ubuntu-phone team mailing list archive

["Vladimir M." <mlvl.jr@xxxxxxxxx>]

Hey, stop sending those cryptic messages! Not everyone understands Russin
here!! :)
Fact is, sometimes it's indeed easier to ask, with QML.
And QML needs a better set of guides on C++ integration, also (btw, if
anyone currently reading this is at DevDays these days, you can find me at
ICS booth -- just near to where the Ubuntu guys are showing their stuff --
and we can discuss some nice aspects of working with QML; and I'm also
giving a talk!! :)).


On Mon, Oct 7, 2013 at 1:07 PM, <mrqtros@xxxxxxxxx> wrote:

> Дружище, ты меня прости, что я по-русски тебе отвечу, но ты не желаешь
> пробовать, прежде чем спрашивать? Или просто документацию посмотреть? А то
> это спам какой-то уже!
>
>
> Best regards,
>
> Roman.
>
> 07.10.13 13:12 Николай Шатохин написал(а):
> Can I use QList of pointers? And get objects in QML.
>
>
> 2013/10/7 Николай Шатохин <n.shatokhin@xxxxxxxxx>
>
>> Can I use QList (or something similar) as Q_PROPERTY? How can I use it in
>> QML?
>>
>> Best regards,
>> Nick
>>
>>
>> 2013/10/2 Vladimir M. <mlvl.jr@xxxxxxxxx>
>>
>> CONSTANT (or whatever the name is) helps here as well -- if the prop does
>>> not change  :)
>>>
>>>
>>> On Wed, Oct 2, 2013 at 7:58 PM, Николай Шатохин <n.shatokhin@xxxxxxxxx>
>>>  wrote:
>>>
>>>> Hm, yes, it helps. Thank you.
>>>>
>>>>
>>>> 2013/10/2 Roman Shchekin <mrqtros@xxxxxxxxx>
>>>>
>>>>> You should register Game via qmlRegisterType too.
>>>>>
>>>>> Your Engine's "game" property used in binding and it has no NOTIFY
>>>>> signal.
>>>>> I hope you know what is it. If no - you should learn basics of Qt
>>>>> first.
>>>>>
>>>>> Cheers,
>>>>> Roman.
>>>>>
>>>>>
>>>>> 2013/10/2 Николай Шатохин <n.shatokhin@xxxxxxxxx>
>>>>>
>>>>>> I did it, but now I got:
>>>>>>
>>>>>> QMetaProperty::read: Unable to handle unregistered datatype 'Game*'
>>>>>> for property 'Engine::game'
>>>>>>
>>>>>> QQmlExpression: Expression qrc:/Reactor.qml:7 depends on
>>>>>> non-NOTIFYable properties:
>>>>>>
>>>>>> Engine::game
>>>>>>
>>>>>> On application startup (game is Q_PROPERY of Engine and has type Game
>>>>>> *).
>>>>>>
>>>>>>
>>>>>> 2013/10/2 Vladimir M. <mlvl.jr@xxxxxxxxx>
>>>>>>
>>>>>>> Just put the star in the property decl -- it's the stock way to do
>>>>>>> it, and the decl w/o star will be deprecated probably soon, as far as I
>>>>>>> know. Then, bind to the props in qml, and that's it!
>>>>>>> 02 окт. 2013 г. 14:31 пользователь "Николай Шатохин" <
>>>>>>> n.shatokhin@xxxxxxxxx> написал:
>>>>>>>
>>>>>>>
>>>>>>>> Ok, I registered as Type class Ship inherited from QObject that
>>>>>>>> have fields:
>>>>>>>>
>>>>>>>> Q_PROPERTY(Hull hull READ hull)
>>>>>>>> Q_PROPERTY(Reactor reactor READ reactor)
>>>>>>>> Q_PROPERTY(Shields shields READ shields)
>>>>>>>>
>>>>>>>> (all field classes inherited from QObject too)
>>>>>>>>
>>>>>>>> But in ship class I'm using this fields as pointers (Hull * hull).
>>>>>>>> So, how to use correctly Q_Properties in this case? (I need call methods
>>>>>>>> from this fields and catch signals from them in QML)
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> 2013/9/30 Vladimir M. <mlvl.jr@xxxxxxxxx>
>>>>>>>>
>>>>>>>>> Sure, you can always wire as many objects as possible to smth
>>>>>>>>> existing in a scene or set as a context property -- it's a simple
>>>>>>>>> Q_PROPERTY assignment on the C++ side, with a pointer passed to the setter
>>>>>>>>> (and works as soon as you declare the property on the QML side (or register
>>>>>>>>> and instantiate a C++ implemented item)).
