Spanner

class maelzel.core.symbols.Spanner(kind='start', uuid='', linetype='solid', placement='', color='', anchor=None)

Bases: Symbol

A Spanner is a line/curve between two anchors (notes/chords/rests)

Spanners always come in pairs start/end.

Example

>>> from maelzel.core import *
>>> from maelzel.core import symbols
>>> chain = Chain(["C4:0.5", "D4:1", "E4:0.5"])
>>> slur = symbols.Slur()
>>> chain[0].addSymbol(slur)
>>> chain[2].addSymbol(slur.makeEndSpanner())

Or you can use the .bind method which is a shortcut:

>>> symbols.Slur().bind(chain[0], chain[2])

Attributes Summary

anchor
appliesToRests
exclusive	Only one of a given class
partner

Methods Summary

applyToNotation(n, parent)	Apply this symbol to the given notation, inplace
applyToPair(start, end)
applyToTiedGroup(notations, parent)	Apply this symbol to a group of tied notations, inplace.
bind(startobj, endobj)	Bind a Spanner to two notes/chords
makePartnerSpanner([anchor])	Creates the partner spanner for an already existing spanner
scoringSpanner()
setAnchor(obj)	Set the anchor for this spanner.
setPartner(partner)	Set the given spanner as the partner spanner of self (and self as partner of other)

Attributes Documentation

anchor

appliesToRests = True

exclusive = False

Only one of a given class

partner

Methods Documentation

applyToNotation(n, parent)

Apply this symbol to the given notation, inplace

Return type:

None

applyToPair(start, end)

Return type:

None

applyToTiedGroup(notations, parent)

Apply this symbol to a group of tied notations, inplace.

Return type:

None

bind(startobj, endobj)

Bind a Spanner to two notes/chords

Parameters:

• startobj (MEvent) – start anchor object

• endobj (MEvent) – end anchor object

Return type:

None

Example

>>> from maelzel.core import *
>>> chain = Chain(["4E:1", "4F:1", "4G:1"])
# slur the first two notes of the chain, customizing the line-type
>>> Slur(linetype='dashed').bind(chain[0], chain[1])
# The same can be achieved as:
>>> chain[0].addSpanner(Slur(linetype='dashed'), chain[1])

makePartnerSpanner(anchor=None)

Creates the partner spanner for an already existing spanner

start and end spanner share the same uuid and have a ref to each other, allowing each of the spanners to access their twin. As each spanner also holds a ref to their anchor, the anchored events can be made aware of each other.

Parameters:

anchor (Optional[MEvent]) – the event to which the end spanner is anchored to.

Return type:

Self

Returns:

the created spanner. This is a copy of the start spanner in every way with the only difference that kind='end'

scoringSpanner()

Return type:

Spanner

setAnchor(obj)

Set the anchor for this spanner.

This is called by :meth:MusicObj.setSymbol or by :meth:Spanner.bind to set the anchor of this spanner. A User should not normally call this method

Parameters:

obj (MEvent) – the object this spanner is anchored to, either as start or end

Return type:

None

setPartner(partner)

Set the given spanner as the partner spanner of self (and self as partner of other)

Parameters:

partner (Spanner) – the partner spanner

Return type:

None