Source Code for Module AEEvent.ViewChange

  1  ''' 
  2  Defines an L{AEEvent} indicating the view has been updated by the 
  3  L{ViewManager}. 
  4   
  5  @author: Peter Parente 
  6  @author: Pete Brunet 
  7  @organization: IBM Corporation 
  8  @copyright: Copyright (c) 2005, 2007 IBM Corporation 
  9  @license: The BSD License 
 10   
 11  All rights reserved. This program and the accompanying materials are made 
 12  available under the terms of the BSD license which accompanies 
 13  this distribution, and is available at 
 14  U{http://www.opensource.org/licenses/bsd-license.php} 
 15  ''' 
 16   
 17  import Base 
 18  import AEConstants 
 19  from AEInterfaces import * 
 20   
 21 -class ViewChange(Base.AccessEngineEvent): 
 22    ''' 
 23    Event that fires when the L{ViewManager} is creating or updating its view. 
 24     
 25    This class registers its name and whether it should be monitored by default 
 26    in an L{AEMonitor} using the L{Base.registerEventType} function when 
 27    this module is first imported. An L{AEMonitor} can use this information to 
 28    build its menus. 
 29   
 30    @ivar gained: Type of view change 
 31    @type gained: boolean 
 32    @ivar title: Name of the root element of the new view (e.g. title of the 
 33      foreground window) 
 34    @type title: string 
 35    ''' 
 36    Base.registerEventType('ViewChange', True) 
 37 -  def __init__(self, por, gained, **kwargs): 
 38      ''' 
 39      Stores the type of view change and intializes the title attribute to 
 40      an empty string. 
 41   
 42      @param por: Point-of-regard to the accessible at the root of the new view 
 43      @type por: L{POR}     
 44      @param gained: Type of view change 
 45      @type gained: integer 
 46      ''' 
 47      focused = gained in (AEConstants.EVENT_VIEW_GAINED,  
 48                           AEConstants.EVENT_VIEW_FIRST_GAINED) 
 49      Base.AccessEngineEvent.__init__(self, focused=focused, **kwargs) 
 50      self.por = por 
 51      self.gained = gained 
 52      self.title = '' 
 53       
 54 -  def __str__(self): 
 55      ''' 
 56      Returns a human readable representation of this event including its name, 
 57      its L{POR}, its type, and the title of the new view. 
 58       
 59      @return: Information about this event 
 60      @rtype: string 
 61      ''' 
 62      name = Base.AccessEngineEvent.__str__(self) 
 63      if self.gained == AEConstants.EVENT_VIEW_GAINED: 
 64        action = 'gained' 
 65      elif self.gained == AEConstants.EVENT_VIEW_LOST: 
 66        action = 'lost' 
 67      elif self.gained == AEConstants.EVENT_VIEW_FIRST_GAINED: 
 68        action = 'first gained' 
 69      elif self.gained == AEConstants.EVENT_VIEW_STARTUP: 
 70        action = 'startup' 
 71      return '%s:\n\tPOR: %s\n\ttitle: %s\n\taction: %s' % (name, self.por, 
 72                                                            self.title, action) 
 73   
 74 -  def execute(self, tier_manager, view_manager, **kwargs): 
 75      ''' 
 76      Stores the name of the root element of the new view in the title 
 77      attribute. Calls L{TierManager.TierManager.switchTier} to switch to the  
 78      appropriate L{Tier} for this view. Calls  
 79      L{TierManager.TierManager.manageEvent} to allow it to dispatch this 
 80      L{AEEvent} to the active L{Tier} and its registered L{Perk}. 
 81   
 82      @param tier_manager: TierManager that will handle the event 
 83      @type tier_manager: L{TierManager} 
 84      @param view_manager: ViewManager defining the current View 
 85      @type view_manager: L{ViewManager} 
 86      @param kwargs: Packed references to other managers not of interest here 
 87      @type kwargs: dictionary 
 88      @return: True to indicate the event executed properly 
 89      @rtype: boolean 
 90      ''' 
 91      # get the accessible name of the root element 
 92      ai = IAccessibleInfo(self.por) 
 93      try: 
 94        self.title = ai.getAccName() 
 95      except LookupError: 
 96        # view is dead 
 97        return True 
 98      if self.gained in (AEConstants.EVENT_VIEW_GAINED,  
 99                         AEConstants.EVENT_VIEW_FIRST_GAINED): 
100        # get information about the accessible's application 
101        try: 
102          aid = ai.getAccAppID() 
103          aname = ai.getAccAppName() 
104        except LookupError: 
105          # view is dead 
106          return True 
107        # inform the view manager of the AE view change 
108        view_manager.setAEView(self.por) 
109        # ask the tier manager to switch tiers first 
110        tier_manager.switchTier(aname, aid, self.por) 
111      elif self.gained == AEConstants.EVENT_VIEW_LOST: 
112        if self.por == view_manager.getAEView(): 
113          # only unset if the view being deactivated is still the active view 
114          view_manager.setAEView(None) 
115      # then process the view change event 
116      tier_manager.manageEvent(self) 
117      return True 
118     
119 -  def getDataForTask(self): 
120      ''' 
121      Fetches data out of this L{ViewChange} for use by a L{Task.ViewTask}. 
122       
123      @return: Dictionary of parameters to be passed to a L{Task.ViewTask} as 
124        follows: 
125          - por: Point of regard to the top of the new view 
126          - title: String containing the window title of the view which changed 
127          - gained: The type of view change, indicated by one of the integer 
128            class variables 
129      @rtype: dictionary 
130      ''' 
131      return {'title':self.title, 'gained':self.gained, 'por':self.getPOR()} 
132