Re: [boost] GUI coordinate units (Was: GUI foundations)

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-10-05 01:22:17

Joel de Guzman wrote:

> Stefan Seefeld wrote:
>> Martin Bonner wrote:
>> 
>> 
>>>I moved from 1024x768 to 1280x1024 because I got given a 17" LCD monitor.
>>>Windows-XP doesn't make a bad fist of scaling everything back again to a
>>>reasonable size, but a lot of GUIs get a bit messed up because people
>>>have done everything in pixels rather than scalable graphics.
>> 
>> 
>> Exactly. To be clear: moving from a 15" to a 17" monitor would, in my
>> ideal world, have *no* impact on the physical size of the displayed
>> graphics, but rather, would add ~ 1.4" in both dimensions to the useful
>> screen area. How many pixels your display has then only affects the
>> quality of the rendering, exactly as what you were looking for.
>> 
>> Of course, this requires a completely vector-graphics-based GUI, which
>> is still the exception.
> 
> Agree 101% !!!
> 
> And that is one area I'd love to work on! This will require a new
> way of thinking and quite a bit of work but I think it's the right
> way to go. --Expecially since we have cool vector libs like
> Antigrain: http://www.antigrain.com/. 

Well, in Qt, the QStyle API is passed QPainter, and in Qt4 the latter does
antialising, so you can get antialised UI styles today.
Say, here's the snapshot they use
http://www.trolltech.com/images/screenshots/qt_demos_vectordeform.png
(linked from http://www.trolltech.com/products/qt/qt4info.html)

> That is why I think forcing 
> the use of only platform specific widgets is very limiting. 

Looks like custom styles is the idea everybody agrees on.

> Take 
> a peek at http://tinyurl.com/c6zhp, for example, where all the
> GUI elements, including menus and buttons (even scroll bars) are
> implemented on the basis of Anti-Grain Geometry, so that, all the
> rendering infrastructure is multi-platform. That's my definition
> of beautiful!

I'd say this is OSX clone ;-) 

> And to follow up on the resolution/scaling issue, this:
> http://tinyurl.com/8dl6u "demonstrates the capability to display
> scalable toolbars. In the chemical sketcher the toolbar buttons
> are represented in a simple vector format and being rendered on
> the fly. Using pure vector graphics to represent all the GUI
> elements, including toolbar buttons allows you to get rid of
> the dependency on the screen resolution."

Yes, vector icons are good idea but let's go back to coordinate unit. If
icon is just and SVG file that can be displayed, that why does it matter
what unit is used to specify dimensions of the toolbar? Displays still have
pixels, and SVG file can be rendered to area of any size. Why don't specify
area size in pixels? Again, in a good application the size of toolbar
should never be manually set by the programmer, but only by layout of code
the library.

- Volodya