#! /usr/bin/env python
import cairo

class Diagram(object):
    def __init__(self, filename, width, height):
        self.surface = cairo.SVGSurface(filename + '.svg', width, height)
        cr = self.cr = cairo.Context(self.surface)
        cr.scale(width, height)
        # Note: bug doesn't show up if no save/restore.
        cr.save()
        self.draw_dest(self.cr)
        cr.restore()
        cr.show_page()
        self.surface.finish()

    def draw_dest(self, cr):
        cr.set_source_rgb(1, 1, 1)
        cr.rectangle(0, 0, 1, 1)
        cr.fill()

class BugText(Diagram):
    def draw_dest(self, cr):
        Diagram.draw_dest(self, cr)
        cr.set_source_rgb(0.0, 0.0, 0.0)
        cr.select_font_face("Arial",
                cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
        cr.set_font_size(1.2)
        # Uncomment to fix bug!
        #self.ff = cr.get_font_face()
        x_bearing, y_bearing, width, height = cr.text_extents("a")[:4]
        cr.move_to(0.5 - width / 2 - x_bearing, 0.5 - height / 2 - y_bearing)
        cr.show_text("a")

if __name__ == '__main__':
    BugText('showtext', 300, 200)