A RoboFont script to expand kerning groups from base glyph to their composites.

expand-groups-to-components.py

from mojo.UI import CurrentWindow
from simpleKerning import *
"""
A RoboFont script to expand kerning groups from base glyph to their composites.
You need the simple kerning extension installed for this to work.

1. Select base glyph(s) (with contours) which are already grouped
2. Run the script
3. The groups will be expanded to the composites, if:
	- Their width is same as the base glyph
	- They're not already grouped
"""

cw = CurrentWindow().doodleWindowName
f = CurrentFont()
g = CurrentGlyph()
groups = f.groups
glyphToGroupMap = getGlyphToGroupDictionary(groups)
compMap = f.getReverseComponentMapping()
selection = []
if cw == 'FontWindow':
	f = CurrentFont()
	s = f.selectedGlyphs
	for gn in s:
		selection.append(gn)
elif cw == 'GlyphWindow':
	g = CurrentGlyph()
	if g is not None:
		selection.append(g)

selectedGlyphNames = [g.name for g in selection if g.name in glyphToGroupMap]

def getComps(glyphName, compMap):
	"""
	Get all the related components recursively.
	"""
	result = set()
	inputGlyphs = set([glyphName])
	while inputGlyphs:
		glyphName = inputGlyphs.pop()
		comps = compMap.get(glyphName, set()) - result - inputGlyphs
		if comps:
			result.update(comps)
			inputGlyphs.update(comps)
	return result

newGroups = dict(groups)
for glyphName in selectedGlyphNames:
	baseGlyphGroups = glyphToGroupMap.get(glyphName, [])
	baseGlyphWidth = f[glyphName].width
	for compGlyphName in getComps(glyphName, compMap):
		compGroups = glyphToGroupMap.get(compGlyphName, [])
		compGlyph = f[compGlyphName]
		if not compGroups:
			if compGlyph.width == baseGlyphWidth:
				for gr in baseGlyphGroups:
					members = list(newGroups[gr])
					members.append(compGlyphName)
					newGroups[gr] = members
				compGlyph.prepareUndo("Mark glyph with changed groups")
				compGlyph.markColor = (0.3364, 0.9951, 0.5913, 1)
			else:
				compGlyph.prepareUndo("Mark glyph with unchanged groups")
				compGlyph.markColor = (1, 0.8907, 0.1478, 1)
			compGlyph.performUndo()


f.groups.clear()
f.groups.update(newGroups)