Re: [pygame] Good code for text wrapping?

["Charlie Nolan" <funnyman3595@xxxxxxxxx>]

A fair amount of this is already in that file, down in print_string
and print_line.  (You're welcome to as much of the file as you like,
but I'd strongly suggest you look into refactoring it.  It's good
enough for one isolated project, but probably not up to library
quality.)

> - aligning text, left, right, center etc.
> - vertical alignment... top, bottom, center.
> - text color
Check.

> - each part of text having a separate font/attributes.  So you can
> then do words with bold, italics etc.
Everything but the font is easy to extend (the font's ugly to do, and
probably overkill).  I've already got underline in there.  Might want
to swap the style list for a style dict/object, though, to avoid
degenerating into positional hell.

> - selecting text.  Based on mouse click, which letter and word does it
> collide with?
I've already got the baseline in for this, by way of EditableText's
handle_click function.

> - breaking words (word-break), so it can add a long word like
> "complexifcation" as "complexif-\ncation"

More-or-less present.  Right now, it'll break on any character,
without adding a hyphen, but extending it shouldn't be hard.  Of
course, if you want intelligent hyphenation, that's an icky can of
worms all by itself.

> - justify text.
> - letter spacing
> - line spacing
> - word spacing
> - indenting
> - padding around text.
Somewhat annoying, mostly because they affect selecting text.  With
this many weird things, it might be a good idea to look for a way to
merge the layout and select code, possibly by storing a map as you lay
things out.

> - flowing around areas...
>     - eg( place an image, and the text flows around it)
>     - example here:  http://www.csstextwrap.com/example_for_demo.php
This one gets a bit ugly, and also runs into the layout/select
duplication mentioned above.

> - splitting text up into 'pages',
>     - different sized pages or Rects could be useful too.
Not too hard.  When the printing clips off the end of the available
area, you move on to the next one.

> - scrolling text.
Are you thinking marquee or scrollbar?  Either one seems out of scope.

> - text render method.
Not sure we need/want this, but it would be easy enough to add.  You'd
also want to add a way to replace the related methods (metrics,
get_linesize, etc.).  My main worry here is scope creep.  Actually, if
you're going into this much depth, wouldn't you just subclass
pygame.Font?

---

>  - text flow other than left->right (right->left, mixed, top->down)
I think this really belongs upstream in SDL, assuming it's not there
already.  Once it renders a string correctly, this is just another
easy layout/select issue.

>  - support for non-letter fonts (e.g. button glyphs for help text) --
>  although I suppose you could handle it by something you described,
>  flowing text around images, if the images could be floated as well
I'm pretty sure you can do this already.  As long as you have the
font, you can render whatever you like in it.

>  - support for non-breaking spaces and hyphens
NBSP is handled correctly.  Hyphens fall under breaking words properly.

>  - proper handling of line-breaking in different languages (e.g.,
>  French inserts a space or two between the last letter of a sentence
>  and a final exclamation point, don't want to break there, some
>  languages consider certain combinations of letters to really be only
>  one, can't break in between them, etc.)
Most of this falls under word breaks again.  French's pre-! space is
kinda annoying, unless they already use an NBSP.

>  - proper support for full Unicode fonts
I haven't run into anything broken here.  DejaVu seems to render
perfectly well.  Most of this is up to SDL, though we'd have to pay
attention to control characters (switching RTL/LTR without warning
does ugly things).

---

Most of this isn't too bad to add to what I've already got, but you'd
want to be really careful with adding them one-by-one.  It'd be really
easy to get scope creep or just turn the entire thing into hacks of
hacks.

In some ways, I'd be relieved if you didn't use my code, because it's
already held together with duct tape and baling wire.  Unfortunately,
I'm not sure there *is* a sane way to handle this stuff, there are
just too many special cases.

I think the important thing is to get something in soonish that
handles as many of the common cases as we can.  We don't want this
degenerating into something that will come out shortly after Duke
Nukem Forever.

-FM