"""
Defining column-specific context menu in a Table

Shows a TableEditor which has column-specific context menus.

The demo is a simple baseball scoring system, which lists each player and
their current batting statistics. After a given player has an at bat, you
right-click on the table cell corresponding to the player and the result of
the at-bat (e.g. 'S' = single) and select the 'Add' menu option to register
that the player hit a single and update the player's overall statistics.

This demo also illustrates the use of Property traits, and how using 'event'
meta-data can simplify event handling by collapsing an event that can
occur on a number of traits into a category of event, which can be handled by
a single event handler defined for the category (in this case, the category
is 'affects_average').
"""

from random import randint
from traits.api import HasStrictTraits, Str, Int, Float, List, Property
from traitsui.api import View, Item, TableEditor
from traitsui.menu import Menu, Action
from traitsui.table_column import ObjectColumn

# Define a custom table column for handling items which affect the player's
# batting average:


class AffectsAverageColumn(ObjectColumn):

    # Define the context menu for the column:
    menu = Menu(Action(name='Add', action='column.add(object)'),
                Action(name='Sub', action='column.sub(object)'))

    # Right-align numeric values (override):
    horizontal_alignment = 'center'

    # Column width (override):
    width = 0.09

    # Don't allow the data to be edited directly:
    editable = False

    # Action methods for the context menu items:

    def add(self, object):
        """ Increment the affected player statistic.
        """
        setattr(object, self.name, getattr(object, self.name) + 1)

    def sub(self, object):
        """ Decrement the affected player statistic.
        """
        setattr(object, self.name, getattr(object, self.name) - 1)


# The 'players' trait table editor:
player_editor = TableEditor(
    editable=True,
    sortable=True,
    auto_size=False,
    columns=[ObjectColumn(name='name',
                          editable=False, width=0.28),
             AffectsAverageColumn(name='at_bats',
                                  label='AB'),
             AffectsAverageColumn(name='strike_outs',
                                  label='SO'),
             AffectsAverageColumn(name='singles',
                                  label='S'),
             AffectsAverageColumn(name='doubles',
                                  label='D'),
             AffectsAverageColumn(name='triples',
                                  label='T'),
             AffectsAverageColumn(name='home_runs',
                                  label='HR'),
             AffectsAverageColumn(name='walks',
                                  label='W'),
             ObjectColumn(name='average',
                          label='Ave',
                          editable=False,
                          width=0.09,
                          horizontal_alignment='center',
                          format='%0.3f')]
)


# 'Player' class:
class Player(HasStrictTraits):

    # Trait definitions:
    name = Str()
    at_bats = Int()
    strike_outs = Int(event='affects_average')
    singles = Int(event='affects_average')
    doubles = Int(event='affects_average')
    triples = Int(event='affects_average')
    home_runs = Int(event='affects_average')
    walks = Int()
    average = Property(Float)

    def _get_average(self):
        """ Computes the player's batting average from the current statistics.
        """
        if self.at_bats == 0:
            return 0.0

        return float(self.singles + self.doubles +
                     self.triples + self.home_runs) / self.at_bats

    def _affects_average_changed(self):
        """ Handles an event that affects the player's batting average.
        """
        self.at_bats += 1


class Team(HasStrictTraits):

    # Trait definitions:
    players = List(Player)

    # Trait view definitions:
    traits_view = View(
        Item('players',
             show_label=False,
             editor=player_editor
             ),
        title='Baseball Scoring Demo',
        width=0.5,
        height=0.5,
        resizable=True
    )


def random_player(name):
    """ Generates and returns a random player.
    """
    p = Player(name=name,
               strike_outs=randint(0, 50),
               singles=randint(0, 50),
               doubles=randint(0, 20),
               triples=randint(0, 5),
               home_runs=randint(0, 30),
               walks=randint(0, 50))
    return p.trait_set(
        at_bats=p.strike_outs +
        p.singles +
        p.doubles +
        p.triples +
        p.home_runs +
        randint(
            100,
            200))

# Create the demo:
demo = view = Team(players=[random_player(name) for name in [
    'Dave', 'Mike', 'Joe', 'Tom', 'Dick', 'Harry', 'Dirk', 'Fields', 'Stretch'
]])

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