Qt Quick by Alexis Menard at Cybercom Developer Day 2010 part 4

Donc,

maintenant, vous savez, comment je peux utiliser ça en QML. Alors, c'est facile. Donc, ici, je vais avoir un projet, qui est un QML. Comme vous pouvez voir ici, il y a un QML. C'est

un projet en

Qt Creator. Et ici,

je

mets mon C++ implementation, qui est customitem, si je enterais,

ici, ici,

vous voyez, il y a le CPP et l'H file.

Il

y a l'SO, qui est built, et il y a

l'est

actually built. Et il y a un small file que vous avez besoin, qui est appelé QMLdir. C'est pour décrire quel plugin il

y

a de load. Et si vous dites QMLdir, c'est quelque chose comme ça. Il y a

un

plugin,

c

'est le nom de le plugin, c'est ce qu

'il y a un. Et

si vous regardez la façon dont

je

construis mon QML, il y

a

un C++, c'est facile.

Je

opene le profil de QMAKE,

et

je dis, c'est un livre,

je dis, c

'est un démo pour l'extension, et il y a

un lien

avec le déclaratif, et c'est un Qt plugin, c'est tout. Et puis, c

'est

mes files.

C

'est tout que je fais. Il y a

un fil,

c'est un fil, et je suis prêt à utiliser le QML.

So,

if I come back to the editor

here,

and then I go to

where

I actually use the file. So, here I've got a rectangle blue. As you can see, Qt Creator show a preview of the element, which is quite cool here.

So,

now I need to import my library, my custom item, right? So, it's easy.

I

do import custom

item 1

.0.

Import

custom item

up. And

then, so let's see, if I run that, what it says.

Oh,

yeah. I need to specify the version. 1.0.

So,

I need to register my type. That's something I forgot. And, let me do it. That's funny.

I

saw that I did it.

1

.0. So, that's what I do. I register my item 1.0, custom item. Okay, let's see why it doesn't work, actually. Custom item,

well,

then it's 1.0. Ah, it's well known the

demo

always failed. 1.0.

Well,

but then it doesn't work. That's a bit annoying. Oh, custom item, no? That's really bad.

Well,

then I'm sorry, it doesn't work for some reason. But, well, we should have seen the elements. We could have imported like this, actually. I'll show you. So, and then use it like that. Custom item,

and

then I could have changed the color, for instance, to, let's say, red. And it would have worked, but

it

would have worked. But for some reason, you don't want to import my library. Perhaps I messed up my computer. I don't know. I'm sorry. But it should have worked.

So,

you have to believe me. There is examples in the Qt, so that shows how to do it. So, I'm really guilty.

So,

now let's have another small example about how you can integrate existing C++ code, like a huge library like Plasma and KDE, which is based on QGraphics widget. And we make it available in QML. So, we can actually work and do Plasma development in QML using Plasma API, which is really cool because we can be faster. So, we can use the Plasma widget and hack them into QML. So, we can actually create user interfaces using QML and using Plasma as well.

So,

we can also connect the Plasma.engin. Marco will explain what it is, but it's basically all the data that we get from the network and everything. And we can use them into QML. We've got theming support.

You

can create applets in Plasma with QML. You can package them, and you can share it online.

Well,

not for now, but

it

works. But since it's not yet released, you can't do it.

But

I have a small example. This one should work,

which

is

here,

my main.qml. So, same, you can import Plasma. So, import Plasma

0

.1.

You

can give an alias, by the way, when you import. So, all classes with Plasma will have a prefix Plasma. So, when I want to use an element,

I

actually do Plasma.pushButton. And then I said, with,

and

then I can send the text. All of that are properties that are exposed from Plasma.

And

I can say,

and

here, I'll just go on the terminal.

And

then I can actually here, oops, run my app. And

it

picked the Plasma button. So, this is a C++. All the button is implemented in C++, right?

And,

but I created via QML. I can animate it. I can do whatever I want with it.

So,

for instance, I can use the encores

on

it. Like, instead of setting the width and the height, I can say

encores fill.

And then, let's say

id rect. And

then it will have the same size as the rect.

You

see?

And

this is C++ code

to

do that. So,

you

can integrate easily Plasma code.

So,

I did the demo. What's coming next? It's a multi-touch support for QML. It's already underway. It will be for Qt 4.8. We have also this project called Qt Mobility, which actually expose mobility APIs for phones. Mostly Nokia phones. So, like having the sensors, the GPS location, mails, SMS and stuff like that. Then via Qt APIs, Qt Mobility, you can access it. So, what we want is also make those APIs available in QML. So, you can actually write the

complete

phone app in QML.

We

are working on Qt Components. This is a huge project, which will bring more advanced elements in QML. Because as I showed,

it

was only basic components. Rectangle, Pix, Map, Text and so on. But we want also people to be able to use easily

already

made push button.

So

that they don't spend time creating, yet again, a button.

So,

and then the button will be styled using the platform that it is running on. So, for now, we've got target Migo

as

a first release. And then we will extend to desktops and everything. So, as I was giving an example, a push button, checkbox, sliders, tab bars, scroll bars and stuff like that.

We

also want to bring our Qt 3D modules into QML. So,

you

can actually do 3D or OpenGL in QML.

And

we are working on this Vahala, which is a new canvas that will replace Graphic View on QML. So, Vahala is actually a canvas that we redesigned from scratch. It has nothing to do with, I mean, we don't use any legacy in Qt.

We

just think the problem from zero. And we want to create a thin graph which is really close to the graphic count. So, we get optimal performance. And then you can actually get nice effects like blur and

stuff

like that really fast.

That's

all. If you have questions, then you can ask. If you want to contribute then in QML or get involved, you can join the RC chat, which is hash Qt-QML on Freenauts. You can sign up on the Qt QML

mailing

list. This mailing list is not for QML development. It's

for

people that are using QML. So, you can ask questions.

We

also have another mailing list where we talk about QML development because we want to do development in the Open.

For

Plasma, if you want to contribute or get involved, the mailing list is there, plasma-dwell or hash Plasma on Freenauts. And for the mobile that we'll show this afternoon, mobile code, which is QML and Plasma,

the

code is on the KDE repo.

Yeah. And

there is my mail addresses if you want to contact me.

That's

all. Thank you.