Qt is a cross-platform application development framework for desktop, embedded and mobile. Supported Platforms include Linux, OS X, Windows, VxWorks, QNX, Android, iOS, BlackBerry, Sailfish OS and others.
Qt is not a programming language on its own. It is a framework written in C++. A preprocessor, the MOC (Meta-Object Compiler), is used to extend the C++ language with features like signals and slots. Before the compilation step, the MOC parses the source files written in Qt-extended C++ and generates standard compliant C++ sources from them. Thus the framework itself and applications/libraries using it can be compiled by any standard compliant C++ compiler like Clang, GCC, ICC, MinGW and MSVC.
the software development framework that enables you to create the user experiences your products deserve and your customers require. We are always working on improving Qt’s cross-platform libraries and tools ensuring it continues to accelerate your development and allowing you to bring amazing products to life on any OS and any device – regardless of size. Qt 5.8 helps you optimize your performance and reduce your footprint for your internet of things, create multi-process devices and easily integrate state machines into any Qt application. There is so much more to say about Qt 5.8 – here are a few or our favorite updates.
- Qt Core
- Added at(), operator, mid(), right() and left() to QLatin1String
- Qt GUI
- QTouchEvent now has uniqueId and rotation
- Support for dithering when converting to all QImage formats
- Previously private QOpenGLTextureBlitter API is made public, to help QtWayland in particular
- Added capHeight() to QFontMetrics, QFontMetricsF, and QRawFont
- Selection handles on Android, with edit menu for copy/paste)
- Added applicationDisplayNameChanged() signal to QGuiApplication
- Qt Quick
- Refactored the Qt Quick scene graph to remove its OpenGL dependency and make it possible to create rendering backends based on other graphics APIs, such as Vulkan or Direct3D.
- Integrated the software renderer for the Qt Quick scene graph as a proper backend for the scene graph (previously known as the Qt Quick 2D Renderer.)
- Implemented support for partial updates in the software backend for the scene graph (2D Renderer) to prevent expensive fullscreen updates when only small areas are changing.
- Added an experimental Direct3D 12 backend
- Implemented caching of code and data structures generated from .qml/.js files to disk to reduce start-up time and memory consumption. The resulting .qmlc and .jsc cache files are memory mapped.
- Cleaned up touch and mouse event delivery and added a new internal class QQuickPointerEvent which is used for that purpose. This is the foundation for further improvements with regards to input event handling, but does not affect any code using Qt Quick yet.
- Qt Quick Controls 2
- Added new QML types: Dialog, DialogButtonBox, MenuSeparator, RoundButton, and ToolSeparator
- Added ripple effects to the Material style
- Added hover effects to the Material and Universal styles
- Added a ‘System’ theme to the Material and Universal styles
- Added new experimental “platform” QML types: MenuBar, Menu, SystemTrayIcon, ColorDialog, FontDialog, MessageDialog, FileDialog and FolderDialog
- Qt Widgets
- Qt WebEngine
- Based on Chromium 53
- Windows: Requires MSVC 2015 Update 2 or later
- view-source: scheme is supported
- Spellchecking with Hunspell
- Tooltips (HTML5 global title attribute) are now also supported in the QML API.
- User scripts now support metadata (@include, @exclude, @match)
- Qt WebEngine (QML) allows defining custom dialogs / context menu’s
- Qt WebEngine (QML) on eglfs uses builtin dialogs based on Qt Quick Controls 2
- Support for printing
- Added setting to enable printing of CSS backgrounds
- Some chrome: schemes now supported, for instance chrome://gpu
- Qt Bluetooth
- Bluetooth Low Energy Peripheral support on macOS & iOS
- Bluetooth Low Energy Central support on WinRT
- Qt Multimedia
- Added QAudio::convertVolume() (and matching QML API) function to convert an audio volume from one scale to another, e.g. logarithmic to linear.
- VideoOutput (QML) now supports rendering YUV 4:2:2 (YUYV, UYVY) video frames.
- GStreamer backend (Unix) now supports video probing on QCamera
- Qt Network
- Support for TLS PSK ciphersuites on server side
- Support for configurable diffie hellman parameters
- Support for HTTP/2 in Network Access Manager
- Qt WebSockets
- Support for TLS PSK ciphersuites on client and server side
- Qt Charts
- Candlestick chart type added.
- Qt 3D
- Main focus on maturation (improving performance, bug fixing and improving test coverage)
- Paint to texture using QPainter from Wayland
- Optional support for issuing commands to Qt3D aspects (e.g. from profiler)
- Screenshot frame graph node.
- Embedded platforms
- Enhanced multi-screen capabilities and configurability with eglfs when running on KMS/DRM, both with GBM and EGLDevice/Stream
- Added support for 90 or 180 degrees rotation of software-rendered content (QWidget) in eglfs
- VNC support
- Qt 5.8 comes with a new QPA backend that supports VNC. This allows running any Qt application in a mode that will make it possible to connect to it remotely through the VNC protocol.
Configurability (Qt Lite project)
Qt 5.8 comes with a rewritten configuration system, that allows for easy customisation of your Qt build. The main focus of this feature is for the Device Creation, but it can also be used to tailor a Qt build for mobile or desktop. The system allows removing individual pieces of functionality and APIs from Qt, thus creating a more lightweight set of libraries for deployment.
- Qt Wayland Compositor
- Qt SCXML
- Qt Serial Bus
- Apple tvOS (technology preview)
- Apple watchOS (technology preview)
Technology Preview Modules
- Qt Gamepad (TP2)
- Qt Speech – A module to make text to speech and speech recognition easy. For Qt 5.8 (and probably even the next few releases) only the text to speech part is released. It has backends for several speech synthesizers on macOS, Android, Windows and Linux currently.
- Qt Network Authentication – currently includes support for OAuth 1 + 2
The following modules are part of Qt 5.8 release, but deprecated and considered for removal in subsequent releases of Qt:
- Qt Script
- Qt Quick 2D Renderer (functionality of the module has been merged into Qt Declarative)
- There are no more separate device and simulator libraries for iOS; they are now combined into a single library (and the same applies for tvOS and watchOS).
- Precompiled headers now supported on iOS