- Qt 5.15
- Qt Widgets
- Qt 5.15.19 Reference Documentation

# Qt Widgets

The Qt Widgets Module provides a set of UI elements to create classic desktop-style user interfaces. See the User Interfaces overview for more information on using widgets.

## Getting Started

To include the definitions of the module's classes, use the following directive:

     #include <QtWidgets>

To link against the module, add this line to your qmake `.pro` file:

     QT += widgets

## Widgets

Widgets are the primary elements for creating user interfaces in Qt. Widgets can display data and status information, receive user input, and provide a container for other widgets that should be grouped together. A widget that is not embedded in a parent widget is called a window.

The QWidget class provides the basic capability to render to the screen, and to handle user input events. All UI elements that Qt provides are either subclasses of QWidget, or are used in connection with a QWidget subclass. Creating custom widgets is done by subclassing QWidget or a suitable subclass and reimplementing the virtual event handlers.

- Window and Dialog Widgets
- Application Main Window
- Dialog Windows
- Keyboard Focus in Widgets

## Styles

Styles draw on behalf of widgets and encapsulate the look and feel of a GUI. Qt's built-in widgets use the QStyle class to perform nearly all of their drawing, ensuring that they look exactly like the equivalent native widgets.

Qt Style Sheets are a powerful mechanism that allows you to customize the appearance of widgets, in addition to what is already possible by subclassing QStyle.

## Layouts

Layouts are an elegant and flexible way to automatically arrange child widgets within their container. Each widget reports its size requirements to the layout through the sizeHint and sizePolicy properties, and the layout distributes the available space accordingly.

Qt Designer is a powerful tool for interactively creating and arranging widgets in layouts.

## Model/View Classes

The model/view architecture provides classes that manage the way data is presented to the user. Data-driven applications which use lists and tables are structured to separate the data and view using models, views, and delegates.

## Graphics View

The Graphics View Framework is for managing and interacting with a large number of custom-made 2D graphical items, and a view widget for visualizing the items, with support for zooming and rotation.

## Licenses

The Qt Widgets module is available under commercial licenses from The Qt Company. In addition, it is available under free software licenses. Since Qt 5.4, these free software licenses are GNU Lesser General Public License, version 3, or the GNU General Public License, version 2. See Qt Licensing for further details.

## Related Information

### Tutorials

- Widgets Tutorial
- Getting Started Programming with Qt Widgets
- Creating a Qt Widget Based Application
- Model/View Tutorial

### Examples

- Qt Widgets Examples
- Layout Examples

## API Reference

These are links to the API reference materials.

- Qt Widgets C++ Classes
  - Basic Widget Classes
  - Advanced Widget Classes
  - Abstract Widget Classes
  - Organizer Widget Classes
  - Graphics View Classes
  - Model/View Classes
  - Main Window and Related Classes
  - Widget Appearance and Style Related Classes
  - Layout Classes
- Qt Style Sheets Reference