Qt 5.8 Beta 版发布了，主要更新内容如下：
New Features (within existing modules)
- 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)
- 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 OS X & 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 Weiland
- Optional support for issuing commands to Qt3D aspects (e.g. from profiler)
- (Screenshot framegraph node STILL UNDER REVIEW)
- 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
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.