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/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:FDL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Free Documentation License Usage
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of
** this file. Please review the following information to ensure
** the GNU Free Documentation License version 1.3 requirements
** will be met: http://www.gnu.org/copyleft/fdl.html.
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\page qt5-intro.html
\title What's New in Qt 5
\brief Qt 5 features and its benefits
Qt 5 is the latest version of Qt. It enables developers to develop
applications with intuitive user interfaces for multiple targets, faster
than ever before. Qt 5 makes it
easier to address the latest UI paradigm shifts that touch screens and
tablets require.
Developers can be more productive and flexible with the improved support
for JavaScript and QML in Qt 5, while still having the C++ foundation
and Qt Widget support. The JavaScript backend powered by V8
and Qt WebKit 2 will make HTML5 developers feel at home.
Qt 5 is highly compatible with Qt 4. It is possible for developers
of Qt 4 applications to seamlessly move on to Qt 5 with their current
functionality and gradually develop new things leveraging all the great
items Qt 5 makes possible.
Cross-platform portability is made simpler in Qt 5, thanks to the new
modularized codebase consisting of the
\l{All Modules}{essential and add-on} modules, and the consolidation
of the \l{Qt Platform Abstraction}.
The following sections summarize some of the key features that Qt 5 brings
to the table.
\section1 Amazing Graphics Capability and Performance
Qt 5 uses an OpenGL based scene graph to accelerate the graphics
of Qt Quick, making it possible to do visually appealing user
interfaces with animations, impressive graphical effects and
particle systems, even on the constrained hardware environments of
mobile and embedded devices.
\table
\header
\li \l ShaderEffect on an \l Image
\row
\li \image qt5_shadereffect.jpg
\row
\endtable
The benefits of this architectural change in the rendering engine is well
demonstrated by the following projects:
\list
\li \l{Livecoding video effects with Qt5} - The Big Buck Bunny you
never saw before. Video effects created using Qt Quick.
\li \l{Pimp my video} - Video effects implemented using the shader language
with QML.
\li \l{QtMediaHub} - The power and convenience of Qt Quick.
\li \l{QtonPi} - Good example of Qt 5 running on the low cost hardware,
Raspberry PI.
\endlist
\section1 Qt Quick in Qt 5
\l {Qt Quick} provides the necessary infrastructure to develop QML
applications. The latest version (v2.0) of this technology also
introduces a set of new C++ classes as a replacement for the
QDeclarative* equivalents in Qt Quick 1. New features in Qt Quick
include:
\list
\li \l Canvas for drawing. Canvas provides an API that is similar to
the HTML5 Canvas API, along with some additional features.
\li \l {ShaderEffect} {Shader Effects} which enable GLSL shader programs to be
integrated directly into QML code and applied to items and
images.
\li \l {Using the Qt Quick Particle System}{Particle Effects} for creating a variety of 2D particle systems.
\li \l {Sprite Animations}{Sprites} can be used in animating 2D graphical objects and as a source
for particle systems.
\li \l {Qt Quick Local Storage QML Types}{Offline storage} is a HTML5 Web Database API conformant JavaScript API
for storing data in Qt Quick applications.
\li \l {Qt Quick Window QML Types}{Window} provides a
top-level window and the Screen type for accessing a screen's
resolution and other details. This is useful for desktop
applications developed using Qt Quick.
\li \l {Qt Quick Scene Graph} {New rendering architecture} based on OpenGL for optimal performance.
\endlist
\table
\header
\li Qt Quick's \l {Using the Qt Quick Particle System}{Particle System}
\row
\li \image qt5_particles.jpg
\row
\endtable
The \l {qtgraphicaleffects-index.html}{Qt Graphical Effects} module provides a number of
ready-made effects for use in Qt Quick applications, including
soft drop shadow, blur, glow and colorize.
\table
\header
\li Excerpts from the Qt Graphical Effects module.
\row
\li \image qt5_graphicaleffects.jpg
\row
\endtable
\section1 WebKit and HTML5
\l {Qt WebKit} is a web content rendering engine based on the open
source WebKit project featuring broad support for standard web
technologies. The Qt WebKit module provides integration with both
Qt Quick and traditional widgets. The module brings the latest in
HTML5 advancements to Qt 5, including CSS filters and animations
and Video, Canvas and WebGL, Canvas support and HTML video.
