(QColor("#444444")));
		painter->drawRect(opt.rect);
	}

if (opt.state & QStyle::State_Selected)
	{
		painter->setBrush(QBrush(QColor("#444444")));
		painter->drawRect(opt.rect);
	}

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Result -