Source Code for Module AEInput.SystemInput

  1  ''' 
  2  Defines an abstract base class for all input devices that serve double duty as  
  3  sources of input for LSR and for the rest of the operating system. 
  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, AEConstants 
 16   
 17 -class SystemInput(Base.AEInput): 
 18    ''' 
 19    Abstract base class for input devices that are used by both LSR and the OS. 
 20    Provides an interface for registering modifier actions that can be used to 
 21    indicate the start of commands intended for LSR. Also provides an interface 
 22    for registering filtered L{GestureList}s that indicate which combination of 
 23    L{Gesture}s should not be passed to other applications. The definition of what 
 24    constitues a valid L{Gesture} and L{GestureList} is left to a subclass. The 
 25    decision as to when registered L{Gesture}s are filtered or not is determined 
 26    by a mode managed in this class via L{getFilterMode} and L{setFilterMode}. 
 27     
 28    This class is abstract as some of the methods inherited from  
 29    L{Base.AEInput} are not overridden and raise NotImplementedError. 
 30     
 31    @ivar modifiers: Dictionary of action codes that are considered modifiers 
 32    @type modifiers: dictionary 
 33    @ivar filter_mode: Mode that determines which L{Gesture}s are filtered 
 34    @type filter_mode: integer 
 35    ''' 
 36 -  def __init__(self): 
 37      ''' 
 38      Initializes the filters to an empty list, the modifiers to an empty 
 39      dictionary, and the filtering mode to none. 
 40      ''' 
 41      Base.AEInput.__init__(self) 
 42      self.modifiers = {} 
 43      self.filter_mode = AEConstants.FILTER_NONE 
 44       
 45 -  def getCapabilities(self): 
 46      ''' 
 47      @return: 'system input' as the only capability of this device. 
 48      @rtype: list of string 
 49      ''' 
 50      return ['system input'] 
 51   
 52 -  def getFilterMode(self): 
 53      ''' 
 54      Gets the current filter mode. 
 55       
 56      @return: Current filter mode 
 57      @rtype: integer 
 58      ''' 
 59      return self.filter_mode 
 60       
 61 -  def setFilterMode(self, mode): 
 62      ''' 
 63      Stores the current filter mode. 
 64       
 65      @param mode: Current filter mode 
 66      @type mode: integer 
 67      ''' 
 68      self.filter_mode = mode 
 69       
 70 -  def addModifier(self, code): 
 71      '''  
 72      Adds an action code to the modifiers dictionary to identify it as a modifier 
 73      for other actions.   
 74       
 75      @param code: Action code to register as a modifier 
 76      @type code: integer 
 77      ''' 
 78      try: 
 79        self.modifiers[code] += 1 
 80      except KeyError: 
 81        self.modifiers[code] = 1 
 82       
 83 -  def removeModifier(self, code): 
 84      ''' 
 85      Removes an action code from the modifiers dictionary if it is no longer 
 86      in use.  Otherwise, it decrements the reference count. 
 87       
 88      @param code: Action code to unregister as a modifier 
 89      @type code: integer 
 90      ''' 
 91      try: 
 92        self.modifiers[code] -= 1 
 93        if self.modifiers[code] <= 0: 
 94          del self.modifiers[code] 
 95      except KeyError: 
 96        pass 
 97       
 98 -  def clearModifiers(self): 
 99      ''' 
100      Removes all modifiers by destroying the modifiers dictionary and recreating 
101      it. 
102      ''' 
103      self.modifiers = {} 
104   
105 -  def addFilter(self, gestures): 
106      ''' 
107      Abstact method. Adds a L{GestureList} as a filter to this device. A filter 
108      typically indicates input that should be consumed and prevented from  
109      reaching other applications. Exactly how the filter is stored and used is  
110      determined by a subclass. 
111       
112      @param gestures: L{Gesture}s to possibly filter 
113      @type gestures: L{GestureList} 
114      @raise NotImplementedError: When this method is not overridden by a  
115        subclass 
116      ''' 
117      raise NotImplementedError 
118       
119 -  def removeFilter(self, gestures): 
120      ''' 
121      Abstract method. Removes a L{GestureList} as a filter from this device.  
122      A filter typically indicates input that should be consumed and prevented  
123      from reaching other applications. How the filter is removed is determined  
124      by a subclass. 
125       
126      @param gestures: L{Gesture}s to no longer filter 
127      @type gestures: L{GestureList} 
128      @raise NotImplementedError: When this method is not overridden by a 
129        subclass 
130      ''' 
131      raise NotImplementedError 
132     
133 -  def clearFilters(self): 
134      '''     
135      Abstract method. Removes all L{GestureList} filters from the device. How  
136      the filters are removed is determined by a subclass. A filter typically  
137      indicates input that should be consumed and prevented from reaching other  
138      applications. Exactly How the filter is removed is determined by a  
139      subclass. 
140       
141      @raise NotImplementedError: When this method is not overridden by a  
142        subclass 
143      ''' 
144      raise NotImplementedError 
145   
146 -  def resetState(self): 
147      ''' 
148      Abstract method. Resets the state of the input device. 
149   
150      @raise NotImplementedError: When not overridden in a subclass 
151      ''' 
152      raise NotImplementedError 
153