<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>spectrograph.cpp Example File | Qt Multimedia 5.11</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td ><a href="../qtdoc/index.html">Qt 5.11</a></td><td ><a href="qtmultimedia-index.html">Qt Multimedia</a></td><td ><a href="qtmultimedia-multimedia-spectrum-example.html">Spectrum Example</a></td><td >spectrograph.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.11.2 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">spectrograph.cpp Example File</h1> <span class="subtitle">multimedia/spectrum/app/spectrograph.cpp</span> <!-- $$$multimedia/spectrum/app/spectrograph.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: ** ** "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 ** "AS IS" 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." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "spectrograph.h"</span> <span class="preprocessor">#include <QDebug></span> <span class="preprocessor">#include <QMouseEvent></span> <span class="preprocessor">#include <QPainter></span> <span class="preprocessor">#include <QTimerEvent></span> <span class="keyword">const</span> <span class="type">int</span> NullTimerId <span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>; <span class="keyword">const</span> <span class="type">int</span> NullIndex <span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>; <span class="keyword">const</span> <span class="type">int</span> BarSelectionInterval <span class="operator">=</span> <span class="number">2000</span>; Spectrograph<span class="operator">::</span>Spectrograph(<span class="type"><a href="../qtwidgets/qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="../qtwidgets/qwidget.html">QWidget</a></span>(parent) <span class="operator">,</span> m_barSelected(NullIndex) <span class="operator">,</span> m_timerId(NullTimerId) <span class="operator">,</span> m_lowFreq(<span class="number">0.0</span>) <span class="operator">,</span> m_highFreq(<span class="number">0.0</span>) { setMinimumHeight(<span class="number">100</span>); } Spectrograph<span class="operator">::</span><span class="operator">~</span>Spectrograph() { } <span class="type">void</span> Spectrograph<span class="operator">::</span>setParams(<span class="type">int</span> numBars<span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> lowFreq<span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> highFreq) { Q_ASSERT(numBars <span class="operator">></span> <span class="number">0</span>); Q_ASSERT(highFreq <span class="operator">></span> lowFreq); m_bars<span class="operator">.</span>resize(numBars); m_lowFreq <span class="operator">=</span> lowFreq; m_highFreq <span class="operator">=</span> highFreq; updateBars(); } <span class="type">void</span> Spectrograph<span class="operator">::</span>timerEvent(<span class="type"><a href="../qtcore/qtimerevent.html">QTimerEvent</a></span> <span class="operator">*</span>event) { Q_ASSERT(event<span class="operator">-</span><span class="operator">></span>timerId() <span class="operator">=</span><span class="operator">=</span> m_timerId); Q_UNUSED(event) <span class="comment">// suppress warnings in release builds</span> killTimer(m_timerId); m_timerId <span class="operator">=</span> NullTimerId; m_barSelected <span class="operator">=</span> NullIndex; update(); } <span class="type">void</span> Spectrograph<span class="operator">::</span>paintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>event) { Q_UNUSED(event) <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>); painter<span class="operator">.</span>fillRect(rect()<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black); <span class="keyword">const</span> <span class="type">int</span> numBars <span class="operator">=</span> m_bars<span class="operator">.</span>count(); <span class="comment">// Highlight region of selected bar</span> <span class="keyword">if</span> (m_barSelected <span class="operator">!</span><span class="operator">=</span> NullIndex <span class="operator">&</span><span class="operator">&</span> numBars) { <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> regionRect <span class="operator">=</span> rect(); regionRect<span class="operator">.</span>setLeft(m_barSelected <span class="operator">*</span> rect()<span class="operator">.</span>width() <span class="operator">/</span> numBars); regionRect<span class="operator">.</span>setWidth(rect()<span class="operator">.</span>width() <span class="operator">/</span> numBars); <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> regionColor(<span class="number">202</span><span class="operator">,</span> <span class="number">202</span><span class="operator">,</span> <span class="number">64</span>); painter<span class="operator">.