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qt4-x11/doc/html/graphicsview-elasticnodes-graphwidget-cpp.html
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<h1 class="title">graphwidget.cpp Example File</h1>
<span class="small-subtitle">graphicsview/elasticnodes/graphwidget.cpp</span>
<!-- $$$graphicsview/elasticnodes/graphwidget.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 &quot;graphwidget.h&quot;</span>
<span class="preprocessor">#include &quot;edge.h&quot;</span>
<span class="preprocessor">#include &quot;node.h&quot;</span>
<span class="preprocessor">#include &lt;QtGui&gt;</span>
<span class="preprocessor">#include &lt;math.h&gt;</span>
GraphWidget<span class="operator">::</span>GraphWidget(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent)
: <span class="type"><a href="qgraphicsview.html">QGraphicsView</a></span>(parent)<span class="operator">,</span> timerId(<span class="number">0</span>)
{
<span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span> <span class="operator">*</span>scene <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span>(<span class="keyword">this</span>);
scene<span class="operator">-</span><span class="operator">&gt;</span>setItemIndexMethod(<span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span><span class="operator">::</span>NoIndex);
scene<span class="operator">-</span><span class="operator">&gt;</span>setSceneRect(<span class="operator">-</span><span class="number">200</span><span class="operator">,</span> <span class="operator">-</span><span class="number">200</span><span class="operator">,</span> <span class="number">400</span><span class="operator">,</span> <span class="number">400</span>);
setScene(scene);
setCacheMode(CacheBackground);
setViewportUpdateMode(BoundingRectViewportUpdate);
setRenderHint(<span class="type"><a href="qpainter.html">QPainter</a></span><span class="operator">::</span>Antialiasing);
setTransformationAnchor(AnchorUnderMouse);
scale(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">0.8</span>)<span class="operator">,</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">0.8</span>));
setMinimumSize(<span class="number">400</span><span class="operator">,</span> <span class="number">400</span>);
setWindowTitle(tr(<span class="string">&quot;Elastic Nodes&quot;</span>));
Node <span class="operator">*</span>node1 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node2 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node3 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node4 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
centerNode <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node6 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node7 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node8 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
Node <span class="operator">*</span>node9 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node1);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node2);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node3);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node4);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(centerNode);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node6);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node7);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node8);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(node9);
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node1<span class="operator">,</span> node2));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node2<span class="operator">,</span> node3));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node2<span class="operator">,</span> centerNode));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node3<span class="operator">,</span> node6));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node4<span class="operator">,</span> node1));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node4<span class="operator">,</span> centerNode));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(centerNode<span class="operator">,</span> node6));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(centerNode<span class="operator">,</span> node8));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node6<span class="operator">,</span> node9));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node7<span class="operator">,</span> node4));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node8<span class="operator">,</span> node7));
scene<span class="operator">-</span><span class="operator">&gt;</span>addItem(<span class="keyword">new</span> Edge(node9<span class="operator">,</span> node8));
node1<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>);
node2<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="number">0</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>);
node3<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="number">50</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>);
node4<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="number">0</span>);
centerNode<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>);
node6<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="number">50</span><span class="operator">,</span> <span class="number">0</span>);
node7<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="number">50</span>);
node8<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="number">0</span><span class="operator">,</span> <span class="number">50</span>);
node9<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="number">50</span><span class="operator">,</span> <span class="number">50</span>);
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>itemMoved()
