6.12. Using Qt

6.12. Using Qt
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6.12.1. Ports That Require Qt

The Ports Collection provides support for Qt 4 and Qt 5 frameworks with USE_QTx, where x is 4 or 5. Set USE_QTx to the list of required Qt components (libraries, tools, plugins). The Qt 4 and Qt 5 frameworks are quite similar. The main difference is the set of supported components.

The Qt framework exports a number of variables which can be used by ports, some of them listed below:

Table 6.11. Variables Provided to Ports That Use Qt

`QT_PREFIX`	Set to the path where Qt was installed (`${LOCALBASE}`).
`QMAKE`	Full path to `qmake` binary.
`LRELEASE`	Full path to `lrelease` utility.
`MOC`	Full path to `moc`.
`RCC`	Full path to `rcc`.
`UIC`	Full path to `uic`.
`QT_INCDIR`	Qt include directory.
`QT_LIBDIR`	Qt libraries path.
`QT_PLUGINDIR`	Qt plugins path.

When using the Qt framework, these settings are deployed:

CONFIGURE_ARGS+=	--with-qt-includes=${QT_INCDIR} \
			--with-qt-libraries=${QT_LIBDIR} \
			--with-extra-libs=${LOCALBASE}/lib \
			--with-extra-includes=${LOCALBASE}/include

CONFIGURE_ENV+=	QTDIR="${QT_PREFIX}" QMAKE="${QMAKE}" \
		MOC="${MOC}" RCC="${RCC}" UIC="${UIC}" \
		QMAKESPEC="${QMAKESPEC}"

PLIST_SUB+=	QT_INCDIR=${QT_INCDIR_REL} \
		QT_LIBDIR=${QT_LIBDIR_REL} \
		QT_PLUGINDIR=${QT_PLUGINDIR_REL}

Some configure scripts do not support the arguments above. To suppress modification ofCONFIGURE_ENV and CONFIGURE_ARGS, set QT_NONSTANDARD.

6.12.2. Component Selection

Individual Qt tool and library dependencies must be specified in USE_QTx. Every component can be suffixed with _build or _run, the suffix indicating whether the dependency on the component is at buildtime or runtime. If unsuffixed, the component will be depended on at both build- and runtime. Usually, library components are specified unsuffixed, tool components are mostly specified with the _build suffix and plugin components are specified with the _run suffix. The most commonly used components are listed below (all available components are listed in _USE_QT_ALL, _USE_QT4_ONLY, and _USE_QT5_ONLY in /usr/ports/Mk/bsd.qt.mk):

Table 6.12. Available Qt Library Components

Name	Description
`core`	core library (Qt 5 only)
`corelib`	core library (Qt 4 only)
`dbus`	Qt DBus library
`gui`	graphical user interface library
`network`	network library
`opengl`	Qt OpenGL library
`script`	script library
`sql`	SQL library
`testlib`	unit testing library
`webkit`	Qt WebKit library
`xml`	Qt XML library

To determine the libraries an application depends on, run ldd on the main executable after a successful compilation.

Table 6.13. Available Qt Tool Components

Name	Description
`qmake`	Makefile generator/build utility
`buildtools`	build tools (`moc`, `rcc`), needed for almost every Qt application (Qt 5 only)
`linguisttools`	localization tools: `lrelease`, `lupdate` (Qt 5 only)
`linguist`	localization tools: `lrelease`, `lupdate` (Qt 4 only)
`moc`	meta object compiler, needed for almost every Qt application at buildtime (Qt 4 only)
`rcc`	resource compiler, needed if the application comes with `.rc` or `.qrc` files (Qt 4 only)
`uic`	user interface compiler, needed if the application comes with `*.ui` files, in practice, every Qt application with a GUI (Qt 4 only)

Table 6.14. Available Qt Plugin Components

Name	Description
`iconengines`	SVG icon engine plugin, needed if the application ships SVG icons (Qt 4 only)
`imageformats`	plugins for TGA, TIFF, and MNG image formats

Example 6.5. Selecting Qt 4 Components

In this example, the ported application uses the Qt 4 graphical user interface library, the Qt 4 core library, all of the Qt 4 code generation tools and Qt 4's Makefile generator. Since the gui library implies a dependency on the core library, corelib does not need to be specified. The Qt 4 code generation tools moc, uic and rcc, as well as the Makefile generator qmake are only needed at buildtime, thus they are specified with the _build suffix:

USE_QT4=	gui moc_build qmake_build rcc_build uic_build

6.12.3. Using `qmake`

If the application provides a qmake project file (*.pro), define USES= qmake along with USE_QTx. Note that USES= qmake already implies a build dependency on qmake, therefore the qmake component can be omitted from USE_QTx. Similar to CMake, qmake supports out-of-source builds, which can be enabled by specifying the outsource argument (see USES= qmake example).

Table 6.15. Variables for Ports That Use qmake

Variable	Means
`QMAKE_ARGS`	Port specific qmake flags to be passed to the `qmake` binary.
`QMAKE_ENV`	Environment variables to be set for the `qmake` binary. The default is `${CONFIGURE_ENV}`.
`QMAKE_SOURCE_PATH`	Path to qmake project files (`.pro`). The default is `${WRKSRC}` if an out-of-source build is requested, empty otherwise.

Example 6.6. USES= qmake Example

This snippet demonstrates the use of qmake for a Qt 4 port:

USES=		qmake:outsource
USE_QT4=	moc_build

For a Qt 5 port:

USES=		qmake:outsource
USE_QT5=	buildtools_build

Qt applications are often written to be cross-platform and often X11/Unix is not the platform they are developed on, which in turn leads to certain loose ends, like:

Missing additional include paths. Many applications come with system tray icon support, but neglect to look for includes and/or libraries in the X11 directories. To add directories to qmake's include and library search paths via the command line, use:
```
QMAKE_ARGS+=	INCLUDEPATH+=${LOCALBASE}/include \
		LIBS+=-L${LOCALBASE}/lib
```
Bogus installation paths. Sometimes data such as icons or .desktop files are by default installed into directories which are not scanned by XDG-compatible applications. editors/texmaker is an example for this - look at patch-texmaker.pro in the files directory of that port for a template on how to remedy this directly in the qmake project file.

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6.11. GNOME Components	Home	6.13. Using KDE

6.12. Using Qt

6.12.1. Ports That Require Qt

6.12.2. Component Selection

6.12.3. Using qmake

6.12.3. Using `qmake`