source: trunk/doc/html/chart-chartform_canvas-cpp.html

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32<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>chart/chartform_canvas.cpp Example File</h1>
33
34
35<pre>#include "canvastext.h"
36#include "chartform.h"
37
38#include &lt;<a href="qbrush-h.html">qbrush.h</a>&gt;
39#include &lt;<a href="qcanvas-h.html">qcanvas.h</a>&gt;
40
41#include &lt;math.h&gt; // sin, cos
42
43#ifndef M_PI
44#define M_PI 3.1415
45#endif
46
47void <a name="f167"></a>ChartForm::drawElements()
48{
49 <a href="qcanvasitemlist.html">QCanvasItemList</a> list = m_canvas-&gt;allItems();
50 for ( QCanvasItemList::iterator it = list.<a href="qvaluelist.html#begin">begin</a>(); it != list.<a href="qvaluelist.html#end">end</a>(); ++it )
51 delete *it;
52
53 // 360 * 16 for pies; Qt works with 16ths of degrees
54 int scaleFactor = m_chartType == PIE ? 5760 :
55 m_chartType == VERTICAL_BAR ? m_canvas-&gt;height() :
56 m_canvas-&gt;width();
57 double biggest = 0.0;
58 int count = 0;
59 double total = 0.0;
60 static double scales[MAX_ELEMENTS];
61
62 for ( int i = 0; i &lt; MAX_ELEMENTS; ++i ) {
63 if ( m_elements[i].isValid() ) {
64 double value = m_elements[i].value();
65 count++;
66 total += value;
67 if ( value &gt; biggest )
68 biggest = value;
69 scales[i] = m_elements[i].value() * scaleFactor;
70 }
71 }
72
73 if ( count ) {
74 // 2nd loop because of total and biggest
75 for ( int i = 0; i &lt; MAX_ELEMENTS; ++i )
76 if ( m_elements[i].isValid() )
77 if ( m_chartType == PIE )
78 scales[i] = (m_elements[i].value() * scaleFactor) / total;
79 else
80 scales[i] = (m_elements[i].value() * scaleFactor) / biggest;
81
82 switch ( m_chartType ) {
83 case PIE:
84 drawPieChart( scales, total, count );
85 break;
86 case VERTICAL_BAR:
87 drawVerticalBarChart( scales, total, count );
88 break;
89 case HORIZONTAL_BAR:
90 drawHorizontalBarChart( scales, total, count );
91 break;
92 }
93 }
94
95 m_canvas-&gt;update();
96}
97
98
99void <a name="f168"></a>ChartForm::drawPieChart( const double scales[], double total, int )
100{
101 double width = m_canvas-&gt;width();
102 double height = m_canvas-&gt;height();
103 int size = int(width &gt; height ? height : width);
104 int x = int(width / 2);
105 int y = int(height / 2);
106 int angle = 0;
107
108 for ( int i = 0; i &lt; MAX_ELEMENTS; ++i ) {
109 if ( m_elements[i].isValid() ) {
110 int extent = int(scales[i]);
111 <a href="qcanvasellipse.html">QCanvasEllipse</a> *arc = new <a href="qcanvasellipse.html">QCanvasEllipse</a>(
112 size, size, angle, extent, m_canvas );
113 arc-&gt;<a href="qcanvasitem.html#setX">setX</a>( x );
114 arc-&gt;<a href="qcanvasitem.html#setY">setY</a>( y );
115 arc-&gt;<a href="qcanvasitem.html#setZ">setZ</a>( 0 );
116 arc-&gt;<a href="qcanvaspolygonalitem.html#setBrush">setBrush</a>( QBrush( m_elements[i].valueColor(),
117 BrushStyle(m_elements[i].valuePattern()) ) );
118 arc-&gt;<a href="qcanvasitem.html#show">show</a>();
119 angle += extent;
120 <a href="qstring.html">QString</a> label = m_elements[i].label();
121 if ( !label.<a href="qstring.html#isEmpty">isEmpty</a>() || m_addValues != NO ) {
122 label = valueLabel( label, m_elements[i].value(), total );
