Qt features multiple technologies for creating user interfaces. While it is possible to mix and match these different technologies as needed, one approach is often better suitable for a certain type of user interface than the others. Qt Creator is a good example of an application that mixes different user interface technologies. In fact, it uses all of the three different approaches described below. Qt Creator uses the traditional Qt Widgets such as menus and dialogs as a basis of the user interface, Qt Quick amongst others for the welcome screen, and Qt WebKit for presenting the Qt reference documentation. The following sections provide brief introductions to the available technologies for creating user interfaces, and a comparison table to help choosing the best suitable technology.

Common Important UI Topics

• High DPI Displays

QML Graphical User Interfaces

QML allows developers to build user interfaces in a declarative way. User interfaces specifically benefit from the simplicity of compounding QML objects and configuring them using property bindings.

Qt Quick is a module which supplies QML types for creating user interfaces such as a visual canvas with its own coordinate system and rendering engine. Animation and transition effects are a first class concept in Qt Quick and visual effects can be supplemented through specialized components for particle and shader effects.

Important UI Topics for QML Applications

• Visual types in QML
• Responding to User Input in QML
• Animations in QML
• Displaying Text in QML
• Layouts in QML
• Style and Theme Support
• Integrating JavaScript in QML
• Scalability

Graphical Controls

The Qt Quick Controls module is new in Qt 5.1 and provides a set of UI elements to create user interfaces using Qt Quick 2.

For more about how to create application user interfaces with QML, visit the QML User Interfaces page.

Widget-based User Interfaces

Qt Widgets are traditional user interface elements that are typically found in desktop environments. The widgets integrate well to the underlying platform providing native look'n'feel on Windows, Linux and Mac OSX. The widgets are mature and feature rich user interface elements suitable for mostly static user interfaces. In contrast to Qt Quick, the widgets do not scale that well for touch screens and fluid, highly animated modern user interfaces. The widgets are a good choice for applications with traditional desktop centric user interfaces, such as office type applications.

Important Concepts in Qt Widgets

• Application Main Window
• Desktop Integration
• Dialog Windows
• Layout Management
• Model/View Programming
• Rich Text Processing
• Drag and Drop
• Internationalization

Displaying Web Content

Qt provides both WebKit-based and Chromium-based (WebEngine) layout engines, which enable you to embed web content into the Qt application. These engines provide both QML and C++ alternatives.

For more information about support for web content in Qt, see Integrating Web Content.

Comparison

Notice that choosing the appropriate technology for building an user interface is not always black and white, but may depend on several criterias, such as other existing technologies used in a project or even target platform constraints. To some extent, many items in the following table can be implemented using any of the three available technologies. The following table merely aims to help you choose the best suited tool for the job.

Internationalization and Translations

Qt provides excellent support for translating applications into local languages. Release managers, translators, and developers can use Qt translation tools to accomplish their tasks.

• Internationalization with Qt - instructions and the process of creating localized applications.
• Qt Linguist Manual - manual of Qt's translation tool