[Tkinter-discuss] Re: Yet Another Table widget...

[Martin Franklin]

Stewart Midwinter wrote:
> Cool!  that would be a very useful little widget.  
> 
> Maybe you'd also like to share with the list generally what's involved
> in writing python bindings for a tcl widget; there are a number of
> others out there that don't have such bindings yet, and maybe some of
> us on the list could take on the task of making them available.
> 
> 

Be glad to.... read on for a few preliminary gotcha's

First thing to note is that tablelist is pure Tcl package and can be
either installed in the standard tcl package location or you can tell
Tcl where it is (I choose the later since I don't always have permission
to install)


So I unwrapped the tarball into my home directory:-

/home/martin/tablelist4.7

To use the package from this location Tcl I need to execute this:-

root.tk.call("lappend", "auto_path", "/home/martin/tablelist3.7")

where root is my main Tk() instance.  I guess this is like appending a
path to python's sys.path


Next you have to register the package so that Tkinter can use/find it

root.tk.call("package", "require", "tablelist")

Next came the TableList class:

from Tkinter import *

class TableList(Widget):
     def __init__(self, master=None, cnf={}, **kw):
         Widget.__init__(self, master, 'tablelist::tablelist', cnf, kw)

Worth a mention is the tablelist::tablelist - it took me 20 minutes to
work this out... tablelist the Tcl widget is in a Tcl namespace called 
tablelist hence the :: notation I guess


After that it is a case of adding all the Tcl tablelist widget commands
(AKA methods) to my class - a slow and boring cut'n'paste from the web
based command reference... I'm still working on that bit but it boils 
down to this:

 From the tablelist reference:

pathName activatecell cellIndex
     Sets the active element to the one indicated by cellIndex if the 
tablelist's state is not disabled.  If cellIndex is outside the range of 
elements in the tablelist or it refers to a hidden element, then the 
closest non-hidden element is activated.  The active element is drawn as 
specified by the -activestyle configuration option when the widget has 
the input focus and the selection type is cell.  Its index may be 
retrieved with the cell index active.  Returns an empty string.



To this method:


     def activatecell(self, cellIndex):
         """Sets the active element to the one indicated by cellIndex
         if the tablelist"s state is not disabled.

         If cellIndex is outside the range of elements in the tablelist
         or it refers to a hidden element, then the closest non-hidden
         element is activated.  The active element is drawn as specified
         by the -activestyle configuration option when the widget has the
         input focus and the selection type is cell.  Its index may be
         retrieved with the cell index active.  Returns an empty string.
         """
         return self.tk.call((self._w, "activatecell", index))


As I said I'm still doing this last bit - I need to wrap all tablelist 
commands and make sure I return the correct type of object.  I also need 
to edit all the doc strings to look more Tkinter'ish and resist changing 
the names of the commands;-)


Cheers,
Martin.