5. Understanding Abjad overrides

5.1. Grob-override component plug-ins

All Abjad containers have a grob-override plug-in:

abjad> staff = Staff("c'4 d'4 e'4 f'4 g'4 a'4 g'2")

abjad> staff.override.staff_symbol.color = 'blue'

abjad> staff.override
LilyPondGrobOverrideComponentPlugIn(staff_symbol__color = 'blue')

All Abjad leaves have a grob-override plug-in, too:

abjad> leaf = staff[-1]

abjad> leaf.override.note_head.color = 'red'
abjad> leaf.override.stem.color = 'red'

abjad> leaf.override
LilyPondGrobOverrideComponentPlugIn(note_head__color = 'red', stem__color = 'red')

And so do Abjad spanners:

abjad> slur = spannertools.SlurSpanner(staff[:])

abjad> slur.override.slur.color = 'red'

abjad> slur.override
LilyPondGrobOverrideComponentPlugIn(slur__color = 'red')

5.2. Grob proxies

Grob-override plug-ins contain grob proxies:

abjad> leaf.override.note_head
LilyPondGrobProxy(color = 'red')

abjad> leaf.override.stem
LilyPondGrobProxy(color = 'red')

5.3. Dot-chained override syntax

The’s dot-chained grob override syntax shown here results from the special way that the Abjad grob-override plug-in and grob proxy set and get their attributes.