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<h1 class="title">scribblearea.cpp Example File</h1>
<span class="small-subtitle">widgets/scribble/scribblearea.cpp</span>
<!-- $$$widgets/scribble/scribblearea.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 &quot;scribblearea.h&quot;</span>
ScribbleArea<span class="operator">::</span>ScribbleArea(<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)
{
setAttribute(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>WA_StaticContents);
modified <span class="operator">=</span> <span class="keyword">false</span>;
scribbling <span class="operator">=</span> <span class="keyword">false</span>;
myPenWidth <span class="operator">=</span> <span class="number">1</span>;
myPenColor <span class="operator">=</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>blue;
}
<span class="type">bool</span> ScribbleArea<span class="operator">::</span>openImage(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&amp;</span>fileName)
{
<span class="type"><a href="qimage.html">QImage</a></span> loadedImage;
<span class="keyword">if</span> (<span class="operator">!</span>loadedImage<span class="operator">.</span>load(fileName))
<span class="keyword">return</span> <span class="keyword">false</span>;
<span class="type"><a href="qsize.html">QSize</a></span> newSize <span class="operator">=</span> loadedImage<span class="operator">.</span>size()<span class="operator">.</span>expandedTo(size());
resizeImage(<span class="operator">&amp;</span>loadedImage<span class="operator">,</span> newSize);
image <span class="operator">=</span> loadedImage;
modified <span class="operator">=</span> <span class="keyword">false</span>;
update();
<span class="keyword">return</span> <span class="keyword">true</span>;
}
<span class="type">bool</span> ScribbleArea<span class="operator">::</span>saveImage(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&amp;</span>fileName<span class="operator">,</span> <span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>fileFormat)
{
<span class="type"><a href="qimage.html">QImage</a></span> visibleImage <span class="operator">=</span> image;
resizeImage(<span class="operator">&amp;</span>visibleImage<span class="operator">,</span> size());
<span class="keyword">if</span> (visibleImage<span class="operator">.</span>save(fileName<span class="operator">,</span> fileFormat)) {
modified <span class="operator">=</span> <span class="keyword">false</span>;
<span class="keyword">return</span> <span class="keyword">true</span>;
} <span class="keyword">else</span> {
<span class="keyword">return</span> <span class="keyword">false</span>;
}
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>setPenColor(<span class="keyword">const</span> <span class="type"><a href="qcolor.html">QColor</a></span> <span class="operator">&amp;</span>newColor)
{
myPenColor <span class="operator">=</span> newColor;
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>setPenWidth(<span class="type">int</span> newWidth)
{
myPenWidth <span class="operator">=</span> newWidth;
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>clearImage()
{
image<span class="operator">.</span>fill(<a href="qcolor.html#qRgb">qRgb</a>(<span class="number">255</span><span class="operator">,</span> <span class="number">255</span><span class="operator">,</span> <span class="number">255</span>));
modified <span class="operator">=</span> <span class="keyword">true</span>;
update();
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>mousePressEvent(<span class="type"><a href="qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event)
{
<span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">&gt;</span>button() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>LeftButton) {
lastPoint <span class="operator">=</span> event<span class="operator">-</span><span class="operator">&gt;</span>pos();
scribbling <span class="operator">=</span> <span class="keyword">true</span>;
}
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>mouseMoveEvent(<span class="type"><a href="qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event)
{
<span class="keyword">if</span> ((event<span class="operator">-</span><span class="operator">&gt;</span>buttons() <span class="operator">&amp;</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>LeftButton) <span class="operator">&amp;</span><span class="operator">&amp;</span> scribbling)
drawLineTo(event<span class="operator">-</span><span class="operator">&gt;</span>pos());
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>mouseReleaseEvent(<span class="type"><a href="qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event)
{
<span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">&gt;</span>button() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>LeftButton <span class="operator">&amp;</span><span class="operator">&amp;</span> scribbling) {
drawLineTo(event<span class="operator">-</span><span class="operator">&gt;</span>pos());
scribbling <span class="operator">=</span> <span class="keyword">false</span>;
}
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>paintEvent(<span class="type"><a href="qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>event)
{
<span class="type"><a href="qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>);
<span class="type"><a href="qrect.html">QRect</a></span> dirtyRect <span class="operator">=</span> event<span class="operator">-</span><span class="operator">&gt;</span>rect();
painter<span class="operator">.</span>drawImage(dirtyRect<span class="operator">,</span> image<span class="operator">,</span> dirtyRect);
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>resizeEvent(<span class="type"><a href="qresizeevent.html">QResizeEvent</a></span> <span class="operator">*</span>event)
{
<span class="keyword">if</span> (width() <span class="operator">&gt;</span> image<span class="operator">.</span>width() <span class="operator">|</span><span class="operator">|</span> height() <span class="operator">&gt;</span> image<span class="operator">.</span>height()) {
