[maemo-developers] [maemo-developers] N800/Newton comparison

From: Sean Luke sean at cs.gmu.edu
Date: Fri Feb 2 17:43:46 EET 2007
Daniel Elstner wrote:

> However, I think he's wrong in picking on GTK+ as the culprit for some
> of the UI annoyances.  For instance, I don't think it's true that GTK+
> only deals with simple input one character at a time.  I'm pretty sure
> it's possible to pull off Newton-style handwriting as described by him
> with a sufficiently sophisticated GTK+ input module.

I'd be glad to modify the article (and have) in response to  
corrections, and actually HWR is rather low on my list of complaints  
in the article.  But no, the Newton's facilities, so far as I can  
tell, cannot be reasonably replicated with a plug-in input module,  
except for providing better recognition perhaps.  But I'm not losing  
sleep over it.  Though GTK is a classic least-common-denominator  
framework, it does allow lots of apps to be ported to the N800  
immediately, and that's a worthy tradeoff.  My article tried to focus  
on things they _could_ change without performing open heart surgery  
on a large open-source framework.  HWR was low on the list.

The Newton's HWR has three relevant characteristics for discussion here:

1. Interpreted handwriting is rarely handled by the underlying  
application through the event system, much less through a keystroke  
event facility; and in fact an application typically doesn't know or  
care that text is being written in one of its fields.  It just shows  
up.  You *can* override this facility to shove text at an application  
through key events (Newtons have keyboards) but it's not the default  
mechanism.  An app could also receive text in whole paragraphs if it  
liked, and that text could include embedded pictures and  
intentionally uninterpreted handwriting in the form of stroke  
sequences (they're called "rich strings").

2. Handwriting happens directly in text fields and text areas, not in  
a separate pop-up region.

3. The recognition is sophisticated.

#3 is doable on the Nokia with a replacement module.  And of course  
#1 and #2 be done inside an application with a writer who is  
sufficiently talented (or demented).  But it's besides the point.   
For #1 and #2, the other applications won't _automatically_ use that  
app writer's handiwork, because GTK's framework [probably] doesn't  
support it.  Each app would have to code for and link against his new  
library.  But the whole _point_ of a GUI is to provide *all*  
applications with a powerful and consistent framework so they don't  
have to do tons of work writing their own (different from one  
another) approaches to user experience.

Note: I wrote [probably] because as best I can tell GTK apps, like  
most UI systems originally created on PCs, routes text in the form of  
key events.  But I'm not positive about this and wouldn't mind being  

Note 2: if you're interested in the Newton's UI and recognition  
system as a developer, you might look at http://www.unna.org/unna/ 
The chapters of interest are 8, 9, and 10.


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