help.txt

<span font_desc="Mono 10">
+ or =      zoom in
-           zoom out
*           fit to window
Home        go to the top sheet
Delete or
Backspace   go to the next higher sheet in hierarchy
PgUp        go to the previous sheet in sequence
PgDn        go to the next sheet in sequence
Up or Down  invoke the revision history (WIP)
Tab         toggle between old and new revision
Esc         cancel current action (exit history, close
            pop-up, de-highlight glabel, close help)
E           show/hide extra information (pin types)
F           toggle showing footprints, even if invisible
Shift+R     idem, for component references
Shift+D     toggle between "diff" and experimental
	    "delta" mode
H           show/hide help window
V           if hovering on commit, show/hide commit viewer
T           toggle performance timer
D           when comparing revisions, show difference
N           show newer sheet
O           show older sheet
Q           quit the viewer
</span>