<span class="type">int</span> newWidth <span class="operator">=</span> <a href="qtglobal.html#qMax">qMax</a>(width() <span class="operator">+</span> <span class="number">128</span><span class="operator">,</span> image<span class="operator">.</span>width());
<span class="type">int</span> newHeight <span class="operator">=</span> <a href="qtglobal.html#qMax">qMax</a>(height() <span class="operator">+</span> <span class="number">128</span><span class="operator">,</span> image<span class="operator">.</span>height());
resizeImage(<span class="operator">&amp;</span>image<span class="operator">,</span> <span class="type"><a href="qsize.html">QSize</a></span>(newWidth<span class="operator">,</span> newHeight));
update();
}
<span class="type"><a href="qwidget.html">QWidget</a></span><span class="operator">::</span>resizeEvent(event);
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>drawLineTo(<span class="keyword">const</span> <span class="type"><a href="qpoint.html">QPoint</a></span> <span class="operator">&amp;</span>endPoint)
{
<span class="type"><a href="qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>image);
painter<span class="operator">.</span>setPen(<span class="type"><a href="qpen.html">QPen</a></span>(myPenColor<span class="operator">,</span> myPenWidth<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>SolidLine<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>RoundCap<span class="operator">,</span>
<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>RoundJoin));
painter<span class="operator">.</span>drawLine(lastPoint<span class="operator">,</span> endPoint);
modified <span class="operator">=</span> <span class="keyword">true</span>;
<span class="type">int</span> rad <span class="operator">=</span> (myPenWidth <span class="operator">/</span> <span class="number">2</span>) <span class="operator">+</span> <span class="number">2</span>;
update(<span class="type"><a href="qrect.html">QRect</a></span>(lastPoint<span class="operator">,</span> endPoint)<span class="operator">.</span>normalized()
<span class="operator">.</span>adjusted(<span class="operator">-</span>rad<span class="operator">,</span> <span class="operator">-</span>rad<span class="operator">,</span> <span class="operator">+</span>rad<span class="operator">,</span> <span class="operator">+</span>rad));
lastPoint <span class="operator">=</span> endPoint;
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>resizeImage(<span class="type"><a href="qimage.html">QImage</a></span> <span class="operator">*</span>image<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qsize.html">QSize</a></span> <span class="operator">&amp;</span>newSize)
{
<span class="keyword">if</span> (image<span class="operator">-</span><span class="operator">&gt;</span>size() <span class="operator">=</span><span class="operator">=</span> newSize)
<span class="keyword">return</span>;
<span class="type"><a href="qimage.html">QImage</a></span> newImage(newSize<span class="operator">,</span> <span class="type"><a href="qimage.html">QImage</a></span><span class="operator">::</span>Format_RGB32);
newImage<span class="operator">.</span>fill(<a href="qcolor.html#qRgb">qRgb</a>(<span class="number">255</span><span class="operator">,</span> <span class="number">255</span><span class="operator">,</span> <span class="number">255</span>));
<span class="type"><a href="qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>newImage);
painter<span class="operator">.</span>drawImage(<span class="type"><a href="qpoint.html">QPoint</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> <span class="operator">*</span>image);
<span class="operator">*</span>image <span class="operator">=</span> newImage;
}
<span class="type">void</span> ScribbleArea<span class="operator">::</span>print()
{
<span class="preprocessor">#ifndef QT_NO_PRINTER</span>
<span class="type"><a href="qprinter.html">QPrinter</a></span> printer(<span class="type"><a href="qprinter.html">QPrinter</a></span><span class="operator">::</span>HighResolution);
<span class="type"><a href="qprintdialog.html">QPrintDialog</a></span> <span class="operator">*</span>printDialog <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qprintdialog.html">QPrintDialog</a></span>(<span class="operator">&amp;</span>printer<span class="operator">,</span> <span class="keyword">this</span>);
<span class="keyword">if</span> (printDialog<span class="operator">-</span><span class="operator">&gt;</span>exec() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qdialog.html">QDialog</a></span><span class="operator">::</span>Accepted) {
<span class="type"><a href="qpainter.html">QPainter</a></span> painter(<span class="operator">&amp;</span>printer);
<span class="type"><a href="qrect.html">QRect</a></span> rect <span class="operator">=</span> painter<span class="operator">.</span>viewport();
<span class="type"><a href="qsize.html">QSize</a></span> size <span class="operator">=</span> image<span class="operator">.</span>size();
size<span class="operator">.</span>scale(rect<span class="operator">.</span>size()<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>KeepAspectRatio);
painter<span class="operator">.</span>setViewport(rect<span class="operator">.</span>x()<span class="operator">,</span> rect<span class="operator">.</span>y()<span class="operator">,</span> size<span class="operator">.</span>width()<span class="operator">,</span> size<span class="operator">.</span>height());
painter<span class="operator">.</span>setWindow(image<span class="operator">.</span>rect());
painter<span class="operator">.</span>drawImage(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> image);
}
<span class="preprocessor">#endif // QT_NO_PRINTER</span>
}</pre>
</div>
<!-- @@@widgets/scribble/scribblearea.cpp -->
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