[pygi] Add examples/cairo-demo.py

[Tomeu Vizoso <tomeuv src gnome org>]

commit 2778f8a1bf6379a46beec6546c8efcb0fec2d7ad
Author: Tomeu Vizoso <tomeu sugarlabs org>
Date:   Sat Apr 17 11:40:14 2010 -0400

    Add examples/cairo-demo.py

 examples/cairo-demo.py |  121 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 121 insertions(+), 0 deletions(-)
---
diff --git a/examples/cairo-demo.py b/examples/cairo-demo.py
new file mode 100755
index 0000000..8420c2f
--- /dev/null
+++ b/examples/cairo-demo.py
@@ -0,0 +1,121 @@
+#!/usr/bin/env python
+"""Based on cairo-demo/X11/cairo-demo.c
+"""
+import cairo
+from gi.repository import Gdk, Gtk
+
+SIZE = 30
+
+def triangle(ctx):
+    ctx.move_to(SIZE, 0)
+    ctx.rel_line_to(SIZE, 2*SIZE)
+    ctx.rel_line_to(-2*SIZE, 0)
+    ctx.close_path()
+
+def square(ctx):
+    ctx.move_to(0, 0)
+    ctx.rel_line_to(2*SIZE, 0)
+    ctx.rel_line_to(0, 2*SIZE)
+    ctx.rel_line_to(-2*SIZE, 0)
+    ctx.close_path()
+
+def bowtie(ctx):
+    ctx.move_to(0, 0)
+    ctx.rel_line_to(2*SIZE, 2*SIZE)
+    ctx.rel_line_to(-2*SIZE, 0)
+    ctx.rel_line_to(2*SIZE, -2*SIZE)
+    ctx.close_path()
+
+def inf(ctx):
+    ctx.move_to(0, SIZE)
+    ctx.rel_curve_to(0,SIZE, SIZE,SIZE, 2*SIZE,0)
+    ctx.rel_curve_to(SIZE,-SIZE, 2*SIZE,-SIZE, 2*SIZE,0)
+    ctx.rel_curve_to(0,SIZE, -SIZE,SIZE, -2*SIZE,0)
+    ctx.rel_curve_to(-SIZE,-SIZE, -2*SIZE,-SIZE, -2*SIZE,0)
+    ctx.close_path()
+
+def draw_shapes(ctx, x, y, fill):
+    ctx.save()
+
+    ctx.new_path()
+    ctx.translate(x+SIZE, y+SIZE)
+    bowtie(ctx)
+    if fill:
+        ctx.fill()
+    else:
+        ctx.stroke()
+
+    ctx.new_path()
+    ctx.translate(3*SIZE, 0)
+    square(ctx)
+    if fill:
+        ctx.fill()
+    else:
+        ctx.stroke()
+
+    ctx.new_path()
+    ctx.translate(3*SIZE, 0)
+    triangle(ctx)
+    if fill:
+        ctx.fill()
+    else:
+        ctx.stroke()
+
+    ctx.new_path()
+    ctx.translate(3*SIZE, 0)
+    inf(ctx)
+    if fill:
+        ctx.fill()
+    else:
+        ctx.stroke()
+
+    ctx.restore()
+
+def fill_shapes(ctx, x, y):
+    draw_shapes(ctx, x, y, True)
+
+def stroke_shapes(ctx, x, y):
+    draw_shapes(ctx, x, y, False)
+
+def expose (da, event):
+    ctx = Gdk.cairo_create(da.window)
+
+    ctx.set_source_rgb(0, 0, 0)
+
+    ctx.set_line_width(SIZE / 4)
+    ctx.set_tolerance(0.1)
+
+    ctx.set_line_join(cairo.LINE_JOIN_ROUND)
+    ctx.set_dash([SIZE/4.0, SIZE/4.0], 0)
+    stroke_shapes(ctx, 0, 0)
+
+    ctx.set_dash([], 0)
+    stroke_shapes(ctx, 0, 3*SIZE)
+
+    ctx.set_line_join(cairo.LINE_JOIN_BEVEL)
+    stroke_shapes(ctx, 0, 6*SIZE)
+
+    ctx.set_line_join(cairo.LINE_JOIN_MITER)
+    stroke_shapes(ctx, 0, 9*SIZE)
+
+    fill_shapes(ctx, 0, 12*SIZE)
+
+    ctx.set_line_join(cairo.LINE_JOIN_BEVEL)
+    fill_shapes(ctx, 0, 15*SIZE)
+    ctx.set_source_rgb(1,0,0)
+    stroke_shapes(ctx, 0, 15*SIZE)
+
+def main():
+    win = Gtk.Window()
+    win.connect('destroy', Gtk.main_quit)
+    win.set_default_size(450, 550)
+
+    drawingarea = Gtk.DrawingArea()
+    win.add(drawingarea)
+    drawingarea.connect('expose_event', expose)
+
+    win.show_all()
+    Gtk.main()
+
+if __name__ == '__main__':
+    main()