overriding tks text insert method

[Christof Ecker]

Hi Joseph, 

thanks for your comments. I have been playing with your code yesterday and I
discoverd an additional problem:
what I need is to execute a cleanup procedure AFTER text has been inserted or
deleted. If you override Tks default binding by an input handler routine, the
handler will be executed BEFORE the default binding.

This is because, the default bindings are bound to the text class, whereas the
"user"-bindings are bound to the class instrance and have therefore higher
priority and are therefore executed first.

Any idea ?

Christof



  > This should work fine. Tkinter.Text *is* a
Python class; its > insert() method just calls into an embedded Tcl interpreter
> to do the actual inserting.
> 
> Now if you want -keypresses- to be handled by your Python
> code, that's a different problem, because the key event
> handling happens at the Tcl level and the insert()
> method doesn't get called. You can handle that
> by binding to the "<Key>" event:
> 
> class MyText(Text):
> 
> 	def __init__(self):
> 		self.bind("<Key>",self.keyHit)
> 
> 	def keyHit(self,ev):
> 		# Process each and every keystroke...
> 
> Warning. This approach is littered with traps for the
> unwary. I went through this a few days ago while trying to
> fix the Tk text-widget bindings in Anygui. You can see how
> I handled various problems with this approach by looking
> at the latest CVS code from the Anygui project on
> SourceForge:
> 
> <URL: http://sourceforge.net/projects/anygui>
> 
> The relevant code is in anygui/lib/anygui/backends/tkgui.py.
> Look at the definition for the TextArea class. My code
> is not pretty, but it handles the particular problem
> I needed to handle, which was to make a Text widget
> selectable and copyable, but not editable (in Tk
> disabling a text widget also disables select+copy
> bindings, on Windows at least).
> 
> You will want to read the Events section of the Tkgui
> docs carefully, and the "bind" documentation that comes
> with Tcl/Tk.
> 
> Cheers,
> 
> -- 
> # Joe Knapka
> # "You know how many remote castles there are along the
> #  gorges? You can't MOVE for remote castles!" - Lu Tze re. Uberwald
> # Linux MM docs:
> http://home.earthlink.net/~jknapka/linux-mm/vmoutline.html
--