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From: John Torjo (john.lists_at_[hidden])
Date: 2004-11-12 14:56:54

Mathew Robertson wrote:

>>>The FOX GUI has exactly this capability, you can connect a variable directly to the widget, without requiring any glue code at all. In fact, you can connect the same variable to multiple widgets at the same time (eg a 'spinner' widget and an 'editeline'), without requiring the programmer to write any type of callback mechanism.
>>>This works because all GUI events are bi-directional. For more information, read:
>>That seems a lot of code, compared to:
>>Not to say about validation...
> The problem with this implementation is that the 'user_name' field cannot (usually)
> connect to more than one widget at a time.

That is a current limitation, but I don't think you need it so much.
Anyway, you can work around it, by listening to kill_focus events:
- you will have temporary variables, and each is bound to a control.
- You listen for kill_focus from these variables
- on kill_focus, you synchronize the temporary variables

> Also, most widget libraries dont allow you to connect a variable to a widget,
>and still allow user validation. This is because the widget library
> doesn't callback into the validation code,
> since it assumes that if it is connected to a widget, then no validation code is necessary.

That's the win32gui' advantage :)

"if it is connected to a widget, then no validation code is necessary."
- that really sounds silly.


John Torjo,    Contributing editor, C/C++ Users Journal
-- "Win32 GUI Generics" -- generics & GUI do mix, after all
-- v1.5 - tooltips at your fingertips (work for menus too!)
    + bitmap buttons (work for MessageBox too!)
    + tab dialogs, hyper links, lite html

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