Thursday, 19 February 2015

RE: [Ubuntu-phone] Qt 5.4 QVariant change and module news

I see there is a branch with unit tests that pass. Are the fixes gonna land soon?

> Date: Thu, 19 Feb 2015 09:19:42 +0100
> From: [email protected]
> To: [email protected]; [email protected]; [email protected]; [email protected]
> Subject: Re: [Ubuntu-phone] Qt 5.4 QVariant change and module news
>
> I confirm that several unit tests don't pass.
>
> https://bugs.launchpad.net/u1db-qt/+bug/1423473
>
> On 18.02.2015 19:51, Bogdan Cuza wrote:
> > I have just received a vivid-proposed image and noticed that U1db no
> > longer loads the defaults (which was probably a processed QVariantMap
> > from JS). Did this change break it/could it break even more components?
> >
> > > Date: Tue, 17 Feb 2015 09:37:38 +0200
> > > From: [email protected]
> > > To: [email protected]
> > > CC: [email protected]
> > > Subject: [Ubuntu-phone] Qt 5.4 QVariant change and module news
> > >
> > > Qt 5.4 is now in vivid, powering Ubuntu Phone starting with devel
> > > image #102, Kubuntu's Plasma 5 and also the Unity 8 desktop preview.
> > > No app changes are generally needed, but there is a change in QVariant
> > > that may be relevant to C++ using apps.
> > >
> > > == QVariant change in Qt 5.4 ==
> > >
> > > QVariant has changed a bit in Qt 5.4, although in a way that fixing
> > > its use does not affect negatively use in Qt 5.3 either.
> > >
> > > Quote: "When a JavaScript object/array is passed to C++ through a
> > > QVariant, the engine no longer immediately converts the object
> > > recursively into a QVariantMap or QVariantList but instead stores a
> > > QJSValue in the QVariant. This prevents a loss of data when the JS
> > > object contains non-primitive types such as function objects for
> > > example. Code that expects the variant type to be exactly
> > > QVariant::Map or QVariant::List may need to be adapted. Registered
> > > conversion functions however ensure that code that merely calls
> > > toMap() or toList() continues to work." [QTBUG-40431]
> > >
> > > Examples of fixes:
> > > - Oxide:
> > https://code.launchpad.net/~aacid/oxide/qt54_variantjs/+merge/248765
> > > - Ubuntu UI Toolkit:
> > >
> > https://code.launchpad.net/~aacid/ubuntu-ui-toolkit/statesaver_54/+merge/247986
> > >
> > > Another noted small difference:
> > > "In Qt 5.4 an alias to a null variable is correctly null instead of
> > > undefined like it was in Qt 5.3"
> > >
> > > == Status of less supported Qt modules ==
> > >
> > > It's useful to remember that not all of Qt we have in Ubuntu is
> > > supported by the Qt Project:
> > >
> > > - qtlocation: Upstream releases this as part of their releases, but
> > > they emphasize that Qt Positioning is API stable while Qt Location
> > > might change. Still, this should be pretty safe to use and will
> > > probably be declared stable soon.
> > > - qt3d: The original module has not been developed for two years. A
> > > complete rewrite has been in development during that time. Qt 3D 2.0
> > > will be available as a preview with Qt 5.5.
> > > - qtsystems: Semi-active development. Qt 5.4 absorbed QStorageInfo to
> > > be official part of qtbase, but it is a bit different and oddly does
> > > not have QML support at this point. We include the SystemInfo module
> > > on the phone images, but currently not the Publish Subscribe or
> > > Service Framework modules from the same source.
> > > - qtpim: Semi-active development, but can be considered supported
> > > since our Renato is one of the upstream developers. Ubuntu uses the
> > > Contacts/Organizer extensively in phone/scheduling apps.
> > > - qtfeedback: Stable in the sense that there is no development
> > > happening. It's also a very small module. If you are interested in the
> > > module, consider taking an active role in the Qt Project where
> > > contributions would surely be welcome.
> > >
> > > -Timo
>
>