Re-render the whole viewport, headers, and all rows.
The tree.columns definition has changed beyond simple width adjustments.
A node's title, icon, columns, or status have changed. Update the existing row markup.
The viewport/window was resized. Adjust layout attributes for all elements.
A node's definition has changed beyond status and data. Re-render the whole row's markup.
Vertical scroll event. Update the 'top' property of all rows.
A node's status has changed. Update current row's classes, to reflect active, selected, ...
Nodes have been added, removed, etc. Update markup.
Possible values for WunderbaumNode.update and Wunderbaum.update.