</span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DiagCrossPattern); painter<span class="operator">.</span>fillRect(regionRect<span class="operator">,</span> regionColor); painter<span class="operator">.</span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>NoBrush); } <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> barColor(<span class="number">51</span><span class="operator">,</span> <span class="number">204</span><span class="operator">,</span> <span class="number">102</span>); <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> clipColor(<span class="number">255</span><span class="operator">,</span> <span class="number">255</span><span class="operator">,</span> <span class="number">0</span>); <span class="comment">// Draw the outline</span> <span class="keyword">const</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> gridColor <span class="operator">=</span> barColor<span class="operator">.</span>darker(); <span class="type"><a href="../qtgui/qpen.html">QPen</a></span> gridPen(gridColor); painter<span class="operator">.</span>setPen(gridPen); painter<span class="operator">.</span>drawLine(rect()<span class="operator">.</span>topLeft()<span class="operator">,</span> rect()<span class="operator">.</span>topRight()); painter<span class="operator">.</span>drawLine(rect()<span class="operator">.</span>topRight()<span class="operator">,</span> rect()<span class="operator">.</span>bottomRight()); painter<span class="operator">.</span>drawLine(rect()<span class="operator">.</span>bottomRight()<span class="operator">,</span> rect()<span class="operator">.</span>bottomLeft()); painter<span class="operator">.</span>drawLine(rect()<span class="operator">.</span>bottomLeft()<span class="operator">,</span> rect()<span class="operator">.</span>topLeft()); <span class="type"><a href="../qtcore/qvector.html">QVector</a></span><span class="operator"><</span><span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">></span> dashes; dashes <span class="operator"><</span><span class="operator"><</span> <span class="number">2</span> <span class="operator"><</span><span class="operator"><</span> <span class="number">2</span>; gridPen<span class="operator">.</span>setDashPattern(dashes); painter<span class="operator">.</span>setPen(gridPen); <span class="comment">// Draw vertical lines between bars</span> <span class="keyword">if</span> (numBars) { <span class="keyword">const</span> <span class="type">int</span> numHorizontalSections <span class="operator">=</span> numBars; <span class="type"><a href="../qtcore/qline.html">QLine</a></span> line(rect()<span class="operator">.</span>topLeft()<span class="operator">,</span> rect()<span class="operator">.</span>bottomLeft()); <span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">1</span>; i<span class="operator"><</span>numHorizontalSections; <span class="operator">+</span><span class="operator">+</span>i) { line<span class="operator">.</span>translate(rect()<span class="operator">.</span>width()<span class="operator">/</span>numHorizontalSections<span class="operator">,</span> <span class="number">0</span>); painter<span class="operator">.</span>drawLine(line); } } <span class="comment">// Draw horizontal lines</span> <span class="keyword">const</span> <span class="type">int</span> numVerticalSections <span class="operator">=</span> <span class="number">10</span>; <span class="type"><a href="../qtcore/qline.html">QLine</a></span> line(rect()<span class="operator">.</span>topLeft()<span class="operator">,</span> rect()<span class="operator">.</span>topRight()); <span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">1</span>; i<span class="operator"><</span>numVerticalSections; <span class="operator">+</span><span class="operator">+</span>i) { line<span class="operator">.</span>translate(<span class="number">0</span><span class="operator">,</span> rect()<span class="operator">.</span>height()<span class="operator">/</span>numVerticalSections); painter<span class="operator">.</span>drawLine(line); } barColor <span class="operator">=</span> barColor<span class="operator">.</span>lighter(); barColor<span class="operator">.</span>setAlphaF(<span class="number">0.75</span>); clipColor<span class="operator">.</span>setAlphaF(<span class="number">0.75</span>); <span class="comment">// Draw the bars</span> <span class="keyword">if</span> (numBars) { <span class="comment">// Calculate width of bars and gaps</span> <span class="keyword">const</span> <span class="type">int</span> widgetWidth <span class="operator">=</span> rect()<span class="operator">.