ets enable all columns and look at the resulting observer widget.

\code
// We need to set the item view column hint on our observer:
observer_widget->activeHints()->setItemViewColumnHint(ObserverHints::ColumnAllHints);
\endcode

After setting the item view column hint, the observer widget will look like this:

\image html observer_widget_doc_tree_view_columns.jpg "Observer Widget With All Columns Enabled"

It is easy to extend an observer widget with custom columns. The Qtilities::Examples::Clipboard examp