Summary: arrow keys

The arrow keys do different things depending on which pane has focus. Using arrow keys is much easier than using the mouse.

Focus in outline pane

The plain arrow keys select nodes, expanding or contracting nodes as needed.

The shift arrow keys move nodes. The Shift-Left-Arrow and Shift-Up-Arrow contract nodes as needed. Note: the Shift-Down-Arrow and Shift-Right-Arrow keys never expand nodes.

Focus in body pane

As usual, the plain arrow keys move the cursor and the shift arrow keys move the cursor and extend the solution.

The alt arrow keys move the focus to the outline pane and then select nodes. The alt-shift arrow keys move the focus to the outline pane and then move nodes.