Thread: Maemo 6 loosing source compatibility with plain Qt, and Symbian^4
View Single Post
svdwal is offline svdwal
2009-11-19 , 09:47
Posts: 19 | Thanked: 56 times | Joined on Nov 2009 @ The Netherlands
#28
[QUOTE=abbra;381424]If you want to maximize cross-platform take, use "standard" widgets. Hopefully, those will work fine and in style with overall system. Of course, certain features would be not possible to implement without going beyond standard widgets -- it is exact reason why QGraphicsView was created by Qt people in 2006, used in KDE for Plasma project and by many others.
[QUOTE]

First things first.

Qt apps start with constructing a QtApplication, Direct UI apps start with constructing a DuiApplication. Two different classes, it is then reasonable to assume that DuiApplication does something that QtApplication does not, and that something is important for multi-touch devices. Now, what are my changes that a Qt application is going to run good enough on a maemo (and symbian ^4 for that matter)? I don't know, unless I compile my plain Qt app, run and test it, and then port it to Dui, and run and test it again.

yes, for a good test I must be able to compare the differences between the plain Qt and the Direct UI versions of the app. Today's commercial mobile software environment is very competitive and having an app that is not top-notch means that your changes are not good.

I can reduce work and increase my changes by not bothering to do the plain Qt build and test, but go straight to porting. And then, I have two (sleightly) different versions of my app, and my maintainence costs are now twice as big, or were, unless I add in even more work to refactor the common stuff out.

This is all under the assumption that DuiApplication is actually doing useful work, and that work cannot be done in QtApplication.

But for the life of me I have no idea what it is that DuiApplication is doing what cannot be done inside QtApplication. So all I am seeing now is more time to spend on things that do not make money, because somebody thought having a Dui instead of a Qt is cute. No, it is not.

Next class, QtWindow versus DuiWindow, same exercise.


If you would re-read what I was saying, my observations were on pointing exactly this fact: Qt has for long time been working on ways to innovate in UI beyond standard widgets for those developers who want it. There probably wasn't enough need and energy in every single Qt-based project to use those enablers but case with KDE4's Plasma shows they are still there. Multiple cases on Windows with commercial applications based on Qt or any other non-standard UI toolkit are also contributing to this view, as standard "Desktop" widgets are relatively rare in use in many Windows applications.

Who will provide "Qt standard widgets" on top of QGraphicsView by default as Qt API, whether this will really happen anytime soon (in next several years), will it be in use by someone on cross-platform market, still remains to be seen. However, I do not see any sort of panic mode activated.
You will find that on mobile devices there is not a big need for lots of screen widgets. Symbian never had many, iPhone doesn't have many either, even less than Symbian. Having a few standard widgets is enough for the bulk of apps. Mobile means simple and intuitive.