1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
# (C) Copyright 2008-2023 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!
# ------------------------------------------------------------------------------
# Copyright (c) 2008, Riverbank Computing Limited
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in enthought/LICENSE.txt and may be redistributed only
# under the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
# Thanks for using Enthought open source!
#
# Author: Riverbank Computing Limited
# Description: <Enthought undo package component>
# ------------------------------------------------------------------------------
# Enthought library imports.
from pyface.action.api import Action
from traits.api import Instance
# Local library imports
from ..i_undo_manager import IUndoManager
class AbstractCommandStackAction(Action):
"""The abstract base class for all actions that operate on a command
stack.
"""
#### 'AbstractCommandStackAction' interface ###############################
#: The undo manager.
undo_manager = Instance(IUndoManager)
###########################################################################
# 'object' interface.
###########################################################################
def __init__(self, **traits):
""" Initialise the instance. """
super().__init__(**traits)
self.undo_manager.observe(
self._on_stack_updated, "stack_updated"
)
# Update the action to initialise it.
self._update_action()
###########################################################################
# 'Action' interface.
###########################################################################
def destroy(self):
"""Called when the action is no longer required.
By default this method does nothing, but this would be a great place to
unhook trait listeners etc.
"""
self.undo_manager.observe(
self._on_stack_updated, "stack_updated", remove=True
)
###########################################################################
# Protected interface.
###########################################################################
def _update_action(self):
""" Update the state of the action. """
raise NotImplementedError
###########################################################################
# Private interface.
###########################################################################
def _on_stack_updated(self, event):
""" Handle changes to the state of a command stack. """
stack = event.new
# Ignore unless it is the active stack.
if stack is self.undo_manager.active_stack:
self._update_action()
|
