root/trunk/RBSkinning/RBSkinning/InheritableSettings.py

#!/usr/bin/env python
##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##~ License 
##~ 
##- The RuneBlade Foundation library is intended to ease some 
##- aspects of writing intricate Jabber, XML, and User Interface (wxPython, etc.) 
##- applications, while providing the flexibility to modularly change the 
##- architecture. Enjoy.
##~ 
##~ Copyright (C) 2002  TechGame Networks, LLC.
##~ 
##~ This library is free software; you can redistribute it and/or
##~ modify it under the terms of the BSD style License as found in the 
##~ LICENSE file included with this distribution.
##~ 
##~ TechGame Networks, LLC can be reached at:
##~ 3578 E. Hartsel Drive #211
##~ Colorado Springs, Colorado, USA, 80920
##~
##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Imports 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

from RBFoundation.ChainedDict import ChainedDict
from RBFoundation.Utilities import *

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#~ Definitions 
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

class InheritSettingsMixin(object):
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Constants / Variables / Etc. 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    BaseNamespace = 'http://namespaces.runeblade.com/skin'

    BaseSettingsSave = (BaseNamespace, 'save')
    BaseSettingsInherit = (BaseNamespace, 'inherit')
    BaseSettingsLoad = (BaseNamespace, 'load')
    BaseSettingsRoot = (BaseNamespace, 'root')

    # SettingsSaveOpt is generally used to signify whether certain attributes
    # should be saved when skin:save is invoked...  True signifies it should be
    # saved, False signifys that it should not be saved.  The default is
    # signified by the None entry.
    SettingsSaveOpt = {
        BaseSettingsSave: False,
        BaseSettingsInherit: False,
        BaseSettingsLoad: False,
        BaseSettingsRoot: False,
        None: True,
        }

    default_settings = {
        BaseSettingsInherit:'',
        BaseSettingsLoad:'',
        #BaseSettingsSave:'',
        #BaseSettingsRoot:'0',
        }

    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Protected Methods 
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def _InheritSettings(self, settings, InheritList, Resilliant=0):
        InheritList.reverse()
        for SettingName in filter(None, InheritList):
            try: InheritedSettings = self.context.getnamedvar(SettingName)
            except AttributeError:
                if not Resilliant: raise
                else: InheritedSettings=None
            if InheritedSettings is not None:
                settings.update(InheritedSettings)
        return settings

    def _SaveSettingsAdv(self, SettingName, settings):
        settings = settings.copy()
        # Prune out settings that shouldn't be saved
        default = self.SettingsSaveOpt.get(None, 1)
        for key in settings.keys():
            if not self.SettingsSaveOpt.get(key, default):
                del settings[key]
            elif isinstance(key, tuple):
                if not self.SettingsSaveOpt.get(key[-1], default):
                    del settings[key]

        # Save settings to be inherited 
        ctx = self.context._OwnerContext(self.BaseSettingsRoot, returnLast=1)
        obj, setname = ctx.getnamedvar(SettingName, -1)
        return setattr(obj, setname[0], settings)

    def _SaveSettings(self, settings=None):
        try: SettingName = self.settings[self.BaseSettingsSave]
        except KeyError: pass
        else: return self._SaveSettingsAdv(SettingName, settings)

    def _InitSettings(self, settings, bAllowInheritance=1):
        if not bAllowInheritance:
            newsettings = settings
        else:
            # Get inherited settings
            newsettings = {}
            BaseSettingsList = self.default_settings.get(self.BaseSettingsInherit)
            if BaseSettingsList: 
                self._InheritSettings(newsettings, strtolist(BaseSettingsList), Resilliant=1)
            BaseSettingsList = settings.get(self.BaseSettingsInherit)
            if BaseSettingsList: 
                self._InheritSettings(newsettings, strtolist(BaseSettingsList))

            # Merge the two settings
            if newsettings: newsettings.update(settings)
            else: newsettings = settings

            # Get the override load settings -- load them over top the passed settings
            BaseSettingsList = self.default_settings.get(self.BaseSettingsLoad)
            if BaseSettingsList: 
                self._InheritSettings(newsettings, strtolist(BaseSettingsList), Resilliant=1)
            BaseSettingsList = settings.get(self.BaseSettingsLoad)
            if BaseSettingsList: 
                self._InheritSettings(newsettings, strtolist(BaseSettingsList))

        # now set our settings to be a chained grouping of
        # the modified incoming settings, and the chained settings
        self.settings = ChainedDict(newsettings)
        self.settings.chained = self.default_settings

        self._SaveSettings(self.source_settings)

    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    #~ Properties
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    def _GetLocalSettings(self):
        try:
            result = {}
            for each in self.settings:
                if not isinstance(each, tuple):
                    result[each] = self.settings[each]
            return result
        except AttributeError: return {}
    local_settings = property(fget=_GetLocalSettings)

    def _GetSourceSettings(self):
        try: return self.settings.source
        except AttributeError: return self.settings
    source_settings = property(fget=_GetSourceSettings)