/usr/share/qt5/doc/qtcharts/qtcharts-donutbreakdown-example.html is in qtcharts5-doc-html 5.9.5-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 | <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- examples-donutbreakdown.qdoc -->
<title>Donut Chart Breakdown Example | Qt Charts 5.9</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 >Qt 5.9</td><td ><a href="qtcharts-index.html">Qt Charts</a></td><td ><a href="qtcharts-examples.html">Qt Charts Examples</a></td><td >Donut Chart Breakdown Example</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.9.5 Reference Documentation</td>
</tr></table>
</div>
</div>
<div class="content">
<div class="line">
<div class="content mainContent">
<div class="sidebar">
<div class="toc">
<h3><a name="toc">Contents</a></h3>
<ul>
<li class="level1"><a href="#running-the-example">Running the Example</a></li>
<li class="level1"><a href="#creating-donut-breakdown-charts">Creating Donut Breakdown Charts</a></li>
</ul>
</div>
<div class="sidebar-content" id="sidebar-content"></div></div>
<h1 class="title">Donut Chart Breakdown Example</h1>
<span class="subtitle"></span>
<!-- $$$donutbreakdown-description -->
<div class="descr"> <a name="details"></a>
<p class="centerAlign"><img src="images/examples_donutbreakdown.png" alt="" /></p><a name="running-the-example"></a>
<h2 id="running-the-example">Running the Example</h2>
<p>To run the example from Qt Creator, open the <b>Welcome</b> mode and select the example from <b>Examples</b>. For more information, visit Building and Running an Example.</p>
<a name="creating-donut-breakdown-charts"></a>
<h2 id="creating-donut-breakdown-charts">Creating Donut Breakdown Charts</h2>
<p>Let's start by defining some data for the chart.</p>
<pre class="cpp">
<span class="comment">// Graph is based on data of 'Total consumption of energy increased by 10 per cent in 2010'</span>
<span class="comment">// Statistics Finland, 13 December 2011</span>
<span class="comment">// http://www.stat.fi/til/ekul/2010/ekul_2010_2011-12-13_tie_001_en.html</span>
<span class="type"><a href="qpieseries.html">QPieSeries</a></span> <span class="operator">*</span>series1 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qpieseries.html">QPieSeries</a></span>();
series1<span class="operator">-</span><span class="operator">></span>setName(<span class="string">"Fossil fuels"</span>);
series1<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Oil"</span><span class="operator">,</span> <span class="number">353295</span>);
series1<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Coal"</span><span class="operator">,</span> <span class="number">188500</span>);
series1<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Natural gas"</span><span class="operator">,</span> <span class="number">148680</span>);
series1<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Peat"</span><span class="operator">,</span> <span class="number">94545</span>);
<span class="type"><a href="qpieseries.html">QPieSeries</a></span> <span class="operator">*</span>series2 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qpieseries.html">QPieSeries</a></span>();
series2<span class="operator">-</span><span class="operator">></span>setName(<span class="string">"Renewables"</span>);
series2<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Wood fuels"</span><span class="operator">,</span> <span class="number">319663</span>);
series2<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Hydro power"</span><span class="operator">,</span> <span class="number">45875</span>);
series2<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Wind power"</span><span class="operator">,</span> <span class="number">1060</span>);
<span class="type"><a href="qpieseries.html">QPieSeries</a></span> <span class="operator">*</span>series3 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qpieseries.html">QPieSeries</a></span>();
series3<span class="operator">-</span><span class="operator">></span>setName(<span class="string">"Others"</span>);
series3<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Nuclear energy"</span><span class="operator">,</span> <span class="number">238789</span>);
series3<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Import energy"</span><span class="operator">,</span> <span class="number">37802</span>);
