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diff --git a/qtsingleapplication/doc/html/qtsingleapplication-example-loader.html b/qtsingleapplication/doc/html/qtsingleapplication-example-loader.html new file mode 100644 index 0000000..c305ae5 --- /dev/null +++ b/qtsingleapplication/doc/html/qtsingleapplication-example-loader.html @@ -0,0 +1,177 @@ +<?xml version="1.0" encoding="iso-8859-1"?> +<!DOCTYPE html + PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> +<!-- loader.qdoc --> +<head> + <title>Loading Documents</title> + <link href="classic.css" rel="stylesheet" type="text/css" /> +</head> +<body> +<table border="0" cellpadding="0" cellspacing="0" width="100%"> +<tr> +<td align="left" valign="top" width="32"><img src="images/qt-logo.png" align="left" width="57" height="67" border="0" /></td> +<td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a></td> +</tr></table><h1 class="title">Loading Documents<br /><span class="subtitle"></span> +</h1> +<p>The application in this example loads or prints the documents passed as commandline parameters to further instances of this application.</p> +<pre><span class="comment"> /**************************************************************************** + ** + ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). + ** All rights reserved. + ** + ** Contact: Nokia Corporation (qt-info@nokia.com) + ** + ** This file is part of a Qt Solutions component. + ** + ** You may use this file under the terms of the BSD license as follows: + ** + ** "Redistribution and use in source and binary forms, with or without + ** modification, are permitted provided that the following conditions are + ** met: + ** * Redistributions of source code must retain the above copyright + ** notice, this list of conditions and the following disclaimer. + ** * Redistributions in binary form must reproduce the above copyright + ** notice, this list of conditions and the following disclaimer in + ** the documentation and/or other materials provided with the + ** distribution. + ** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor + ** the names of its contributors may be used to endorse or promote + ** products derived from this software without specific prior written + ** permission. + ** + ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." + ** + ****************************************************************************/</span> + + #include <qtsingleapplication.h> + #include <QtCore/QFile> + #include <QtGui/QMainWindow> + #include <QtGui/QPrinter> + #include <QtGui/QPainter> + #include <QtGui/QTextEdit> + #include <QtGui/QMdiArea> + #include <QtCore/QTextStream> + + class MainWindow : public QMainWindow + { + Q_OBJECT + public: + MainWindow(); + + public slots: + void handleMessage(const QString& message); + + signals: + void needToShow(); + + private: + QMdiArea *workspace; + };</pre> +<p>The user interface in this application is a <a href="http://qt.nokia.com/doc/4.6/qmainwindow.html">QMainWindow</a> subclass with a <a href="http://qt.nokia.com/doc/4.6/qmdiarea.html">QMdiArea</a> as the central widget. It implements a slot <tt>handleMessage()</tt> that will be connected to the messageReceived() signal of the <a href="qtsingleapplication.html">QtSingleApplication</a> class.</p> +<pre> MainWindow::MainWindow() + { + workspace = new QMdiArea(this); + + setCentralWidget(workspace); + }</pre> +<p>The <a href="http://qt.nokia.com/doc/4.6/designer-to-know.html">MainWindow</a> constructor creates a minimal user interface.</p> +<pre> void MainWindow::handleMessage(const QString& message) + { + enum Action { + Nothing, + Open, + Print + } action; + + action = Nothing; + QString filename = message; + if (message.toLower().startsWith("/print ")) { + filename = filename.mid(7); + action = Print; + } else if (!message.isEmpty()) { + action = Open; + } + if (action == Nothing) { + emit needToShow(); + return; + } + + QFile file(filename); + QString contents; + if (file.open(QIODevice::ReadOnly)) + contents = file.readAll(); + else + contents = "[[Error: Could not load file " + filename + "]]"; + + QTextEdit *view = new QTextEdit; + view->setPlainText(contents); + + switch(action) {</pre> +<p>The handleMessage() slot interprets the message passed in as a filename that can be prepended with <i>/print</i> to indicate that the file should just be printed rather than loaded.</p> +<pre> case Print: + { + QPrinter printer; + view->print(&printer); + delete view; + } + break; + + case Open: + { + workspace->addSubWindow(view); + view->setWindowTitle(message); + view->show(); + emit needToShow(); + } + break; + default: + break; + }; + }</pre> +<p>Loading the file will also activate the window.</p> +<pre> #include "main.moc" + + int main(int argc, char **argv) + { + QtSingleApplication instance("File loader QtSingleApplication example", argc, argv); + QString message; + for (int a = 1; a < argc; ++a) { + message += argv[a]; + if (a < argc-1) + message += " "; + } + + if (instance.sendMessage(message)) + return 0;</pre> +<p>The <tt>main</tt> entry point function creates a <a href="qtsingleapplication.html">QtSingleApplication</a> object, and creates a message to send to a running instance of the application. If the message was sent successfully the process exits immediately.</p> +<pre> MainWindow mw; + mw.handleMessage(message); + mw.show(); + + QObject::connect(&instance, SIGNAL(messageReceived(const QString&)), + &mw, SLOT(handleMessage(const QString&))); + + instance.setActivationWindow(&mw, false); + QObject::connect(&mw, SIGNAL(needToShow()), &instance, SLOT(activateWindow())); + + return instance.exec(); + }</pre> +<p>If the message could not be sent the application starts up. Note that <tt>false</tt> is passed to the call to setActivationWindow() to prevent automatic activation for every message received, e.g. when the application should just print a file. Instead, the message handling function determines whether activation is requested, and signals that by emitting the needToShow() signal. This is then simply connected directly to <a href="qtsingleapplication.html">QtSingleApplication</a>'s activateWindow() slot.</p> +<p /><address><hr /><div align="center"> +<table width="100%" cellspacing="0" border="0"><tr class="address"> +<td width="30%" align="left">Copyright © 2010 Nokia Corporation and/or its subsidiary(-ies)</td> +<td width="40%" align="center"><a href="http://qt.nokia.com/doc/trademarks.html">Trademarks</a></td> +<td width="30%" align="right"><div align="right">Qt Solutions</div></td> +</tr></table></div></address></body> +</html> |