Displaying a tooltip for QTreeWidgetItem when it's hovered without calling setTooltip() for every item

Question

I want to display a tooltip for QTreeWidgetItem that's hovered. However, getting a tooltip is not a very fast process in my case, so I don't want to call setTooltip() for every single item. I want to do it on demand, on some event or signal. What's the easiest way to do it?

Answer 1

The best solution I've found is to subclass QTreeWidgetItem, override virtual QVariant data(int column, int role) const; and return a tooltip for this item when data is called for Qt::ToolTipRole.

Answer 2

I think that it should be easier to achieve what you want if you migrate to a QTreeView/Model pattern.

QAbstractItemModel has a role for tooltips: Qt::ToolTipRole

You could subclass a Model to reimplement the

QVariant QAbstractItemModel::data ( const QModelIndex & index, int role = Qt::DisplayRole ) const [pure virtual

method.

So, when receives a Qt::TooltipRole, it calculates/recovers from an internal cache.