123 CanvasText *text = new CanvasText( i, label, m_font, m_canvas );
124 double proX = m_elements[i].proX( PIE );
125 double proY = m_elements[i].proY( PIE );
126 if ( proX &lt; 0 || proY &lt; 0 ) {
127 // Find the centre of the pie segment
128 <a href="qrect.html">QRect</a> rect = arc-&gt;<a href="qcanvaspolygonalitem.html#boundingRect">boundingRect</a>();
129 proX = ( rect.<a href="qcanvasrectangle.html#width">width</a>() / 2 ) + rect.<a href="qcanvasitem.html#x">x</a>();
130 proY = ( rect.<a href="qcanvasrectangle.html#height">height</a>() / 2 ) + rect.<a href="qcanvasitem.html#y">y</a>();
131 // Centre text over the centre of the pie segment
132 rect = text-&gt;<a href="qcanvastext.html#boundingRect">boundingRect</a>();
133 proX -= ( rect.<a href="qcanvasrectangle.html#width">width</a>() / 2 );
134 proY -= ( rect.<a href="qcanvasrectangle.html#height">height</a>() / 2 );
135 // Make proportional
136 proX /= width;
137 proY /= height;
138 }
139 text-&gt;<a href="qcanvastext.html#setColor">setColor</a>( m_elements[i].labelColor() );
140 text-&gt;<a href="qcanvasitem.html#setX">setX</a>( proX * width );
141 text-&gt;<a href="qcanvasitem.html#setY">setY</a>( proY * height );
142 text-&gt;<a href="qcanvasitem.html#setZ">setZ</a>( 1 );
143 text-&gt;<a href="qcanvasitem.html#show">show</a>();
144 m_elements[i].setProX( PIE, proX );
145 m_elements[i].setProY( PIE, proY );
146 }
147 }
148 }
149}
150
151
152void <a name="f169"></a>ChartForm::drawVerticalBarChart(
153 const double scales[], double total, int count )
154{
155 double width = m_canvas-&gt;width();
156 double height = m_canvas-&gt;height();
157 int prowidth = int(width / count);
158 int x = 0;
159 <a href="qpen.html">QPen</a> pen;
160 pen.<a href="qpen.html#setStyle">setStyle</a>( NoPen );
161
162 for ( int i = 0; i &lt; MAX_ELEMENTS; ++i ) {
163 if ( m_elements[i].isValid() ) {
164 int extent = int(scales[i]);
165 int y = int(height - extent);
166 <a href="qcanvasrectangle.html">QCanvasRectangle</a> *rect = new <a href="qcanvasrectangle.html">QCanvasRectangle</a>(
167 x, y, prowidth, extent, m_canvas );
168 rect-&gt;<a href="qcanvaspolygonalitem.html#setBrush">setBrush</a>( QBrush( m_elements[i].valueColor(),
169 BrushStyle(m_elements[i].valuePattern()) ) );
170 rect-&gt;<a href="qcanvaspolygonalitem.html#setPen">setPen</a>( pen );
171 rect-&gt;<a href="qcanvasitem.html#setZ">setZ</a>( 0 );
172 rect-&gt;<a href="qcanvasitem.html#show">show</a>();
173 <a href="qstring.html">QString</a> label = m_elements[i].label();
174 if ( !label.<a href="qstring.html#isEmpty">isEmpty</a>() || m_addValues != NO ) {
175 double proX = m_elements[i].proX( VERTICAL_BAR );
176 double proY = m_elements[i].proY( VERTICAL_BAR );
177 if ( proX &lt; 0 || proY &lt; 0 ) {
178 proX = x / width;
179 proY = y / height;
180 }
181 label = valueLabel( label, m_elements[i].value(), total );
182 CanvasText *text = new CanvasText( i, label, m_font, m_canvas );
183 text-&gt;<a href="qcanvastext.html#setColor">setColor</a>( m_elements[i].labelColor() );
184 text-&gt;<a href="qcanvasitem.html#setX">setX</a>( proX * width );
185 text-&gt;<a href="qcanvasitem.html#setY">setY</a>( proY * height );
