Hi,
Thanks for the info, I did took a look at the QML_ELEMENT at
https://www.qt.io/blog/qml-type-registration-in-qt-5.15
I was a bit confuse about how this actually do the the convertion between
people and person in the following example given:
***********************
qmlRegisterType<Person>("People", 1,0, "Person");
This would register the C++ class "Person" as a QML element also called
"Person", into the module "People" under the version 1.0. This line has
disappeared in Qt 5.15. Instead, the following lines have been added to the
adding.pro file:
CONFIG += qmltypes
QML_IMPORT_NAME = People
QML_IMPORT_MAJOR_VERSION = 1
These lines specify the import name and major version for all types exposed to
QML. Finally, the most important change, is the "QML_ELEMENT" macro added to
the person.h file:
class Person : public QObject
{
Q_OBJECT
Q_PROPERTY(QString name READ name WRITE setName)
Q_PROPERTY(int shoeSize READ shoeSize WRITE setShoeSize)
QML_ELEMENT
public:
Person(QObject *parent = nullptr);
[...]
};
***********************
how does the Person class is link to the People name exactly?!? I do not
understand how can it known that the C++ class should be link the given People
import name?! Is like a stack, if I change the QML_IMPORT_NAMES before using
any HEADERS += or SOURCES += ? like this:
CONFIG += qmltypes
QML_IMPORT_NAME = People
QML_IMPORT_MAJOR_VERSION = 1
HEADERS += Person.h
SOURCES += Person.cpp
QML_IMPORT_NAME = MyOtherModule
QML_IMPORT_MAJOR_VERSION = 1
HEADERS += MyOtherClass.h
SOURCES += MyOtherClass.cpp
Is that how it should work? Is the order of declaration into .pro and .pri
matter to make this work or there is something I don’t get here? Thanks
-----Original Message-----
From: Ulf Hermann <ulf.herm...@qt.io>
Sent: September 12, 2020 3:24 AM
To: Jérôme Godbout <godbo...@amotus.ca>; interest@qt-project.org
Subject: Re: [Interest] QML/C++ interaction in Qt6
> Will Qt 6 still use the Meta information to access Qml properties or
> it rely more on compiled C++ now? I guess it still the same as before.
> Is the properties declaration of Qt for MCU (Qml lite or soemthign
> like that) be available (syntax wise, template)? That would leverage
> soo much redundent code to expose properties with get/set and changed
> event. That will be a slim fast for code that expose to Qml (to Meta
> data actually, Qml use the meta data) and maybe event make that layer
> disapear one day.
Registration of C++ types for QML in dev is largely unchanged from 5.15.
You get the QML_ELEMENT etc. macros we introduced in 5.15 to make the
registration as painless as possible. The indirection through the metatype
system is necessary for the case of dynamically interpreted QML. We can
generate C++ code from your QML to directly access your C++ types, but if you
want to execute that same QML in interpreted mode, those C++ types need to be
visible to metatype system in order to be accessible.
Also, the new property system is being introduced. If you provide a BINDABLE
property, you may be able to skip the READ, WRITE, and NOTIFY methods in the
future. This is still being worked on, though.
best,
Ulf
_______________________________________________
Interest mailing list
Interest@qt-project.org
https://lists.qt-project.org/listinfo/interest
