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<h1 class="title">sourcewidget.cpp Example File</h1>
<span class="small-subtitle">draganddrop/delayedencoding/sourcewidget.cpp</span>
<!-- $$$draganddrop/delayedencoding/sourcewidget.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp"> <span class="comment">/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** &quot;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 The Qt Company Ltd 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
** &quot;AS IS&quot; 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.&quot;
**
** $QT_END_LICENSE$
**
****************************************************************************/</span>
<span class="preprocessor">#include &lt;QtGui&gt;</span>
<span class="preprocessor">#include &lt;QtSvg&gt;</span>
<span class="preprocessor">#include &quot;mimedata.h&quot;</span>
<span class="preprocessor">#include &quot;sourcewidget.h&quot;</span>
SourceWidget<span class="operator">::</span>SourceWidget(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent)
: <span class="type"><a href="qwidget.html">QWidget</a></span>(parent)
{
<span class="type"><a href="qfile.html">QFile</a></span> imageFile(<span class="string">&quot;:/images/example.svg&quot;</span>);
imageFile<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly);
imageData <span class="operator">=</span> imageFile<span class="operator">.</span>readAll();
imageFile<span class="operator">.</span>close();
<span class="type"><a href="qscrollarea.html">QScrollArea</a></span> <span class="operator">*</span>imageArea <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qscrollarea.html">QScrollArea</a></span>;
imageLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qsvgwidget.html">QSvgWidget</a></span>;
imageLabel<span class="operator">-</span><span class="operator">&gt;</span>renderer()<span class="operator">-</span><span class="operator">&gt;</span>load(imageData);
imageArea<span class="operator">-</span><span class="operator">&gt;</span>setWidget(imageLabel);
<span class="comment">//imageLabel-&gt;setMinimumSize(imageLabel-&gt;renderer()-&gt;viewBox().size());</span>
<span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>instructTopLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">&quot;This is an SVG drawing:&quot;</span>));
<span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>instructBottomLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(
tr(<span class="string">&quot;Drag the icon to copy the drawing as a PNG file:&quot;</span>));
instructBottomLabel<span class="operator">-</span><span class="operator">&gt;</span>setWordWrap(<span class="keyword">true</span>);
<span class="type"><a href="qpushbutton.html">QPushButton</a></span> <span class="operator">*</span>dragIcon <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qpushbutton.html">QPushButton</a></span>(tr(<span class="string">&quot;Export&quot;</span>));
dragIcon<span class="operator">-</span><span class="operator">&gt;</span>setIcon(<span class="type"><a href="qicon.html">QIcon</a></span>(<span class="string">&quot;:/images/drag.png&quot;</span>));
connect(dragIcon<span class="operator">,</span> SIGNAL(pressed())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(startDrag()));
<span class="type"><a href="qgridlayout.html">QGridLayout</a></span> <span class="operator">*</span>layout <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgridlayout.html">QGridLayout</a></span>;
layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(instructTopLabel<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">2</span>);
layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(imageArea<span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">2</span><span class="operator">,</span> <span class="number">2</span>);
layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(instructBottomLabel<span class="operator">,</span> <span class="number">3</span><span class="operator">,</span> <span class="number">0</span>);
layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(dragIcon<span class="operator">,</span> <span class="number">3</span><span class="operator">,</span> <span class="number">1</span>);
setLayout(layout);
setWindowTitle(tr(<span class="string">&quot;Delayed Encoding&quot;</span>));
}
<span class="type">void</span> SourceWidget<span class="operator">::</span>createData(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&amp;</span>mimeType)
{
<span class="keyword">if</span> (mimeType <span class="operator">!</span><span class="operator">=</span> <span class="string">&quot;image/png&quot;</span>)
<span class="keyword">return</span>;
<span class="type"><a href="qimage.html">QImage</a></span> image(imageLabel<span class="operator">-</span><span class="operator">&gt;</span>size()<span class="operator">,</span> <span class="type"><a href="qimage.html">QImage</a></span><span class="operator">::</span>Format_RGB32);
<span class="type"><a href="qpainter.html">QPainter</a></span> painter;
painter<span class="operator">.</span>begin(<span class="operator">&amp;</span>image);
imageLabel<span class="operator">-</span><span class="operator">&gt;</span>renderer()<span class="operator">-</span><span class="operator">&gt;</span>render(<span class="operator">&amp;</span>painter);
painter<span class="operator">.</span>end();
<span class="type"><a href="qbytearray.html">QByteArray</a></span> data;
<span class="type"><a href="qbuffer.html">QBuffer</a></span> buffer(<span class="operator">&amp;</span>data);
buffer<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>WriteOnly);
image<span class="operator">.</span>save(<span class="operator">&amp;</span>buffer<span class="operator">,</span> <span class="string">&quot;PNG&quot;</span>);
buffer<span class="operator">.</span>close();
mimeData<span class="operator">-</span><span class="operator">&gt;</span>setData(<span class="string">&quot;image/png&quot;</span><span class="operator">,</span> data);
}
<span class="type">void</span> SourceWidget<span class="operator">::</span>startDrag()
{
mimeData <span class="operator">=</span> <span class="keyword">new</span> MimeData;
connect(mimeData<span class="operator">,</span> SIGNAL(dataRequested(<span class="type"><a href="qstring.html">QString</a></span>))<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span> SLOT(createData(<span class="type"><a href="qstring.html">QString</a></span>))<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>DirectConnection);
<span class="type"><a href="qdrag.html">QDrag</a></span> <span class="operator">*</span>drag <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qdrag.html">QDrag</a></span>(<span class="keyword">this</span>);
drag<span class="operator">-</span><span class="operator">&gt;</span>setMimeData(mimeData);
drag<span class="operator">-</span><span class="operator">&gt;</span>setPixmap(<span class="type"><a href="qpixmap.html">QPixmap</a></span>(<span class="string">&quot;:/images/drag.png&quot;</span>));
drag<span class="operator">-</span><span class="operator">&gt;</span>exec(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>CopyAction);
}</pre>
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<!-- @@@draganddrop/delayedencoding/sourcewidget.cpp -->
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