Source Code for Module Task.ViewTask

  1  ''' 
  2  Defines a L{Task} to execute in response to a L{AEEvent.ViewChange}. 
  3   
  4  @author: Peter Parente 
  5  @organization: IBM Corporation 
  6  @copyright: Copyright (c) 2005, 2007 IBM Corporation 
  7  @license: The BSD License 
  8   
  9  All rights reserved. This program and the accompanying materials are made  
 10  available under the terms of the BSD license which accompanies 
 11  this distribution, and is available at 
 12  U{http://www.opensource.org/licenses/bsd-license.php} 
 13  ''' 
 14   
 15  import Base, EventTask, AEConstants 
 16  import AEEvent 
 17   
 18 -class ViewTask(EventTask.EventTask): 
 19    ''' 
 20    Executed when a view change occurs. 
 21     
 22    This class registers its name and whether it should be monitored by default 
 23    in an L{AEMonitor} using the L{Base.registerTaskType} function when this 
 24    module is first imported. An L{AEMonitor} can use this information to build 
 25    its menus.  
 26    ''' 
 27    Base.registerTaskType('ViewTask', True) 
 28     
 29 -  def getEventType(self): 
 30      ''' 
 31      @return: Type of L{AEEvent} this L{Task} wants to handle 
 32      @rtype: class 
 33      ''' 
 34      return AEEvent.ViewChange 
 35     
 36 -  def update(self, por, title, gained, layer, **kwargs): 
 37      ''' 
 38      Updates this L{Task} in response to a consumed view change event. Called by  
 39      L{Tier.Tier._executeTask}. 
 40       
 41      @param por: Point of regard to the root of the new view 
 42      @type por: L{POR} 
 43      @param title: Title of the view 
 44      @type title: string 
 45      @param gained: The kind of view change event 
 46      @type gained: integer 
 47      @param layer: Layer on which the event occurred 
 48      @type layer: integer 
 49      ''' 
 50      pass 
 51   
 52 -  def execute(self, por, title, gained, layer, **kwargs): 
 53      ''' 
 54      Executes this L{Task} in response to a view change event. Called by  
 55      L{Tier.Tier._executeTask}. 
 56       
 57      @param por: Point of regard to the root of the new view 
 58      @type por: L{POR} 
 59      @param title: Title of the view 
 60      @type title: string 
 61      @param gained: The kind of view change event 
 62      @type gained: integer 
 63      @param layer: Layer on which the event occurred 
 64      @type layer: integer 
 65      @return: True to allow other L{Task}s to process this event 
 66      @rtype: boolean 
 67      ''' 
 68      if gained == AEConstants.EVENT_VIEW_GAINED: 
 69        return self.executeGained(por=por, title=title, layer=layer, **kwargs) 
 70      elif gained == AEConstants.EVENT_VIEW_LOST: 
 71        return self.executeLost(por=por, title=title, layer=layer, **kwargs) 
 72      elif gained == AEConstants.EVENT_VIEW_STARTUP: 
 73        return self.executeStartup(por=por, title=title, layer=layer, **kwargs) 
 74      elif gained == AEConstants.EVENT_VIEW_FIRST_GAINED: 
 75        return self.executeFirstGained(por=por, title=title, layer=layer,  
 76                                       **kwargs) 
 77       
 78 -  def executeGained(self, por, title, layer, **kwargs): 
 79      ''' 
 80      Executes this L{Task} in response to a view gained event. Called by  
 81      L{execute}. 
 82       
 83      @param por: Point of regard to the root of the new view 
 84      @type por: L{POR} 
 85      @param title: Title of the view 
 86      @type title: string 
 87      @param layer: Layer on which the event occurred 
 88      @type layer: integer 
 89      @return: True to allow other L{Task}s to process this event 
 90      @rtype: boolean 
 91      ''' 
 92      return True 
 93     
 94 -  def executeLost(self, por, title, layer, **kwargs): 
 95      '''     
 96      Executes this L{Task} in response to a view lost event. Called by 
 97      L{execute}. 
 98       
 99      @param por: Point of regard to the root of the lost view 
100      @type por: L{POR} 
101      @param title: Title of the view 
102      @type title: string 
103      @param layer: Layer on which the event occurred 
104      @type layer: integer 
105      @return: True to allow other L{Task}s to process this event 
106      @rtype: boolean 
107      ''' 
108      return True 
109     
110 -  def executeStartup(self, por, title, layer, **kwargs): 
111      ''' 
112      Executes this L{Task} in response to the view being identified during LSR 
113      startup. Called by L{execute}. 
114       
115      @param por: Point of regard to the root of the mutated view 
116      @type por: L{POR} 
117      @param title: Title of the view 
118      @type title: string 
119      @param layer: Layer on which the event occurred 
120      @type layer: integer 
121      @return: True to allow other L{Task}s to process this event 
122      @rtype: boolean 
123      ''' 
124      return True 
125   
126 -  def executeFirstGained(self, por, title, layer, **kwargs): 
127      ''' 
128      Executes this L{Task} in response to the view being identified as the  
129      active view during LSR startup. Called by L{execute}. 
130       
131      @param por: Point of regard to the root of the mutated view 
132      @type por: L{POR} 
133      @param title: Title of the view 
134      @type title: string 
135      @param layer: Layer on which the event occurred 
136      @type layer: integer 
137      @return: True to allow other L{Task}s to process this event 
138      @rtype: boolean 
139      ''' 
140      return True 
141