Paint a single icon.

def _paint_icon(self, iconic, painter, rect, mode, state, options):
        """Paint a single icon."""
        painter.save()
        color = options['color']
        char = options['char']

        color_options = {
            QIcon.On: {
                QIcon.Normal: (options['color_on'], options['on']),
                QIcon.Disabled: (options['color_on_disabled'],
                                 options['on_disabled']),
                QIcon.Active: (options['color_on_active'],
                               options['on_active']),
                QIcon.Selected: (options['color_on_selected'],
                                 options['on_selected']) 
            },

            QIcon.Off: {
                QIcon.Normal: (options['color_off'], options['off']),
                QIcon.Disabled: (options['color_off_disabled'],
                                 options['off_disabled']),
                QIcon.Active: (options['color_off_active'],
                               options['off_active']),
                QIcon.Selected: (options['color_off_selected'],
                                 options['off_selected']) 
            }
        }

        color, char = color_options[state][mode]

        painter.setPen(QColor(color))

        # A 16 pixel-high icon yields a font size of 14, which is pixel perfect
        # for font-awesome. 16 * 0.875 = 14
        # The reason why the glyph size is smaller than the icon size is to
        # account for font bearing.

        draw_size = 0.875 * round(rect.height() * options['scale_factor'])
        prefix = options['prefix']

        # Animation setup hook
        animation = options.get('animation')
        if animation is not None:
            animation.setup(self, painter, rect)

        painter.setFont(iconic.font(prefix, draw_size))
        if 'offset' in options:
            rect = QRect(rect)
            rect.translate(options['offset'][0] * rect.width(),
                           options['offset'][1] * rect.height())

        painter.setOpacity(options.get('opacity', 1.0))

        painter.drawText(rect, Qt.AlignCenter | Qt.AlignVCenter, char)
        painter.restore()