186 text-&gt;<a href="qcanvasitem.html#setZ">setZ</a>( 1 );
187 text-&gt;<a href="qcanvasitem.html#show">show</a>();
188 m_elements[i].setProX( VERTICAL_BAR, proX );
189 m_elements[i].setProY( VERTICAL_BAR, proY );
190 }
191 x += prowidth;
192 }
193 }
194}
195
196
197void <a name="f170"></a>ChartForm::drawHorizontalBarChart(
198 const double scales[], double total, int count )
199{
200 double width = m_canvas-&gt;width();
201 double height = m_canvas-&gt;height();
202 int proheight = int(height / count);
203 int y = 0;
204 <a href="qpen.html">QPen</a> pen;
205 pen.<a href="qpen.html#setStyle">setStyle</a>( NoPen );
206
207 for ( int i = 0; i &lt; MAX_ELEMENTS; ++i ) {
208 if ( m_elements[i].isValid() ) {
209 int extent = int(scales[i]);
210 <a href="qcanvasrectangle.html">QCanvasRectangle</a> *rect = new <a href="qcanvasrectangle.html">QCanvasRectangle</a>(
211 0, y, extent, proheight, m_canvas );
212 rect-&gt;<a href="qcanvaspolygonalitem.html#setBrush">setBrush</a>( QBrush( m_elements[i].valueColor(),
213 BrushStyle(m_elements[i].valuePattern()) ) );
214 rect-&gt;<a href="qcanvaspolygonalitem.html#setPen">setPen</a>( pen );
215 rect-&gt;<a href="qcanvasitem.html#setZ">setZ</a>( 0 );
216 rect-&gt;<a href="qcanvasitem.html#show">show</a>();
217 <a href="qstring.html">QString</a> label = m_elements[i].label();
218 if ( !label.<a href="qstring.html#isEmpty">isEmpty</a>() || m_addValues != NO ) {
219 double proX = m_elements[i].proX( HORIZONTAL_BAR );
220 double proY = m_elements[i].proY( HORIZONTAL_BAR );
221 if ( proX &lt; 0 || proY &lt; 0 ) {
222 proX = 0;
223 proY = y / height;
224 }
225 label = valueLabel( label, m_elements[i].value(), total );
226 CanvasText *text = new CanvasText( i, label, m_font, m_canvas );
227 text-&gt;<a href="qcanvastext.html#setColor">setColor</a>( m_elements[i].labelColor() );
228 text-&gt;<a href="qcanvasitem.html#setX">setX</a>( proX * width );
229 text-&gt;<a href="qcanvasitem.html#setY">setY</a>( proY * height );
230 text-&gt;<a href="qcanvasitem.html#setZ">setZ</a>( 1 );
231 text-&gt;<a href="qcanvasitem.html#show">show</a>();
232 m_elements[i].setProX( HORIZONTAL_BAR, proX );
233 m_elements[i].setProY( HORIZONTAL_BAR, proY );
234 }
235 y += proheight;
236 }
237 }
238}
239
240
241QString <a name="f171"></a>ChartForm::valueLabel(
242 const <a href="qstring.html">QString</a>&amp; label, double value, double total )
243{
244 if ( m_addValues == NO )
245 return label;
246
247 <a href="qstring.html">QString</a> newLabel = label;
248 if ( !label.<a href="qstring.html#isEmpty">isEmpty</a>() )
249 if ( m_chartType == VERTICAL_BAR )
250 newLabel += '\n';
251 else
252 newLabel += ' ';
253 if ( m_addValues == YES )
254 newLabel += QString::<a href="qstring.html#number">number</a>( value, 'f', m_decimalPlaces );
255 else if ( m_addValues == AS_PERCENTAGE )
256 newLabel += QString::<a href="qstring.html#number">number</a>( (value / total) * 100, 'f', m_decimalPlaces )
257 + '%';
258 return newLabel;
259}
260
261</pre><!-- eof -->
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264<td>Copyright &copy; 2007
265<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a>
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