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from __future__ import with_statement
import numpy as np
from enable.api import Component, ComponentEditor
from traits.api import HasTraits, Instance
from traitsui.api import Item, View
class MyCanvas(Component):
def draw(self, gc, **kwargs):
w,h = gc.width(), gc.height()
# colors are 5 doubles: offset, red, green, blue, alpha
starting_color = np.array([0.0, 1.0, 1.0, 1.0, 1.0])
ending_color = np.array([1.0, 0.0, 0.0, 0.0, 1.0])
gc.clear()
# radial reflected background
with gc:
gc.rect(0, 0, w, h)
start = np.array([0.0, 1.0, 0.0, 0.0, 1.0])
end = np.array([1.0, 1.0, 1.0, 1.0, 1.0])
gc.radial_gradient(w/4, h/4, 200, w/4+100, h/4+100,
np.array([start, end]), 'reflect')
gc.fill_path()
# diagonal
with gc:
gc.rect(50,25,150,100)
gc.linear_gradient(0,0,1,1,
np.array([starting_color, ending_color]),
"pad", 'objectBoundingBox')
gc.fill_path()
# vertical
with gc:
gc.rect(50,150,150,100)
gc.linear_gradient(50,150,50,250,
np.array([starting_color, ending_color]),
"pad", 'userSpaceOnUse')
gc.fill_path()
# horizontal
with gc:
gc.rect(50,275,150,100)
gc.linear_gradient(0,0,1,0,
np.array([starting_color, ending_color]),
"pad", 'objectBoundingBox')
gc.fill_path()
# radial
with gc:
gc.arc(325, 75, 50, 0.0, 2*np.pi)
gc.radial_gradient(325, 75, 50, 325, 75,
np.array([starting_color, ending_color]),
"pad", 'userSpaceOnUse')
gc.fill_path()
# radial with focal point in upper left
with gc:
gc.arc(325, 200, 50, 0.0, 2*np.pi)
gc.radial_gradient(0.5, 0.5, 0.5, 0.25, 0.75,
np.array([starting_color, ending_color]),
"pad", 'objectBoundingBox')
gc.fill_path()
# radial with focal point in bottom right
with gc:
gc.arc(325, 325, 50, 0.0, 2*np.pi)
gc.radial_gradient(325, 325, 50, 350, 300,
np.array([starting_color, ending_color]),
"pad", 'userSpaceOnUse')
gc.fill_path()
return
class Demo(HasTraits):
canvas = Instance(Component)
traits_view = View(Item('canvas', editor=ComponentEditor(bgcolor="lightgray"),
show_label=False, width=500, height=500),
resizable=True, title="Gradient Example")
def _canvas_default(self):
return MyCanvas()
if __name__ == "__main__":
Demo().configure_traits()
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