[Tutor] Tkinter: Can's figure out how to put a frame in a second window

[Chris Roy-Smith]

On 9/3/19 10:13 pm, Alan Gauld via Tutor wrote:
> On 09/03/2019 02:53, Chris Roy-Smith wrote:
>
>> What is happening is that the contents of the frame appear in the master
>> window. I was expecting them to show in the second window. Also I
>> expected the frame to be sunken, but there is no obvious signs of the
>> frame, not even a colored background.
>>
>> What am I doing wrong?
> Its a very common mistake in Tkinter.
> When you use one of the layout managers, in this case grid()
> the return value is always None.
>
>> def NewWindow():
>>       sw=Toplevel(master)
>>       sw.title('New Window')
>>       Label(sw, text='new window').grid(row=0, column=0)
>>       sframe=Frame(sw, relief=SUNKEN, bg='red').grid(row=1, column=0)
> So you are here assigning None to sframe.
>
>>       Label(sframe, text='Label in a frame').grid(row=2, column=0)
>>       Label(sframe, text='Second label in this frame').grid(row=3, column=0)
> And when you pass None as the parent to a widget Tk
> defaults to the root. So your widgets appear in your main window.
>
> Change the sframe line to two lines:
>
> sframe=Frame(sw, relief=SUNKEN, bg='red')
> sframe.grid(row=1, column=0)
>
>
> and all will be well....
>
> except the sunken relief wont work.
> TYhats because the sunken form requires a border width of at least 2
> pixels to be visible. So you need to add border=2 (or more) to make
> it work.
>
> So the final line should be:
>
> sframe=Frame(sw, border=2, relief=SUNKEN, bg='red')
> sframe.grid(row=1, column=0)
>
> As I say its a very common mistake and so, any time weird things
> happen, always check that anywhere you assign a widget to a variable
> you call the layout manager on a separate line.
>
> HTH

Thanks Alan,

Simple when you know. I remember having a similar issue with Entry widgets,

Regards, Chris Roy-Smith