series3<span class="operator">-</span><span class="operator">></span>append(<span class="string">"Other"</span><span class="operator">,</span> <span class="number">32441</span>);
</pre>
<p>Then we create a chart where we add the data. Note that this is our own chart derived from <a href="qchart.html">QChart</a>.</p>
<pre class="cpp">
DonutBreakdownChart <span class="operator">*</span>donutBreakdown <span class="operator">=</span> <span class="keyword">new</span> DonutBreakdownChart();
donutBreakdown<span class="operator">-</span><span class="operator">></span>setAnimationOptions(<span class="type"><a href="qchart.html">QChart</a></span><span class="operator">::</span>AllAnimations);
donutBreakdown<span class="operator">-</span><span class="operator">></span>setTitle(<span class="string">"Total consumption of energy in Finland 2010"</span>);
donutBreakdown<span class="operator">-</span><span class="operator">></span>legend()<span class="operator">-</span><span class="operator">></span>setAlignment(<span class="type">Qt</span><span class="operator">::</span>AlignRight);
donutBreakdown<span class="operator">-</span><span class="operator">></span>addBreakdownSeries(series1<span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>red);
donutBreakdown<span class="operator">-</span><span class="operator">></span>addBreakdownSeries(series2<span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>darkGreen);
donutBreakdown<span class="operator">-</span><span class="operator">></span>addBreakdownSeries(series3<span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>darkBlue);
</pre>
<p>Our own chart works in such a way that we create a main series in the constructor we create a main series, which aggregates the data provided by the breakdown series. This is the piechart in the center.</p>
<pre class="cpp">
DonutBreakdownChart<span class="operator">::</span>DonutBreakdownChart(<span class="type">QGraphicsItem</span> <span class="operator">*</span>parent<span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>WindowFlags wFlags)
: <span class="type"><a href="qchart.html">QChart</a></span>(<span class="type"><a href="qchart.html">QChart</a></span><span class="operator">::</span>ChartTypeCartesian<span class="operator">,</span> parent<span class="operator">,</span> wFlags)
{
<span class="comment">// create the series for main center pie</span>
m_mainSeries <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qpieseries.html">QPieSeries</a></span>();
m_mainSeries<span class="operator">-</span><span class="operator">></span>setPieSize(<span class="number">0.7</span>);
<span class="type"><a href="qchart.html">QChart</a></span><span class="operator">::</span>addSeries(m_mainSeries);
}
</pre>
<p>When a breakdown series is added the data is used to create a slice in the main series and the breakdown series itself is used to create a segment of a donut positioned so that it is aligned with the corresponding slice in the main series.</p>
<pre class="cpp">
<span class="type">void</span> DonutBreakdownChart<span class="operator">::</span>addBreakdownSeries(<span class="type"><a href="qpieseries.html">QPieSeries</a></span> <span class="operator">*</span>breakdownSeries<span class="operator">,</span> <span class="type">QColor</span> color)
{
<span class="type">QFont</span> font(<span class="string">"Arial"</span><span class="operator">,</span> <span class="number">8</span>);
<span class="comment">// add breakdown series as a slice to center pie</span>
MainSlice <span class="operator">*</span>mainSlice <span class="operator">=</span> <span class="keyword">new</span> MainSlice(breakdownSeries);
mainSlice<span class="operator">-</span><span class="operator">></span>setName(breakdownSeries<span class="operator">-</span><span class="operator">></span>name());
mainSlice<span class="operator">-</span><span class="operator">></span>setValue(breakdownSeries<span class="operator">-</span><span class="operator">></span>sum());
m_mainSeries<span class="operator">-</span><span class="operator">></span>append(mainSlice);
<span class="comment">// customize the slice</span>
mainSlice<span class="operator">-</span><span class="operator">></span>setBrush(color);
mainSlice<span class="operator">-</span><span class="operator">></span>setLabelVisible();
mainSlice<span class="operator">-</span><span class="operator">></span>setLabelColor(<span class="type">Qt</span><span class="operator">::</span>white);
