Lib/lib-tk/tkSimpleDialog.py

   1 #
   2 # An Introduction to Tkinter
   3 # tkSimpleDialog.py
   4 #
   5 # Copyright (c) 1997 by Fredrik Lundh
   6 #
   7 # fredrik@pythonware.com
   8 # http://www.pythonware.com
   9 #
  10
  11 # --------------------------------------------------------------------
  12 # dialog base class
  13
  14 '''Dialog boxes
  15
  16 This module handles dialog boxes. It contains the following
  17 public symbols:
  18
  19 Dialog -- a base class for dialogs
  20
  21 askinteger -- get an integer from the user
  22
  23 askfloat -- get a float from the user
  24
  25 askstring -- get a string from the user
  26 '''
  27
  28 from Tkinter import *
  29 import os
  30
  31 class Dialog(Toplevel):
  32
  33     '''Class to open dialogs.
  34
  35     This class is intended as a base class for custom dialogs
  36     '''
  37
  38     def __init__(self, parent, title = None):
  39
  40         '''Initialize a dialog.
  41
  42         Arguments:
  43
  44             parent -- a parent window (the application window)
  45
  46             title -- the dialog title
  47         '''
  48         Toplevel.__init__(self, parent)
  49         self.transient(parent)
  50
  51         if title:
  52             self.title(title)
  53
  54         self.parent = parent
  55
  56         self.result = None
  57
  58         body = Frame(self)
  59         self.initial_focus = self.body(body)
  60         body.pack(padx=5, pady=5)
  61
  62         self.buttonbox()
  63
  64         self.grab_set()
  65
  66         if not self.initial_focus:
  67             self.initial_focus = self
  68
  69         self.protocol("WM_DELETE_WINDOW", self.cancel)
  70
  71         self.geometry("+%d+%d" % (parent.winfo_rootx()+50,
  72                                   parent.winfo_rooty()+50))
  73
  74         self.initial_focus.focus_set()
  75
  76         self.wait_window(self)
  77
  78     def destroy(self):
  79         '''Destroy the window'''
  80         self.initial_focus = None
  81         Toplevel.destroy(self)
  82
  83     #
  84     # construction hooks
  85
  86     def body(self, master):
  87         '''create dialog body.
  88
  89         return widget that should have initial focus.
  90         This method should be overridden, and is called
  91         by the __init__ method.
  92         '''
  93         pass
  94
  95     def buttonbox(self):
  96         '''add standard button box.
  97
  98         override if you don't want the standard buttons
  99         '''
 100
 101         box = Frame(self)
 102
 103         w = Button(box, text="OK", width=10, command=self.ok, default=ACTIVE)
 104         w.pack(side=LEFT, padx=5, pady=5)
 105         w = Button(box, text="Cancel", width=10, command=self.cancel)
 106         w.pack(side=LEFT, padx=5, pady=5)
 107
 108         self.bind("<Return>", self.ok)
 109         self.bind("<Escape>", self.cancel)
 110
 111         box.pack()
 112
 113     #
 114     # standard button semantics
 115
 116     def ok(self, event=None):
 117
 118         if not self.validate():
 119             self.initial_focus.focus_set() # put focus back
 120             return
 121
 122         self.withdraw()
 123         self.update_idletasks()
 124
 125         self.apply()
 126
 127         self.cancel()
 128
 129     def cancel(self, event=None):
 130
 131         # put focus back to the parent window
 132         self.parent.focus_set()
 133         self.destroy()
 134
 135     #
 136     # command hooks
 137
 138     def validate(self):
 139         '''validate the data
 140
 141         This method is called automatically to validate the data before the
 142         dialog is destroyed. By default, it always validates OK.
 143         '''
 144
 145         return 1 # override
 146
 147     def apply(self):
 148         '''process the data
 149
 150         This method is called automatically to process the data, *after*
 151         the dialog is destroyed. By default, it does nothing.
