Qt Platform Abstraction | Qt 5.5

- Qt 5.5
- Qt Platform Abstraction
- Qt 5.5.1 Reference Documentation

# Qt Platform Abstraction

The Qt Platform Abstraction (QPA) is the platform abstraction layer for Qt 5 and replaces Qt for Embedded Linux and the platform ports from Qt 4.

QPA plugins are implemented by subclassing various QPlatform* classes. There are two “root” classes: QPlatformIntegration for window system integration and QPlatformTheme for deeper platform theming and integration. QStyle is not a part of QPA.

There are no source or binary compatibility guarantees for the QPA classes, meaning that a platform plugin is only guaranteed to work with the Qt version it was developed against. API changes will however only be made in minor releases. (5.1, 5.2, and so on.)

There is no detailed tutorial documentation for writing QPA plugins at this time. However, there are two example plugins shipped with Qt5:

- `qtbase/src/plugins/platforms/minimal/`
- `qtbase/src/plugins/platforms/minimalegl/`

## Class Overview

- QPlatformIntegration
  - QPlatformWindow
  - QPlatformBackingStore
  - QPlatformOpenGLContext
  - QPlatformSharedGraphicsCache
  - QPlatformFontDatabase
  - QPlatformClipboard
  - QPlatformDrag
  - QAbstractEventDispatcher
  - QPlatformInputContext
  - QPlatformAccessibility
  - QPlatformNativeInterface
  - QPlatformServices
- QPlatformTheme
  - QPlatformMenu
  - QPlatformMenuBar
  - QPlatformDialogHelper
  - platform palettes
  - platform fonts
  - theme hints

`qtbase/src/platformsupport` contains several helper classes for implementing platform plugins on Unix-like systems.