mainSlice<span class="operator">-</span><span class="operator">></span>setLabelPosition(<span class="type"><a href="qpieslice.html">QPieSlice</a></span><span class="operator">::</span>LabelInsideHorizontal);
mainSlice<span class="operator">-</span><span class="operator">></span>setLabelFont(font);
<span class="comment">// position and customize the breakdown series</span>
breakdownSeries<span class="operator">-</span><span class="operator">></span>setPieSize(<span class="number">0.8</span>);
breakdownSeries<span class="operator">-</span><span class="operator">></span>setHoleSize(<span class="number">0.7</span>);
breakdownSeries<span class="operator">-</span><span class="operator">></span>setLabelsVisible();
<span class="keyword">const</span> <span class="keyword">auto</span> slices <span class="operator">=</span> breakdownSeries<span class="operator">-</span><span class="operator">></span>slices();
<span class="keyword">for</span> (<span class="type"><a href="qpieslice.html">QPieSlice</a></span> <span class="operator">*</span>slice : slices) {
color <span class="operator">=</span> color<span class="operator">.</span>lighter(<span class="number">115</span>);
slice<span class="operator">-</span><span class="operator">></span>setBrush(color);
slice<span class="operator">-</span><span class="operator">></span>setLabelFont(font);
}
<span class="comment">// add the series to the chart</span>
<span class="type"><a href="qchart.html">QChart</a></span><span class="operator">::</span>addSeries(breakdownSeries);
<span class="comment">// recalculate breakdown donut segments</span>
recalculateAngles();
<span class="comment">// update customize legend markers</span>
updateLegendMarkers();
}
</pre>
<p>Here's how the start and end angles for the donut segments are calculated.</p>
<pre class="cpp">
<span class="type">void</span> DonutBreakdownChart<span class="operator">::</span>recalculateAngles()
{
<span class="type">qreal</span> angle <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">const</span> <span class="keyword">auto</span> slices <span class="operator">=</span> m_mainSeries<span class="operator">-</span><span class="operator">></span>slices();
<span class="keyword">for</span> (<span class="type"><a href="qpieslice.html">QPieSlice</a></span> <span class="operator">*</span>slice : slices) {
<span class="type"><a href="qpieseries.html">QPieSeries</a></span> <span class="operator">*</span>breakdownSeries <span class="operator">=</span> qobject_cast<span class="operator"><</span>MainSlice <span class="operator">*</span><span class="operator">></span>(slice)<span class="operator">-</span><span class="operator">></span>breakdownSeries();
breakdownSeries<span class="operator">-</span><span class="operator">></span>setPieStartAngle(angle);
angle <span class="operator">+</span><span class="operator">=</span> slice<span class="operator">-</span><span class="operator">></span>percentage() <span class="operator">*</span> <span class="number">360.0</span>; <span class="comment">// full pie is 360.0</span>
breakdownSeries<span class="operator">-</span><span class="operator">></span>setPieEndAngle(angle);
}
}
</pre>
<p>The legend markers are customized to show the breakdown percentage. The markers for the main level slices are hidden.</p>
<pre class="cpp">
<span class="type">void</span> DonutBreakdownChart<span class="operator">::</span>updateLegendMarkers()
{
<span class="comment">// go through all markers</span>
<span class="keyword">const</span> <span class="keyword">auto</span> allseries <span class="operator">=</span> series();
<span class="keyword">for</span> (<span class="type"><a href="qabstractseries.html">QAbstractSeries</a></span> <span class="operator">*</span>series : allseries) {
<span class="keyword">const</span> <span class="keyword">auto</span> markers <span class="operator">=</span> legend()<span class="operator">-</span><span class="operator">></span>markers(series);
<span class="keyword">for</span> (<span class="type"><a href="qlegendmarker.html">QLegendMarker</a></span> <span class="operator">*</span>marker : markers) {
<span class="type"><a href="qpielegendmarker.html">QPieLegendMarker</a></span> <span class="operator">*</span>pieMarker <span class="operator">=</span> qobject_cast<span class="operator"><</span><span class="type"><a href="qpielegendmarker.html">QPieLegendMarker</a></span> <span class="operator">*</span><span class="operator">></span>(marker);