</span>width(); <span class="keyword">const</span> <span class="type">int</span> barPlusGapWidth <span class="operator">=</span> widgetWidth <span class="operator">/</span> numBars; <span class="keyword">const</span> <span class="type">int</span> barWidth <span class="operator">=</span> <span class="number">0.8</span> <span class="operator">*</span> barPlusGapWidth; <span class="keyword">const</span> <span class="type">int</span> gapWidth <span class="operator">=</span> barPlusGapWidth <span class="operator">-</span> barWidth; <span class="keyword">const</span> <span class="type">int</span> paddingWidth <span class="operator">=</span> widgetWidth <span class="operator">-</span> numBars <span class="operator">*</span> (barWidth <span class="operator">+</span> gapWidth); <span class="keyword">const</span> <span class="type">int</span> leftPaddingWidth <span class="operator">=</span> (paddingWidth <span class="operator">+</span> gapWidth) <span class="operator">/</span> <span class="number">2</span>; <span class="keyword">const</span> <span class="type">int</span> barHeight <span class="operator">=</span> rect()<span class="operator">.</span>height() <span class="operator">-</span> <span class="number">2</span> <span class="operator">*</span> gapWidth; <span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">0</span>; i<span class="operator"><</span>numBars; <span class="operator">+</span><span class="operator">+</span>i) { <span class="keyword">const</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> value <span class="operator">=</span> m_bars<span class="operator">[</span>i<span class="operator">]</span><span class="operator">.</span>value; Q_ASSERT(value <span class="operator">></span><span class="operator">=</span> <span class="number">0.0</span> <span class="operator">&</span><span class="operator">&</span> value <span class="operator"><</span><span class="operator">=</span> <span class="number">1.0</span>); <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> bar <span class="operator">=</span> rect(); bar<span class="operator">.</span>setLeft(rect()<span class="operator">.</span>left() <span class="operator">+</span> leftPaddingWidth <span class="operator">+</span> (i <span class="operator">*</span> (gapWidth <span class="operator">+</span> barWidth))); bar<span class="operator">.</span>setWidth(barWidth); bar<span class="operator">.</span>setTop(rect()<span class="operator">.</span>top() <span class="operator">+</span> gapWidth <span class="operator">+</span> (<span class="number">1.0</span> <span class="operator">-</span> value) <span class="operator">*</span> barHeight); bar<span class="operator">.</span>setBottom(rect()<span class="operator">.</span>bottom() <span class="operator">-</span> gapWidth); <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> color <span class="operator">=</span> barColor; <span class="keyword">if</span> (m_bars<span class="operator">[</span>i<span class="operator">]</span><span class="operator">.</span>clipped) color <span class="operator">=</span> clipColor; painter<span class="operator">.</span>fillRect(bar<span class="operator">,</span> color); } } } <span class="type">void</span> Spectrograph<span class="operator">::</span>mousePressEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">const</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span> pos <span class="operator">=</span> event<span class="operator">-</span><span class="operator">></span>pos(); <span class="keyword">const</span> <span class="type">int</span> index <span class="operator">=</span> m_bars<span class="operator">.</span>count() <span class="operator">*</span> (pos<span class="operator">.</span>x() <span class="operator">-</span> rect()<span class="operator">.</span>left()) <span class="operator">/</span> rect()<span class="operator">.</span>width(); selectBar(index); } <span class="type">void</span> Spectrograph<span class="operator">::</span>reset() { m_spectrum<span class="operator">.</span>reset(); spectrumChanged(m_spectrum); } <span class="type">void</span> Spectrograph<span class="operator">::</span>spectrumChanged(<span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum) { m_spectrum <span class="operator">=</span> spectrum; updateBars(); } <span class="type">int</span> Spectrograph<span class="operator">::</span>barIndex(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> frequency) <span class="keyword">const</span> { Q_ASSERT(frequency <span class="operator">></span><span class="operator">=</span> m_lowFreq <span class="operator">&</span><span class="operator">&</span> frequency <span class="operator"><</span> m_highFreq); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> bandWidth <span class="operator">=</span> (m_highFreq <span class="operator">-</span> m_lowFreq) <span class="operator">/</span> m_bars<span class="operator">.