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diff --git a/doc/src/examples/queuedcustomtype.qdoc b/doc/src/examples/queuedcustomtype.qdoc deleted file mode 100644 index cd3b40f0c7..0000000000 --- a/doc/src/examples/queuedcustomtype.qdoc +++ /dev/null @@ -1,163 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies). -** Contact: http://www.qt-project.org/legal -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and Digia. For licensing terms and -** conditions see http://qt.digia.com/licensing. For further information -** use the contact form at http://qt.digia.com/contact-us. -** -** GNU Free Documentation License Usage -** 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. Please review the following information to ensure -** the GNU Free Documentation License version 1.3 requirements -** will be met: http://www.gnu.org/copyleft/fdl.html. -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \example threads/queuedcustomtype - \title Queued Custom Type Example - - The Queued Custom Type example shows how to send custom types between - threads with queued signals and slots. - - \image queuedcustomtype-example.png - - Contents: - - \tableofcontents - - \section1 Overview - - In the \l{Custom Type Sending Example}, we showed how to use a custom type - with signal-slot communication within the same thread. - - In this example, we create a new value class, \c Block, and register it - with the meta-object system to enable us to send instances of it between - threads using queued signals and slots. - - \section1 The Block Class - - The \c Block class is similar to the \c Message class described in the - \l{Custom Type Example}. It provides the default constructor, copy - constructor and destructor in the public section of the class that the - meta-object system requires. It describes a colored rectangle. - - \snippet examples/threads/queuedcustomtype/block.h custom type definition and meta-type declaration - - We will still need to register it with the meta-object system at - run-time by calling the qRegisterMetaType() template function before - we make any signal-slot connections that use this type. - Even though we do not intend to use the type with QVariant in this example, - it is good practice to also declare the new type with Q_DECLARE_METATYPE(). - - The implementation of the \c Block class is trivial, so we avoid quoting - it here. - - \section1 The Window Class - - We define a simple \c Window class with a public slot that accepts a - \c Block object. The rest of the class is concerned with managing the - user interface and handling images. - - \snippet examples/threads/queuedcustomtype/window.h Window class definition - - The \c Window class also contains a worker thread, provided by a - \c RenderThread object. This will emit signals to send \c Block objects - to the window's \c addBlock(Block) slot. - - The parts of the \c Window class that are most relevant are the constructor - and the \c addBlock(Block) slot. - - The constructor creates a thread for rendering images, sets up a user - interface containing a label and two push buttons that are connected to - slots in the same class. - - \snippet examples/threads/queuedcustomtype/window.cpp Window constructor start - \snippet examples/threads/queuedcustomtype/window.cpp set up widgets and connections - \snippet examples/threads/queuedcustomtype/window.cpp connecting signal with custom type - - In the last of these connections, we connect a signal in the - \c RenderThread object to the \c addBlock(Block) slot in the window. - - \dots - \snippet examples/threads/queuedcustomtype/window.cpp Window constructor finish - - The rest of the constructor simply sets up the layout of the window. - - The \c addBlock(Block) slot receives blocks from the rendering thread via - the signal-slot connection set up in the constructor: - - \snippet examples/threads/queuedcustomtype/window.cpp Adding blocks to the display - - We simply paint these onto the label as they arrive. - - \section1 The RenderThread Class - - The \c RenderThread class processes an image, creating \c Block objects - and using the \c sendBlock(Block) signal to send them to other components - in the example. - - \snippet examples/threads/queuedcustomtype/renderthread.h RenderThread class definition - - The constructor and destructor are not quoted here. These take care of - setting up the thread's internal state and cleaning up when it is destroyed. - - Processing is started with the \c processImage() function, which calls the - \c RenderThread class's reimplementation of the QThread::run() function: - - \snippet examples/threads/queuedcustomtype/renderthread.cpp processing the image (start) - - Ignoring the details of the way the image is processed, we see that the - signal containing a block is emitted in the usual way: - - \dots - \snippet examples/threads/queuedcustomtype/renderthread.cpp processing the image (finish) - - Each signal that is emitted will be queued and delivered later to the - window's \c addBlock(Block) slot. - - \section1 Registering the Type - - In the example's \c{main()} function, we perform the registration of the - \c Block class as a custom type with the meta-object system by calling the - qRegisterMetaType() template function: - - \snippet examples/threads/queuedcustomtype/main.cpp main function - - This call is placed here to ensure that the type is registered before any - signal-slot connections are made that use it. - - The rest of the \c{main()} function is concerned with setting a seed for - the pseudo-random number generator, creating and showing the window, and - setting a default image. See the source code for the implementation of the - \c createImage() function. - - \section1 Further Reading - - This example showed how a custom type can be registered with the - meta-object system so that it can be used with signal-slot connections - between threads. For ordinary communication involving direct signals and - slots, it is enough to simply declare the type in the way described in the - \l{Custom Type Sending Example}. - - In practice, both the Q_DECLARE_METATYPE() macro and the qRegisterMetaType() - template function can be used to register custom types, but - qRegisterMetaType() is only required if you need to perform signal-slot - communication or need to create and destroy objects of the custom type - at run-time. - - More information on using custom types with Qt can be found in the - \l{Creating Custom Qt Types} document. -*/ |