""" Defines the Preferences class for the Chaco shell.
"""

from enable.api import white_color_trait
from traits.api import Enum, HasTraits, Int, Str


class Preferences(HasTraits):
    """ Contains all the preferences that configure the Chaco shell session.
    """

    # Width of the plot window, in pixels.
    window_width = Int(600)

    # Height of the plot window, in pixels.
    window_height = Int(600)

    # The type of plot to display.
    plot_type = Enum("line", "scatter")

    # Default name to use for the plot window.
    default_window_name = Str("Chaco Plot")

    # The default background color.
    bgcolor = white_color_trait

    # The default location of the origin for new image plots
    image_default_origin = Enum("top left", "bottom left",
                                "bottom right", "top right")

    @classmethod
    def from_file(cls, filename):
        """ Creates a new preferences object from a file on disk.
        """
        prefs = cls()
        prefs.load(filename)
        return prefs


    def load(self, filename):
        """ Loads a preferences file; existing settings are overwritten.
        """
        pass


    def save(self, filename):
        """ Saves the preferences to *filename*.
        """
        pass


# EOF