drawing.py 文件源码

def text_path(context, font, size, text, debug=False):
    """Create a Pango text layout and return it as a Cairo path"""

    context.save()

    pg_layout = PangoCairo.create_layout(context)
    pg_context = pg_layout.get_context()

    font_options = cairo.FontOptions()
    font_options.set_antialias(cairo.ANTIALIAS_SUBPIXEL)
    PangoCairo.context_set_font_options(pg_context, font_options)
    font_descp = "{0} {1:d}".format(font, size)
    pg_layout.set_font_description(Pango.FontDescription(font_descp))
    pg_layout.set_text(text, -1) # force length calculation

    PangoCairo.update_layout(context, pg_layout)
    # TODO watch out for ink & logical, need check
    extents = pg_layout.get_pixel_extents()[0]
    # TODO debug necessary?
    if debug:
        context.set_source_rgb(0, 0, 0)
        PangoCairo.show_layout(context, pg_layout)
        print("text_path: ({0}, {1}, {2}, {3})".format(
            extents.x, extents.y, extents.width, extents.height))
        context.rectangle(extents.x, extents.y, extents.width, extents.height)
        context.set_line_width(1.0)
        context.set_line_join(cairo.LINE_JOIN_MITER)
        context.set_source_rgb(0, 0.8, 0)
        context.stroke()

    #PangoCairo.layout_path(context, pg_layout)
    PangoCairo.layout_line_path(context, pg_layout.get_line(0))
    path = context.copy_path()
    # clear the path
    context.new_path()
    context.restore()
    return (path, extents, xheight(pg_layout).height)