--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bGrease/component/field.py	Mon Sep 05 15:00:34 2011 +0200
@@ -0,0 +1,303 @@
+#############################################################################
+#
+# Copyright (c) 2010 by Casey Duncan and contributors
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the MIT License
+# A copy of the license should accompany this distribution.
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+#
+#############################################################################
+
+__version__ = '$Id$'
+
+import operator
+from bGrease.geometry import Vec2d, Vec2dArray, Rect
+from bGrease import color
+
+# Allowed field types -> default values
+types = {int:lambda: 0, 
+         float:lambda: 0.0, 
+         bool:lambda: False,
+         str:lambda:"", 
+         object:lambda:None,
+         Vec2d:lambda: Vec2d(0,0), 
+         Vec2dArray:lambda: Vec2dArray(),
+         color.RGBA: lambda: color.RGBA(0.0, 0.0, 0.0, 0.0),
+         Rect: lambda: Rect(0.0, 0.0, 0.0, 0.0),
+         list: lambda: list(),
+         dict: lambda: dict(),
+         }
+
+class Schema(dict):
+        """Field schema definition for custom components"""
+
+        def __init__(self, **fields):
+                for ftype in fields.values():
+                        assert ftype in types, fname + " has an illegal field type"
+                self.update(fields)
+
+
+class FieldAccessor(object):
+        """Facade for manipulating a field for a set of entities"""
+
+        __field = None
+        __entities = None
+        __attrs = None
+        __getter = None
+        __parent_getters = ()
+
+        def __init__(self, field, entities, attrs=()):
+                self.__field = field
+                self.__entities = entities
+                field_getter = operator.attrgetter(field.name)
+                self.__attrs = attrs
+                if attrs:
+                        getters = [field_getter] + [operator.attrgetter(attr) for attr in attrs]
+                        def get(entity):
+                                value = entity
+                                for getter in getters:
+                                        value = getter(value)
+                                return value
+                        self.__getter = get
+                        self.__parent_getters = getters[:-1]
+                else:
+                        self.__getter = field_getter
+
+        def __getattr__(self, name):
+                """Return a FieldAccessor for the child attribute"""
+                return self.__class__(self.__field, self.__entities, self.__attrs + (name,))
+
+        def __setattr__(self, name, value):
+                if value is self:
+                        return # returned by mutators
+                if hasattr(self.__class__, name):
+                        # Set local attr
+                        self.__dict__[name] = value
+                elif not name.startswith('_'):
+                        getattr(self, name).__set__(value)
+                else:
+                        raise AttributeError("Cannot set field attribute: %s" % name)
+
+        @property
+        def __setter(self):
+                """Return the proper setter function for setting the field value"""
+                if not self.__attrs:
+                        return setattr
+                else:
+                        parent_getters = self.__parent_getters
+                        def setter(data, name, value):
+                                for getter in parent_getters:
+                                        data = getter(data)
+                                setattr(data, name, value)
+                        self.__setter = setter
+                        return setter
+
+        def __set__(self, value):
+                """Set field values en masse"""
+                # Mass set field attr
+                setter = self.__setter
+                component = self.__field.component
+                if self.__attrs:
+                        name = self.__attrs[-1]
+                else:
+                        name = self.__field.name
+                if isinstance(value, FieldAccessor):
+                        # Join set between two entity sets
+                        if not self.__attrs:
+                                cast = self.__field.cast
+                        else: 
+                                cast = lambda x: x
+                        for entity in self.__entities:
+                                try:
+                                        setter(component[entity], name, cast(value[entity]))
+                                except KeyError:
+                                        pass
+                else:
+                        if not self.__attrs:
+                                value = self.__field.cast(value)
+                        for entity in self.__entities:
+                                try:
+                                        setter(component[entity], name, value)
+                                except KeyError:
+                                        pass
+
+        def __getitem__(self, entity):
+                """Return the field value for a single entity (used for joins)"""
+                if entity in self.__entities:
+                        return self.__getter(self.__field.component[entity])
+                raise KeyError(entity)
+
+        def __contains__(self, entity):
+                return entity in self.__entities
+
+        def __repr__(self):
+                return '<%s %s @ %x>' % (
+                        self.__class__.__name__, 
+                        '.'.join((self.__field.name,) + self.__attrs), id(self))
+
+        def __nonzero__(self):
+                return bool(self.__entities)
+
+        def __iter__(self):
+                """Return an iterator of all field values in the set"""
+                component = self.__field.component
+                getter = self.__getter
+                for entity in self.__entities:
+                        try:
+                                data = component[entity]
+                        except KeyError:
+                                continue
+                        yield getter(data)
