[tkinter] two questions regarding Canvas

[Greg McFarlane]

This is small attempt at adding editing bindings to canvas text items. 
This *must* have been done before, but a search of comp.lang.tcl did
not come up with anything, except a mention of pg_access in postgresql
which I could not find.  Does anyone know of it?

======================================================================
import Tkinter 

def click(event):
    canvas.delete('rect')
    region = canvas.bbox('current')
    if region is None:
        canvas.focus('')
    else:
        canvas.create_rectangle(region, outline = 'blue', tags = 'rect')
        canvas.focus('current')
        canvas.icursor('current', '@%d,%d' % (event.x, event.y))

def double(event):
    canvas.select_from('current', 0)
    canvas.select_to('current', 'end')

root = Tkinter.Tk()
canvas = Tkinter.Canvas(root)
canvas.pack()

canvas.bind('<Button-1>', click)
item1 = canvas.create_text(100, 100, text = 'Hello\nthere', tags = 'text')
item2 = canvas.create_text(200, 100, text = 'Good evening', tags = 'text')

canvas.focus_set()

# Need lots more bindings: button motion (for changing the selection),
# keys (for adding and deleting text), etc (same as text widget).
canvas.tag_bind('text', '<Double-1>', double)

root.mainloop()   
======================================================================

On 2 Jun, Joseph Robertson wrote:
> Sure does,  heres some relevant clips.  Sorry I couldn't send the whole
> thing but its too big.
> I have a class that creates the canvas, then I set the binding:
> 
> def __init__(self)
> ...
> self.canvas.bind('<Button-1>', self.CellClick)
> ...
> 
> Heres the working method:
> def CellClick(self, event):
>         self.canvas.delete('rect')
>         cellbbox = self.canvas.bbox('current')
>         self.canvas.create_rectangle(cellbbox, outline='blue',
> tags='rect')
> 
> 
> Now I don't have it editable yet, I am using this,
>     item = self.canvas.create_text(xpos, ypos,  text=field, font=self.f)
> 
> in a loop to put data onto the canvas.
> 
> I'm sure that creating a hidden Entry and the moving it and making it
> visible would work fine, or don't move it and make a 'status line' type
> of data editing, like Lotus did.
> 
> Good Luck,
> Joe
> 
> 
> 
> mlauer at amalia-atm.rz.uni-frankfurt.de wrote:
> 
> > Howdy, though I'm gaining knowledge through
> > browsing through all the available documentation
> > (that is, the tkinter life-preserver, tkinter.py
> > and the tk/tcl documentation) some things
> > remain misterious...
> >
> > For instance:
> >
> > a) Does the tk Canvas support "inplace" editing of
> > text items or what are the functions Canvas.icursor
> > and Canvas.focus for ? If so, how ? For instance,
> > binding the <Any-Enter> to a text item function,
> > which sets icursor and focus doesn't work for me
> > (yes, the canvas has the current focus)
> >
> > b) Does the Canvas support a visible selection
> > of items (such as a boundaring rectangle or so)
> > on its own or have I to do this via binding <Any-Enter>
> > and <Any-Leave> ?
> >
> > Have a nice day!
> >
> > --
> >     Regards & Gruesse from Mickey @ http://www.Vanille.de
> >   ---------------------------------------------------------
> >   How could anyone know me - when I don't even know myself ?
> 
> 
> 
> 
> 

-- 
Greg McFarlane:    INMS Telstra Australia (gregm at iname.com)
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