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<h1 class="title">svgview.cpp Example File</h1>
<span class="subtitle">svgviewer/svgview.cpp</span>
<!-- $$$svgviewer/svgview.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2017 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, 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;svgview.h&quot;</span>

  <span class="preprocessor">#include &lt;QSvgRenderer&gt;</span>

  <span class="preprocessor">#include &lt;QWheelEvent&gt;</span>
  <span class="preprocessor">#include &lt;QMouseEvent&gt;</span>
  <span class="preprocessor">#include &lt;QGraphicsRectItem&gt;</span>
  <span class="preprocessor">#include &lt;QGraphicsSvgItem&gt;</span>
  <span class="preprocessor">#include &lt;QPaintEvent&gt;</span>
  <span class="preprocessor">#include &lt;qmath.h&gt;</span>

  <span class="preprocessor">#ifndef QT_NO_OPENGL</span>
  <span class="preprocessor">#include &lt;QGLWidget&gt;</span>
  <span class="preprocessor">#endif</span>

  SvgView<span class="operator">::</span>SvgView(<span class="type"><a href="../qtwidgets/qwidget.html">QWidget</a></span> <span class="operator">*</span>parent)
      : <span class="type"><a href="../qtwidgets/qgraphicsview.html">QGraphicsView</a></span>(parent)
      <span class="operator">,</span> m_renderer(Native)
      <span class="operator">,</span> m_svgItem(nullptr)
      <span class="operator">,</span> m_backgroundItem(nullptr)
      <span class="operator">,</span> m_outlineItem(nullptr)
  {
      setScene(<span class="keyword">new</span> <span class="type"><a href="../qtwidgets/qgraphicsscene.html">QGraphicsScene</a></span>(<span class="keyword">this</span>));
      setTransformationAnchor(AnchorUnderMouse);
      setDragMode(ScrollHandDrag);
      setViewportUpdateMode(FullViewportUpdate);

      <span class="comment">// Prepare background check-board pattern</span>
      <span class="type"><a href="../qtgui/qpixmap.html">QPixmap</a></span> tilePixmap(<span class="number">64</span><span class="operator">,</span> <span class="number">64</span>);
      tilePixmap<span class="operator">.</span>fill(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>white);
      <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> tilePainter(<span class="operator">&amp;</span>tilePixmap);
      <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> color(<span class="number">220</span><span class="operator">,</span> <span class="number">220</span><span class="operator">,</span> <span class="number">220</span>);
      tilePainter<span class="operator">.</span>fillRect(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> color);
      tilePainter<span class="operator">.</span>fillRect(<span class="number">32</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> <span class="number">32</span><span class="operator">,</span> color);
      tilePainter<span class="operator">.</span>end();

      setBackgroundBrush(tilePixmap);
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>drawBackground(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> <span class="operator">*</span>p<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> <span class="operator">&amp;</span>)
  {
      p<span class="operator">-</span><span class="operator">&gt;</span>save();
      p<span class="operator">-</span><span class="operator">&gt;</span>resetTransform();
      p<span class="operator">-</span><span class="operator">&gt;</span>drawTiledPixmap(viewport()<span class="operator">-</span><span class="operator">&gt;</span>rect()<span class="operator">,</span> backgroundBrush()<span class="operator">.</span>texture());
      p<span class="operator">-</span><span class="operator">&gt;</span>restore();
  }

  <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> SvgView<span class="operator">::</span>svgSize() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> m_svgItem <span class="operator">?</span> m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>boundingRect()<span class="operator">.</span>size()<span class="operator">.</span>toSize() : <span class="type"><a href="../qtcore/qsize.html">QSize</a></span>();
  }

  bool SvgView<span class="operator">::</span>openFile(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>fileName)
  {
      <span class="type"><a href="../qtwidgets/qgraphicsscene.html">QGraphicsScene</a></span> <span class="operator">*</span>s <span class="operator">=</span> scene();

      <span class="keyword">const</span> bool drawBackground <span class="operator">=</span> (m_backgroundItem <span class="operator">?</span> m_backgroundItem<span class="operator">-</span><span class="operator">&gt;</span>isVisible() : <span class="keyword">false</span>);
      <span class="keyword">const</span> bool drawOutline <span class="operator">=</span> (m_outlineItem <span class="operator">?</span> m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>isVisible() : <span class="keyword">true</span>);

