Qt 5.9 | Qt Quick | Important Concepts In Qt Quick - User Input

Qt 5.9.9 Reference Documentation

# Important Concepts In Qt Quick - User Input

Being able to respond to user-input is a fundamental part of user-interface design. Depending on the use-case that an application solves, and the form-factor of the device that the application runs on, the best way to receive user-input may be different.

## Touch

Allowing users to physically touch a screen to interact with an application is a popular user-interface paradigm on portable devices like smartphones and tablets.

Qt Quick was designed specifically with touch-driven user-interfaces in mind, and thus touch events are supported in various visual object types, from Flickable lists to the generic MultiPointTouchArea type, as well as in the MouseArea type (which will be documented thoroughly in a proceeding section).

## Mouse

Mouse input is another important user input for user interfaces. Detecting and reacting to clicks and presses according to the mouse cursor position is a fundamental concept in user-interface design.

Qt Quick provides the MouseArea visual object type which automatically receives mouse events (including clicks and wheel events) which allows developers to create custom user-interface objects to handle mouse input. Please see the documentation about mouse events in Qt Quick for more information on the topic.

## Keyboard Input and Keyboard Focus

Supporting input from a keyboard is a vital component of the user interface of many applications.

Any visual item can receive keyboard input through the Keys attached type. Additionally, the issue of keyboard focus arises when multiple items are required to receive key events, as these events must be passed to the correct item. See the documentation about Keyboard focus in Qt Quick for more information on this topic.

Qt Quick also provides visual text items which automatically receive keyboard events and key-presses, and displays the appropriate text. See the documentation about text input for in-depth information on the topic.

## Device Motion Gestures

Detecting device gestures with an accelerometer, or through camera-based gesture recognition, can allow users to interact with an application without requiring their full and undevided attention. It can also provide a more interactive and engaging experience.

Qt Quick itself does not offer first-class support for physical device motion gestures; however, the Qt Sensors module provides QML types with support for such gestures. See the Qt Sensors module documentation for more information on the topic.