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# format described in ../help.readme


TITLE		Tree display keyboard reference

OCCURRENCE	Focus tree display area and press one of the hotkeys described below.

DESCRIPTION     List of keys recognized by the ARB tree display

SECTION         Marking species and folding groups

                    Key   Description
                   ==========================================
                    m     mark/unmark (sub-)tree
                    i     invert marks of (sub-)tree
                    x     expand (Marked->Unmarked->All)
                    c     collapse (Terminal->All)

                  If you point to a subtree with the mouse while pressing one of these keys, the action is
                  performed on the subtree. Otherwise (if you point somewhere outside of the tree)
                  the whole tree is targeted.

                  If you press < SHIFT + Key > the function works on the opposite set:

                     - Instead of the subtree, the rest of the tree is targeted.
                     - Instead of the whole tree, all species NOT in tree are targeted.

                  If you press < CTRL + Key > the function works on ALL species (if it makes sense).

                  SPACE toggles the mark(s) of the LINK{selected.hlp} or group.

                  RETURN toggles the folding of the selected group.


SECTION         Selecting species

                    Key              Description
                   ===============================================
                    Cursor up/down   select previous/next species
                    Home/End         select first/last species

                  If you press < CTRL + Key > these function only select marked species
                  and if the selected species is inside a folded subtree all parent groups
                  will be unfolded temporarily (to make the species visible).

                  If you press < SHIFT + Key > folded groups will temporarily unfolded and traversed,
                  without SHIFT folded groups will be skipped.


SECTION         Selecting groups

                    Key                       Description
                   ===============================================================================
                    ALT + Cursor up/down      select previous/next group (inside enclosing group)
                    ALT + Home/End            select first/last group    (inside enclosing group)
                    ALT + Cursor left/right   ascend/descend out-of/into groups

                  Terminal groups will unfold when trying to descend further.

SECTION         Howto switch selection between groups and species

                * when a group is selected, you can use SHIFT + Cursor down/up to
                  select the first/last species of that group.
                * when a species is selected, you can use ALT + Cursor left/right to
                  select the enclosing group.

NOTES           Expanding/collapsing is implemented in such way, that some key-combinations lead to
                determined tree-displays.

                Examples:

                  Key-Combo   similar to
                 =================================================
                  cc          group all
                  ccx         group all except marked
                  xxx         ungroup all
                  xxxc        group terminal groups

                If a subtree does not contain unfolded groups the collapse keys target the first
                parent group instead.

SECTION         Focus

                ARB supports two different focus strategies via 'ARB/Properties/Toggle focus follows mouse'.

                When using the default focus strategy, you must click once into the tree display for the
                keys described above to function properly.

                In contrast, with the alternative strategy the focus will follow the mouse pointer. In
                this case, you don't need to click in the tree display, instead the mouse pointer has to
                be positioned within the tree display area for the described keys to work.

EXAMPLES	None

WARNINGS	None

BUGS		No bugs known