{
<span class="keyword">if</span> (<span class="operator">!</span>timerId)
timerId <span class="operator">=</span> startTimer(<span class="number">1000</span> <span class="operator">/</span> <span class="number">25</span>);
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>keyPressEvent(<span class="type"><a href="qkeyevent.html">QKeyEvent</a></span> <span class="operator">*</span>event)
{
<span class="keyword">switch</span> (event<span class="operator">-</span><span class="operator">&gt;</span>key()) {
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Up:
centerNode<span class="operator">-</span><span class="operator">&gt;</span>moveBy(<span class="number">0</span><span class="operator">,</span> <span class="operator">-</span><span class="number">20</span>);
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Down:
centerNode<span class="operator">-</span><span class="operator">&gt;</span>moveBy(<span class="number">0</span><span class="operator">,</span> <span class="number">20</span>);
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Left:
centerNode<span class="operator">-</span><span class="operator">&gt;</span>moveBy(<span class="operator">-</span><span class="number">20</span><span class="operator">,</span> <span class="number">0</span>);
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Right:
centerNode<span class="operator">-</span><span class="operator">&gt;</span>moveBy(<span class="number">20</span><span class="operator">,</span> <span class="number">0</span>);
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Plus:
zoomIn();
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Minus:
zoomOut();
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Space:
<span class="keyword">case</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>Key_Enter:
shuffle();
<span class="keyword">break</span>;
<span class="keyword">default</span>:
<span class="type"><a href="qgraphicsview.html">QGraphicsView</a></span><span class="operator">::</span>keyPressEvent(event);
}
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>timerEvent(<span class="type"><a href="qtimerevent.html">QTimerEvent</a></span> <span class="operator">*</span>event)
{
Q_UNUSED(event);
<span class="type"><a href="qlist.html">QList</a></span><span class="operator">&lt;</span>Node <span class="operator">*</span><span class="operator">&gt;</span> nodes;
foreach (<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span>item<span class="operator">,</span> scene()<span class="operator">-</span><span class="operator">&gt;</span>items()) {
<span class="keyword">if</span> (Node <span class="operator">*</span>node <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>Node <span class="operator">*</span><span class="operator">&gt;</span>(item))
nodes <span class="operator">&lt;</span><span class="operator">&lt;</span> node;
}
foreach (Node <span class="operator">*</span>node<span class="operator">,</span> nodes)
node<span class="operator">-</span><span class="operator">&gt;</span>calculateForces();
<span class="type">bool</span> itemsMoved <span class="operator">=</span> <span class="keyword">false</span>;
foreach (Node <span class="operator">*</span>node<span class="operator">,</span> nodes) {
<span class="keyword">if</span> (node<span class="operator">-</span><span class="operator">&gt;</span>advance())
itemsMoved <span class="operator">=</span> <span class="keyword">true</span>;
}
<span class="keyword">if</span> (<span class="operator">!</span>itemsMoved) {
killTimer(timerId);
timerId <span class="operator">=</span> <span class="number">0</span>;
}
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>wheelEvent(<span class="type"><a href="qwheelevent.html">QWheelEvent</a></span> <span class="operator">*</span>event)
{
scaleView(pow((<span class="type">double</span>)<span class="number">2</span><span class="operator">,</span> <span class="operator">-</span>event<span class="operator">-</span><span class="operator">&gt;</span>delta() <span class="operator">/</span> <span class="number">240.0</span>));
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>drawBackground(<span class="type"><a href="qpainter.html">QPainter</a></span> <span class="operator">*</span>painter<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qrectf.html">QRectF</a></span> <span class="operator">&amp;</span>rect)
{
Q_UNUSED(rect);
<span class="comment">// Shadow</span>
<span class="type"><a href="qrectf.html">QRectF</a></span> sceneRect <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>sceneRect();
<span class="type"><a href="qrectf.html">QRectF</a></span> rightShadow(sceneRect<span class="operator">.</span>right()<span class="operator">,</span> sceneRect<span class="operator">.</span>top() <span class="operator">+</span> <span class="number">5</span><span class="operator">,</span> <span class="number">5</span><span class="operator">,</span> sceneRect<span class="operator">.</span>height());
<span class="type"><a href="qrectf.html">QRectF</a></span> bottomShadow(sceneRect<span class="operator">.</span>left() <span class="operator">+</span> <span class="number">5</span><span class="operator">,</span> sceneRect<span class="operator">.</span>bottom()<span class="operator">,</span> sceneRect<span class="operator">.</span>width()<span class="operator">,</span> <span class="number">5</span>);
<span class="keyword">if</span> (rightShadow<span class="operator">.</span>intersects(rect) <span class="operator">|</span><span class="operator">|</span> rightShadow<span class="operator">.</span>contains(rect))
painter<span class="operator">-</span><span class="operator">&gt;</span>fillRect(rightShadow<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>darkGray);
