diff options
Diffstat (limited to 'doc/src/files-and-resources')
| -rw-r--r-- | doc/src/files-and-resources/datastreamformat.qdoc | 361 | ||||
| -rw-r--r-- | doc/src/files-and-resources/resources.qdoc | 214 |
2 files changed, 575 insertions, 0 deletions
diff --git a/doc/src/files-and-resources/datastreamformat.qdoc b/doc/src/files-and-resources/datastreamformat.qdoc new file mode 100644 index 0000000000..086c74e9f9 --- /dev/null +++ b/doc/src/files-and-resources/datastreamformat.qdoc @@ -0,0 +1,361 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** 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 Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \page datastreamformat.html + \title Serializing Qt Data Types + \ingroup qt-network + \brief Representations of data types that can be serialized by QDataStream. + + The \l QDataStream allows you to serialize some of the Qt data types. + The table below lists the data types that QDataStream can serialize + and how they are represented. The format described below is + \l{QDataStream::setVersion()}{version 12}. + + It is always best to cast integers to a Qt integer type, such as + qint16 or quint32, when reading and writing. This ensures that + you always know exactly what size integers you are reading and + writing, no matter what the underlying platform and architecture + the application happens to be running on. + + \table + \row \o bool + \o \list + \o boolean + \endlist + \row \o qint8 + \o \list + \o signed byte + \endlist + \row \o qint16 + \o \list + \o signed 16-bit integer + \endlist + \row \o qint32 + \o \list + \o signed 32-bit integer + \endlist + \row \o qint64 + \o \list + \o signed 64-bit integer + \endlist + \row \o quint8 + \o \list + \o unsigned byte + \endlist + \row \o quint16 + \o \list + \o unsigned 16-bit integer + \endlist + \row \o quint32 + \o \list + \o unsigned 32-bit integer + \endlist + \row \o quint64 + \o \list + \o unsigned 64-bit integer + \endlist + \row \o \c float + \o \list + \o 32-bit floating point number using the standard IEEE 754 format + \endlist + \row \o \c double + \o \list + \o 64-bit floating point number using the standard IEEE 754 format + \endlist + \row \o \c {const char *} + \o \list + \o The string length (quint32) + \o The string bytes, excluding the terminating 0 + \endlist + \row \o QBitArray + \o \list + \o The array size (quint32) + \o The array bits, i.e. (size + 7)/8 bytes + \endlist + \row \o QBrush + \o \list + \o The brush style (quint8) + \o The brush color (QColor) + \o If style is CustomPattern, the brush pixmap (QPixmap) + \endlist + \row \o QByteArray + \o \list + \o If the byte array is null: 0xFFFFFFFF (quint32) + \o Otherwise: the array size (quint32) followed by the array bytes, i.e. size bytes + \endlist + \row \o \l QColor + \o \list + \o Color spec (qint8) + \o Alpha value (quint16) + \o Red value (quint16) + \o Green value (quint16) + \o Blue value (quint16) + \o Pad value (quint16) + \endlist + \row \o QCursor + \o \list + \o Shape ID (qint16) + \o If shape is BitmapCursor: The bitmap (QPixmap), mask (QPixmap), and hot spot (QPoint) + \endlist + \row \o QDate + \o \list + \o Julian day (quint32) + \endlist + \row \o QDateTime + \o \list + \o Date (QDate) + \o Time (QTime) + \o 0 for Qt::LocalTime, 1 for Qt::UTC (quint8) + \endlist + \row \o QEasingCurve + \o \list + \o type (quint8) + \o func (quint64) + \o hasConfig (bool) + \o If hasConfig is true then these fields follow: + \o list + \o period (double) + \o amplitude (double) + \o overshoot (double) + \endlist + \row \o QFont + \o \list + \o The family (QString) + \o The point size (qint16) + \o The style hint (quint8) + \o The char set (quint8) + \o The weight (quint8) + \o The font bits (quint8) + \endlist + \row \o QHash<Key, T> + \o \list + \o The number of items (quint32) + \o For all items, the key (Key) and value (T) + \endlist + \row \o QIcon + \o \list + \o The number of pixmap entries (quint32) + \o For all pixmap entries: + \list + \o The pixmap (QPixmap) + \o The file name (QString) + \o The pixmap size (QSize) + \o The \l{QIcon::Mode}{mode} (quint32) + \o The \l{QIcon::State}{state} (quint32) + \endlist + \endlist + \row \o QImage + \o \list + \o If the image is null a "null image" marker is saved; + otherwise the image is saved in PNG or BMP format (depending + on the stream version). If you want control of the format, + stream the image into a QBuffer (using QImageIO) and stream + that. + \endlist + \row \o QKeySequence + \o \list + \o A QList<int>, where each integer is a key in the key sequence + \endlist + \row \o QLinkedList<T> + \o \list + \o The number of items (quint32) + \o The items (T) + \endlist + \row \o QList<T> + \o \list + \o The number of items (quint32) + \o The items (T) + \endlist + \row \o QMap<Key, T> + \o \list + \o The number of items (quint32) + \o For all items, the key (Key) and value (T) + \endlist + \row \o QMatrix + \o \list + \o m11 (double) + \o m12 (double) + \o m21 (double) + \o m22 (double) + \o dx (double) + \o dy (double) + \endlist + \row \o QMatrix4x4 + \o \list + \o m11 (double) + \o m12 (double) + \o m13 (double) + \o m14 (double) + \o m21 (double) + \o m22 (double) + \o m23 (double) + \o m24 (double) + \o m31 (double) + \o m32 (double) + \o m33 (double) + \o m34 (double) + \o m41 (double) + \o