[Adonthell-devel] Re: GUI border and background

[Kai Sterker]

On Sat, Aug 7, 2010 at 5:48 PM, Kai Sterker <address@hidden> wrote:

> Started with that work, and came up with the following concept:
>
> We create a "decoration" class that is initialized from a data file.
> The decoration class can then create a widget/container background
> with an optional border (and a scrollbar in the future). All these
> elements are painted onto a surface the size of the widget/container
> and can then be used as a rubber stamp whenever the widget/container
> needs to be redrawn. If the container/widget is resized, we'll
> recreate the surface.

Well, I've pretty much implemented the decoration class and started
updating the rest of the gui stuff to make use of it.

In doing so, I've also started formatting and documenting the gui code
and tying it a bit more into the engine, in places. One of the things
I've done is letting gui::base inherit from gfx::drawable, as
gui::base had both a draw method and a width and height. All that is
exactly what gfx::drawable already provides. And it kind of was the
plan to make anything that can be drawn somewhere a drawable. So far
so good, but here's the issue:

gfx::drawable::draw is declared as const. gui::base::draw was not and
quite a few of the widgets have code in their draw() implementation
that modifies class members. So here's the question: is there a quick
way to work around these problems (other than removing the const from
drawable::draw), which will open other issues? Or will I have to go
over each widget and rewrite it even more than I already did?

Personally, I see a few possibilities:

* divide the code into an update() and draw() method. (drawable
already provides an update() methodl, probably exactly for that
purpose).
* move the stuff that changes (like the text of a label) into a class
of its own, as inside a const method we can call non-const methods of
other objects.
* do the changes before the drawing (i.e. render the label text
whenever a new string is set or the color is changed), even though
this might add some overhead.

Or should I give up on making widgets drawables? From looking at v0.3,
they weren't there either and I don't really know if there's any
benefit to it.

Opinions? Suggestions? Otherwise I'll sleep over it and see if a good
solution presents itself.

Kai

P.S.: Nothing to commit, yet, as it's horribly broken right now.
Expect working stuff later in the week.