Re: Properties

[Maciej Sobczak <see.my.homepage@gmail.com>]

On Dec 3, 5:43 am, "Randy Brukardt" <ra...@rrsoftware.com> wrote:

> When it comes to GUI programming, this supposedly "good design principle"
> often doesn't make any sense.
>
> For example, consider the series of SLED (Simple Little EDitor) examples in
> Claw. These show how a Notepad-like editor could be constructed using Claw.

Yes. There are two points, however:

1. Text editors (in particular text widgets) are both sources and
destinations of data. That is, they not only display something, they
also control the content by allowing the user to interact with it and
modify it. Thanks to this coupling of functionality (content control
and rendering) it makes sense to delegate the data structure
management to the same component as well. In this regard text widgets
are self-contained.
Unfortunately this reasoning has no applicability in a real-time
oscilloscope display, where such coupling does not occur - data source
is definitely separate from the rendering component so there is no
justification for coupling data model with widgets. On the contrary,
it makes perfect sense to decouple them - for starters, did I mention
several displays showing the same signal, but with different filtering
settings?

2. Your text-editing example has little relation to multitasking as a
general GUI feature. Of course one can imagine, for example, a
background spellchecker task or something in this area, but this is so
particular to the text editing domain that is hardly a justification
for requiring that the whole GUI framework must be task-safe.

--
Maciej Sobczak * http://www.inspirel.com