#------------------------------------------------------------------------------
#
#  Copyright (c) 2005, Enthought, Inc.
#  All rights reserved.
#
#  This software is provided without warranty under the terms of the BSD
#  license included in enthought/LICENSE.txt and may be redistributed only
#  under the conditions described in the aforementioned license.  The license
#  is also available online at http://www.enthought.com/licenses/BSD.txt
#
#  Thanks for using Enthought open source!
#
#  Author: David C. Morrill
#  Date:   12/22/2004
#
#------------------------------------------------------------------------------

""" Trait definition for an RGB-based color, which is a tuple of the form
    (*red*, *green*, *blue*), where *red*, *green* and *blue* are floats in the
    range from 0.0 to 1.0.
"""

#-------------------------------------------------------------------------------
#  Imports:
#-------------------------------------------------------------------------------
import wx

from traits.api \
    import Trait, TraitError

from traits.trait_base \
    import SequenceTypes

### Note: Import from the source rather than the api to avoid circular imports
# since some classes declared in the traits UI api define Color traits which
# will end up importing this file.
from traitsui.editors.rgb_color_editor \
    import RGBColorEditor

from traitsui.wx.color_trait \
    import standard_colors, w3c_color_database

#-------------------------------------------------------------------------------
#  Convert a number into an RGB tuple:
#-------------------------------------------------------------------------------

def range_check ( value ):
    """ Checks that *value* can be converted to a value in the range 0.0 to 1.0.

        If so, it returns the floating point value; otherwise, it raises a
        TraitError.
    """
    value = float( value )
    if 0.0 <= value <= 1.0:
        return value
    raise TraitError

def convert_to_color ( object, name, value ):
    """ Converts a tuple or an integer to an RGB color value, or raises a
        TraitError if that is not possible.
    """
    if (type( value ) in SequenceTypes) and (len( value ) == 3):
        return ( range_check( value[0] ),
                 range_check( value[1] ),
                 range_check( value[2] ) )
    if type( value ) is int:
        num = int( value )
        return ( (num / 0x10000)        / 255.0
                 ((num / 0x100) & 0xFF) / 255.0,
                 (num & 0xFF)           / 255.0 )
    if isinstance(value, wx.Colour):
        return (value.Red()/255.0,
                value.Green()/255.0,
                value.Blue()/255.0)
    raise TraitError

convert_to_color.info = ('a tuple of the form (r,g,b), where r, g, and b '
    'are floats in the range from 0.0 to 1.0, or an integer which in hex is of '
    'the form 0xRRGGBB, where RR is red, GG is green, and BB is blue')

#-------------------------------------------------------------------------------
#  Standard colors:
#-------------------------------------------------------------------------------

# RGB versions of standard colors:
rgb_standard_colors = {}
for name, color in standard_colors.items():
    rgb_standard_colors[ name ] = ( color.Red() / 255.0,
                                    color.Green() / 255.0,
                                    color.Blue()  / 255.0 )
# Add the W3C colors
for color_name in w3c_color_database._color_names:
    color = w3c_color_database.Find(color_name)
    rgb_standard_colors[color_name] = (color.Red() / 255.0,
                                       color.Green() / 255.0,
                                       color.Blue()  / 255.0)

#-------------------------------------------------------------------------------
#  Define wxPython specific color traits:
#-------------------------------------------------------------------------------

### Note: Declare the editor to be a function which returns the RGBColorEditor
# class from traits ui to avoid circular import issues. For backwards
# compatibility with previous Traits versions, the 'editors' folder in Traits
# project declares 'from api import *' in its __init__.py. The 'api' in turn
# can contain classes that have a RGBColor trait which lead to this file getting
# imported. This will lead to a circular import when declaring a RGBColor trait.
def get_rgb_color_editor(*args, **traits):
    from rgb_color_editor import ToolkitEditorFactory
    return ToolkitEditorFactory(*args, **traits)

# Trait whose value must be an RGB color:
RGBColor = Trait( 'white', convert_to_color, rgb_standard_colors,
                  editor = get_rgb_color_editor )

