The Tree Display Class


The tree display class is for displaying nested slotfillers as treelike data structures. The symbolic indices are shown; the values at the leaves are omitted, since the primary intended use is to display layouts in tree form. The number of children per node is limited to 128.

If you want to have values at the leaves shown, you must doctor the nested slotfiller, if possible, to turn the values into symbolic indices in slotfillers with arbitrary artificial values. For example, if you want the numeric values shown for the slotfiller

t(`a;<(`b`c`d;(7;(`e`f;(8;9));10)))

you could construct something like

t1(`a;<
    (`b`c`d;
     ((`7;<0);(`e`f;((`8;<0);(`9;<0)));(`10;<0))))

and show t1 as a tree representing t.

Visual Representation
A complicated layout can be represented as a nested slotfiller, and then displayed as a tree for a convenient view of its structure. In fact, the appropriate nested slotfiller representation is produced by the familytree attribute. For example, if ly is a layout, then its organization may look as follows:
     tr0`familytree of `ly
     show `tr is `tree
A Layout Represented as a Tree:

In this example, the ".table1" button has been selected by clicking on it.
 

User Interactions

If a callback function for the object is defined, it is called when: In such a call, the path variable (see "Callback Functions") is the symbol vector path to the node.
Attributes

See the "Display Attributes" chapter for details concerning all the attributes that apply to objects in the tree display class, as well as lists of colors and fonts. The keys in the Table of All Display Attributes that pertain to this class are R, ALL, CNFT, NFT, and TOP.

The attributes that are meaningful for the tree display class (other than the print... attributes) are:

active
ancestors
arrowdown
arrowkeys
arrowleft
arrowlist
arrowright
arrowup
at
atsector
b
bg
bound
class
clear
deiconized
doc
downto
dynamic
eval
evaluate
exit
extent
f1-f12
fg
fkeys
focus
followers
followertree
font
foot
freeze
fullscreen
h
H
has
head
hide
hl
hlthickness
horizontalspace
icon
iconic
iconized
icontitle
incurrentworkspace
is
l
label
labelfg
labelfont
leader
leftto
linecolor
literal
lower
mapped
naturalsize
nodebg
nodefg
notify
orientation
outofcurrentworkspace
parent
pin
preset
primary
r
raise
realize
refer
refresh
request
resize
resizeable
rightto
script
select
selected
selectednodebg
selectednodefg
sensitive
set
settings
shadowthickness
shell
shelltitle
show
state
stateself
syncshow
t
tabfrom
tablist
tabto
title
titlefg
titlefont
titlejustify
upto
vcol
vcols
verify
verticalspace
vrow
vrows
w
W
ws
x
X
xs
y
Y
ys
yx
YX
yxs
(Point the mouse cursor to an attribute to display a short description at the bottom of the screen)


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