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diff --git a/doc/src/emb-features.qdoc b/doc/src/emb-features.qdoc new file mode 100644 index 0000000000..67f92a5a31 --- /dev/null +++ b/doc/src/emb-features.qdoc @@ -0,0 +1,147 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \page fine-tuning-features.html + \title Fine-Tuning Features in Qt + \ingroup qtce + \ingroup qt-embedded-linux + \brief Describes how to reduce the size of Qt libraries by selecting only + the features that are needed. + + In many cases, only a fixed set of applications are deployed on an + embedded device, making it possible to save resources by minimizing + the size of the associated libraries. The Qt installation can easily + be optimized by avoiding to compile in the features that are not + required. + + \tableofcontents + + A wide range of features are defined, covering classes and technologies + provided by several of Qt's modules. + You can look up the different feature definitions in the + \c{src/corelib/global/qfeatures.txt} file within the Qt source + distribution. + + \section1 Simple Customization + + \section2 Embedded Linux + + To disable a particular feature, just run the \c configure script + for Qt for Embedded Linux with the \c -no-feature-<feature> option. + For example: + + \snippet doc/src/snippets/code/doc_src_emb-features.qdoc 1 + + The feature can easily be enabled again by running \c configure + with the \c -feature-<feature> option. + + See also \l{Qt Performance Tuning}. + + \section2 Windows CE + + To disable a particular feature, just run the \c configure script + with the set of required \c -D<feature> options. For example, + you can use the \c -D option to define \c{QT_NO_THREAD}: + + \snippet doc/src/snippets/code/doc_src_emb-features.qdoc 0 + + The \c -D option only creates a Qt internal define. If you get linker + errors you have to define \c QT_NO_THREAD also for your project. + You can do this by adding \c DEFINES += \c QT_NO_THREAD to your + \c .pro file. + + See also \l{Qt Performance Tuning}. + + \section1 Managing Large Numbers of Features + + If you want to disable a lot of features, it is more comfortable + to use the \c qconfig tool. + You can disable a \e set of features by creating a custom + configuration file that defines the preferred subset of Qt's + functionality. Such a file uses macros to disable the unwanted + features, and can be created manually or by using the \c qconfig + tool located in the \c{tools/qconfig} directory of the Qt source + distribution. + + \note The \c qconfig tool is intended to be built against Qt on + desktop platforms. + + \bold{Windows CE:} The Qt for Windows CE package contains a \c qconfig + executable that you can run on a Windows desktop to configure the build. + + \image qt-embedded-qconfigtool.png + + The \c qconfig tool's interface displays all of Qt's + functionality, and allows the user to both disable and enable + features. The user can open and edit any custom configuration file + located in the \c{src/corelib/global} directory. When creating a + custom configuration file manually, a description of the currently + available Qt features can be found in the + \c{src/corelib/global/qfeatures.txt} file. + + Note that some features depend on others; disabling any feature + will automatically disable all features depending on it. The + feature dependencies can be explored using the \c qconfig tool, + but they are also described in the \c{src/corelib/global/qfeatures.h} + file. + + To be able to apply the custom configuration, it must be saved in + a file called \c qconfig-myfile.h in the \c{src/corelib/global} + directory. Then use the \c configure tool's \c -qconfig option + and pass the configuration's file name without the \c qconfig- + prefix and \c .h extension, as argument. + The following examples show how this is invoked on each of the + embedded platforms for a file called \c{qconfig-myfile.h}: + + \bold{Embedded Linux:} + + \snippet doc/src/snippets/code/doc_src_emb-features.qdoc 3 + + \bold{Windows CE:} + + \snippet doc/src/snippets/code/doc_src_emb-features.qdoc 2 + + Qt provides several ready-made custom configuration files, + defining minimal, small, medium and large installations, + respectively. These files are located in the + \c{/src/corelib/global} directory in the Qt source distribution. +*/ |