\section1 Multimedia
\l {Qt Multimedia} provides a rich set of QML types and C++ classes to
handle multimedia content. It also provides necessary APIs to
access the camera and radio functionality. Qt 5 brings the Qt
Multimedia module into the set of essential modules with support
on all major platforms.
\table
\header
\li \l Video embedded into a Qt Quick application with a displacement effect
\row
\li \image qt5_video.jpg
\endtable
\section1 Modularized Qt Libraries
Qt 5 splits the Qt libraries into domain specific libraries and
modules. This means that an application can choose which libraries
it requires and only compile, use and deploy those.
For a complete list of modules and libraries, see \l {All
Modules}{all Qt modules}.
\section2 Widgets in Qt 5
The \l {Qt Widgets} have been separated into their own module in Qt 5,
the Qt Widgets module. It is part of the essential modules.
\table
\header
\li Screenshots of widget based applications running Qt 5.
\row
\li \image qt5_widgets.jpg
\endtable
\section1 Qt Platform Abstraction
The windowing system dependent parts of Qt have been completely
rewritten for Qt 5, based on the Qt Platform Abstraction, a plugin
architecture which allows Qt to dynamically load a windowing
system integration based on what system it is running on. This
gives several benefits:
\list
\li Centralize the windowing system integration codebase into
classes shared for all platforms.
\li Simplify the work required when porting Qt to new platforms.
\li Remove the windowing system dependency from Qt, making it
possible to have the same Qt binaries run against multiple
windowing systems. For instance, the Qt Linux binaries can run
against both X11 and Wayland.
\endlist
\section1 New Connection Syntax
In addition to the still available well known way to connect signals and slots,
new overloads of QObject::connect have been added allowing you to connect signals
and slot using pointer to member functions:
\code
QObject::connect(sender, &Sender::valueChanged, receiver, &Receiver::updateValue);
\endcode
The new syntax provides compile time checking of the compatibility between signals
and slots, automatic conversion of the arguments if there is an implicit cast between
the types, and solve many problems occurring because of typedef or namespaces.
Additionally, if your compiler supports C++11 lambdas, you can even connect directly
to a lambda function.
\code
connect(sender, &QObject::destroyed, [=](){ this->m_objects.remove(sender); });
\endcode
\section1 Connectivity and Networking
Qt 5 provides better support for IPv6 and dual mode networks. Most
applications using host names and network layer transparent protocols
can now gain IPv6 support transparently. Such applications can also choose
to receive both IPv4 and IPv6 connections or bind to only one of the two
connection types. In the case of outgoing HTTP connections using
\c{QNetworkAccessManager}, both IPv4 and IPv6 connections are attempted in
parallel, and the one that succeeds first is used. This is useful in
environments where one of the two types has limited connectivity.
Qt 5 also provides better ways to handle TCP socket-based connections and
SSL certificates. This means developers can now:
\list
\li bind a TCP socket to an IP address before connecting,
\li verify an SSL certificate chain,
\li and access legacy systems.
\endlist
Stricter client authentication is one of the primary concerns for many
applications handling confidential/critical data. The opaque Private Keys
support in Qt 5 enables applications to read private keys from devices such
as PKCS#11 dongles for stricter client authentication. The \l{qsslkey
example} illustrates reading private keys from a device.
\section1 JSON Support
Qt applications that use simple data structures to store small amount of
data, can now choose to use JSON documents over the complex database
backends that need necessary drivers or plugins to access data. The fact
that JSON is a text-based open standard derived from JavaScript, makes it
the obvious choice for QML applications as well.
The Qt Core provides a set of classes to enable parsing and generating JSON
documents. These classes also allow you to convert between an in-memory
binary representation of JSON to a standard textual JSON format. The goal
is to make common operations on JSON faster.
\section1 User Input
Qt 4 already had support for handling multi-point touch input in
C++. Qt 5 extends this support to include Qt Quick, covering all
the information about the touch points, including the touch
position, pressure, and velocity.
The mouse event handling in Qt 5 has been improved from its
predecessor. Applications have more control to handle mouse
events in Qt Quick. The mouse area in a QML document can propagate
the mouse wheel and click events and also ignore propagated
events.
Besides this, Qt 5 adds support for more mouse buttons on
platforms where this is supported. This comes in handy for gaming
applications developed using Qt.
\section1 Related Topics
\list
\li \l{What's New in Qt 5.1}
\li \l{What's New in Qt 5.0}
\li \l{Porting Guide}
\endlist
*/
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