PyGobject（九十二）Pango系列——文本旋转

例子

代码：

#!/usr/bin/env python3# Created by xiaosanyu at 16/7/6# section 142TITLE = "Rotated Text"DESCRIPTION = """This demo shows how to use PangoCairo to draw rotated and transformedtext.  The right pane shows a rotated GtkLabel widget.In both cases, a custom PangoCairo shape renderer is installed to drawa red heard using cairo drawing operations instead of the Unicode heartcharacter."""import gigi.require_version("Gtk", "3.0")gi.require_version('PangoCairo', '1.0')from gi.repository import Gtk, Gdk, Pango, PangoCairo, GLibimport cairoimport sys# Python 2 and 3 handle UTF8 differentlyif sys.version_info < (3, 0):    BYTES_TEXT = "I \xe2\x99\xa5 GTK+"    UTF8_TEXT = unicode(BYTES_TEXT, 'UTF-8')    BYTES_HEART = "\xe2\x99\xa5"    HEART = unicode(BYTES_HEART, 'UTF-8')else:    UTF8_TEXT = "I ♥ GTK+"    BYTES_TEXT = bytes(UTF8_TEXT, 'utf-8')    HEART = "♥"    BYTES_HEART = bytes(HEART, 'utf-8')RADIUS = 150N_WORDS = 5class PyApp(Gtk.Window):    def __init__(self):        super(PyApp, self).__init__()        self.connect("destroy", Gtk.main_quit)        self.set_title("Rotated Text")        self.set_size_request(600, 300)        box = Gtk.Box()        box.set_homogeneous(True)        self.add(box)        # Add a drawing area        drawing_area = Gtk.DrawingArea()        box.add(drawing_area)        drawing_area.get_style_context().add_class(Gtk.STYLE_CLASS_VIEW)        drawing_area.connect("draw", self.rotated_text_draw)        # And a label        label = Gtk.Label()        label.set_markup(UTF8_TEXT.replace(HEART, "<span foreground=\"#FF0000\">%s</span>" % HEART))        box.add(label)        label.set_angle(45)        # Set up fancy stuff on the label        layout = label.get_layout()        PangoCairo.context_set_shape_renderer(layout.get_context(), self.fancy_shape_renderer, None)        self.show_all()    # this method not run??    def fancy_shape_renderer(self, cr, attr, do_path, data):        x, y = cr.get_current_point()        cr.translate(x, y)        cr.scale(attr.ink_rect.width,  # PANGO_SCALE,                 attr.ink_rect.height  # PANGO_SCALE                 )        if attr.data == 0x2665:  # U+2665 BLACK HEART SUIT            cr.move_to(0.5, 0)            cr.line_to(0.9, -0.4)            cr.curve_to(1.1, -0.8, 0.5, -.09, 0.5, -0.5)            cr.curve_to(0.5, -0.9, -0.1, -.08, 0.1, -0.4)            cr.close_path()        if not do_path:            cr.set_source_rgb(1., 0., 0.)            cr.fill()    def rotated_text_draw(self, widget, cr):        # Create a cairo context and set up a transformation matrix so that the user        # space coordinates for the centered square where we draw are [-RADIUS, RADIUS],        # [-RADIUS, RADIUS].        # We first center, then change the scale.         width = widget.get_allocated_width()        height = widget.get_allocated_height()        device_radius = min(width, height) / 2        cr.translate(device_radius + (width - 2 * device_radius) / 2,                     device_radius + (height - 2 * device_radius) / 2)        cr.scale(device_radius / RADIUS, device_radius / RADIUS)        # Create and a subtle gradient source and use it.         pattern = cairo.LinearGradient(-RADIUS, -RADIUS, RADIUS, RADIUS)        pattern.add_color_stop_rgb(0, 0.5, 0, 0)        pattern.add_color_stop_rgb(1, 0, 0, 0.5)        cr.set_source(pattern)        # Create a PangoContext and set up our shape renderer         context = widget.create_pango_context()        PangoCairo.context_set_shape_renderer(context, self.fancy_shape_renderer)        # Create a PangoLayout, set the text, font, and attributes         layout = Pango.Layout.new(context)        layout.set_text(UTF8_TEXT, -1)        desc = Pango.FontDescription.from_string("Serif 18")        layout.set_font_description(desc)        # Draw the layout N_WORDS times in a circle         for i in range(N_WORDS):            # Inform Pango to re-layout the text with the new transformation matrix             layout.set_markup(layout.get_text().replace(HEART, "<span foreground=\"#FF0000\">%s</span>" % HEART), -1)            PangoCairo.update_layout(cr, layout)            width, height = layout.get_pixel_size()            cr.move_to(- width / 2, - RADIUS * .9)            PangoCairo.show_layout(cr, layout)            # Rotate for the next turn             cr.rotate(GLib.PI * 2 / N_WORDS)        return Falsedef main():    PyApp()    Gtk.main()if __name__ == '__main__':    main()

代码下载地址：http://download.csdn.net/detail/a87b01c14/9594728