qt quick (qml)

Alexander TrufanovSenior Technical ConsultantForum Nokia

Qt 4.7: Qt Quick

September 18, 2010

What is Qt?• Qt (”cute”) is a cross-platform C++ application development framework

– Set of cross-platform APIs and cross-platform GUI framework

– C++ class library

– Development tools

• Qt was originally designed for efficient creation of platform-independent desktop GUI programs

• Developed by a Norwegian company called Trolltech, which has been part of Nokia since 2008

• Latest version is 4.6.3 (under development 4.7 RC)

Qt Architecture• Qt uses native styles to draw UI

– UI elements have original

look & feel

– Can be adapted by the developer

• Built on low level APIs of platform

– No runtime!

• Cross-platform

– Single source for multiple platforms

– Only requires recompilation

Qt Licensing• LGPL license

• Qt is completely free!

– Unlike GPL, the LGPL:

• Allows using Qt for free in commercial, closed source apps

– Complete development source code of Qt available

• Commercial version

– Code changes to Qt source code don’t have to be shared

– Included support options

Platforms Windows

Mac OS

Linux / X11

Embedded Linux

Windows CE

Maemo / MeeGo

Symbian (S60)

C++

Java

Python

Ada

Pascal

Perl

PHP

Maintained by

Qt open source community.

Not officially supported by Qt Development Frameworks.

Symbian and Qt• Qt for Symbian:

– Compatible to S60 3rd. Edition, FP1+ (for example Nokia N95, E71)

– Install SDK for your device, or lowest denominator for devices you want

to support with your product

• Info about system version of Nokia S60 devices:

http://www.forum.nokia.com/devices/

Series 60

1st Ed.

Series 60

2nd Ed.

(+ 3 FPs)

S60

3rd Ed.

S60

3rd Ed.

FP1

S60

3rd Ed.

FP2

S60

5th Ed.

=

Symbian^1

Symbian^3 Symbian^4

Maemo / MeeGo and Qt• Maemo 5

– GTK+ based UI

– Qt pre-installed

– Final Qt support: H1 2010 (4.6.2)

• MeeGo 1.0 N (formerly: Maemo 6)

– Qt replaces GTK+

– Multi-touch, gestures support

– GTK and Clutter will stay in MeeGo

Simple installation

Qt Creator in nutshell

From the scratch to devices in 5min.

Simulator

On-device-debugging

Remote Compiler

Hybrid ApplicationsHTML App

Qt Web Technology

Qt

Advantages of Hybrid Applications

C++

Full device access

Powerful libraries

HTML, CSS,

JavaScript

Rapid development

Broad reach

http://qt.nokia.com/forms/whitepapers/reg-whitepaper-hybrid

Qt Quick (Qt User Interface Creation Kit)• Create UIs as a designer

– Without C++ knowledge

– Using visual tools

– Module: Declarative UI

– Based on QML language

(extension to JavaScript)

– Supported in Qt 4.7

http://blog.qt.nokia.com/2010/02/15/meet-qt-quick/

QML• Describe UI by tree structure of property bindings

– Properties dynamically evaluated

– Communication through

signals & slots

– Bindings to C++ code possible

– Animate properties using states

and transitions

Rectangle{

width: 200

height: 200

color: "white"

Image {

source: "pics/logo.png"

anchors.centerIn: parent

}

}

Qt Quick videos & demos