[Tutor] Dynamic TKinter widgets?

[Nathan]

Okay, now I see what I was doing wrong. For some dumb reason, I had
forgotten that you can create a widget without assigning a variable. That
helps runtime widget creation a LOT.

The Frame idea I had was actually writing out one Frame per type of spread;
I would have had, for example, celtic_cross_frame,
past_present_future_frame, etc. Selecting a different spread would hotswap
one spread Frame out for a new one and configure the widgets already
hardcoded in the Frame.

Then I remembered that all I need to do to create a widget is simply call
it and add it to the layout, so I just created a single Frame and a loop
that adds a variable number of widgets. Now I just destroy that Frame (and
thus, the widgets it holds), recreate it, and repopulate it.

Which, re-reading this discussion, is probably what you meant by standard
practice.

Thanks for your help!
On Nov 25, 2012 8:10 PM, "Nathan" <sdragon1984 at gmail.com> wrote:

>
> On Nov 25, 2012 6:49 PM, "ALAN GAULD" <alan.gauld at btinternet.com> wrote:
> >
> > CC'ing the list...
> >
>
> Oops, my bad. I forget to hit Reply All.
>
> >>
> >> I know you can use images instead of text with Labels, like you can
> with Buttons.
> >> The advantage of a Text widget, in this case, is that you can use both
> in the same widget.
> >> That way, I don't need to worry about how widgets are displayed,
> shuffled around, and
> >> undisplayed during runtime. One widget should handle everything.
> >>
> > Don't get hung up on the number of widgets. In the scheme of things
> widgets are not
> > expensive. Create them as you need them, delete them when you are done.
> Layout
> > managers are there to manage the layout for you. if you can define the
> layout in terms
> > of a grid then you can fill the grid with blanks to hold the shape and
> add/remove
> > widgets as you like.
> >
> > If you use pack you can either force the containing frame to a fixed
> size or allow it
> > to grow/shrink with the widgets. Either approach can work.
> >>
> >> This is standard? That's interesting to know. The biggest issue I'm
> having here is scalability.
> >> Each new spread is going to need a new frame widget, which in turn will
> need
> >> (number of cards in spread)*2 more widgets.
> >>
> > But that's how many? If its getting up beyond a couple of thousand then
> you might
> > have a problem. If its less than a hundred its not an issue. In between
> you might want
> > to be a bit clever.
>
> Well, that depends entirely on how many spreads I'll eventually have, and
> the average number of cards per spread. Celtic Cross, for example, is a ten
> card spread, so it needs 21 widgets by itself. A hundred widgets is reached
> with just 10 spreads averaging 4.5 cards each. I expect, ultimately, to
> have more than that.
>
> >>
> >> As noted above, the Text widget solution only needs one.
> >>
> > Actually it probably needs more. Each image is a widget too, so you just
> organise
> > the widgets inside a Text instead of inside a Frame or Canvas.
>
> Is that how it works on the source level, or "under the hood"? The code
> makes it look like I'm only writing one widget, with multiple text and
> image elements within it, but perhaps I'm misunderstanding something.
>
> The approach I'm taking now is a Label widget, containing a single string
> constructed with elements from lists. I'm hoping that I can take the same
> approach using a single Text widget, and just convert every other string
> element from a filename to an image.
>
> >All these things are
> > just containers for more widgets. Frames are designed to hold widgets,
> end of story.
> > Text is designed to *display* images and text - usually within a Frame.
> Canvas is
> > designed to *display* images and graphics shapes. If you want your
> images joined
> > or surrounded by lines/circles etc then go with Canvas. If you need to
> include
> > explanatory text around the images use a Text. If you want to create a
> reusable
> > widget that you can use in multiple screens or hot swap with other
> variants of
> > the same go with a Frame and build a display widget hierarchy. If you
> just want to
> > display a bunch of images it doesn't matter much which one you pick.
> >
>
> Then it seems Text it is. Perhaps later in development, Frames and/or
> Canvases might be appropriate for more complex designs.
>
> > I repeat, don't sweat over the widget count, that's not usually an issue.
> >
> > Alan G.
> >
>
> Thanks!
>
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