8.5 Graph Functions

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add-links

add-links/text-colors

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8.5Graph Functions🔗 i

procedure
( add-links parentchild)→void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )
(add-links parentchild)→void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )

(add-links parent
child
dark-pen
light-pen
dark-brush
light-brush
[ label]) → void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )
dark-pen:(or/c (is-a?/c pen% )false/c )
light-pen:(or/c (is-a?/c pen% )false/c )
dark-brush:(or/c (is-a?/c brush% )false/c )
light-brush:(or/c (is-a?/c brush% )false/c )
label:(or/c string? false/c )=#f

(add-links parent
child
dark-pen
light-pen
dark-brush
light-brush
dx
dy
[ label]) → void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )
dark-pen:(or/c (is-a?/c pen% )false/c )
light-pen:(or/c (is-a?/c pen% )false/c )
dark-brush:(or/c (is-a?/c brush% )false/c )
light-brush:(or/c (is-a?/c brush% )false/c )
dx:real?
dy:real?
label:(or/c string? false/c )=#f

Connects a parent snip to a child snip within a pasteboard.

The default dark-pen/dark-brush and light-pen/light-brush are blue and purple, respectively. The dark-pen and dark-brush are used when the mouse cursor is over the snip (or a child or parent), and the light-pen and light-brush are used when the mouse cursor is not over the snip. The brush is used to draw inside the arrow head and the pen is used to draw the border of the arrowhead and the line connecting the two snips.

if label is provided and not #f, it is used as a label on the edge.

When dx and dy are provided, the are offsets for the head and the tail of the arrow. Otherwise, 0 offsets are used.

procedure
( add-links/text-colors parent
child
dark-pen
light-pen
dark-brush
light-brush
dark-text
light-text
dx
dy
label) → void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )
dark-pen:(or/c (is-a?/c pen% )false/c )
light-pen:(or/c (is-a?/c pen% )false/c )
dark-brush:(or/c (is-a?/c brush% )false/c )
light-brush:(or/c (is-a?/c brush% )false/c )
dark-text:(or/c (is-a?/c color% )false/c )
light-text:(or/c (is-a?/c color% )false/c )
dx:real?
dy:real?
label:(or/c string? false/c )

Like add-links , but with extra dark-text and light-text arguments to set the colors of the label.

procedure
( remove-links parentchild)→void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )

Disconnects a parent snip from a child snip within a pasteboard.

procedure
( set-link-label parentchildlabel)→void?
parent:(is-a?/c graph-snip<%> )
child:(is-a?/c graph-snip<%> )
label:(or/c string? false/c )

Changes the label on the edge going from child to parent to be label. If there is no existing edge between the two nodes, then nothing happens.

procedure
( dot-positioning pb
[ option
overlap-or-horizontal?]) → void?
pb:(is-a?/c pasteboard% )

option : (or/c dot-label neato-label neato-hier-label neato-ipsep-label )
= dot-label
overlap-or-horizontal?:boolean? =#f

This finds the sizes of the graph-snip<%> s in pb and their children and then passes that information to dot or neato (depending on option), extracting a layout and then applying it to the snips in pb.

If option is dot-label , then overlap-or-horizontal? controls whether dot uses a horizontal or vertical alignment. If option is any of the other options, it controls whether or not neato is allowed to overlap nodes.

If find-dot returns #f, this function does nothing.

procedure
( find-dot [neato?])→(or/c path? #f)
neato?:boolean? =#f

Tries to find the dot or neato binary and, if it succeeds, returns the path to it. If it cannot find it, returns #f.

value
dot-label :string?

A string describing the regular dot option for graph layout that dot-positioning uses.

value
neato-label :string?

A string describing the neato option for graph layout that dot-positioning uses.

value
neato-hier-label :string?

A string describing the neato hierarchical option for graph layout that dot-positioning uses.

value
neato-ipsep-label :string?

A string describing the neato ipsep option for graph layout that dot-positioning uses.

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