+
+        ## batch comparison operators ##
+
+        def __match(self, value, op):
+                component = self.__field.component
+                getter = self.__getter
+                matches = set()
+                add = matches.add
+                if isinstance(value, FieldAccessor):
+                        # Join match between entity sets
+                        for entity in self.__entities:
+                                try:
+                                        data = component[entity]
+                                        other = value[entity]
+                                except KeyError:
+                                        continue
+                                if op(getter(data), other):
+                                        add(entity)
+                else:
+                        for entity in self.__entities:
+                                try:
+                                        data = component[entity]
+                                except KeyError:
+                                        continue
+                                if op(getter(data), value):
+                                        add(entity)
+                return matches
+
+        def __eq__(self, value):
+                """Return an entity set of all entities with a matching field value"""
+                return self.__match(value, operator.eq)
+
+        def __ne__(self, value):
+                """Return an entity set of all entities not matching field value"""
+                return self.__match(value, operator.ne)
+
+        def __gt__(self, value):
+                """Return an entity set of all entities with a greater field value"""
+                return self.__match(value, operator.gt)
+
+        def __ge__(self, value):
+                """Return an entity set of all entities with a greater or equal field value"""
+                return self.__match(value, operator.ge)
+
+        def __lt__(self, value):
+                """Return an entity set of all entities with a lesser field value"""
+                return self.__match(value, operator.lt)
+
+        def __le__(self, value):
+                """Return an entity set of all entities with a lesser or equal field value"""
+                return self.__match(value, operator.le)
+
+        def _contains(self, values):
+                """Return an entity set of all entities with a field value contained in values"""
+                return self.__match(values, operator.contains)
+
+        ## Batch in-place mutator methods
+
+        def __mutate(self, value, op):
+                component = self.__field.component
+                if self.__attrs:
+                        name = self.__attrs[-1]
+                else:
+                        name = self.__field.name
+                getter = self.__getter
+                setter = self.__setter
+                if isinstance(value, FieldAccessor):
+                        # Join between entity sets
+                        for entity in self.__entities:
+                                try:
+                                        data = component[entity]
+                                        other = value[entity]
+                                except KeyError:
+                                        continue
+                                setter(data, name, op(getter(data), other))
+                else:
+                        for entity in self.__entities:
+                                try:
+                                        data = component[entity]
+                                except KeyError:
+                                        continue
+                                setter(data, name, op(getter(data), value))
+                return self
+
+        def __iadd__(self, value):
+                return self.__mutate(value, operator.iadd)
+
+        def __isub__(self, value):
+                return self.__mutate(value, operator.isub)
+
+        def __imul__(self, value):
+                return self.__mutate(value, operator.imul)
+
+        def __idiv__(self, value):
+                return self.__mutate(value, operator.idiv)
+
+        def __itruediv__(self, value):
+                return self.__mutate(value, operator.itruediv)
+
+        def __ifloordiv__(self, value):
+                return self.__mutate(value, operator.ifloordiv)
+
+        def __imod__(self, value):
+                return self.__mutate(value, operator.imod)
+
+        def __ipow__(self, value):
+                return self.__mutate(value, operator.ipow)
+
+        def __ilshift__(self, value):
+                return self.__mutate(value, operator.ilshift)
+
+        def __irshift__(self, value):
+                return self.__mutate(value, operator.irshift)
+
+        def __iand__(self, value):
+                return self.__mutate(value, operator.iand)
+
+        def __ior__(self, value):
+                return self.__mutate(value, operator.ior)
+
+        def __ixor__(self, value):
+                return self.__mutate(value, operator.ixor)
+
+
+class Field(object):
+        """Component field metadata and accessor interface"""
+
+        def __init__(self, component, name, type, accessor_factory=FieldAccessor):
+                self.component = component
+                self.name = name
+                self.type = type
+                self.default = types.get(type)
+                self.accessor_factory = accessor_factory
+
+        def cast(self, value):
+                """Cast value to the appropriate type for thi field"""
+                if self.type is not object:
+                        return self.type(value)
+                else:
+                        return value
+
+        def accessor(self, entities=None):
+                """Return the field accessor for the entities in the component,
+                or all entities in the set specified that are also in the component
+                """
+                if entities is None or entities is self.component.entities:
+                        entities = self.component.entities
+                else:
+                        entities = entities & self.component.entities
+                return self.accessor_factory(self, entities)