Determining word wraps in Tkinter text widget

[Matthew Dixon Cowles]

On 28 Nov 2001 12:24:46 -0800, David Wangerin <dwangeri at uci.edu> wrote:

>By floating, I mean that I have a frame on the side of the textbox
>(it's filled so it is the same size as the textbox) that will contain
>the widgets.  There will be a set of widgets corresponding to each
>line in the textbox.  To keep the appearance of the text consistent, I
>would like to keep the controls outside of the textbox.  As the text
>is scrolled up or down, the frame with the widgets gets redrawn to
>reflect the new viewable text.  If I lock the size of the textbox, I
>can always know how many lines are being displayed, but whenever a
>line wraps, I need to lower that number by one (I can't have two sets
>of controls, one for the start of the line and another for the end of
>the line).  Horizontal scrollbars would solve this problem, but I will
>only use them as a last resort.

Dear David,

You can do that but the only technique I can think of is something of
a nuisance. You'll need to figure out how many dots tall a line is
(the tkFont module may help here) and then step down the widget one
line-height at a time and use the widget's index() method with
argument of the form @x,y to see if you've gone on to the next line of
text when you've gone down one line-height.

Here's a small example:

>>> from Tkinter import *
>>> r=Tk()
>>> t=Text(r,width=10)
>>> t.pack()
>>> t.insert(END,"one\ntwo\n")
>>> t.index("@0,5")
'1.0'
>>> t.index("@0,25")
'2.0'
>>> t.delete("1.0",END)
>>> t.insert("1.0","one two three four five six")
>>> t.index("@0,5")
'1.0'
>>> t.index("@0,25")
'1.10'

In the first case, going down 25 dots puts us at the beginning of line
two but in the second case, we're at the tenth character of line one.

Regards,
Matt