</span>count(); <span class="keyword">const</span> <span class="type">int</span> index <span class="operator">=</span> (frequency <span class="operator">-</span> m_lowFreq) <span class="operator">/</span> bandWidth; <span class="keyword">if</span> (index <span class="operator"><</span><span class="number">0</span> <span class="operator">|</span><span class="operator">|</span> index <span class="operator">></span><span class="operator">=</span> m_bars<span class="operator">.</span>count()) Q_ASSERT(<span class="keyword">false</span>); <span class="keyword">return</span> index; } <span class="type"><a href="../qtcore/qpair.html">QPair</a></span><span class="operator"><</span><span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">></span> Spectrograph<span class="operator">::</span>barRange(<span class="type">int</span> index) <span class="keyword">const</span> { Q_ASSERT(index <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> index <span class="operator"><</span> m_bars<span class="operator">.</span>count()); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> bandWidth <span class="operator">=</span> (m_highFreq <span class="operator">-</span> m_lowFreq) <span class="operator">/</span> m_bars<span class="operator">.</span>count(); <span class="keyword">return</span> <span class="type"><a href="../qtcore/qpair.html">QPair</a></span><span class="operator"><</span><span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">></span>(index <span class="operator">*</span> bandWidth<span class="operator">,</span> (index<span class="operator">+</span><span class="number">1</span>) <span class="operator">*</span> bandWidth); } <span class="type">void</span> Spectrograph<span class="operator">::</span>updateBars() { m_bars<span class="operator">.</span>fill(Bar()); FrequencySpectrum<span class="operator">::</span>const_iterator i <span class="operator">=</span> m_spectrum<span class="operator">.</span>begin(); <span class="keyword">const</span> FrequencySpectrum<span class="operator">::</span>const_iterator end <span class="operator">=</span> m_spectrum<span class="operator">.</span>end(); <span class="keyword">for</span> ( ; i <span class="operator">!</span><span class="operator">=</span> end; <span class="operator">+</span><span class="operator">+</span>i) { <span class="keyword">const</span> FrequencySpectrum<span class="operator">::</span>Element e <span class="operator">=</span> <span class="operator">*</span>i; <span class="keyword">if</span> (e<span class="operator">.</span>frequency <span class="operator">></span><span class="operator">=</span> m_lowFreq <span class="operator">&</span><span class="operator">&</span> e<span class="operator">.</span>frequency <span class="operator"><</span> m_highFreq) { Bar <span class="operator">&</span>bar <span class="operator">=</span> m_bars<span class="operator">[</span>barIndex(e<span class="operator">.</span>frequency)<span class="operator">]</span>; bar<span class="operator">.</span>value <span class="operator">=</span> <a href="../qtcore/qtglobal.html#qMax">qMax</a>(bar<span class="operator">.</span>value<span class="operator">,</span> e<span class="operator">.</span>amplitude); bar<span class="operator">.</span>clipped <span class="operator">|</span><span class="operator">=</span> e<span class="operator">.</span>clipped; } } update(); } <span class="type">void</span> Spectrograph<span class="operator">::</span>selectBar(<span class="type">int</span> index) { <span class="keyword">const</span> <span class="type"><a href="../qtcore/qpair.html">QPair</a></span><span class="operator"><</span><span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span><span class="operator">></span> frequencyRange <span class="operator">=</span> barRange(index); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> message <span class="operator">=</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span>(<span class="string">"%1 - %2 Hz"</span>) <span class="operator">.</span>arg(frequencyRange<span class="operator">.</span>first) <span class="operator">.</span>arg(frequencyRange<span class="operator">.</span>second); <span class="keyword">emit</span> infoMessage(message<span class="operator">,</span> BarSelectionInterval); <span class="keyword">if</span> (NullTimerId <span class="operator">!</span><span class="operator">=</span> m_timerId) killTimer(m_timerId); m_timerId <span class="operator">=</span> startTimer(BarSelectionInterval); m_barSelected <span class="operator">=</span> index; update(); } </pre> </div> <!-- @@@multimedia/spectrum/app/spectrograph.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2018 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>