[Sugar-devel] F11 for XO1 - Fonts

[Art Hunkins]

I've developed a way to handle fonts both on the XO-1 and on SoaS that fits 
text nicely, on fixed pages, to all-sized screens.

I've written up this material immediately below, and invite everyone's 
critique. I'd particularly be interested in any example cases in which it 
would not work. I'm assuming that all monitor ratios will fall in the range 
of from slightly less than 4:3 up to 16:9 (wide-screen format).

If the consensus is that the material would be worth posting on the Sugar 
wiki, I will do that - and I'd appreciate suggestions as to where would be 
the most appropriate place.

Also, if it would help for me to forward (to the sugarlabs list) one of the 
text-based .xo's I've developed, in order to facilitate testing, I'd be 
happy to do so.

Art Hunkins

Fixed-Screen Text Formatting for Sugar (XO-1 and SoaS)

Formatting text for the various-sized screens that are used with 
Sugar-on-a-Stick, is a tricky proposition. The activities I am developing 
are text-based, requiring only buttons, spinners, frames and boxes 
otherwise. They are intended to fit on a single screen, with no scrollbars. 
The challenge is to create a text layout that looks pretty much the same on 
all screens. (Typical screen ratios vary from slightly less that 4:3 up to 
16:9 [wide-screen].)

There are two problems: 1) choosing the right font size to fill screens 
similarly as width varies; 2) adjustment for different width-to-height 
ratios (4:3, 16-9 and everything in between). This latter boils down to a 
variable number of text rows.

The issue is complicated by the fact that while the XO-1 is a normal 4:3 
ratio, it doesn't count pixels the way SoaS does. As far as font size is 
concerned, the XO-1 must be treated as its own special case.

I have pretty much solved these knotty problems by incorporating the code 
below, as well as by following this plan:

1) Compose my basic screen (4:3) on the native XO-1.

2) Copy it to SoaS and make sure it looks good on a 4:3 non-XO system. (My 
desktop monitor is a bit less than 4:3, which is, I think, the lowest ratio 
you'll find.)

3) Add to the script a "16:9 alternative," reducing the number of text lines 
so that everything fits on this size screen. (I used an asus eeePC900 
netbook here.)

4) Test my SoaS script on other screen formats.

The code:

import os

width = gtk.gdk.screen_width() # determine screen dimensions

height = gtk.gdk.screen_height()

if not os.path.exists("/sys/power/olpc-pm"): # test for XO-1; leave XO-1 
alone

settings = gtk.settings_get_default() # non-XO code begins

size = width * .0125 # font size is a function of screen width

settings.set_property("gtk-font-name", " %s " % size) # set font size

if (height * 1.35) > width: # examine width-to-height ratio

# code for 4:3 (or less) ratio screen; same as native XO-1 (4:3)

else:

# code for > 4:3 up to 16:9 ratio screens (reduced number of lines)


----- Original Message ----- 
From: "Daniel Drake" <dsd at laptop.org>
To: "Art Hunkins" <abhunkin at uncg.edu>
Cc: "Martin Langhoff" <martin.langhoff at gmail.com>; 
<sugar-devel at lists.sugarlabs.org>; <fedora-olpc-list at redhat.com>
Sent: Tuesday, August 18, 2009 1:19 PM
Subject: Re: [Sugar-devel] F11 for XO1 - Fonts


> 2009/8/18 Art Hunkins <abhunkin at uncg.edu>:
>> I'm thoroughly confused and frustrated.
>>
>> My POV: I'm authoring an Activity *today*. I'd like it to look good on 
>> all
>> XO and (other) Sugar on a Stick screens (monitors) *today*.
>
> I think you're out of luck then.  You could detect the XO somehow and
> choose a good setting that works there, but as for all of the SoaS
> machines in the world, they all have different displays and there
> isn't going to be one default setting that looks good on them all
> (hence our discussion of making this customizable by deployers and
> users). Unless you want to place a personal guarantee that you'll
> purchase any display that any SoaS user is ever possibly going to use,
> before they use it. and even then you aren't considering the quality
> of the users eyesight or the distance they will sit from the monitor.
>
>> I am lukewarm at best to having a user option in Control Panel to make 
>> font
>> size smaller or larger. (Please count me as a -1 for this suggestion.) 
>> For
>> *my* activity, this would only allow kids to make text too small to read, 
>> or
>> possibly overflow the screen
>
> If the user clicks "make text smaller" to the point where the font is
> too small to read then that's their problem, not yours, and they'll
> hopefully realise that they can fix the situation by clicking the
> "make text bigger" button.
>
> If they make it so big that you run out of space in your activity, you
> could dynamically add scroll bars.
>
> If it really is important that you fill the screen with text without
> scroll bars, then your activity would be an exceptional case that
> ignores the Sugar font size setting, and instead dynamically
> calculates the font point size needed to make the text fill the screen
> nicely.
>
>> Basically, I strongly feel that *authors* - not users, not the system
>> (including upstream), nor even deployments - should determine their basic
>> screen layouts. "One size" certainly does *not* fit all; and any/all
>> defaults should be overridable by authors in their scripts. It should be 
>> the
>> *author's* responsibility to make their activities look right on various
>> monitors.
>
> I disagree. This is an impractical responsibility to pass on. However,
> activity authors can of course render any graphics that they like, at
> any size, including fonts. They do not have to obey the font sizes
> suggested by Sugar, as is the situation now (sugar provides one font
> size in the GTK+ RC and another in profile.py but you can actually use
> any font size that you want).
>
> Daniel