"""
Implementation of an InstanceEditor demo plugin for the Traits UI demo program.

This demo shows each of the four styles of the InstanceEditor.

Fixme: This version of the demo only shows the old-style InstanceEditor
capabilities.
"""

from traits.api import HasTraits, Str, Range, Bool, Trait
from traitsui.api import Item, Group, View

#-------------------------------------------------------------------------
#  Classes:
#-------------------------------------------------------------------------


class SampleClass(HasTraits):
    """ This Sample class is used to demonstrate the InstanceEditor demo.
    """

    #--------------------------------------------------------------------------
    # The actual attributes don't matter here; we just need an assortment
    # to demonstrate the InstanceEditor's capabilities.
    #--------------------------------------------------------------------------

    name = Str()
    occupation = Str()
    age = Range(21, 65)
    registered_voter = Bool()

    #--------------------------------------------------------------------------
    # The InstanceEditor uses whatever view is defined for the class.  The
    # default view lists the fields alphabetically, so it's best to define one
    # explicitly.
    #--------------------------------------------------------------------------

    view = View('name', 'occupation', 'age', 'registered_voter')


class InstanceEditorDemo(HasTraits):
    """ This class specifies the details of the InstanceEditor demo.
    """

    # To demonstrate any given Trait editor, an appropriate Trait is required.
    sample_instance = Trait(SampleClass())

    # Items are used to define the demo display - one item per
    # editor style
    inst_group = Group(Item('sample_instance', style='simple', label='Simple'),
                       Item('_'),
                       Item('sample_instance', style='custom', label='Custom'),
                       Item('_'),
                       Item('sample_instance', style='text', label='Text'),
                       Item('_'),
                       Item('sample_instance',
                            style='readonly',
                            label='ReadOnly'))

    # Demo View
    view1 = View(inst_group,
                 title='InstanceEditor',
                 buttons=['OK'])


# Create the demo:
popup = InstanceEditorDemo()

# Run the demo (if invoked from the command line):
if __name__ == '__main__':
    popup.configure_traits()