>>>>>>>>>
>>>>>>>>> After all, these are ordinary QObejcts passing pointers (to each
>>>>>>>>> other) to each other :)
>>>>>>>>> (plus some memory management -- automatic on the QML side, and
>>>>>>>>> QObject parent-tree based on the C++ side)
>>>>>>>>>
>>>>>>>>> Vladimir
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mon, Sep 30, 2013 at 6:24 PM, Николай Шатохин <
>>>>>>>>> n.shatokhin@xxxxxxxxx> wrote:
>>>>>>>>>
>>>>>>>>>> What if I will create property backend in QML type and then I
>>>>>>>>>> will set this property in all QML objects to global object? So,
>>>>>>>>>> theoretically this can solve my problem.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> 2013/9/30 Vladimir M. <mlvl.jr@xxxxxxxxx>
>>>>>>>>>>
>>>>>>>>>> Then, it looks like the standard way would be to have an instance
>>>>>>>>>>> of the item embedded in each page in the stack.
>>>>>>>>>>>
>>>>>>>>>>> If this turns out to be too resource consuming, you may try to
>>>>>>>>>>> play some tricks like removing it from all the pages and overlaying over
>>>>>>>>>>> the whole stack (if the item will always be in the same place, and have the
>>>>>>>>>>> same geometry, this will be rather simple, children order or z-value will
>>>>>>>>>>> allow it place it on top).
>>>>>>>>>>>
>>>>>>>>>>> If geometry is different for each page, this may get trickier
>>>>>>>>>>> (ultimate solution may be some sort of a "placeholder item" having the
>>>>>>>>>>> right place in each page, to which the item gets parented when the
>>>>>>>>>>> placeholder becomes visible, with "fill" anchoring).
>>>>>>>>>>>
>>>>>>>>>>> On the other hand, if the item has to have it's state consistent
>>>>>>>>>>> between the pages, then even if its is feasible performance-wise to embed
>>>>>>>>>>> it into all of them, some sort of common "view state model" should probably
>>>>>>>>>>> exist, and this again suggests just using a single instance...
>>>>>>>>>>>
>>>>>>>>>>> Vladimir
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Mon, Sep 30, 2013 at 3:07 PM, Николай Шатохин <
>>>>>>>>>>> n.shatokhin@xxxxxxxxx> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> I need to have this object in different qml files (for i.e.
>>>>>>>>>>>> GameChat must be shown on GameCreation,Game,GameResults pages: this it
>>>>>>>>>>>> differents QML files and differents pages in PageStack), but I created only
>>>>>>>>>>>> one QtQuickView in main.cpp. So, do view is qml file or QtQuckView object?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> 2013/9/30 Vladimir M. <mlvl.jr@xxxxxxxxx>
>>>>>>>>>>>>
>>>>>>>>>>>> You probably can't share a single instance of a QML visual item
>>>>>>>>>>>>> between views, but as soon as you have the type registered properly /
>>>>>>>>>>>>> importable / etc, you can use instantiate it in as many views as you like.
>>>>>>>>>>>>> A QObject pointer can be passed around to items living in
>>>>>>>>>>>>> different veiws inside the same application, of course (but watch out for
>>>>>>>>>>>>> memory management issues -- see CppOwnership / QMLOwnership  / etc in the
>>>>>>>>>>>>> docs under "memory management").
>>>>>>>>>>>>>
>>>>>>>>>>>>> Easiest way may be to set the same object as a context prop
>>>>>>>>>>>>> for several views (unless you have some objections to this practice, like
>>>>>>>>>>>>> ones mentioned up in the thread).
>>>>>>>>>>>>>
>>>>>>>>>>>>> Lastly, there is that (legitimate) trick allowing QML items to
>>>>>>>>>>>>> be "rendered" by other items, resulting in the same item being shown in
>>>>>>>>>>>>> multiple places of the same scene (but being manipalatable anywhere except
>>>>>>>>>>>>> its actual position) -- look into the shader effects and such.
