What?

This is a monkey patcher for fontParts and defcon objects. It's one way of adding more high level functions to these packages without having to modify their code directly. This package already adds more methods and attributes to font objects. Some examples are glyph.features for finding glyph related substitutions and some other methods to make it easier to change kerning groups. Also you can use font.scale to scale the whole font or font.subset to subset the font to a smaller glyph set.

Usage

Add your own methods to fontpart/defcon objects by simply defining a function. The first argument of the function should be a name of a defcon object, like font, glyph, etc. Before the function use the one of the decorators from this package: fontMethod or fontCachedMethod.

Exmaples

Define a new method for glyph object:

from fontGadgets.tools import fontMethod

@fontMethod
def isComposite(glyph):
    return len(glyph.contours) == 0 and len(glyph.components) > 0

Now glyph object has a new property. fontGadgets adds functions which have only one argument as a property.

>>> glyph.isComposite
True

You can also define a method that can be more efficient if the code is performance heavy. Make sure the argument types are immutable (e.g. int, str, etc.):

from fontGadgets.tools import fontCachedMethod
from drawBot import BezierPath
from defcon import Glyph
from fontTools.pens.cocoaPen import CocoaPen

@fontCachedMethod("Glyph.ContoursChanged", "Glyph.ComponentsChanged", "Component.BaseGlyphChanged")
def getStroked(glyph, strokeWidth):
    """
    Returns a stroked copy of the glyph with the defined stroked width. The `strokeWidth` is an integer.
    """
    print('One more time')
    pen = CocoaPen(glyph.font)
    glyph.draw(pen)
    bezierPath = BezierPath(pen.path)
    bezierPath.removeOverlap()
    newPath = bezierPath.expandStroke(strokeWidth).removeOverlap()
    union = newPath.union(bezierPath)
    result = Glyph()
    p = result.getPen()
    union.drawToPen(p)
    return result

g = CurrentGlyph()
g.getStroked(10)

This new method will only be executed if any of the destructive notifications from the fontCachedMethod have been posted from changes. This makes it faster to fetch the result if you want to call it over and over. In the above example if you run the code in RoboFont, you can see that in the output 'One more time' will be printed only when you run the code first time.

Warning

This is WIP, use it at your own risk!