Rc Traits

Here is some example code showing how to define some representative rc properties and construct a Matplotlib artist using traits. Matplotlib does not ship with enthought.traits, so you will need to install it separately.

from __future__ import print_function

import sys
import os
import re
import traits.api as traits
from matplotlib.artist import Artist

doprint = True
flexible_true_trait = traits.Trait(
   True,
   {'true': True, 't': True, 'yes': True, 'y': True, 'on': True, True: True,
    'false': False, 'f': False, 'no': False, 'n': False, 'off': False, False: False
    })
flexible_false_trait = traits.Trait(False, flexible_true_trait)

colors = {
   'c': '#00bfbf',
   'b': '#0000ff',
   'g': '#008000',
   'k': '#000000',
   'm': '#bf00bf',
   'r': '#ff0000',
   'w': '#ffffff',
   'y': '#bfbf00',
   'gold':        '#FFD700',
   'peachpuff':   '#FFDAB9',
   'navajowhite': '#FFDEAD',
   }


def hex2color(s):
    "Convert hex string (like html uses, eg, #efefef) to a r,g,b tuple"
    return tuple([int(n, 16)/255.0 for n in (s[1:3], s[3:5], s[5:7])])


class RGBA(traits.HasTraits):
    # r,g,b,a in the range 0-1 with default color 0,0,0,1 (black)
    r = traits.Range(0., 1., 0.)
    g = traits.Range(0., 1., 0.)
    b = traits.Range(0., 1., 0.)
    a = traits.Range(0., 1., 1.)

    def __init__(self, r=0., g=0., b=0., a=1.):
        self.r = r
        self.g = g
        self.b = b
        self.a = a

    def __repr__(self):
        return 'r,g,b,a = (%1.2f, %1.2f, %1.2f, %1.2f)' %\
               (self.r, self.g, self.b, self.a)


def tuple_to_rgba(ob, name, val):
    tup = [float(x) for x in val]
    if len(tup) == 3:
        r, g, b = tup
        return RGBA(r, g, b)
    elif len(tup) == 4:
        r, g, b, a = tup
        return RGBA(r, g, b, a)
    else:
        raise ValueError
tuple_to_rgba.info = 'a RGB or RGBA tuple of floats'


def hex_to_rgba(ob, name, val):
    rgx = re.compile('^#[0-9A-Fa-f]{6}$')

    if not isinstance(val, six.string_types):
        raise TypeError
    if rgx.match(val) is None:
        raise ValueError
    r, g, b = hex2color(val)
    return RGBA(r, g, b, 1.0)
hex_to_rgba.info = 'a hex color string'


def colorname_to_rgba(ob, name, val):
    hex = colors[val.lower()]
    r, g, b = hex2color(hex)
    return RGBA(r, g, b, 1.0)
colorname_to_rgba.info = 'a named color'


def float_to_rgba(ob, name, val):
    val = float(val)
    return RGBA(val, val, val, 1.)
float_to_rgba.info = 'a grayscale intensity'


Color = traits.Trait(RGBA(), float_to_rgba, colorname_to_rgba, RGBA,
                     hex_to_rgba, tuple_to_rgba)


def file_exists(ob, name, val):
    fh = file(val, 'r')
    return val

linestyles = ('-', '--', '-.', ':', 'steps', 'None')
TICKLEFT, TICKRIGHT, TICKUP, TICKDOWN = range(4)
linemarkers = (None, '.', ',', 'o', '^', 'v', '<', '>', 's',
               '+', 'x', 'd', 'D', '|', '_', 'h', 'H',
               'p', '1', '2', '3', '4',
               TICKLEFT,
               TICKRIGHT,
               TICKUP,
               TICKDOWN,
               'None'
               )


class LineRC(traits.HasTraits):
    linewidth = traits.Float(0.5)
    linestyle = traits.Trait(*linestyles)
    color = Color
    marker = traits.Trait(*linemarkers)
    markerfacecolor = Color
    markeredgecolor = Color
    markeredgewidth = traits.Float(0.5)
    markersize = traits.Float(6)
    antialiased = flexible_true_trait
    data_clipping = flexible_false_trait


class PatchRC(traits.HasTraits):
    linewidth = traits.Float(1.0)
    facecolor = Color
    edgecolor = Color
    antialiased = flexible_true_trait

timezones = 'UTC', 'US/Central', 'ES/Eastern'  # fixme: and many more
backends = ('GTKAgg', 'Cairo', 'GDK', 'GTK', 'Agg',
            'GTKCairo', 'PS', 'SVG', 'Template', 'TkAgg',
            'WX')


class RC(traits.HasTraits):
    backend = traits.Trait(*backends)
    interactive = flexible_false_trait
    toolbar = traits.Trait('toolbar2', 'classic', None)
    timezone = traits.Trait(*timezones)
    lines = traits.Trait(LineRC())
    patch = traits.Trait(PatchRC())

rc = RC()
rc.lines.color = 'r'
if doprint:
    print('RC')
    rc.print_traits()
    print('RC lines')
    rc.lines.print_traits()
    print('RC patches')
    rc.patch.print_traits()


class Patch(Artist, traits.HasTraits):
    linewidth = traits.Float(0.5)
    facecolor = Color
    fc = facecolor
    edgecolor = Color
    fill = flexible_true_trait

    def __init__(self,
                 edgecolor=None,
                 facecolor=None,
                 linewidth=None,
                 antialiased=None,
                 fill=1,
                 **kwargs
                 ):
        Artist.__init__(self)

        if edgecolor is None:
            edgecolor = rc.patch.edgecolor
        if facecolor is None:
            facecolor = rc.patch.facecolor
        if linewidth is None:
            linewidth = rc.patch.linewidth
        if antialiased is None:
            antialiased = rc.patch.antialiased

        self.edgecolor = edgecolor
        self.facecolor = facecolor
        self.linewidth = linewidth
        self.antialiased = antialiased
        self.fill = fill


p = Patch()
p.facecolor = '#bfbf00'
p.edgecolor = 'gold'
p.facecolor = (1, .5, .5, .25)
p.facecolor = 0.25
p.fill = 'f'
print('p.facecolor', type(p.facecolor), p.facecolor)
print('p.fill', type(p.fill), p.fill)
if p.fill_:
    print('fill')
else:
    print('no fill')
if doprint:
    print()
    print('Patch')
    p.print_traits()