QTextDocument should expose a tree model for an outline view

Another feature that some word processors have is an outline view. Documents tend to have hierarchical structure: different levels of headings, indented quotes, tables and so on. So it would map naturally to have a QAIM to expose this structure. That could also provide a way of organizing sub-models for tables: if a cell in the outline tree model represents a table, you should be able to get another QAIM from that cell, for the table, which can then be used with TableView etc.

Word processors sometimes allow outline drag-and-drop to rearrange documents.