Source Code for Module AccessEngine.AEDevice.AEInput.SystemInput

  1  ''' 
  2  Defines an abstract base class for all input devices that serve double duty as  
  3  sources of input for SUE 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  @author: Frank Zenker 
 11  @organization: IT Science Center Ruegen gGmbH, Germany 
 12  @copyright: Copyright (c) 2007, 2008 ITSC Ruegen 
 13  @license: The BSD License 
 14   
 15  All rights reserved. This program and the accompanying materials are made  
 16  available under the terms of the BSD license which accompanies 
 17  this distribution, and is available at 
 18  U{http://www.opensource.org/licenses/bsd-license.php} 
 19  ''' 
 20  import Base 
 21  from AccessEngine import AEConstants 
 22   
 23 -class SystemInput(Base.AEInput): 
 24    ''' 
 25    Abstract base class for input devices that are used by both SUE and the OS. 
 26    Provides an interface for registering modifier actions that can be used to 
 27    indicate the start of commands intended for SUE. Also provides an interface 
 28    for registering filtered L{GestureList}s that indicate which combination of 
 29    L{Gesture}s should not be passed to other applications. The definition of what 
 30    constitues a valid L{Gesture} and L{GestureList} is left to a subclass. The 
 31    decision as to when registered L{Gesture}s are filtered or not is determined 
 32    by a mode managed in this class via L{getFilterMode} and L{setFilterMode}. 
 33     
 34    This class is abstract as some of the methods inherited from  
 35    L{Base.AEInput} are not overridden and raise NotImplementedError. 
 36     
 37    @ivar modifiers: Dictionary of action codes that are considered modifiers 
 38    @type modifiers: dictionary 
 39    @ivar filter_mode: Mode that determines which L{Gesture}s are filtered 
 40    @type filter_mode: integer 
 41    ''' 
 42 -  def __init__(self): 
 43      ''' 
 44      Initializes the filters to an empty list, the modifiers to an empty 
 45      dictionary, and the filtering mode to none. 
 46      ''' 
 47      Base.AEInput.__init__(self) 
 48      self.modifiers = {} 
 49      self.filter_mode = AEConstants.FILTER_NONE 
 50       
 51 -  def getCapabilities(self): 
 52      ''' 
 53      @return: 'system input' as the only capability of this device. 
 54      @rtype: list of string 
 55      ''' 
 56      return ['system input'] 
 57   
 58 -  def getFilterMode(self): 
 59      ''' 
 60      Gets the current filter mode. 
 61       
 62      @return: Current filter mode 
 63      @rtype: integer 
 64      ''' 
 65      return self.filter_mode 
 66       
 67 -  def setFilterMode(self, mode): 
 68      ''' 
 69      Stores the current filter mode. 
 70       
 71      @param mode: Current filter mode 
 72      @type mode: integer 
 73      ''' 
 74      self.filter_mode = mode 
 75       
 76 -  def addModifier(self, code): 
 77      '''  
 78      Adds an action code to the modifiers dictionary to identify it as a modifier 
 79      for other actions.   
 80       
 81      @param code: Action code to register as a modifier 
 82      @type code: integer 
 83      ''' 
 84      try: 
 85        self.modifiers[code] += 1 
 86      except KeyError: 
 87        self.modifiers[code] = 1 
 88       
 89 -  def removeModifier(self, code): 
 90      ''' 
 91      Removes an action code from the modifiers dictionary if it is no longer 
 92      in use.  Otherwise, it decrements the reference count. 
 93       
 94      @param code: Action code to unregister as a modifier 
 95      @type code: integer 
 96      ''' 
 97      try: 
 98        self.modifiers[code] -= 1 
 99        if self.modifiers[code] <= 0: 
100          del self.modifiers[code] 
101      except KeyError: 
102        pass 
103       
104 -  def clearModifiers(self): 
105      ''' 
106      Removes all modifiers by destroying the modifiers dictionary and recreating 
107      it. 
108      ''' 
109      self.modifiers = {} 
110   
111 -  def addFilter(self, gestures): 
112      ''' 
113      Abstact method. Adds a L{GestureList} as a filter to this device. A filter 
114      typically indicates input that should be consumed and prevented from  
115      reaching other applications. Exactly how the filter is stored and used is  
116      determined by a subclass. 
117       
118      @param gestures: L{Gesture}s to possibly filter 
119      @type gestures: L{GestureList} 
120      @raise NotImplementedError: When this method is not overridden by a  
121        subclass 
122      ''' 
123      raise NotImplementedError 
124       
125 -  def removeFilter(self, gestures): 
126      ''' 
127      Abstract method. Removes a L{GestureList} as a filter from this device.  
128      A filter typically indicates input that should be consumed and prevented  
129      from reaching other applications. How the filter is removed is determined  
130      by a subclass. 
131       
132      @param gestures: L{Gesture}s to no longer filter 
133      @type gestures: L{GestureList} 
134      @raise NotImplementedError: When this method is not overridden by a 
135        subclass 
136      ''' 
137      raise NotImplementedError 
138     
139 -  def clearFilters(self): 
140      '''     
141      Abstract method. Removes all L{GestureList} filters from the device. How  
142      the filters are removed is determined by a subclass. A filter typically  
143      indicates input that should be consumed and prevented from reaching other  
144      applications. Exactly How the filter is removed is determined by a  
145      subclass. 
146       
147      @raise NotImplementedError: When this method is not overridden by a  
148        subclass 
149      ''' 
150      raise NotImplementedError 
151   
152 -  def resetState(self): 
153      ''' 
154      Abstract method. Resets the state of the input device. 
155   
156      @raise NotImplementedError: When not overridden in a subclass 
157      ''' 
158      raise NotImplementedError 
159