From 71e1976bccbe3809eed1b8d4a69b45963e29cb69 Mon Sep 17 00:00:00 2001 From: Nico Vertriest Date: Tue, 8 Jul 2014 13:54:21 +0200 Subject: Doc: moved streambookmarks example files MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Moved to qtbase/examples/xml/streambookmarks. Files: qxmlstreambookmarks.qdoc and png files Change-Id: I6edf975f1e0666a4283e65c933d31923695f8b4c Reviewed-by: Topi Reiniö --- .../doc/src/qxmlstreambookmarks.qdoc | 194 +++++++++++++++++++++ 1 file changed, 194 insertions(+) create mode 100644 examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc (limited to 'examples/xml/streambookmarks/doc/src') diff --git a/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc b/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc new file mode 100644 index 0000000000..123058b02d --- /dev/null +++ b/examples/xml/streambookmarks/doc/src/qxmlstreambookmarks.qdoc @@ -0,0 +1,194 @@ +/**************************************************************************** +** +** Copyright (C) 2013 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 streambookmarks + \title QXmlStream Bookmarks Example + \brief Demonstrates how to read and write to XBEL files + \ingroup xml-examples + + The QXmlStream Bookmarks example provides a reader for XML Bookmark + Exchange Language (XBEL) files using Qt's QXmlStreamReader class + for reading, and QXmlStreamWriter class for writing the files. + + \image xmlstreamexample-screenshot.png + + \section1 XbelWriter Class Definition + + The \c XbelWriter class contains a private instance of QXmlStreamWriter, + which provides an XML writer with a streaming API. \c XbelWriter also + has a reference to the QTreeWidget instance where the bookmark hierarchy + is stored. + + \snippet streambookmarks/xbelwriter.h 0 + + \section1 XbelWriter Class Implementation + + The \c XbelWriter constructor accepts a \a treeWidget to initialize within + its definition. We enable \l{QXmlStreamWriter}'s auto-formatting property + to ensure line-breaks and indentations are added automatically to empty + sections between elements, increasing readability as the data is split into + several lines. + + \snippet streambookmarks/xbelwriter.cpp 0 + + The \c writeFile() function accepts a QIODevice object and sets it using + \c setDevice(). This function then writes the document type + definition(DTD), the start element, the version, and \c{treeWidget}'s + top-level items. + + \snippet streambookmarks/xbelwriter.cpp 1 + + The \c writeItem() function accepts a QTreeWidgetItem object and writes it + to the stream, depending on its \c tagName, which can either be a "folder", + "bookmark", or "separator". + + \snippet streambookmarks/xbelwriter.cpp 2 + + \section1 XbelReader Class Definition + + The \c XbelReader contains a private instance of QXmlStreamReader, the + companion class to QXmlStreamWriter. \c XbelReader also contains a + reference to the QTreeWidget that is used to group the bookmarks according + to their hierarchy. + + \snippet streambookmarks/xbelreader.h 0 + + \section1 XbelReader Class Implementation + + The \c XbelReader constructor accepts a QTreeWidget to initialize the + \c treeWidget within its definition. A QStyle object is used to set + \c{treeWidget}'s style property. The \c folderIcon is set to QIcon::Normal + mode where the pixmap is only displayed when the user is not interacting + with the icon. The QStyle::SP_DirClosedIcon, QStyle::SP_DirOpenIcon, and + QStyle::SP_FileIcon correspond to standard pixmaps that follow the style + of your GUI. + + \snippet streambookmarks/xbelreader.cpp 0 + + The \c read() function accepts a QIODevice and sets it using + \l{QXmlStreamReader::}{setDevice()}. The actual process of reading only + takes place if the file is a valid XBEL 1.0 file. Note that the XML input + needs to be well-formed to be accepted by QXmlStreamReader. Otherwise, the + \l{QXmlStreamReader::}{raiseError()} function is used to display an error + message. Since the XBEL reader is only concerned with reading XML elements, + it makes extensive use of the \l{QXmlStreamReader::}{readNextStartElement()} + convenience function. + + \snippet streambookmarks/xbelreader.cpp 1 + + The \c errorString() function is used if an error occurred, in order to + obtain a description of the error complete with line and column number + information. + + \snippet streambookmarks/xbelreader.cpp 2 + + The \c readXBEL() function reads the name of a startElement and calls + the appropriate function to read it, depending on whether if its a + "folder", "bookmark" or "separator". Otherwise, it calls + \l{QXmlStreamReader::}{skipCurrentElement()}. The Q_ASSERT() macro is used + to provide a pre-condition for the function. + + \snippet streambookmarks/xbelreader.cpp 3 + + The \c readTitle() function reads the bookmark's title. + + \snippet streambookmarks/xbelreader.cpp 4 + + The \c readSeparator() function creates a separator and sets its flags. + The text is set to 30 "0xB7", the HEX equivalent for period. The element + is then skipped using \l{QXmlStreamReader::}{skipCurrentElement()}. + + \snippet streambookmarks/xbelreader.cpp 5 + + \section1 MainWindow Class Definition + + The \c MainWindow class is a subclass of QMainWindow, with a + \c File menu and a \c Help menu. + + \snippet streambookmarks/mainwindow.h 0 + + \section1 MainWindow Class Implementation + + The \c MainWindow constructor instantiates the QTreeWidget object, \c + treeWidget and sets its header with a QStringList object, \c labels. + The constructor also invokes \c createActions() and \c createMenus() + to set up the menus and their corresponding actions. The \c statusBar() + is used to display the message "Ready" and the window's size is fixed + to 480x320 pixels. + + \snippet streambookmarks/mainwindow.cpp 0 + + The \c open() function enables the user to open an XBEL file using + QFileDialog::getOpenFileName(). A warning message is displayed along + with the \c fileName and \c errorString if the file cannot be read or + if there is a parse error. + + \snippet streambookmarks/mainwindow.cpp 1 + + The \c saveAs() function displays a QFileDialog, prompting the user for + a \c fileName using QFileDialog::getSaveFileName(). Similar to the + \c open() function, this function also displays a warning message if + the file cannot be written to. + + \snippet streambookmarks/mainwindow.cpp 2 + + The \c about() function displays a QMessageBox with a brief description + of the example. + + \snippet streambookmarks/mainwindow.cpp 3 + + In order to implement the \c open(), \c saveAs(), \c exit(), \c about() + and \c aboutQt() functions, we connect them to QAction objects and + add them to the \c fileMenu and \c helpMenu. The connections are as shown + below: + + \snippet streambookmarks/mainwindow.cpp 4 + + The \c createMenus() function creates the \c fileMenu and \c helpMenu + and adds the QAction objects to them in order to create the menu shown + in the screenshot below: + + \table + \row + \li \inlineimage xmlstreamexample-filemenu.png + \li \inlineimage xmlstreamexample-helpmenu.png + \endtable + + \snippet streambookmarks/mainwindow.cpp 5 + + \section1 \c{main()} Function + + The \c main() function instantiates \c MainWindow and invokes the \c show() + function. + + \snippet streambookmarks/main.cpp 0 + + See the \l{http://pyxml.sourceforge.net/topics/xbel/} + {XML Bookmark Exchange Language Resource Page} for more information + about XBEL files. +*/ -- cgit v1.2.3