examples/cairo-demo.py

   1 #!/usr/bin/env python
   2 """
   3 Based on cairo-demo/X11/cairo-demo.c
   4 """
   5
   6 import cairo
   7 from gi.repository import Gtk
   8
   9 SIZE = 30
  10
  11
  12 def triangle(ctx):
  13     ctx.move_to(SIZE, 0)
  14     ctx.rel_line_to(SIZE, 2 * SIZE)
  15     ctx.rel_line_to(-2 * SIZE, 0)
  16     ctx.close_path()
  17
  18
  19 def square(ctx):
  20     ctx.move_to(0, 0)
  21     ctx.rel_line_to(2 * SIZE, 0)
  22     ctx.rel_line_to(0, 2 * SIZE)
  23     ctx.rel_line_to(-2 * SIZE, 0)
  24     ctx.close_path()
  25
  26
  27 def bowtie(ctx):
  28     ctx.move_to(0, 0)
  29     ctx.rel_line_to(2 * SIZE, 2 * SIZE)
  30     ctx.rel_line_to(-2 * SIZE, 0)
  31     ctx.rel_line_to(2 * SIZE, -2 * SIZE)
  32     ctx.close_path()
  33
  34
  35 def inf(ctx):
  36     ctx.move_to(0, SIZE)
  37     ctx.rel_curve_to(0, SIZE, SIZE, SIZE, 2 * SIZE, 0)
  38     ctx.rel_curve_to(SIZE, -SIZE, 2 * SIZE, -SIZE, 2 * SIZE, 0)
  39     ctx.rel_curve_to(0, SIZE, -SIZE, SIZE, - 2 * SIZE, 0)
  40     ctx.rel_curve_to(-SIZE, -SIZE, - 2 * SIZE, -SIZE, - 2 * SIZE, 0)
  41     ctx.close_path()
  42
  43
  44 def draw_shapes(ctx, x, y, fill):
  45     ctx.save()
  46
  47     ctx.new_path()
  48     ctx.translate(x + SIZE, y + SIZE)
  49     bowtie(ctx)
  50     if fill:
  51         ctx.fill()
  52     else:
  53         ctx.stroke()
  54
  55     ctx.new_path()
  56     ctx.translate(3 * SIZE, 0)
  57     square(ctx)
  58     if fill:
  59         ctx.fill()
  60     else:
  61         ctx.stroke()
  62
  63     ctx.new_path()
  64     ctx.translate(3 * SIZE, 0)
  65     triangle(ctx)
  66     if fill:
  67         ctx.fill()
  68     else:
  69         ctx.stroke()
  70
  71     ctx.new_path()
  72     ctx.translate(3 * SIZE, 0)
  73     inf(ctx)
  74     if fill:
  75         ctx.fill()
  76     else:
  77         ctx.stroke()
  78
  79     ctx.restore()
  80
  81
  82 def fill_shapes(ctx, x, y):
  83     draw_shapes(ctx, x, y, True)
  84
  85
  86 def stroke_shapes(ctx, x, y):
  87     draw_shapes(ctx, x, y, False)
  88
  89
  90 def draw(da, ctx):
  91     ctx.set_source_rgb(0, 0, 0)
  92
  93     ctx.set_line_width(SIZE / 4)
  94     ctx.set_tolerance(0.1)
  95
  96     ctx.set_line_join(cairo.LINE_JOIN_ROUND)
  97     ctx.set_dash([SIZE / 4.0, SIZE / 4.0], 0)
  98     stroke_shapes(ctx, 0, 0)
  99
 100     ctx.set_dash([], 0)
 101     stroke_shapes(ctx, 0, 3 * SIZE)
 102
 103     ctx.set_line_join(cairo.LINE_JOIN_BEVEL)
 104     stroke_shapes(ctx, 0, 6 * SIZE)
 105
 106     ctx.set_line_join(cairo.LINE_JOIN_MITER)
 107     stroke_shapes(ctx, 0, 9 * SIZE)
 108
 109     fill_shapes(ctx, 0, 12 * SIZE)
 110
 111     ctx.set_line_join(cairo.LINE_JOIN_BEVEL)
 112     fill_shapes(ctx, 0, 15 * SIZE)
 113     ctx.set_source_rgb(1, 0, 0)
 114     stroke_shapes(ctx, 0, 15 * SIZE)
 115
 116
 117 def main():
 118     win = Gtk.Window()
 119     win.connect('destroy', lambda w: Gtk.main_quit())
 120     win.set_default_size(450, 550)
 121
 122     drawingarea = Gtk.DrawingArea()
 123     win.add(drawingarea)
 124     drawingarea.connect('draw', draw)
 125
 126     win.show_all()
 127     Gtk.main()
 128
 129 if __name__ == '__main__':
 130     main()