Sophie: qt4-doc-4:4.6.3-0.2mdv2010.2 i586

qt4-doc-4.6.3-0.2mdv2010.2.i586.rpm

<?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">
<head>
  <title>Qt 4.6: imagescaling.cpp Example File (qtconcurrent/imagescaling/imagescaling.cpp)</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"><a href="http://qt.nokia.com/"><img src="images/qt-logo.png" align="left" border="0" /></a></td>
<td width="1">&nbsp;&nbsp;</td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a>&nbsp;&middot; <a href="classes.html"><font color="#004faf">All&nbsp;Classes</font></a>&nbsp;&middot; <a href="functions.html"><font color="#004faf">All&nbsp;Functions</font></a>&nbsp;&middot; <a href="overviews.html"><font color="#004faf">Overviews</font></a></td></tr></table><h1 class="title">imagescaling.cpp Example File<br /><span class="small-subtitle">qtconcurrent/imagescaling/imagescaling.cpp</span>
</h1>
<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 the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 ** 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 1.1, 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 have questions regarding the use of this file, please contact
 ** Nokia at qt-info@nokia.com.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/</span>
 #include &quot;imagescaling.h&quot;
 #include &quot;math.h&quot;

 #ifndef QT_NO_CONCURRENT

 const int imageSize = 100;

 QImage scale(const QString &amp;imageFileName)
 {
     QImage image(imageFileName);
     return image.scaled(QSize(imageSize, imageSize), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
 }

 Images::Images(QWidget *parent)
 : QWidget(parent)
 {
     setWindowTitle(tr(&quot;Image loading and scaling example&quot;));
     resize(800, 600);

     imageScaling = new QFutureWatcher&lt;QImage&gt;(this);
     connect(imageScaling, SIGNAL(resultReadyAt(int)), SLOT(showImage(int)));
     connect(imageScaling, SIGNAL(finished()), SLOT(finished()));

     openButton = new QPushButton(tr(&quot;Open Images&quot;));
     connect(openButton, SIGNAL(clicked()), SLOT(open()));

     cancelButton = new QPushButton(tr(&quot;Cancel&quot;));
     cancelButton-&gt;setEnabled(false);
     connect(cancelButton, SIGNAL(clicked()), imageScaling, SLOT(cancel()));

     pauseButton = new QPushButton(tr(&quot;Pause/Resume&quot;));
     pauseButton-&gt;setEnabled(false);
     connect(pauseButton, SIGNAL(clicked()), imageScaling, SLOT(togglePaused()));

     QHBoxLayout *buttonLayout = new QHBoxLayout();
     buttonLayout-&gt;addWidget(openButton);
     buttonLayout-&gt;addWidget(cancelButton);
     buttonLayout-&gt;addWidget(pauseButton);
     buttonLayout-&gt;addStretch();

     imagesLayout = new QGridLayout();

     mainLayout = new QVBoxLayout();
     mainLayout-&gt;addLayout(buttonLayout);
     mainLayout-&gt;addLayout(imagesLayout);
     mainLayout-&gt;addStretch();
     setLayout(mainLayout);
 }

 Images::~Images()
 {
     imageScaling-&gt;cancel();
     imageScaling-&gt;waitForFinished();
 }

 void Images::open()
 {
     <span class="comment">// Cancel and wait if we are already loading images.</span>
     if (imageScaling-&gt;isRunning()) {
         imageScaling-&gt;cancel();
         imageScaling-&gt;waitForFinished();
     }

     <span class="comment">// Show a file open dialog at QDesktopServices::PicturesLocation.</span>
     QStringList files = QFileDialog::getOpenFileNames(this, tr(&quot;Select Images&quot;),
                             QDesktopServices::storageLocation(QDesktopServices::PicturesLocation),
                             &quot;*.jpg *.png&quot;);

     if (files.count() == 0)
         return;

     <span class="comment">// Do a simple layout.</span>
     qDeleteAll(labels);
     labels.clear();

     int dim = sqrt(qreal(files.count())) + 1;
     for (int i = 0; i &lt; dim; ++i) {
         for (int j = 0; j &lt; dim; ++j) {
             QLabel *imageLabel = new QLabel;
             imageLabel-&gt;setFixedSize(imageSize,imageSize);
             imagesLayout-&gt;addWidget(imageLabel,i,j);
             labels.append(imageLabel);
         }
     }

     <span class="comment">// Use mapped to run the thread safe scale function on the files.</span>
     imageScaling-&gt;setFuture(QtConcurrent::mapped(files, scale));

     openButton-&gt;setEnabled(false);
     cancelButton-&gt;setEnabled(true);
     pauseButton-&gt;setEnabled(true);
 }

 void Images::showImage(int num)
 {
     labels[num]-&gt;setPixmap(QPixmap::fromImage(imageScaling-&gt;resultAt(num)));
 }

 void Images::finished()
 {
     openButton-&gt;setEnabled(true);
     cancelButton-&gt;setEnabled(false);
     pauseButton-&gt;setEnabled(false);
 }

 #endif <span class="comment">// QT_NO_CONCURRENT</span></pre>
<p /><address><hr /><div align="center">
<table width="100%" cellspacing="0" border="0"><tr class="address">
<td width="40%" align="left">Copyright &copy; 2010 Nokia Corporation and/or its subsidiary(-ies)</td>
<td width="20%" align="center"><a href="trademarks.html">Trademarks</a></td>
<td width="40%" align="right"><div align="right">Qt 4.6.3</div></td>
</tr></table></div></address></body>
</html>