 152         '''
 153
 154         pass # override
 155
 156
 157 # --------------------------------------------------------------------
 158 # convenience dialogues
 159
 160 class _QueryDialog(Dialog):
 161
 162     def __init__(self, title, prompt,
 163                  initialvalue=None,
 164                  minvalue = None, maxvalue = None,
 165                  parent = None):
 166
 167         if not parent:
 168             import Tkinter
 169             parent = Tkinter._default_root
 170
 171         self.prompt   = prompt
 172         self.minvalue = minvalue
 173         self.maxvalue = maxvalue
 174
 175         self.initialvalue = initialvalue
 176
 177         Dialog.__init__(self, parent, title)
 178
 179     def destroy(self):
 180         self.entry = None
 181         Dialog.destroy(self)
 182
 183     def body(self, master):
 184
 185         w = Label(master, text=self.prompt, justify=LEFT)
 186         w.grid(row=0, padx=5, sticky=W)
 187
 188         self.entry = Entry(master, name="entry")
 189         self.entry.grid(row=1, padx=5, sticky=W+E)
 190
 191         if self.initialvalue:
 192             self.entry.insert(0, self.initialvalue)
 193             self.entry.select_range(0, END)
 194
 195         return self.entry
 196
 197     def validate(self):
 198
 199         import tkMessageBox
 200
 201         try:
 202             result = self.getresult()
 203         except ValueError:
 204             tkMessageBox.showwarning(
 205                 "Illegal value",
 206                 self.errormessage + "\nPlease try again",
 207                 parent = self
 208             )
 209             return 0
 210
 211         if self.minvalue is not None and result < self.minvalue:
 212             tkMessageBox.showwarning(
 213                 "Too small",
 214                 "The allowed minimum value is %s. "
 215                 "Please try again." % self.minvalue,
 216                 parent = self
 217             )
 218             return 0
 219
 220         if self.maxvalue is not None and result > self.maxvalue:
 221             tkMessageBox.showwarning(
 222                 "Too large",
 223                 "The allowed maximum value is %s. "
 224                 "Please try again." % self.maxvalue,
 225                 parent = self
 226             )
 227             return 0
 228
 229         self.result = result
 230
 231         return 1
 232
 233
 234 class _QueryInteger(_QueryDialog):
 235     errormessage = "Not an integer."
 236     def getresult(self):
 237         return int(self.entry.get())
 238
 239 def askinteger(title, prompt, **kw):
 240     '''get an integer from the user
 241
 242     Arguments:
 243
 244         title -- the dialog title
 245         prompt -- the label text
 246         **kw -- see SimpleDialog class
 247
 248     Return value is an integer
 249     '''
 250     d = apply(_QueryInteger, (title, prompt), kw)
 251     return d.result
 252
 253 class _QueryFloat(_QueryDialog):
 254     errormessage = "Not a floating point value."
 255     def getresult(self):
 256         return float(self.entry.get())
 257
 258 def askfloat(title, prompt, **kw):
 259     '''get a float from the user
 260
 261     Arguments:
 262
 263         title -- the dialog title
 264         prompt -- the label text
 265         **kw -- see SimpleDialog class
 266
 267     Return value is a float
 268     '''
 269     d = apply(_QueryFloat, (title, prompt), kw)
 270     return d.result
 271
 272 class _QueryString(_QueryDialog):
 273     def getresult(self):
 274         return self.entry.get()
 275
 276 def askstring(title, prompt, **kw):
 277     '''get a string from the user
 278
 279     Arguments:
 280
 281         title -- the dialog title
 282         prompt -- the label text
 283         **kw -- see SimpleDialog class
 284
 285     Return value is a string
 286     '''
 287     d = apply(_QueryString, (title, prompt), kw)
 288     return d.result
 289
 290 if __name__ == "__main__":
 291
 292     root = Tk()
 293     root.update()
 294
 295     print askinteger("Spam", "Egg count", initialvalue=12*12)
 296     print askfloat("Spam", "Egg weight\n(in tons)", minvalue=1, maxvalue=100)
 297     print askstring("Spam", "Egg label")