Qt: A multi-platform graphics toolkit comprising a library and a skinnable widget set. Relies on other software for low-level drawing operations (which may be X or whatever Mac OS X or Windows provides).
So apps written using QT can (with some care and work) be made to run on linux, macOS and windows? (non-Zaurus question).
Qtopia: Formerly known as the Qt Palmtop Environment or QPE. A graphic user environment (GUI) built with Qt/Embedded. This is what you interact with when using a Zaurus with its original Sharp ROM.
So Qtopia is the GUI (like KDE, windowmaker, etc), which runs on Qt/E (which does drawing operations so X is not needed (as well as providing the widget set))?
Opie: Open Palmtop Integrated Environment. A graphic user environment (GUI) derived from Qtopia. This is what you usually interact with when using OpenZaurus. Opie's development is less reliant on Trolltech (creators of Qt, Qt/E and Qtopia) as it is basically an independent fork of Qtopia.
Opie just replaces Qtopia, and still needs Qt/E to control drawing operations, right? Or is opie just the name which covers the replacements for Qtopia and Qt/E (maybe that's where the "integrated" part comes in?)?
Basically, if you have a clamshell Zaurus, you can run Qt/E and X applications side-by-side if you run pdaXrom which is a ROM that includes an X server.
How does pdaXrom manage to do both? Is it an X server which can run Qt/E apps or Qt/E running X support? Or neither?
Note that Opie and Qtopia seem to be slowly diverging so applications written for one are not necessarily compatible with the other.
Could you explain more where they are diverging and why this makes apps incompatible?
However, if you have the time and inclination, you could install X/Qt, an X server that runs under Qt/e. This allows applications that require X to dsplay graphics. If you don't know what any of this means, likelihood is it isn't worth the hassle - Just stick with either Opie or GPE for a while
I would have understood most of that before I started this thread- that's the easy part
Seems rather silly though: thats a program, which uses GTK widgets for example, which ask X to do some drawing, which is using Qt widgets, which asks Qt/E to draw on the framebuffer.
Or have I completely misunderstood?
With OpenZaurus, you have the choice of two environments - GPE, which uses an X server to display to the screen (and uses the GTK2 graphics toolkit), or Opie, which uses Qt/e, as mentioned previously.
It is not currently feasible to run Opie/Qtopia applications in GPE, or vice-versa.
Right, here's where I still don't get it, but in case I'm wrong above I'll save the long version till the next post. Here's the short version (or part of it)...
Why aren't [Qt/E] and [Qt running on X] the same thing as far as a program which uses Qt widgets is concerned?
Thankyou all for the very helpful replies
Simon