m42 (double) + \o m43 (double) + \o m44 (double) + \endlist + \row \o QPair<T1, T2> + \o \list + \o first (T1) + \o second (T2) + \endlist + \row \o QPalette + \o The disabled, active, and inactive color groups, each of which consists + of the following: + \list + \o foreground (QBrush) + \o button (QBrush) + \o light (QBrush) + \o midlight (QBrush) + \o dark (QBrush) + \o mid (QBrush) + \o text (QBrush) + \o brightText (QBrush) + \o buttonText (QBrush) + \o base (QBrush) + \o background (QBrush) + \o shadow (QBrush) + \o highlight (QBrush) + \o highlightedText (QBrush) + \o link (QBrush) + \o linkVisited (QBrush) + \endlist + \row \o QPen + \o \list + \o The pen styles (quint8) + \o The pen width (quint16) + \o The pen color (QColor) + \endlist + \row \o QPicture + \o \list + \o The size of the picture data (quint32) + \o The raw bytes of picture data (char) + \endlist + \row \o QPixmap + \o \list + \o Save it as a PNG image. + \endlist + \row \o QPoint + \o \list + \o The x coordinate (qint32) + \o The y coordinate (qint32) + \endlist + \row \o QQuaternion + \o \list + \o The scalar component (double) + \o The x coordinate (double) + \o The y coordinate (double) + \o The z coordinate (double) + \endlist + \row \o QRect + \o \list + \o left (qint32) + \o top (qint32) + \o right (qint32) + \o bottom (qint32) + \endlist + \row \o QRegExp + \o \list + \o The regexp pattern (QString) + \o Case sensitivity (quint8) + \o Regular expression syntax (quint8) + \o Minimal matching (quint8) + \endlist + \row \o QRegion + \o \list + \o The size of the data, i.e. 8 + 16 * (number of rectangles) (quint32) + \o 10 (qint32) + \o The number of rectangles (quint32) + \o The rectangles in sequential order (QRect) + \endlist + \row \o QSize + \o \list + \o width (qint32) + \o height (qint32) + \endlist + \row \o QString + \o \list + \o If the string is null: 0xFFFFFFFF (quint32) + \o Otherwise: The string length in bytes (quint32) followed by the data in UTF-16 + \endlist + \row \o QTime + \o \list + \o Milliseconds since midnight (quint32) + \endlist + \row \o QTransform + \o \list + \o m11 (double) + \o m12 (double) + \o m13 (double) + \o m21 (double) + \o m22 (double) + \o m23 (double) + \o m31 (double) + \o m32 (double) + \o m33 (double) + \endlist + \row \o QUrl + \o \list + \o Holds an URL (QString) + \endlist + \row \o QVariant + \o \list + \o The type of the data (quint32) + \o The null flag (qint8) + \o The data of the specified type + \endlist + \row \o QVector2D + \o \list + \o the x coordinate (double) + \o the y coordinate (double) + \endlist + \row \o QVector3D + \o \list + \o the x coordinate (double) + \o the y coordinate (double) + \o the z coordinate (double) + \endlist + \row \o QVector4D + \o \list + \o the x coordinate (double) + \o the y coordinate (double) + \o the z coordinate (double) + \o the w coordinate (double) + \endlist + \row \o QVector<T> + \o \list + \o The number of items (quint32) + \o The items (T) + \endlist + \endtable +*/ diff --git a/doc/src/files-and-resources/resources.qdoc b/doc/src/files-and-resources/resources.qdoc new file mode 100644 index 0000000000..35e6a9086f --- /dev/null +++ b/doc/src/files-and-resources/resources.qdoc @@ -0,0 +1,214 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** 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 Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \group io + \title Input/Output and Networking + \ingroup groups + + \brief Classes providing file input and output along with directory and + network handling. + + These classes are used to handle input and output to and from external + devices, processes, files etc. as well as manipulating files and directories. +*/ + +/*! + \page resources.html + \title The Qt Resource System + \ingroup qt-network + \brief A platform-independent mechanism for storing binary files in an application. + + \keyword resource system + + The Qt resource system is a platform-independent mechanism for + storing binary files in the application's executable. This is + useful if your application always needs a certain set of files + (icons, translation files, etc.) and you don't want to run the + risk of losing the files. + + The resource system is based on tight cooperation between \l qmake, + \l rcc (Qt's resource compiler), and QFile. It obsoletes Qt 3's + \c qembed tool and the + \l{http://qt.nokia.com/doc/qq/qq05-iconography.html#imagestorage}{image + collection} mechanism. + + \section1 Resource Collection Files (\c{.qrc}) + + The resources associated with an application are specified in a + \c .qrc file, an XML-based file format that lists files on the + disk and optionally assigns them a resource name that the + application must use to access the resource. + + Here's an example \c .qrc file: + + \quotefile mainwindows/application/application.qrc + + The resource files listed in the \c .qrc file are files that are + part of the application's source tree. The specified paths are + relative to the directory containing the \c .qrc file. Note that + the listed resource files must be located in the same directory as + the \c .qrc file, or one of its subdirectories. + + Resource data can either be compiled into the binary and thus accessed + immediately in application code, or a binary resource can be created + and at a later