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"""
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()
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