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# Copyright (c) 2001, 2002 by Intevation GmbH |
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# Authors: |
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# Jan-Oliver Wagner <[email protected]> |
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# |
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# This program is free software under the GPL (>=v2) |
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# Read the file COPYING coming with Thuban for details. |
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|
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__version__ = "$Revision$" |
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|
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from messages import EXTENSION_CHANGED, EXTENSION_OBJECTS_CHANGED |
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|
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from base import TitledObject, Modifiable |
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|
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|
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class Extension(TitledObject, Modifiable): |
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|
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"""Represent a extension. A extension is a package of additional |
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functionality to Thuban and contains a number of Objects |
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that can be freely defined in an extension. |
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Each object must a a TitleObject with additional set "object.name". |
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|
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Extension objects send the following message types: |
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|
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EXTENSION_CHANGED -- Something in the extension has changed. |
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|
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EXTENSION_OBJECTS_CHANGED -- Something in the objects has changed. |
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|
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""" |
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|
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forwarded_channels = (EXTENSION_CHANGED, EXTENSION_OBJECTS_CHANGED) |
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|
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def __init__(self, title): |
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"""Initialize the extension.""" |
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TitledObject.__init__(self, title) |
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self.objects = [] |
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|
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def Destroy(self): |
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for object in self.objects: |
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object.Destroy() |
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Modifiable.Destroy(self) |
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|
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def AddObject(self, object): |
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self.objects.append(object) |
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for channel in self.forwarded_channels: |
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object.Subscribe(channel, self.forward, channel) |
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self.changed(EXTENSION_OBJECTS_CHANGED, self) |
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|
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def RemoveObject(self, object): |
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for channel in self.forwarded_channels: |
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object.Unsubscribe(channel, self.forward, channel) |
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self.layers.remove(layer) |
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self.changed(EXTENSION_OBJECTS_CHANGED, self) |
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object.Destroy() |
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|
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def Objects(self): |
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return self.objects |
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|
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def HasObjects(self): |
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return len(self.objects) > 0 |
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|
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def FindObject(self, title): |
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"""Find an object by title. If found, return it, else return None.""" |
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for object in self.objects: |
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if object.title == title: |
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return object |
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return None |
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|
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def forward(self, *args): |
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"""Reissue events""" |
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if len(args) > 1: |
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args = (args[-1],) + args[:-1] |
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apply(self.issue, args) |
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|
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def WasModified(self): |
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"""Return true if something of the extension was modified""" |
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if self.modified: |
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return 1 |
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else: |
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return 0 |
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|
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def UnsetModified(self): |
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"""Unset the modified flag of the extension""" |
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Modifiable.UnsetModified(self) |