Qt5.7新特性

简述

Qt5.7发布了，新特性如下。

新特性

C++11 Support Required from the compiler

Qt has enabled usage of C++11 in Qt applications for a long time, but with Qt 5.7 we are also enabling use of C++11 in the Qt modules. Therefore Qt 5.7 requires C++11 support from the compiler, and has removed support from older compilers not providing adequate C++11 support.

New Features (within existing modules)

• Qt Core

  • Added qAsConst function to help using non-const Qt containers in C++11 range for loops
  • Qt event dispatchers use the poll() function on Unix now, making it possible for applications to have file descriptors > 1024
  • Added the ability to convert a floating point to its shortest, exact string form, without having to pre-calculate how many digits that is; QVariant uses this
  • Many clean-ups related to C++11, including using std::atomic as backend for QAtomic classes and adding QTypeInfo for char16_t and char32_t
  • QIODevice now supports multistreaming
  • QPluginLoader now works even if QT_NO_LIBRARY is set (e.g., linking against a static libc)

• Qt GUI

  • QImage smooth scale optimized for NEON.
  • Optimized the OpenGL function wrappers for speed and code size. QtGui library size has been significantly reduced due to a massive reduction in symbols.
  • QIcon::fromTheme can now use GTK+ icon theme caches for faster icon lookup

• Qt Widgets

  • QTabBar now delegates placement of tab scroll buttons to the style.
  • Qt Style Sheets can now optionally let widgets inherit font and palette from their parents.

• Qt WebEngine

  • Based on Chromium 49
  • Drag’n’Drop
  • Printing to PDF
  • Audio played in tab notification.
  • Support for DRM-protected HTML5 video using Widevine pepper plugin
  • API for evaluating javascript or installing qwebchannel in secure isolated javascript worlds
  • Data to make better custom context menus
  • Compile time switch for AppStore compatibility on OS X

• Qt QML

  • Added JIT support for WinRT on x86 and x64.
  • Enabled JIT for 64-bit ARM Linux platforms.
  • All debug services now work with QJSEngine rather than QQmlEngine, which allows for non-QML JavaScript debugging or profiling.
  • The JavaScript debug service now supports debugging of multiple QJSEngine instances at the same time.
  • The profiler service can generate much larger traces without running out of memory, and will take much less time to do so now.
  • Custom connectors for debugging and profiling can be loaded with QQmlDebuggingEnabler::startDebugConnector() now.
  • The JavaScript debug service can now evaluate expressions without the QML engine being paused in a breakpoint.

• Qt Quick

  • The inspector service now supports all subclasses of QQuickWindow, which makes Qt Creator’s inspection feature useful.

• Embedded platforms

  • Added support for NVIDIA DRIVE CX boards (Tegra X1, AArch64)
  • Added support for the Raspberry Pi 3 (32-bit mode)
  • Added support for NXP i.MX7-based devices (no GPU; uses linuxfb and the Qt Quick 2D Renderer)
  • Improved theming support with eglfs

• Desktop platforms

  • X11: QMenuBar uses the unified D-Bus AppMenu menubar when the desktop environment supports it (e.g. Ubuntu Unity)

• Mobile platforms

  • Android: Qt can now be used to easily create Android Services.

• Qt Canvas 3D

  • New version of three.js

• Qt NFC

  • API ported to Android.

• Qt Multimedia

  • Added support for tvOS.
  • Extended QML playlist API.

• Qt Bluetooth

  • Technical preview for Qt Bluetooth Low Energy peripheral role feature (Bluez only)

• Qt Sensors

  • Added iio-sensor-proxy backend for Linux. It provides light, orientation, and compass sensors.

New Modules

• Qt 3D

  • Support for Compute Shaders on supported hardware
  • Support for loading multi-image DDS and KTX textures including cubemaps, mip chains, array textures
  • Improved support for compressed texture formats
  • Render surface made explicit - will later allow for multiple renders of the same scene to different surfaces and other use cases
  • Extended Input API and support for device plugins
  • Picking support improved

• Qt Quick Controls 2

  • A new light-weight set of embedded and mobile oriented controls
  • Based on a flexible template system that enables rapid development of entire custom styles and user experiences
  • Built-in styles:
  • Default style - a simple and minimal all-round style that offers the maximum performance
  • Material style - a style based on the Google Material Design Guidelines
  • Universal style - a style based on the Microsoft Universal Design Guidelines
  • Can be mixed with Qt Quick Controls 1.0, but the APIs are not compatible

• Qt Charts

  • Previously commercial-only Qt Charts module is now included in Qt under also GPLv3 license for open source users

• Qt Data Visualization

  • Previously commercial-only Qt Data Visualization module is now included in Qt under also GPLv3 license for open source users

• Qt Virtual Keyboard

  • Previously commercial-only Qt Virtual Keyboard module is now included in Qt under also GPLv3 license for open source users

• Qt Purchasing

  • Previously commercial-only Qt Purchasing module is now included in Qt under also LGPLv3 and GPLv3 license for open source users

• Qt Quick 2D Renderer

  • Previously commercial-only Qt Quick 2D Renderer module is now included in Qt under also GPLv3 license for open source users

Technology Preview Modules

• Qt Wayland Compositor

  • Pure QML API
  • Improved C++ API with added convenience
  • New convenient API for making extensions and using them from both QML and C++

• Qt SCXML

  • Completely new module for C++ and QML
  • Static and runtime integration of SCXML models into Qt code

• Qt Gamepad

  • New module to process input from gamepads in C++ and QML applications.
  • Supports Windows (XInput), Linux (evdev), Android, iOS.

• Qt Serial Bus

  • New module for C++
  • Supports Modbus and CAN bus

Deprecated Modules

The following modules are part of Qt 5.6 release, but deprecated and considered for removal in subsequent releases of Qt:

• Qt Script

Removed Modules

With Qt 5.7 the following modules are no longer part of the final release packages:

• Qt Enginio

Configurations

• Qt 5.7 has deprecated configurations that do not provide adequate C++11 support. For details, please see Qt 5.7 Tools and Versions in the wiki.
• Mobile platforms: Minimum required versions upgraded to iOS 7 and Android 4.1

安装配置

关于Qt5.7的安装配置，请参考之前所写环境搭建相关的资料：

• Qt环境搭建(Visual Studio)
• Qt环境搭建(Qt Creator)

安装过程中，新添加的模块（如：Qt Charts）默认不被安装，请自行勾选（我一般会全选）。

使用

打开Creator，进入：欢迎 -> 示例，我们可以运行新添加的一些模块示例：

Qt Charts效果也很棒，效果如下：

效果棒棒哒，看起来不必QWT等其它图形库逊色，而且支持QML，后期有时间好好研究一番。

更多参考

• Qt 5.7 released
• New Features in Qt 5.7