Source Code for Module Task.ScreenTask

  1  ''' 
  2  Defines a L{Task} to execute when some aspective of an accessible's or item's 
  3  appearance on the screen changes. 
  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   
 16  import Base, EventTask, AEConstants 
 17  import AEEvent 
 18   
 19 -class ScreenTask(EventTask.EventTask): 
 20    ''' 
 21    Executed when bounds or visible data changes. 
 22   
 23    This class registers its name and whether it should be monitored by default  
 24    in an L{AEMonitor} using the L{Base.registerTaskType} function 
 25    when this module is first imported. The L{AEMonitor} can use this 
 26    information to build its menus. 
 27    ''' 
 28    Base.registerTaskType('ScreenTask', False) 
 29   
 30 -  def getEventType(self): 
 31      ''' 
 32      @return: Type of L{AEEvent} this L{Task} wants to handle 
 33      @rtype: class 
 34      ''' 
 35      return AEEvent.ScreenChange 
 36     
 37 -  def update(self, por, kind, layer, **kwargs): 
 38      ''' 
 39      Updates this L{Task} in response to a consumed screen change event. Called  
 40      by L{Tier.Tier._executeTask}. 
 41       
 42      @param por: Point of regard for the related accessible/item 
 43      @type por: L{POR} 
 44      @param kind: Indicates the kind of selection event 
 45      @type kind: integer 
 46      @param layer: Layer on which the event occurred 
 47      @type layer: integer 
 48      ''' 
 49      pass 
 50     
 51 -  def execute(self, por, kind, layer, **kwargs): 
 52      ''' 
 53      Executes this L{Task} in response to a screen change event. Called by  
 54      L{Tier.Tier._executeTask}. 
 55       
 56      @param por: Point of regard for the related accessible/item 
 57      @type por: L{POR} 
 58      @param kind: Indicates the kind of selection event 
 59      @type kind: integer 
 60      @param layer: Layer on which the event occurred 
 61      @type layer: integer 
 62      @return: True to allow other L{Task}s to process this event 
 63      @rtype: boolean 
 64      ''' 
 65      if kind == AEConstants.SCREEN_OBJECT_BOUNDS: 
 66        return self.executeResized(por=por, layer=layer, **kwargs) 
 67      elif kind == AEConstants.SCREEN_TEXT_BOUNDS: 
 68        return self.executeReflowed(por=por, layer=layer, **kwargs) 
 69      else: 
 70        return self.executeRefreshed(por=por, layer=layer, **kwargs) 
 71         
 72 -  def executeResized(self, por, layer, **kwargs): 
 73      ''' 
 74      Executes this L{Task} in response to a change in the bounds of an object. 
 75       
 76      @param por: Point of regard for the related accessible/item 
 77      @type por: L{POR} 
 78      @param layer: Layer on which the event occurred 
 79      @type layer: integer 
 80      @return: True to allow other L{Task}s to process this event 
 81      @rtype: boolean 
 82      ''' 
 83      return True 
 84     
 85 -  def executeReflowed(self, por, layer, **kwargs): 
 86      ''' 
 87      Executes this L{Task} in response to a change in the bounds of a body of 
 88      text. 
 89       
 90      @param por: Point of regard for the related accessible/item 
 91      @type por: L{POR} 
 92      @param layer: Layer on which the event occurred 
 93      @type layer: integer 
 94      @return: True to allow other L{Task}s to process this event 
 95      @rtype: boolean 
 96      ''' 
 97      return True 
 98     
 99 -  def executeRefreshed(self, por, layer, **kwargs): 
100      ''' 
101      Executes this L{Task} in response to a change in the visible data on an 
102      object. 
103       
104      @param por: Point of regard for the related accessible/item 
105      @type por: L{POR} 
106      @param layer: Layer on which the event occurred 
107      @type layer: integer 
108      @return: True to allow other L{Task}s to process this event 
109      @rtype: boolean 
110      ''' 
111      return True 
112