''' This module contains TextForWeights class which is a text widget
used for displaying and editing weight restrictions.
Attributes:
TEXT_WIDTH_VAL (int): width of Text widget.
TEXT_HEIGHT_VAL (int): heigth of Text widget.
'''
from tkinter import Text, NONE, N, W, E, S, HORIZONTAL, END, TclError
from tkinter import StringVar, LEFT
from tkinter.ttk import Frame, Label, Scrollbar
from pyDEA.core.utils.dea_utils import create_bounds, contraint_is_price_ratio_type
TEXT_WIDTH_VAL = 50
TEXT_HEIGHT_VAL = 10
class TextForWeights(Frame):
''' Implements text widget used for displaying and editing weight
restrictions.
Attributes:
parent (Tk object): parent of this widget.
weight_name (str): text describing type of weight restrictions,
e.g. absolute, virtual, etc.
examples (str): string with an example of usage of this
type of weight restrictions, e.g. I1 <= 2.
current_categories (list of str): list of current categories.
params (Parameters): parameters.
param_name (str): parameter name that corresponds to this type
of weight restrictions, e.g. ABS_WEIGHT_RESTRICTIONS.
text (Text): text widget used for displaying weight restrictions.
error_tag_exists (bool): if set to True, means that there are
invalid weight restrictions, False otherwise.
errors_strvar (StringVar): is used for storing and displaying
error messages for invalid weight restrictions.
is_price_ratio (bool): if True price ratio constraints are
expected to be entered, if False other constraint types are
expected to be entered. Defaults to False.
Args:
parent (Tk object): parent of this widget.
weight_name (str): text describing type of weight restrictions,
e.g. absolute, virtual, etc.
examples (str): string with an example of usage of this
type of weight restrictions, e.g. I1 <= 2.
current_categories (list of str): list of current categories.
params (Parameters): parameters.
param_name (str): parameter name that corresponds to this type
of weight restrictions, e.g. ABS_WEIGHT_RESTRICTIONS.
is_price_ratio (bool): if True price ratio constraints are
expected to be entered, if False other constraint types are
expected to be entered. Defaults to False.
'''
def __init__(self, parent, weight_name, examples,
current_categories, params, param_name,
is_price_ratio_constraint = False, *args, **kw):
Frame.__init__(self, parent, *args, **kw)
self.parent = parent
self.examples = examples
self.current_categories = current_categories
self.params = params
self.param_name = param_name
self.text = None
self.error_tag_exists = False
self.errors_strvar = StringVar()
self.weight_name = weight_name
self.is_price_ratio_constraint = is_price_ratio_constraint
self.create_widgets(weight_name)
def create_widgets(self, weight_name):
''' Creates all widgets.
'''
constraints_lbl = Label(
self, text='Enter {0} weight restrictions:'.format(
weight_name))
constraints_lbl.grid(padx=10, pady=2, sticky=N+W)
examples_lbl = Label(self, text='e.g. {0}'.format(self.examples))
examples_lbl.grid(row=1, column=0, padx=10, pady=5, sticky=N+W)
errors_lbl = Label(self, textvariable=self.errors_strvar,
foreground='red', anchor=W, justify=LEFT,
wraplength=80)
errors_lbl.grid(row=2, column=2, sticky=N+W, padx=5, pady=5)
self.grid_rowconfigure(2, weight=1)
self.grid_columnconfigure(0, weight=1)
xscrollbar = Scrollbar(self, orient=HORIZONTAL)
xscrollbar.grid(row=3, column=0, sticky=E+W)
yscrollbar = Scrollbar(self)
yscrollbar.grid(row=2, column=1, sticky=N+S)
self.text = Text(self, wrap=NONE, width=TEXT_WIDTH_VAL,
height=TEXT_HEIGHT_VAL,
xscrollcommand=xscrollbar.set,
yscrollcommand=yscrollbar.set)
self.text.grid(row=2, column=0, sticky=N+S+E+W)
xscrollbar.config(command=self.text.xview)
yscrollbar.config(command=self.text.yview)
def delete_weights(self):
''' Removes all weight restrictions.
'''
self.text.delete(1.0, END)
self.error_tag_exists = False
def insert_weight(self, weight):
''' Add a given weight restriction in the end of the
text widget.
Args:
weight (str): string that describes a given weight
restriction.
'''
# we assume that inserted weight is always correct
self.text.insert(END, weight + '\n')
def validate_weights(self):
''' Checks if all weight restrictions are valid.
Returns:
bool: True if all weight restrictions are valid,
False otherwise.
'''
self.text.config(foreground='black')
if self.error_tag_exists:
try:
self.text.tag_remove('error', 'error.first', 'error.last')
except TclError:
# there is no error tag
pass
self.error_tag_exists = False
self.errors_strvar.set('')
errors = []
all_constraints = []
for count, line in enumerate(self.text.get('1.0', 'end-1c').splitlines()):
# Iterate lines
if line:
weight_as_list = []
weight_as_list.append(line)
try:
bounds = create_bounds(weight_as_list, self.current_categories)
assert len(bounds) == 1
key, value = bounds.popitem()
is_price_ratio = contraint_is_price_ratio_type(key)
if self.is_price_ratio_constraint and not is_price_ratio:
raise ValueError('Constraint {0} is not a price ratio constraint'.
format(line))
if not self.is_price_ratio_constraint and is_price_ratio:
raise ValueError('Constraint {0} is a price ratio constraint.'
' Use {1} weight restriction type constraint instead.'.
format(line, self.weight_name))
except ValueError as err:
self.text.tag_add('error', '%d.0' % (count + 1),
'%d.end' % (count + 1))
self.error_tag_exists = True
errors.append('* ' + str(err) + '\n')
else:
# combine correct lines for parameters
all_constraints.append(line)
errors.append('\n')
if self.error_tag_exists:
self.text.tag_config('error', foreground='red')
constraints = '; '.join(all_constraints)
self.params.update_parameter(self.param_name, constraints)
if self.error_tag_exists:
self.errors_strvar.set(self.get_all_errors(errors))
if constraints:
return True
return False
def get_all_errors(self, error_list):
''' Returns given list of errors as one string.
Args:
error_list (list of str): list of strings to concatenate.
Returns:
str: concatenated string.
'''
if len(error_list) == 0:
return ''
return ''.join(error_list)