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Mon, Sep 30, 2013 at 2:34 PM, Николай Шатохин <
>>>>>>>>>>>>> n.shatokhin@xxxxxxxxx> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> What if I need to show the same QML object in two different
>>>>>>>>>>>>>> places? How to do this? How to create new QML object without recreating it
>>>>>>>>>>>>>> in C++?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> 2013/9/30 Николай Шатохин <n.shatokhin@xxxxxxxxx>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 0_o. I didn't know that all objects in QML are global. Thank
>>>>>>>>>>>>>>> you very much.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> 2013/9/30 <mrqtros@xxxxxxxxx>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Omg declare global engine object in main qml file and that's
>>>>>>>>>>>>>>>> all
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 30.09.13 13:19 Николай Шатохин написал(а):
>>>>>>>>>>>>>>>> I'm using qmlRegisterType now. I have problems, because two
>>>>>>>>>>>>>>>> QML objects in different QML files it is two different objects in C++. I
>>>>>>>>>>>>>>>> registered as type class that have static object of Engine, but now I have
>>>>>>>>>>>>>>>> butthurt with it (I need retranslate all signals, getters and setters)
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2013/9/30 Michael Zanetti <michael.zanetti@xxxxxxxxxxxxx>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> On Monday 30 September 2013 12:05:03 Николай Шатохин wrote:
>>>>>>>>>>>>>>>>> > Can I set only one object as context property that
>>>>>>>>>>>>>>>>> contains other objects
>>>>>>>>>>>>>>>>> > (and this objects contain objects too) and get this deep
>>>>>>>>>>>>>>>>> objects in QML?
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > For i.e. I have object of class Engine that has object
>>>>>>>>>>>>>>>>> of class Game, Game
>>>>>>>>>>>>>>>>> > contains object of Ship and Ship contains object of
>>>>>>>>>>>>>>>>> Reactor. So, I set
>>>>>>>>>>>>>>>>> > object of Engine as context property and in QML write:
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > engine.game.ship.reactor
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > Can I use it?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Yes, given that "game" is a Q_PROPERTY() of "enigne",
>>>>>>>>>>>>>>>>> "ship" is a Q_PROPERTY()
>>>>>>>>>>>>>>>>> of "game" etc...
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Still, I recommend to register the type of the Engine
>>>>>>>>>>>>>>>>> instead of setting it as
>>>>>>>>>>>>>>>>> a context property.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> It's really just using qmlRegisterType() instead of
>>>>>>>>>>>>>>>>> setContextProperty(). It's
>>>>>>>>>>>>>>>>> not more or more complex code, but gives you better ways
>>>>>>>>>>>>>>>>> of structuring your
>>>>>>>>>>>>>>>>> QML code.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > 2013/9/30 Николай Шатохин <n.shatokhin@xxxxxxxxx>
>>>>>>>>>>>>>>>>> >
>>>>>>>>>>>>>>>>> > > I've already found this solution:
>>>>>>>>>>>>>>>>> > >
>>>>>>>>>>>>>>>>> http://qt-project.org/doc/qt-5.0/qtqml/qtqml-cppintegration-contextpropert
>>>>>>>>>>>>>>>>> > > ies.html It helps. Thanks.
>>>>>>>>>>>>>>>>> > >
>>>>>>>>>>>>>>>>> > >
>>>>>>>>>>>>>>>>> > > 2013/9/30 Michael Zanetti <
>>>>>>>>>>>>>>>>> michael.zanetti@xxxxxxxxxxxxx>
>>>>>>>>>>>>>>>>> > >
>>>>>>>>>>>>>>>>> > >> On Sunday 29 September 2013 13:45:01 Vladimir M.
>>>>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>>>> > >> > Sounds like a "context property" use case (you
>>>>>>>>>>>>>>>>> plain set a QObject as a
>>>>>>>>>>>>>>>>> > >> > context property for a view's root scope, w/o even
>>>>>>>>>>>>>>>>> registering the
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> object's
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> > type, and all its properties and invokables become
>>>>>>>>>>>>>>>>> available).
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> I don't recommend using context properties. While
>>>>>>>>>>>>>>>>> they are useful for
>>>>>>>>>>>>>>>>> > >> some
>>>>>>>>>>>>>>>>> > >> cases, this one doesn't seem to be one of those.
>>>>>>>>>>>>>>>>> Using too many global
>>>>>>>>>>>>>>>>> > >> context
>>>>>>>>>>>>>>>>> > >> properties can make the code very ugly to work with.
