Source Code for Module Task.ChooserTask

 1  ''' 
 2  Defines a L{Task} to execute when a L{AEEvent.InputGesture} occurs in order to 
 3  start an L{AEChooser} dialog with the user. 
 4   
 5  @author: Peter Parente 
 6  @organization: IBM Corporation 
 7  @copyright: Copyright (c) 2005, 2007 IBM Corporation 
 8  @license: The BSD License 
 9   
10  All rights reserved. This program and the accompanying materials are made  
11  available under the terms of the BSD license which accompanies 
12  this distribution, and is available at 
13  U{http://www.opensource.org/licenses/bsd-license.php} 
14  ''' 
15  import Base, InputTask 
16   
17 -class ChooserTask(InputTask.InputTask): 
18    ''' 
19    Executes when an input gesture occurs or a chooser changes state. 
20     
21    This class registers its name and whether it should be monitored by default 
22    in an L{AEMonitor} using the L{Base.registerTaskType} function when this 
23    module is first imported. The L{AEMonitor} can use this information to build 
24    its menus. 
25    ''' 
26    Base.registerTaskType('ChooserTask', False) 
27     
28 -  def execute(self, chooser=None, kind=None, **kwargs): 
29      ''' 
30      Executes this L{Task} in response to some change in a L{AEChooser},  
31      starting it, ending it, or applying its current options. Called by  
32      L{Tier.Tier._executeTask}. 
33       
34      @param chooser: Chooser that fired the event 
35      @type chooser: L{AEChooser} 
36      @param kind: Kind of signal, APPLY, OK, or CANCEL or an arbitrary 
37      constant provided by the L{AEChooser} 
38      @type kind: integer 
39      @return: Should processing continue? Always returns True by default. 
40      @rtype: boolean 
41      ''' 
42      if chooser is None: 
43        return self.executeStart(**kwargs) 
44      elif kind in (chooser.OK, chooser.CANCEL): 
45        # call signal then end 
46        # return the AND of the return values 
47        update = self.executeSignal(chooser=chooser, kind=kind, **kwargs) 
48        end = self.executeEnd(chooser=chooser, kind=kind, **kwargs) 
49        return end and update 
50      else: 
51        # call signal 
52        return self.executeSignal(chooser=chooser, kind=kind, **kwargs)      
53   
54 -  def executeStart(self, **kwargs): 
55      ''' 
56      Executes this L{Task} to start a new L{AEChooser}, typically in response 
57      to input on an L{AEInput} device. Called by L{Tier.Tier._executeTask}. 
58       
59      @return: Should processing continue? Always returns True by default. 
60      @rtype: boolean 
61      ''' 
62      return True 
63     
64 -  def executeSignal(self, chooser, kind, **kwargs): 
65      '''   
66      Executes this L{Task} in response to a chooser request to have its current 
67      options immediately applied without its completion. Called by 
68      L{Tier.Tier._executeTask}. 
69       
70      @param chooser: Chooser that fired the event 
71      @type chooser: L{AEChooser} 
72      @param kind: Kind of signal, APPLY, OK, or CANCEL or an arbitrary 
73      constant provided by the L{AEChooser} 
74      @type kind: integer 
75      @param kwargs: Arbitrary keyword arguments returned by the chooser 
76      @type kwargs: dictionary 
77      ''' 
78      return True 
79     
80 -  def executeEnd(self, chooser, **kwargs): 
81      ''' 
82      Executes this L{Task} in response to the ending of a chooser dialog.  
83      Called by L{Tier.Tier._executeTask}. 
84   
85      The default implementation calls L{Task.Tools.System.System.unloadChooser} 
86      which is the desired behavior for most L{ChooserTask}s. 
87   
88      @param chooser: Chooser that fired the event 
89      @type chooser: L{AEChooser} 
90      @param kwargs: Arbitrary keyword arguments returned by the chooser 
91      @type kwargs: dictionary 
92      ''' 
93      self.unloadChooser(chooser) 
94      return True 
95