<span class="keyword">if</span> (series <span class="operator">=</span><span class="operator">=</span> m_mainSeries) {
<span class="comment">// hide markers from main series</span>
pieMarker<span class="operator">-</span><span class="operator">></span>setVisible(<span class="keyword">false</span>);
} <span class="keyword">else</span> {
<span class="comment">// modify markers from breakdown series</span>
pieMarker<span class="operator">-</span><span class="operator">></span>setLabel(<span class="type">QString</span>(<span class="string">"%1 %2%"</span>)
<span class="operator">.</span>arg(pieMarker<span class="operator">-</span><span class="operator">></span>slice()<span class="operator">-</span><span class="operator">></span>label())
<span class="operator">.</span>arg(pieMarker<span class="operator">-</span><span class="operator">></span>slice()<span class="operator">-</span><span class="operator">></span>percentage() <span class="operator">*</span> <span class="number">100</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="char">'f'</span><span class="operator">,</span> <span class="number">2</span>));
pieMarker<span class="operator">-</span><span class="operator">></span>setFont(<span class="type">QFont</span>(<span class="string">"Arial"</span><span class="operator">,</span> <span class="number">8</span>));
}
}
}
}
</pre>
<p>Instead the main level slices show the percentage on the label.</p>
<pre class="cpp">
MainSlice<span class="operator">::</span>MainSlice(<span class="type"><a href="qpieseries.html">QPieSeries</a></span> <span class="operator">*</span>breakdownSeries<span class="operator">,</span> <span class="type">QObject</span> <span class="operator">*</span>parent)
: <span class="type"><a href="qpieslice.html">QPieSlice</a></span>(parent)<span class="operator">,</span>
m_breakdownSeries(breakdownSeries)
{
connect(<span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>MainSlice<span class="operator">::</span>percentageChanged<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>MainSlice<span class="operator">::</span>updateLabel);
}
<span class="type">void</span> MainSlice<span class="operator">::</span>updateLabel()
{
<span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>setLabel(<span class="type">QString</span>(<span class="string">"%1 %2%"</span>)<span class="operator">.</span>arg(m_name)<span class="operator">.</span>arg(percentage() <span class="operator">*</span> <span class="number">100</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="char">'f'</span><span class="operator">,</span> <span class="number">2</span>));
}
</pre>
<p>Now that we have our chart defined, we can finally create a <a href="qchartview.html">QChartView</a> and show the chart.</p>
<pre class="cpp">
<span class="type">QMainWindow</span> window;
<span class="type"><a href="qchartview.html">QChartView</a></span> <span class="operator">*</span>chartView <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qchartview.html">QChartView</a></span>(donutBreakdown);
chartView<span class="operator">-</span><span class="operator">></span>setRenderHint(<span class="type">QPainter</span><span class="operator">::</span>Antialiasing);
window<span class="operator">.</span>setCentralWidget(chartView);
window<span class="operator">.</span>resize(<span class="number">800</span><span class="operator">,</span> <span class="number">500</span>);
window<span class="operator">.</span>show();
</pre>
<p>Files:</p>
<ul>
<li><a href="qtcharts-donutbreakdown-donutbreakdownchart-cpp.html">donutbreakdown/donutbreakdownchart.cpp</a></li>
<li><a href="qtcharts-donutbreakdown-donutbreakdownchart-h.html">donutbreakdown/donutbreakdownchart.h</a></li>
<li><a href="qtcharts-donutbreakdown-mainslice-cpp.html">donutbreakdown/mainslice.cpp</a></li>
<li><a href="qtcharts-donutbreakdown-mainslice-h.html">donutbreakdown/mainslice.h</a></li>
<li><a href="qtcharts-donutbreakdown-main-cpp.html">donutbreakdown/main.cpp</a></li>
<li><a href="qtcharts-donutbreakdown-donutbreakdown-pro.html">donutbreakdown/donutbreakdown.pro</a></li>
</ul>
</div>
<!-- @@@donutbreakdown -->
</div>
</div>
</div>
</div>
</div>
<div class="footer">
<p>
<acronym title="Copyright">©</acronym> 2017 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>
|