> From: Alan Alpert <alan.alp...@nokia.com> > To: development@qt-project.org > Cc: > Sent: Thursday, April 12, 2012 6:20 AM > Subject: Re: [Development] Qt5 missing features > > On Thu, 12 Apr 2012 11:28:43 ext Lincoln Ramsay wrote: >> On 04/12/2012 11:00 AM, ext Alan Alpert wrote: >> > One thing I don't understand in this discussion is this theme > manager >> > concept (like QStyle). >> >> ... >> >> > Why exactly do we need this level of indirection >> >> Because of this: >> >> import Widgets 1.0 >> >> As opposed to this: >> >> //import MeeGoWidgets 1.0 >> //import SymbianWidgets 1.0 >> import DesktopWidgets 1.0 >> >> >> If there was a "standard API" defined for a > "components" and each >> platform provided something that was source-compatible with this API >> then that would work too (without indirection) but I haven't seen > anyone >> suggesting that a platform's "components" should adhere to > some >> "standard API". > > I suggest it :) . It's a de-facto standard already if you can simply comment > > in the appropriate import. > >> People are coming at this from a "one source, multiple targets" >> viewpoint, which clashes with QML's "one source, one target" > design. I >> suspect that people do not want to maintain otherwise >> virtually-identical .qml files for each target platform just because the >> components have a different import, or a different name for an element. > > This doesn't require a theme manager abstraction. It could be handled with a > > Widgets import that resolves to MeeGoWidget,SymbianWidgets or DesktopWidgets > based on runtime platform. (this approach does also require the 'standard > API' > you mention, but that's still not a theme manager - it requires quite > different actions to make it a reality)
A theme manager will make the things much more simpler and clear for the user and when it comes to add support for other platforms. Let me try explain more: >From user perspective: * AFAIK currently there is no easy way to create a custom theme for QML controls, so if I want to completely change the look of my controls I don't want to rewrite them :) I want to specify simple attributes to the theme manager and it should do the magic for me, something similar with Qt Style Sheets, of course now you'll say that it was too complex and almost nobody use it, I agree that it was complex but something simple must take its place, because I believe that something is better than nothing :) ! >From developer perspective who wants to add support for another platform: * I want to do the style job once for both QML and classic widgets, without a theme manager I don't see how it can be done ! * Some platforms have too complex controls to be draw using an existing QML implementation, the live example is Android platform where almost nothing can be used from existing style implementations, not even BorderImage [1] I can't use it because Android has another (IMHO smarter) approach [2], the image contains all the informations you need to draw it properly, it contains padding informations and informations about the margins, even the name says it has 9 patches, is not true, it can contain more than 9 check [3], which is great, because you can draw much more complex controls with it. Probably again you'll complain that it doesn't follow the standard you followed[4]:). Cheers, BogDan. [1] http://doc-snapshot.qt-project.org/4.8/qdrawutil-h.html#qDrawBorderPixmap [2] http://developer.android.com/guide/developing/tools/draw9patch.html [3] http://androidxref.com/source/xref/frameworks/base/include/utils/ResourceTypes.h [4] http://www.w3.org/TR/css3-background/ _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