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> You probably want to create something like this:
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> class ViewController: public QObject
>>>>>>>>>>>>>>>>> > >> {
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>   Q_PROPERTY(QList<MyClass> viewObjects READ
>>>>>>>>>>>>>>>>> viewObjects NOTIFY
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> viewObjectsChanged)
>>>>>>>>>>>>>>>>> > >> ...
>>>>>>>>>>>>>>>>> > >> QList<MyClass> viewObjects() const {
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>   return objectList;
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> }
>>>>>>>>>>>>>>>>> > >> ...
>>>>>>>>>>>>>>>>> > >> };
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> qmlRegisterType<ViewController>(uri, 0, 1,
>>>>>>>>>>>>>>>>> "ViewController");
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> Then in QML you can do something like this:
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> ViewController {
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>   id: viewController
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> }
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> Repeater {
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>   model: viewController.viewObjects
>>>>>>>>>>>>>>>>> > >>   MyView {
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>     property var viewObject:
>>>>>>>>>>>>>>>>> viewController.viewObjects[index]
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>   }
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> }
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> Note that if you want your code to adjust more
>>>>>>>>>>>>>>>>> flexible (i.e. the
>>>>>>>>>>>>>>>>> > >> viewObjects
>>>>>>>>>>>>>>>>> > >> change a lot), consider using a QAbstractListModel
>>>>>>>>>>>>>>>>> (or some other model)
>>>>>>>>>>>>>>>>> > >> instead of a QList.
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> Hope this helps,
>>>>>>>>>>>>>>>>> > >> Michael
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> > On Sun, Sep 29, 2013 at 6:38 AM, Николай Шатохин
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> <n.shatokhin@xxxxxxxxx>wrote:
>>>>>>>>>>>>>>>>> > >> > > Hello.
>>>>>>>>>>>>>>>>> > >> > >
>>>>>>>>>>>>>>>>> > >> > > When I create a class in C++, I can register it
>>>>>>>>>>>>>>>>> for QML and can
>>>>>>>>>>>>>>>>> > >> > > create
>>>>>>>>>>>>>>>>> > >> > > view for it. It's very convenient. But, if I need
>>>>>>>>>>>>>>>>> many objects of the
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> same
>>>>>>>>>>>>>>>>> > >>
>>>>>>>>>>>>>>>>> > >> > > type, and need to show few views on screen, I got
>>>>>>>>>>>>>>>>> problems.
>>>>>>>>>>>>>>>>> > >> > > Is it possible to register QML type for object,
>>>>>>>>>>>>>>>>> not for class?
>>>>>>>>>>>>>>>>> > >> > > If I change some object, I need to see only its
>>>>>>>>>>>>>>>>> view changed.
>>>>>>>>>>>>>>>>> > >> > >
>>>>>>>>>>>>>>>>> > >> > > Best regard,
>>>>>>>>>>>>>>>>> > >> > > Nick
>>>>>>>>>>>>>>>>> > >> > >
>>>>>>>>>>>>>>>>> > >> > > --
>>>>>>>>>>>>>>>>> > >> > > Mailing list: https://launchpad.net/~ubuntu-phone
>>>>>>>>>>>>>>>>> > >> > > Post to     : ubuntu-phone@xxxxxxxxxxxxxxxxxxx
>>>>>>>>>>>>>>>>> > >> > > Unsubscribe : https://launchpad.net/~ubuntu-phone
>>>>>>>>>>>>>>>>> > >> > > More help   : https://help.launchpad.net/ListHelp
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> Mailing list: https://launchpad.net/~ubuntu-phone
>>>>>>>>>>>>>> Post to     : ubuntu-phone@xxxxxxxxxxxxxxxxxxx
>>>>>>>>>>>>>> Unsubscribe : https://launchpad.net/~ubuntu-phone
>>>>>>>>>>>>>> More help   : https://help.launchpad.net/ListHelp
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>
>>>>
>>>> --
>>>> Mailing list: https://launchpad.net/~ubuntu-phone
>>>> Post to     : ubuntu-phone@xxxxxxxxxxxxxxxxxxx
>>>> Unsubscribe : https://launchpad.net/~ubuntu-phone
>>>> More help   : https://help.launchpad.net/ListHelp
>>>>
>>>>
>>>
>>
>