[tkinter] widget size adjustment

[Pierre-Alain Dorange]

Christian Gollwitzer <auriocus at gmx.de> wrote:

> Perhaps your assumption is wrong. Maybe the canvas itself *is* resized,
> so the white space you see around the image is the background of the 
> canvas. To test this easily, set a strong color for the background:
> 
>       blabla = tk.Canvas(..., bg='red')
> 
> You should see red space appear when you resize the window. If you see
> white space, then the options are not set properly and the canvas is not
> resized.

I've allready a background by not displayed, so the canvas is not
automatilly resized.

> 
> I assume that you want the following: Upon resizing the main window, the
> map image should be stretched to fill the space, right? Then you'll have
> to do that on your own. First, bind a Configure event to the canvas
> 
>       canvas.bind('<Configure>', callback)

I do this, the callback is called when window was resized, but
unfortunnally i was not able to get the "available space (in pixels)".

event.width and event.height just return the actual canvas size... not
useful

canvas.winfo_width() return the actual canvas size... not useful
just note that it works when user resize down, the returned values
correspond to the visual portion of the canvas. But do not work when
enlarge...

canvas.winfo_reqwidth() just return the size when the canvas was
originally created... not useful...
> 
> The callback functino now gets called when the canvas needs to be 
> redrawn. In that callback function, you get the new width and height 
> from the event object. Resize the image accordingly (using a PIL function).

I miss something, here event.width just return me the canvas size, not
resized...

The full code was on github :
<https://github.com/padorange/pmx-bigmap>

the tkinter code is in pmx.py
        the canvas class was TMap
        GUI was created in main_gui.__init__()
        callback function was main_gui.resize()

-- 
Pierre-Alain Dorange        <http://microwar.sourceforge.net/>

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