Source Code for Module diffpy.pdfgui.gui.wxExtensions.validators

  1  ############################################################################## 
  2  # 
  3  # wxExtensions      by DANSE Diffraction group 
  4  #                   Simon J. L. Billinge 
  5  #                   (c) 2006 trustees of the Michigan State University. 
  6  #                   All rights reserved. 
  7  # 
  8  # File coded by:    Chris Farrow 
  9  # 
 10  # See AUTHORS.txt for a list of people who contributed. 
 11  # See LICENSE.txt for license information. 
 12  # 
 13  ############################################################################## 
 14   
 15  """This module contains TextValidator, which is an input validator for the 
 16  wxTextCtrl. See the wxPython documentation for wxTextCtrl for more about text 
 17  validators. Three constants are defined for use in TextValidator: ALPHA_ONLY, 
 18  DIGIT_ONLY, and FLOAT_ONLY. See the TextValidator class for how these are used. 
 19  """ 
 20   
 21  # version 
 22  __id__ = "$Id: validators.py 2980 2009-04-02 00:14:33Z juhas $" 
 23   
 24  ALPHA_ONLY = 1 
 25  DIGIT_ONLY = 2 
 26  FLOAT_ONLY = 3 
 27  import wx 
 28  import string 
 29   
 30 -class TextValidator(wx.PyValidator): 
 31      """This validator is designed to check text input for wxTextCtrls. (It might 
 32      have uses in other widgets.) It can validate for letters only, digits only, 
 33      floats only, and can allow for a negative at the beginning of a digit string 
 34      or a negative float. 
 35      """ 
 36   
 37 -    def __init__(self, flag=DIGIT_ONLY, allowNeg=False): 
 38          """Initialize the validator. 
 39   
 40          flag        --  DIGIT_ONLY, allow only digits (default) 
 41                          ALPHA_ONLY, allow only letters 
 42                          FLOAT_ONLY, allow only floats 
 43   
 44          allowNeg    --  Allow a negative sign in front of DIGIT_ONLY, or 
 45                          FLOAT_ONLY text. (default False) 
 46          """ 
 47          wx.PyValidator.__init__(self) 
 48          self.flag = flag 
 49          self.allowNeg = allowNeg 
 50          self.Bind(wx.EVT_CHAR, self.OnChar) 
 51   
 52 -    def Clone(self): 
 53          return TextValidator(self.flag, self.allowNeg) 
 54   
 55 -    def Validate(self, win): 
 56          tc = self.GetWindow() 
 57          val = tc.GetValue() 
 58           
 59          if self.flag == ALPHA_ONLY: 
 60              # Check for letters 
 61              for x in val: 
 62                  if x not in string.letters: 
 63                      return False 
 64   
 65          elif self.flag == DIGIT_ONLY: 
 66   
 67              # Check for an initial negative 
 68              if self.allowNeg: 
 69                  if val[0] == '-': 
 70                      # Clip the negative for the next check 
 71                      if len(val) > 1: 
 72                          val = val[1:] 
 73                      else: 
 74                          val = "" 
 75   
 76              # Check the digits 
 77              for x in val: 
 78                  if x not in string.digits: 
 79                      return False 
 80   
 81          elif self.flag == FLOAT_ONLY: 
 82              try: 
 83                  x = float(val) 
 84                  if x < 0 and not self.allowNeg: 
 85                      return False 
 86              except ValueError: 
 87                  return False 
 88   
 89          return True 
 90   
 91 -    def OnChar(self, event): 
 92          key = event.GetKeyCode() 
 93   
 94          if key < wx.WXK_SPACE or key == wx.WXK_DELETE or key > 255: 
 95              event.Skip() 
 96              return 
 97   
 98          if self.flag == ALPHA_ONLY and chr(key) in string.letters: 
 99              event.Skip() 
100              return 
101   
102          if self.flag == DIGIT_ONLY:  
103              if chr(key) in string.digits: 
104                  event.Skip() 
105                  return 
106   
107              if self.allowNeg and chr(key) == '-': 
108                  # Don't allow a '-' sign any place but at the beginning 
109                  win = self.GetWindow() 
110                  if win.GetInsertionPoint() == 0 and win.GetValue().count('-') == 0: 
111                      event.Skip() 
112                      return 
113   
114          if self.flag == FLOAT_ONLY:  
115              win = self.GetWindow() 
116              val = win.GetValue() 
117              i = win.GetInsertionPoint() 
118              newval = val[:i]+chr(key)+val[i:] 
119              try: 
120                  x = float(newval+"1") # Catches "1e", a float to be 
121                  if x < 0: 
122                      if self.allowNeg: 
123                          event.Skip() 
124                          return 
125                  else: 
126                      event.Skip() 
127                      return 
128   
129              except ValueError: 
130                  pass 
131   
132          if not wx.Validator_IsSilent(): 
133              wx.Bell() 
134   
135          # Returning without calling even. Skip eats the event before it 
136          # gets to the text control 
137          return 
138   
139      # These are needed so the validator can work in dialogs. 
140 -    def TransferToWindow(self): 
141          return True 
142   
143 -    def TransferFromWindow(self): 
144          return True 
145   
146  # End of class TextValidator 
147