Robofont: startup script to find out which kerning group the selected glyph belongs to

which_kerning_group.py

'''
Robofont startup script to find out which kerning group
the selected glyph belongs to.
'''

import AppKit
from mojo.UI import CurrentFontWindow
from mojo.events import addObserver
from mojo.roboFont import CurrentFont


class KernGroupContextualMenu(object):
    '''
    This follows
    https://robofont.com/documentation/building-tools/toolspace/observers/custom-font-overview-contextual-menu/
    '''

    def __init__(self):
        addObserver(
            self,
            "fontOverviewAdditionContextualMenuItems",
            "fontOverviewAdditionContextualMenuItems"
        )

    def fontOverviewAdditionContextualMenuItems(self, notification):
        font = CurrentFont()
        if font.selectedGlyphNames:
            myMenuItems = [
                ("L kerning group",
                    self.add_attribute(self.kerning_glyph_group, font, 'R')),
                ("R kerning group",
                    self.add_attribute(self.kerning_glyph_group, font, 'L')),
            ]
            notification["additionContextualMenuItems"].extend(myMenuItems)

    def add_attribute(self, func, font, attribute):
        '''
        Allows adding a font and an attribute to a callback,
        such as the side of the kerning group. This avoids writing a function
        for each side.
        '''
        def wrapper(sender):
            func(sender, font, attribute)
        return wrapper

    def make_query(self, glyph_list):
        '''
        Filter the font overview, just like when searching it
        '''
        query_text = 'Name in {"%s"}' % '", "'.join(glyph_list)
        query = AppKit.NSPredicate.predicateWithFormat_(query_text)
        CurrentFontWindow().getGlyphCollection().setQuery(query)

    def kerning_glyph_group(self, sender, font, side):
        '''
        make the selection, heavily based on groups.findGlyph
        '''
        gname = font.selectedGlyphNames[0]
        if len(font.selectedGlyphNames) > 1:
            print('using first selected glyph:', gname)

        containing_groups = font.groups.findGlyph(gname)
        if containing_groups:
            if side == 'L':
                kern_group = next((
                    gr_name for gr_name in containing_groups if
                    gr_name.startswith('public.kern1.')), None)
                if kern_group:
                    self.make_query(font.groups.get(kern_group))
                else:
                    self.make_query([gname])
            elif side == 'R':
                kern_group = next((
                    gr_name for gr_name in containing_groups if
                    gr_name.startswith('public.kern2.')), None)
                if kern_group:
                    self.make_query(font.groups.get(kern_group))
                else:
                    self.make_query([gname])


KernGroupContextualMenu()