<span class="keyword">if</span> (bottomShadow<span class="operator">.</span>intersects(rect) <span class="operator">|</span><span class="operator">|</span> bottomShadow<span class="operator">.</span>contains(rect))
painter<span class="operator">-</span><span class="operator">&gt;</span>fillRect(bottomShadow<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>darkGray);
<span class="comment">// Fill</span>
<span class="type"><a href="qlineargradient.html">QLinearGradient</a></span> gradient(sceneRect<span class="operator">.</span>topLeft()<span class="operator">,</span> sceneRect<span class="operator">.</span>bottomRight());
gradient<span class="operator">.</span>setColorAt(<span class="number">0</span><span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>white);
gradient<span class="operator">.</span>setColorAt(<span class="number">1</span><span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>lightGray);
painter<span class="operator">-</span><span class="operator">&gt;</span>fillRect(rect<span class="operator">.</span>intersect(sceneRect)<span class="operator">,</span> gradient);
painter<span class="operator">-</span><span class="operator">&gt;</span>setBrush(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>NoBrush);
painter<span class="operator">-</span><span class="operator">&gt;</span>drawRect(sceneRect);
<span class="preprocessor">#if !defined(Q_OS_SYMBIAN) &amp;&amp; !defined(Q_WS_MAEMO_5)</span>
<span class="comment">// Text</span>
<span class="type"><a href="qrectf.html">QRectF</a></span> textRect(sceneRect<span class="operator">.</span>left() <span class="operator">+</span> <span class="number">4</span><span class="operator">,</span> sceneRect<span class="operator">.</span>top() <span class="operator">+</span> <span class="number">4</span><span class="operator">,</span>
sceneRect<span class="operator">.</span>width() <span class="operator">-</span> <span class="number">4</span><span class="operator">,</span> sceneRect<span class="operator">.</span>height() <span class="operator">-</span> <span class="number">4</span>);
<span class="type"><a href="qstring.html">QString</a></span> message(tr(<span class="string">&quot;Click and drag the nodes around, and zoom with the mouse &quot;</span>
<span class="string">&quot;wheel or the '+' and '-' keys&quot;</span>));
<span class="type"><a href="qfont.html">QFont</a></span> font <span class="operator">=</span> painter<span class="operator">-</span><span class="operator">&gt;</span>font();
font<span class="operator">.</span>setBold(<span class="keyword">true</span>);
font<span class="operator">.</span>setPointSize(<span class="number">14</span>);
painter<span class="operator">-</span><span class="operator">&gt;</span>setFont(font);
painter<span class="operator">-</span><span class="operator">&gt;</span>setPen(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>lightGray);
painter<span class="operator">-</span><span class="operator">&gt;</span>drawText(textRect<span class="operator">.</span>translated(<span class="number">2</span><span class="operator">,</span> <span class="number">2</span>)<span class="operator">,</span> message);
painter<span class="operator">-</span><span class="operator">&gt;</span>setPen(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>black);
painter<span class="operator">-</span><span class="operator">&gt;</span>drawText(textRect<span class="operator">,</span> message);
<span class="preprocessor">#endif</span>
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>scaleView(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> scaleFactor)
{
<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> factor <span class="operator">=</span> transform()<span class="operator">.</span>scale(scaleFactor<span class="operator">,</span> scaleFactor)<span class="operator">.</span>mapRect(<span class="type"><a href="qrectf.html">QRectF</a></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">1</span>))<span class="operator">.</span>width();
<span class="keyword">if</span> (factor <span class="operator">&lt;</span> <span class="number">0.07</span> <span class="operator">|</span><span class="operator">|</span> factor <span class="operator">&gt;</span> <span class="number">100</span>)
<span class="keyword">return</span>;
scale(scaleFactor<span class="operator">,</span> scaleFactor);
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>shuffle()
{
foreach (<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span>item<span class="operator">,</span> scene()<span class="operator">-</span><span class="operator">&gt;</span>items()) {
<span class="keyword">if</span> (qgraphicsitem_cast<span class="operator">&lt;</span>Node <span class="operator">*</span><span class="operator">&gt;</span>(item))
item<span class="operator">-</span><span class="operator">&gt;</span>setPos(<span class="operator">-</span><span class="number">150</span> <span class="operator">+</span> qrand() <span class="operator">%</span> <span class="number">300</span><span class="operator">,</span> <span class="operator">-</span><span class="number">150</span> <span class="operator">+</span> qrand() <span class="operator">%</span> <span class="number">300</span>);
}
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>zoomIn()
{
scaleView(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">1.2</span>));
}
<span class="type">void</span> GraphWidget<span class="operator">::</span>zoomOut()
{
scaleView(<span class="number">1</span> <span class="operator">/</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">1.2</span>));
}</pre>
</div>
<!-- @@@graphicsview/elasticnodes/graphwidget.cpp -->
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