I guess you can use setItemDelegate method of the treeview to setup custom painter for your treeview items. In the delegate's paint method you can use QTextDocument to load item's text as html and render it. Please check if an example below would work for you:
treeview initialization:
...
// create simple model for a tree view
QStandardItemModel *model = new QStandardItemModel();
QModelIndex parentItem;
for (int i = 0; i < 4; ++i)
{
parentItem = model->index(0, 0, parentItem);
model->insertRows(0, 1, parentItem);
model->insertColumns(0, 1, parentItem);
QModelIndex index = model->index(0, 0, parentItem);
model->setData(index, "<span>blah-blah <b>some text</b> other blah</span>");
}
// create custom delegate
HTMLDelegate* delegate = new HTMLDelegate();
// set model and delegate to the treeview object
ui->treeView->setModel(model);
ui->treeView->setItemDelegate(delegate);
...
custom delegate implementation
class HTMLDelegate : public QStyledItemDelegate
{
protected:
void paint ( QPainter * painter, const QStyleOptionViewItem & option, const QModelIndex & index ) const;
QSize sizeHint ( const QStyleOptionViewItem & option, const QModelIndex & index ) const;
};
void HTMLDelegate::paint(QPainter* painter, const QStyleOptionViewItem & option, const QModelIndex &index) const
{
QStyleOptionViewItemV4 options = option;
initStyleOption(&options, index);
painter->save();
QTextDocument doc;
doc.setHtml(options.text);
options.text = "";
options.widget->style()->drawControl(QStyle::CE_ItemViewItem, &options, painter);
painter->translate(options.rect.left(), options.rect.top());
QRect clip(0, 0, options.rect.width(), options.rect.height());
doc.drawContents(painter, clip);
painter->restore();
}
QSize HTMLDelegate::sizeHint ( const QStyleOptionViewItem & option, const QModelIndex & index ) const
{
QStyleOptionViewItemV4 options = option;
initStyleOption(&options, index);
QTextDocument doc;
doc.setHtml(options.text);
doc.setTextWidth(options.rect.width());
return QSize(doc.idealWidth(), doc.size().height());
}
hope this helps, regards
update0: changes to HTMLDelegate to make icons visible and different pen color for selected items
void HTMLDelegate::paint(QPainter* painter, const QStyleOptionViewItem & option, const QModelIndex &index) const
{
QStyleOptionViewItemV4 options = option;
initStyleOption(&options, index);
painter->save();
QTextDocument doc;
doc.setHtml(options.text);
options.text = "";
options.widget->style()->drawControl(QStyle::CE_ItemViewItem, &options, painter);
// shift text right to make icon visible
QSize iconSize = options.icon.actualSize(options.rect.size());
painter->translate(options.rect.left()+iconSize.width(), options.rect.top());
QRect clip(0, 0, options.rect.width()+iconSize.width(), options.rect.height());
//doc.drawContents(painter, clip);
painter->setClipRect(clip);
QAbstractTextDocumentLayout::PaintContext ctx;
// set text color to red for selected item
if (option.state & QStyle::State_Selected)
ctx.palette.setColor(QPalette::Text, QColor("red"));
ctx.clip = clip;
doc.documentLayout()->draw(painter, ctx);
painter->restore();
}