PyGobject（九十一）Pango系列——文本漸變

例子

代碼：

#!/usr/bin/env python3
# Created by xiaosanyu at 16/7/6
# section 141
TITLE = "Gradient"
DESCRIPTION = """
This demo shows how to use PangoCairo to draw text with more than
just a single color.
"""

import gi

gi.require_version("Gtk", "3.0")
gi.require_version('PangoCairo', '1.0')
from gi.repository import Gtk, Gdk, Pango, PangoCairo
import cairo


class PyApp(Gtk.Window):
    def __init__(self):
        super(PyApp, self).__init__()
        self.set_size_request(350, 250)
        self.set_border_width(8)
        self.connect("destroy", Gtk.main_quit)
        self.set_title("Text Mask")
        da = Gtk.DrawingArea()

        self.add(da)
        da.connect("draw", self.draw_text)
        self.show_all()

    def draw_text(self, da, cr):
        cr.save()

        layout = da.create_pango_layout("Pango power!\nPango power!\nPango power!")
        desc = Pango.FontDescription.from_string("sans bold 34")
        layout.set_font_description(desc)
        cr.move_to(30, 20)
        PangoCairo.layout_path(cr, layout)

        pattern = cairo.LinearGradient(0.0, 0.0,
                                       da.get_allocated_width(),
                                       da.get_allocated_height())
        pattern.add_color_stop_rgb(0.0, 1.0, 0.0, 0.0)
        pattern.add_color_stop_rgb(0.2, 1.0, 0.0, 0.0)
        pattern.add_color_stop_rgb(0.3, 1.0, 1.0, 0.0)
        pattern.add_color_stop_rgb(0.4, 0.0, 1.0, 0.0)
        pattern.add_color_stop_rgb(0.6, 0.0, 1.0, 1.0)
        pattern.add_color_stop_rgb(0.7, 0.0, 0.0, 1.0)
        pattern.add_color_stop_rgb(0.8, 1.0, 0.0, 1.0)
        pattern.add_color_stop_rgb(1.0, 1.0, 0.0, 1.0)

        cr.set_source(pattern)
        cr.fill_preserve()

        cr.set_source_rgb(0.0, 0.0, 0.0)
        cr.set_line_width(0.5)
        cr.stroke()

        cr.restore()

        return True


def main():
    PyApp()
    Gtk.main()


if __name__ == '__main__':
    main()

代碼下載地址：http://download.csdn.net/detail/a87b01c14/9594728