      <span class="type"><a href="../qtcore/qscopedpointer.html">QScopedPointer</a></span><span class="operator">&lt;</span><span class="type"><a href="qgraphicssvgitem.html">QGraphicsSvgItem</a></span><span class="operator">&gt;</span> svgItem(<span class="keyword">new</span> <span class="type"><a href="qgraphicssvgitem.html">QGraphicsSvgItem</a></span>(fileName));
      <span class="keyword">if</span> (<span class="operator">!</span>svgItem<span class="operator">-</span><span class="operator">&gt;</span>renderer()<span class="operator">-</span><span class="operator">&gt;</span>isValid())
          <span class="keyword">return</span> <span class="keyword">false</span>;

      s<span class="operator">-</span><span class="operator">&gt;</span>clear();
      resetTransform();

      m_svgItem <span class="operator">=</span> svgItem<span class="operator">.</span>take();
      m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>setFlags(<span class="type"><a href="../qtwidgets/qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">::</span>ItemClipsToShape);
      m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>setCacheMode(<span class="type"><a href="../qtwidgets/qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">::</span>NoCache);
      m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>setZValue(<span class="number">0</span>);

      m_backgroundItem <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="../qtwidgets/qgraphicsrectitem.html">QGraphicsRectItem</a></span>(m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>boundingRect());
      m_backgroundItem<span class="operator">-</span><span class="operator">&gt;</span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>white);
      m_backgroundItem<span class="operator">-</span><span class="operator">&gt;</span>setPen(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>NoPen);
      m_backgroundItem<span class="operator">-</span><span class="operator">&gt;</span>setVisible(drawBackground);
      m_backgroundItem<span class="operator">-</span><span class="operator">&gt;</span>setZValue(<span class="operator">-</span><span class="number">1</span>);

      m_outlineItem <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="../qtwidgets/qgraphicsrectitem.html">QGraphicsRectItem</a></span>(m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>boundingRect());
      <span class="type"><a href="../qtgui/qpen.html">QPen</a></span> outline(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black<span class="operator">,</span> <span class="number">2</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DashLine);
      outline<span class="operator">.</span>setCosmetic(<span class="keyword">true</span>);
      m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>setPen(outline);
      m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>NoBrush);
      m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>setVisible(drawOutline);
      m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>setZValue(<span class="number">1</span>);

      s<span class="operator">-</span><span class="operator">&gt;</span>addItem(m_backgroundItem);
      s<span class="operator">-</span><span class="operator">&gt;</span>addItem(m_svgItem);
      s<span class="operator">-</span><span class="operator">&gt;</span>addItem(m_outlineItem);

      s<span class="operator">-</span><span class="operator">&gt;</span>setSceneRect(m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>boundingRect()<span class="operator">.</span>adjusted(<span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="number">10</span><span class="operator">,</span> <span class="number">10</span>));
      <span class="keyword">return</span> <span class="keyword">true</span>;
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>setRenderer(RendererType type)
  {
      m_renderer <span class="operator">=</span> type;

      <span class="keyword">if</span> (m_renderer <span class="operator">=</span><span class="operator">=</span> OpenGL) {
  <span class="preprocessor">#ifndef QT_NO_OPENGL</span>
          setViewport(<span class="keyword">new</span> <span class="type">QGLWidget</span>(<span class="type">QGLFormat</span>(QGL<span class="operator">::</span>SampleBuffers)));
  <span class="preprocessor">#endif</span>
      } <span class="keyword">else</span> {
          setViewport(<span class="keyword">new</span> <span class="type"><a href="../qtwidgets/qwidget.html">QWidget</a></span>);
      }
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>setHighQualityAntialiasing(bool highQualityAntialiasing)
  {
  <span class="preprocessor">#ifndef QT_NO_OPENGL</span>
      setRenderHint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span><span class="operator">::</span>HighQualityAntialiasing<span class="operator">,</span> highQualityAntialiasing);
  <span class="preprocessor">#else</span>
      Q_UNUSED(highQualityAntialiasing);
  <span class="preprocessor">#endif</span>
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>setViewBackground(bool enable)
  {
      <span class="keyword">if</span> (<span class="operator">!</span>m_backgroundItem)
            <span class="keyword">return</span>;

