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<td ><a href="index.html">Qt 5.9</a></td><td >Qt Platform Abstraction</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td>
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<h3><a name="toc">Contents</a></h3>
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<li class="level1"><a href="#qpa-minimal-plugins">QPA Minimal Plugins</a></li>
<li class="level1"><a href="#class-overview">Class Overview</a></li>
<li class="level1"><a href="#qpa-plugins">QPA Plugins</a></li>
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<h1 class="title">Qt Platform Abstraction</h1>
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<p>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.</p>
<p>QPA plugins are implemented by subclassing various <code>QPlatform*</code> classes. There are several <i>root</i> classes, such as <code>QPlatformIntegration</code> and <code>QPlatformWindow</code> for window system integration and <code>QPlatformTheme</code> for deeper platform theming and integration. QStyle is not a part of QPA.</p>
<p>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.)</p>
<a name="qpa-minimal-plugins"></a>
<h2 id="qpa-minimal-plugins">QPA Minimal Plugins</h2>
<p>There is no detailed tutorial documentation for writing QPA plugins at this time. However, there are two minimal plugins shipped with Qt 5 for testing and other special purposes that you can use as examples:</p>
<ul>
<li><code>qtbase/src/plugins/platforms/minimal/</code></li>
<li><code>qtbase/src/plugins/platforms/minimalegl/</code></li>
</ul>
<p>The <code>qminimal</code> plugin is used for tools that link against Qt GUI, but do not require window system integration (for example, <code>qmlplugindump</code>). It also has diagnostic support for dumping window contents to image files as determined by environment variables.</p>
<a name="class-overview"></a>
<h2 id="class-overview">Class Overview</h2>
<ul>
<li>QPlatformIntegration<ul>
<li>QAbstractEventDispatcher</li>
<li>QPlatformAccessibility</li>
<li>QPlatformBackingStore</li>
<li>QPlatformClipboard</li>
<li>QPlatformCursor</li>
<li>QPlatformDrag</li>
<li>QPlatformFontDatabase</li>
<li>QPlatformGraphicsBuffer</li>
<li>QPlatformInputContext</li>
<li>QPlatformNativeInterface</li>
<li>QPlatformOffscreenSurface</li>
<li>QPlatformOpenGLContext</li>
<li>QPlatformScreen</li>
<li>QPlatformServices</li>
<li>QPlatformSharedGraphicsCache</li>
<li>QPlatformSurface</li>
<li>QPlatformWindow</li>
</ul>
</li>
<li>QPlatformTheme<ul>
<li>QPlatformDialogHelper</li>
<li>QPlatformMenu</li>
<li>QPlatformMenuBar</li>
<li>QPlatformMenuItem</li>
<li>QPlatformSystemTrayIcon</li>
<li>platform palettes</li>
<li>platform fonts</li>
<li>theme hints</li>
</ul>
</li>
</ul>
<p><code>qtbase/src/platformsupport</code> contains several helper classes for implementing platform plugins on Unix-like systems.</p>
<a name="qpa-plugins"></a>
<h2 id="qpa-plugins">QPA Plugins</h2>
<p>The following table summarizes the platform plugins available for QPA:</p>
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<thead><tr class="qt-style"><th >Plugin Name</th><th >Plugin Class Name</th><th >Description</th></tr></thead>
<tr valign="top" class="odd"><td ><code>qandroid</code></td><td >QAndroidPlatformIntegration</td><td ><a href="android-support.html">Android support</a></td></tr>
<tr valign="top" class="even"><td ><code>qbsdfb</code></td><td >QBsdFbIntegration</td><td >BsdFb support</td></tr>
<tr valign="top" class="odd"><td ><code>qcocoa</code></td><td >QCocoaIntegrationPlugin</td><td ><a href="osx.html">Cocoa support</a></td></tr>
<tr valign="top" class="even"><td ><code>qdirect2d</code></td><td >QWindowsDirect2DIntegrationPlugin</td><td >Similar to the <code>qwindows</code> plugin, but replaces the raster paint engine with a Direct2D-based paint engine for QPixmap and QBackingStore.</td></tr>
<tr valign="top" class="odd"><td ><code>qdirectfb</code></td><td >QDirectFbIntegrationPlugin</td><td >DirectFB is centered around <i>surfaces</i>, which are the equivalent of a QPaintDevice.</td></tr>
<tr valign="top" class="even"><td ><code>qeglfs</code></td><td >QEglFSIntegrationPlugin</td><td ><a href="vxworks.html#eglfs">EGLFS</a> support for embedded Linux devices.</td></tr>
<tr valign="top" class="odd"><td ><code>qhaiku</code></td><td >QHaikuIntegration</td><td >Haiku support</td></tr>
<tr valign="top" class="even"><td ><code>qios</code></td><td >QIOSIntegrationPlugin</td><td ><a href="ios-support.html">iOS support</a></td></tr>
<tr valign="top" class="odd"><td ><code>qlinuxfb</code></td><td >QLinuxFbIntegrationPlugin</td><td ><a href="embedded-linux.html#linuxfb">LinuxFB</a> support for embedded Linux devices.</td></tr>
<tr valign="top" class="even"><td ><code>qmirclient</code></td><td >QMirClientIntegration</td><td >Mir client support</td></tr>
<tr valign="top" class="odd"><td ><code>qopenwf</code></td><td >QOpenWFDIntegrationPlugin</td><td >OpenWF Display support for managing display control hardware.</td></tr>
<tr valign="top" class="even"><td ><code>qqnx</code></td><td >QQnxIntegrationPlugin</td><td ><a href="platform-notes-qnx.html">QNX support</a></td></tr>
<tr valign="top" class="odd"><td ><code>qvnc</code></td><td >QVncIntegration</td><td >VNC support</td></tr>
<tr valign="top" class="even"><td ><code>qwayland</code></td><td ><ul>
<li>QWaylandIntegrationPlugin</li>
<li>QWaylandBrcmEglPlatformIntegrationPlugin</li>
<li>QWaylandEglPlatformIntegrationPlugin</li>
<li>QWaylandXCompositeEglPlatformIntegrationPlugin</li>
<li>QWaylandXCompositeGlxPlatformIntegrationPlugin</li>
</ul>
</td><td >Wayland support</td></tr>
<tr valign="top" class="odd"><td ><code>qwindows</code></td><td >QWindowsIntegrationPlugin</td><td ><a href="windows-support.html">Windows support</a></td></tr>
<tr valign="top" class="even"><td ><code>qwinrt</code></td><td >QWinRTIntegrationPlugin</td><td ><a href="winrt-support.html">WinRT and Windows Phone support</a></td></tr>
<tr valign="top" class="odd"><td ><code>qxcb</code></td><td >QXcbIntegrationPlugin</td><td ><a href="linux.html">X Window System (X11) support</a></td></tr>
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