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Diffstat (limited to 'src/sugar/tutorius/constraints.py')
| -rw-r--r-- | src/sugar/tutorius/constraints.py | 207 |
1 files changed, 0 insertions, 207 deletions
diff --git a/src/sugar/tutorius/constraints.py b/src/sugar/tutorius/constraints.py deleted file mode 100644 index 36abdfb..0000000 --- a/src/sugar/tutorius/constraints.py +++ /dev/null @@ -1,207 +0,0 @@ -# Copyright (C) 2009, Tutorius.org -# -# This program is free software; you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation; either version 2 of the License, or -# (at your option) any later version. -# -# This program is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with this program; if not, write to the Free Software -# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA -""" -Constraints - -Defines a set of constraints with their related errors. These constraints are -made to be used inside TutoriusProperties in order to limit the values that -they might take. They can also be used to enforce a particular format or type -for some properties. -""" - -# For the File Constraint -import os - -class Constraint(): - """ - Basic block for defining constraints on a TutoriusProperty. Every class - inheriting from Constraint will have a validate function that will be - executed when the property's value is to be changed. - """ - def validate(self, value): - """ - This function receives the value that is proposed as a new value for - the property. It needs to raise an Error in the case where the value - does not respect this constraint. - """ - raise NotImplementedError("Unable to validate a base Constraint") - -class ValueConstraint(Constraint): - """ - A value constraint contains a _limit member that can be used in a children - class as a basic value. See UpperLimitConstraint for an exemple. - """ - def __init__(self, limit): - self.limit = limit - -class UpperLimitConstraintError(Exception): - pass - -class UpperLimitConstraint(ValueConstraint): - def validate(self, value): - """ - Evaluates whether the given value is smaller than the limit. - - @raise UpperLimitConstraintError When the value is strictly higher than - the limit. - """ - if self.limit is not None: - if self.limit >= value: - return - raise UpperLimitConstraintError() - return - -class LowerLimitConstraintError(Exception): - pass - -class LowerLimitConstraint(ValueConstraint): - def validate(self, value): - """ - If the value is lower than the limit, this function raises an error. - - @raise LowerLimitConstraintError When the value is strictly smaller - than the limit. - """ - if self.limit is not None: - if value >= self.limit: - return - raise LowerLimitConstraintError() - return - -class MaxSizeConstraintError(Exception): - pass - -class MaxSizeConstraint(ValueConstraint): - def validate(self, value): - """ - Evaluate whether a given object is smaller than the given size when - run through len(). Great for string, lists and the like. ;) - - @raise SizeConstraintError If the length of the value is strictly - bigger than the limit. - """ - if self.limit is not None: - if self.limit >= len(value): - return - raise MaxSizeConstraintError("Setter : trying to set value of length %d while limit is %d"%(len(value), self.limit)) - return - -class MinSizeConstraintError(Exception): - pass - -class MinSizeConstraint(ValueConstraint): - def validate(self, value): - """ - Evaluate whether a given object is smaller than the given size when - run through len(). Great for string, lists and the like. ;) - - @raise SizeConstraintError If the length of the value is strictly - bigger than the limit. - """ - if self.limit is not None: - if self.limit <= len(value): - return - raise MinSizeConstraintError("Setter : trying to set value of length %d while limit is %d"%(len(value), self.limit)) - return - -class ColorConstraintError(Exception): - pass - -class ColorArraySizeError(ColorConstraintError): - pass - -class ColorTypeError(ColorConstraintError): - pass - -class ColorValueError(ColorConstraintError): - pass - -class ColorConstraint(Constraint): - """ - Validates that the value is an array of size 3 with three numbers between - 0 and 255 (inclusively) in it. - - """ - def validate(self, value): - if len(value) != 3: - raise ColorArraySizeError("The value is not an array of size 3") - - if not (type(value[0]) == type(22) and type(value[1]) == type(22) and type(value[2]) == type(22)): - raise ColorTypeError("Not all the elements of the array are integers") - - if value[0] > 255 or value[0] <0: - raise ColorValueError("Red value is not between 0 and 255") - - if value[1] > 255 or value[1] <0: - raise ColorValueError("Green value is not between 0 and 255") - - if value[2] > 255 or value[2] <0: - raise ColorValueError("Blue value is not between 0 and 255") - - return - -class BooleanConstraintError(Exception): - pass - -class BooleanConstraint(Constraint): - """ - Validates that the value is either True or False. - """ - def validate(self, value): - if value == True or value == False: - return - raise BooleanConstraintError("Value is not True or False") - -class EnumConstraintError(Exception): - pass - -class EnumConstraint(Constraint): - """ - Validates that the value is part of a set of well-defined values. - """ - def __init__(self, accepted_values): - """ - Creates the constraint and stores the list of accepted values. - - @param correct_values A list that contains all the values that will - be declared as satisfying the constraint - """ - self._accepted_values = accepted_values - - def validate(self, value): - """ - Ensures that the value that is passed is part of the list of accepted - values. - """ - if not value in self._accepted_values: - raise EnumConstraintError("Value is not part of the enumeration") - return - -class FileConstraintError(Exception): - pass - -class FileConstraint(Constraint): - """ - Ensures that the string given corresponds to an existing file on disk. - """ - def validate(self, value): - # TODO : Decide on the architecture for file retrieval on disk - # Relative paths? From where? Support macros? - # - if not os.path.isfile(value): - raise FileConstraintError("Non-existing file : %s"%value) - return - |