point in application code registered with the resource + system. + + By default, resources are accessible in the application under the + same file name as they have in the source tree, with a \c :/ prefix, + or by a \link QUrl URL\endlink with a \c qrc scheme. + + For example, the file path \c :/images/cut.png or the URL + \c qrc:///images/cut.png would give access to the + \c cut.png file, whose location in the application's source tree + is \c images/cut.png. This can be changed using the \c file tag's + \c alias attribute: + + \snippet doc/src/snippets/code/doc_src_resources.qdoc 0 + + The file is then accessible as \c :/cut-img.png from the + application. It is also possible to specify a path prefix for all + files in the \c .qrc file using the \c qresource tag's \c prefix + attribute: + + \snippet doc/src/snippets/code/doc_src_resources.qdoc 1 + + In this case, the file is accessible as \c + :/myresources/cut-img.png. + + Some resources, such as translation files and icons, many need to + change based on the user's locale. This is done by adding a \c lang + attribute to the \c qresource tag, specifying a suitable locale + string. For example: + + \snippet doc/src/snippets/code/doc_src_resources.qdoc 2 + + If the user's locale is French (i.e., QLocale::system().name() returns + "fr_FR"), \c :/cut.jpg becomes a reference to the \c cut_fr.jpg + image. For other locales, \c cut.jpg is used. + + See the QLocale documentation for a description of the format to use + for locale strings. + + + \section2 External Binary Resources + + For an external binary resource to be created you must create the resource + data (commonly given the \c .rcc extension) by passing the -binary switch to + \l rcc. Once the binary resource is created you can register the resource + with the QResource API. + + For example, a set of resource data specified in a \c .qrc file can be + compiled in the following way: + + \snippet doc/src/snippets/code/doc_src_resources.qdoc 3 + + In the application, this resource would be registered with code like this: + + \snippet doc/src/snippets/code/doc_src_resources.cpp 4 + + \section2 Compiled-In Resources + + For a resource to be compiled into the binary the \c .qrc file must be + mentioned in the application's \c .pro file so that \c qmake knows + about it. For example: + + \snippet examples/mainwindows/application/application.pro 0 + + \c qmake will produce make rules to generate a file called \c + qrc_application.cpp that is linked into the application. This + file contains all the data for the images and other resources as + static C++ arrays of compressed binary data. The \c + qrc_application.cpp file is automatically regenerated whenever + the \c .qrc file changes or one of the files that it refers to + changes. If you don't use \c .pro files, you can either invoke + \c rcc manually or add build rules to your build system. + + \image resources.png Building resources into an application + + Currently, Qt always stores the data directly in the executable, + even on Windows and Mac OS X, where the operating system provides + native support for resources. This might change in a future Qt + release. + + \section1 Compression + + Resources are compressed by default (in the \c ZIP format). It is + possible to turn off compression. This can be useful if your + resources already contain a compressed format, such as \c .png + files. You do this by giving the \c {-no-compress} command line + argument. + + \code + rcc -no-compress myresources.qrc + \endcode + + \c rcc also gives you some control over the compression. You can + specify the compression level and the threshold level to consider + while compressing files, for example: + + \code + rcc -compress 2 -threshold 3 myresources.qrc + \endcode + + \section1 Using Resources in the Application + + In the application, resource paths can be used in most places + instead of ordinary file system paths. In particular, you can + pass a resource path instead of a file name to the QIcon, QImage, + or QPixmap constructor: + + \snippet examples/mainwindows/application/mainwindow.cpp 21 + + See the \l{mainwindows/application}{Application} example for an + actual application that uses Qt's resource system to store its + icons. + + In memory, resources are represented by a tree of resource + objects. The tree is automatically built at startup and used by + QFile for resolving paths to resources. You can use a QDir initialized + with ":/" to navigate through the resource tree from the root. + + Qt's resources support the concept of a search path list. If you then + refer to a resource with \c : instead of \c :/ as the prefix, the + resource will be looked up using the search path list. The search + path list is empty at startup; call QDir::addSearchPath() to + add paths to it. + + If you have resources in a static library, you might need to + force initialization of your resources by calling \l + Q_INIT_RESOURCE() with the base name of the \c .qrc file. For + example: + + \snippet doc/src/snippets/code/doc_src_resources.cpp 5 + + Similarly, if you must unload a set of resources explicitly + (because a plugin is being unloaded or the resources are not valid + any longer), you can force removal of your resources by calling + Q_CLEANUP_RESOURCE() with the same base name as above. +*/ |