New Features in Qt 5.12
From Qt Wiki
New Features (within existing modules)
- Qt Gui
- Added presets for QGradient based on https://webgradients.com/
- Added 64bits RGBA formats to QImage, and reading them from PNGs.
- Qt Network
- Added Datagram Transport Layer Security over UDP support.
- Added renegotiation to Security Transport back-end.
- Added ALPN support and HTTP/2 protocol negotiation to Security Transport back-end.
- Qt QML
- ECMAScript modules can be loaded directly with QJSEngine::importModule() and imported in .qml files when using the .mjs file extension.
- Qt Quick
- Pointer Handlers are renamed to Input Handlers (we include the pre-existing Keys attached property in this category) and are now fully supported as a first-class QML feature in Qt Quick. (C++ API for them is still not public yet.)
- HoverHandler is a new type of handler for detecting mouse hover. It can detect hover even in cases of deep nesting: unlike MouseArea, you can hover multiple nested Items with HoverHandlers in them at the same time. (For example, a sidebar and an individual button on the sidebar)
- DragHandler is now a multi-point handler: if you set minimumPointCount to 2, to will react only to a 2-finger drag, for example. This can give you another degree of freedom: single-finger drag can perform the typical item movement, and 2-finger drag can do something else (change the tilt angle, for example).
- Tech Preview: Added TableView as another type of Item View: on par with ListView but having multiple columns. Unlike the one in QtQuick Controls 1.x, it does not do any styling; rather it provides the optimal solution for instantiating (and pooling and reusing) delegates on-demand as you scroll through the rows and columns.
- Tech Preview: Added DelegateChooser as a means of choosing different delegates in Item Views (such as TableView) depending on role values from the model, or depending on the index.
- Qt Quick Controls 2
- Added inputMode property to dial, which adds two new ways of interacting with it: horizontally and vertically. These new input modes use a relative input system, which means that, unlike the old absolute input system, changes to the dial's position are "added" to its value. This results in a dial that is less "jumpy", making it safe for operations that could be harmful if done incorrectly, like adjusting audio levels.
- Added topInset, bottomInset, leftInset, and rightInset properties to control the geometry of the background similarly to how paddings control the geometry of the contentItem.
- Added implicit*Width and implicit*Height properties (e.g. implicitHeaderWidth, implicitContentWidth, etc.) to simplify complex implicit size bindings.
- SwipeView, DialogButtonBox: added contentWidth and contentHeight properties.
- RangeSlider: added valueAt() function, which allows seeing up-to-date values in tooltips for each handle when live is set to false (copied from Slider).
- RangeSlider: added first.moved() and second.moved() signals, similar to Slider's moved() signal.
- Control: unless explicitly specified, baselineOffset is now automatically updated based on the top padding of the control and the baselineOffset of the contentItem. Styles no longer need to specify the baselineOffset in QML.
- Popup: added anchors.centerIn to allow a convenient way of centering a popup.
- QQuickStyle: added stylePathList() and addStylePath() methods for managing the list of directories where Qt Quick Controls 2 searches for available styles.
- Slider, RangeSlider: added touchDragThreshold property for configuring the threshold to initiate the touch 'drag' of the handle of the slider. The mouse 'drag' won't be affected by the property.
- TextArea, TextField: added placeholderTextColor property for user convenience to customize the placeholderText color to fit the backgrounds.
- Material: added a Dense variant of the Material style for use on desktop platforms. Some controls are slightly smaller in height and use smaller font sizes. The variant can be enabled by setting QT_QUICK_CONTROLS_MATERIAL_VARIANT to Dense or setting Variant=Dense in the qtquickcontrols.conf file.
- DialogButtonBox: added buttonLayout property that can be used to arrange the buttons.
- Tumbler: added positionViewAtIndex() function that calls the respective PathView/ListView function, depending on the value of wrap. This allows changing currentIndex without animations.
- Added horizontalPadding and verticalPadding properties as a convenient way to set both left and right, or top and bottom paddings in one go.
- Added non-attached show() and hide() methods to give the same level of convenience for showing non-attached popups with certain parameters.
- Qt Serial Bus
- Added a virtual CAN bus plugin for simulation without CAN hardware
- Added configuration options to canbusutil, e.g. for bitrate setting
- Added CAN FD functionality to the PeakCAN plugin
- Added the readAllFrames() and clear() functions to QCanBusDevice
- Qt WebEngine
- Updated to Chromium 69
- Qt Labs Platform
- Menu, MenuItem, SystemTrayIcon: deprecated iconName and iconSource in favor of icon.name and icon.source grouped properties.
- Menu, MenuItem, SystemTrayIcon: added icon.mask grouped property.
- Qt Virtual Keyboard
- Introduced an extension interface for the virtual keyboard. All the current input methods and some special keyboard layouts (e.g. Hunspell, OpenWnn, etc.) have been moved to extensions. The extension interface allows third parties to create a new input method without having to modify or rebuild the virtual keyboard. In addition, this change makes it possible to add features and languages independently by copying the desired extension to the system.
- Introduced a virtualkeyboard module, which can be linked against an extension plugin. This module provides the C++ API necessary for creating an input method.
- Added build time option to exclude all styles from the plugin.
- Added Vietnamese handwriting recognition (T9 Write).
- Added new layouts: Albanian, Slovak, Slovenian, Thai, Turkish, Vietnamese and Ukrainian.
- Added latin extra layout for Russian.
- The pinyin and tcime dictionaries are now bundled in the plugin by default.
- Added user dictionary and learning for Hunspell.
- No new modules added
- Now uses ICU, when available, in preference to Microsoft's native APIs
Technology Preview Modules
- Qt WebGL Streaming Plugin (TP2) - Stream applications to browsers over the network
The following modules are part of Qt 5.12 release, but deprecated and considered for removal in subsequent releases of Qt:
- Qt Script
- Qt Quick Controls 1