self.clearAllText()
self.text.edit_reset() # 2.0: clear undo/redo stks
self.text.edit_modified(0) # 2.0: clear modified flag
self.knownEncoding = None # 2.1: Unicode type unknown

def onQuit(self):
"""
on Quit menu/toolbar select and wm border X button in toplevel windows;
2.1: don't exit app if others changed; 2.0: don't ask if self unchanged;
moved to the top-level window classes at the end since may vary per usage:
a Quit in GUI might quit() to exit, destroy() just one Toplevel, Tk, or
edit frame, or not be provided at all when run as an attached component;
check self for changes, and if might quit(), main windows should check
other windows in the process-wide list to see if they have changed too;
"""
assert False, 'onQuit must be defined in window-specific sublass'

def text_edit_modified(self):
"""
2.1: this now works! seems to have been a bool result type issue in tkinter;
2.0: self.text.edit_modified() broken in Python 2.4: do manually for now;
"""
return self.text.edit_modified()
#return self.tk.call((self.text._w, 'edit') + ('modified', None))

############################################################################

Edit menu commands

############################################################################

def onUndo(self): # 2.0
try: # tk8.4 keeps undo/redo stacks
self.text.edit_undo() # exception if stacks empty
except TclError: # menu tear-offs for quick undo
showinfo('PyEdit', 'Nothing to undo')

def onRedo(self): # 2.0: redo an undone
try:
self.text.edit_redo()
except TclError:
showinfo('PyEdit', 'Nothing to redo')

def onCopy(self): # get text selected by mouse, etc.
if not self.text.tag_ranges(SEL): # save in cross-app clipboard
showerror('PyEdit', 'No text selected')
else:
text = self.text.get(SEL_FIRST, SEL_LAST)
self.clipboard_clear()
self.clipboard_append(text)

def onDelete(self): # delete selected text, no save
if not self.text.tag_ranges(SEL):
showerror('PyEdit', 'No text selected')
else:
self.text.delete(SEL_FIRST, SEL_LAST)

PyEdit: A Text Editor Program/Object | 705