      m_backgroundItem<span class="operator">-</span><span class="operator">&gt;</span>setVisible(enable);
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>setViewOutline(bool enable)
  {
      <span class="keyword">if</span> (<span class="operator">!</span>m_outlineItem)
          <span class="keyword">return</span>;

      m_outlineItem<span class="operator">-</span><span class="operator">&gt;</span>setVisible(enable);
  }

  <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> SvgView<span class="operator">::</span>zoomFactor() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> transform()<span class="operator">.</span>m11();
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>zoomIn()
  {
      zoomBy(<span class="number">2</span>);
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>zoomOut()
  {
      zoomBy(<span class="number">0.5</span>);
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>resetZoom()
  {
      <span class="keyword">if</span> (<span class="operator">!</span><a href="../qtcore/qfloat16.html#qFuzzyCompare">qFuzzyCompare</a>(zoomFactor()<span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">1</span>))) {
          resetTransform();
          <span class="keyword">emit</span> zoomChanged();
      }
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>paintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>event)
  {
      <span class="keyword">if</span> (m_renderer <span class="operator">=</span><span class="operator">=</span> Image) {
          <span class="keyword">if</span> (m_image<span class="operator">.</span>size() <span class="operator">!</span><span class="operator">=</span> viewport()<span class="operator">-</span><span class="operator">&gt;</span>size()) {
              m_image <span class="operator">=</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span>(viewport()<span class="operator">-</span><span class="operator">&gt;</span>size()<span class="operator">,</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span><span class="operator">::</span>Format_ARGB32_Premultiplied);
          }

          <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> imagePainter(<span class="operator">&amp;</span>m_image);
          <span class="type"><a href="../qtwidgets/qgraphicsview.html">QGraphicsView</a></span><span class="operator">::</span>render(<span class="operator">&amp;</span>imagePainter);
          imagePainter<span class="operator">.</span>end();

          <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> p(viewport());
          p<span class="operator">.</span>drawImage(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> m_image);

      } <span class="keyword">else</span> {
          <span class="type"><a href="../qtwidgets/qgraphicsview.html">QGraphicsView</a></span><span class="operator">::</span>paintEvent(event);
      }
  }

  <span class="type">void</span> SvgView<span class="operator">::</span>wheelEvent(<span class="type"><a href="../qtgui/qwheelevent.html">QWheelEvent</a></span> <span class="operator">*</span>event)
  {
      zoomBy(<a href="../qtcore/qtmath.html#qPow">qPow</a>(<span class="number">1.2</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> SvgView<span class="operator">::</span>zoomBy(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> factor)
  {
      <span class="keyword">const</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> currentZoom <span class="operator">=</span> zoomFactor();
      <span class="keyword">if</span> ((factor <span class="operator">&lt;</span> <span class="number">1</span> <span class="operator">&amp;</span><span class="operator">&amp;</span> currentZoom <span class="operator">&lt;</span> <span class="number">0.1</span>) <span class="operator">|</span><span class="operator">|</span> (factor <span class="operator">&gt;</span> <span class="number">1</span> <span class="operator">&amp;</span><span class="operator">&amp;</span> currentZoom <span class="operator">&gt;</span> <span class="number">10</span>))
          <span class="keyword">return</span>;
      scale(factor<span class="operator">,</span> factor);
      <span class="keyword">emit</span> zoomChanged();
  }

  <span class="type"><a href="qsvgrenderer.html">QSvgRenderer</a></span> <span class="operator">*</span>SvgView<span class="operator">::</span>renderer() <span class="keyword">const</span>
  {
      <span class="keyword">if</span> (m_svgItem)
          <span class="keyword">return</span> m_svgItem<span class="operator">-</span><span class="operator">&gt;</span>renderer();
      <span class="keyword">return</span> nullptr;
  }

</pre>
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<!-- @@@svgviewer/svgview.cpp -->
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