source: trunk/examples/chart/chartform_canvas.cpp

Last change on this file was 160, checked in by dmik, 19 years ago

Imported table and iconview modules and a bunch of dependent examples from the official release 3.3.1 from Trolltech.
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File size: 6.5 KB
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1#include "canvastext.h"
2#include "chartform.h"
3
4#include <qbrush.h>
5#include <qcanvas.h>
6
7#include <math.h> // sin, cos
8
9#ifndef M_PI
10#define M_PI 3.1415
11#endif
12
13void ChartForm::drawElements()
14{
15 QCanvasItemList list = m_canvas->allItems();
16 for ( QCanvasItemList::iterator it = list.begin(); it != list.end(); ++it )
17 delete *it;
18
19 // 360 * 16 for pies; Qt works with 16ths of degrees
20 int scaleFactor = m_chartType == PIE ? 5760 :
21 m_chartType == VERTICAL_BAR ? m_canvas->height() :
22 m_canvas->width();
23 double biggest = 0.0;
24 int count = 0;
25 double total = 0.0;
26 static double scales[MAX_ELEMENTS];
27
28 for ( int i = 0; i < MAX_ELEMENTS; ++i ) {
29 if ( m_elements[i].isValid() ) {
30 double value = m_elements[i].value();
31 count++;
32 total += value;
33 if ( value > biggest )
34 biggest = value;
35 scales[i] = m_elements[i].value() * scaleFactor;
36 }
37 }
38
39 if ( count ) {
40 // 2nd loop because of total and biggest
41 for ( int i = 0; i < MAX_ELEMENTS; ++i )
42 if ( m_elements[i].isValid() )
43 if ( m_chartType == PIE )
44 scales[i] = (m_elements[i].value() * scaleFactor) / total;
45 else
46 scales[i] = (m_elements[i].value() * scaleFactor) / biggest;
47
48 switch ( m_chartType ) {
49 case PIE:
50 drawPieChart( scales, total, count );
51 break;
52 case VERTICAL_BAR:
53 drawVerticalBarChart( scales, total, count );
54 break;
55 case HORIZONTAL_BAR:
56 drawHorizontalBarChart( scales, total, count );
57 break;
58 }
59 }
60
61 m_canvas->update();
62}
63
64
65void ChartForm::drawPieChart( const double scales[], double total, int )
66{
67 double width = m_canvas->width();
68 double height = m_canvas->height();
69 int size = int(width > height ? height : width);
70 int x = int(width / 2);
71 int y = int(height / 2);
72 int angle = 0;
73
74 for ( int i = 0; i < MAX_ELEMENTS; ++i ) {
75 if ( m_elements[i].isValid() ) {
76 int extent = int(scales[i]);
77 QCanvasEllipse *arc = new QCanvasEllipse(
78 size, size, angle, extent, m_canvas );
79 arc->setX( x );
80 arc->setY( y );
81 arc->setZ( 0 );
82 arc->setBrush( QBrush( m_elements[i].valueColor(),
83 BrushStyle(m_elements[i].valuePattern()) ) );
84 arc->show();
85 angle += extent;
86 QString label = m_elements[i].label();
87 if ( !label.isEmpty() || m_addValues != NO ) {
88 label = valueLabel( label, m_elements[i].value(), total );
89 CanvasText *text = new CanvasText( i, label, m_font, m_canvas );
90 double proX = m_elements[i].proX( PIE );
91 double proY = m_elements[i].proY( PIE );
92 if ( proX < 0 || proY < 0 ) {
93 // Find the centre of the pie segment
94 QRect rect = arc->boundingRect();
95 proX = ( rect.width() / 2 ) + rect.x();
96 proY = ( rect.height() / 2 ) + rect.y();
97 // Centre text over the centre of the pie segment
98 rect = text->boundingRect();
99 proX -= ( rect.width() / 2 );
100 proY -= ( rect.height() / 2 );
101 // Make proportional
102 proX /= width;
103 proY /= height;
104 }
105 text->setColor( m_elements[i].labelColor() );
106 text->setX( proX * width );
107 text->setY( proY * height );
108 text->setZ( 1 );
109 text->show();
110 m_elements[i].setProX( PIE, proX );
111 m_elements[i].setProY( PIE, proY );
112 }
113 }
114 }
115}
116
117
118void ChartForm::drawVerticalBarChart(
119 const double scales[], double total, int count )
120{
121 double width = m_canvas->width();
122 double height = m_canvas->height();
123 int prowidth = int(width / count);
124 int x = 0;
125 QPen pen;
126 pen.setStyle( NoPen );
127
128 for ( int i = 0; i < MAX_ELEMENTS; ++i ) {
129 if ( m_elements[i].isValid() ) {
130 int extent = int(scales[i]);
131 int y = int(height - extent);
132 QCanvasRectangle *rect = new QCanvasRectangle(
133 x, y, prowidth, extent, m_canvas );
134 rect->setBrush( QBrush( m_elements[i].valueColor(),
135 BrushStyle(m_elements[i].valuePattern()) ) );
136 rect->setPen( pen );
137 rect->setZ( 0 );
138 rect->show();
139 QString label = m_elements[i].label();
140 if ( !label.isEmpty() || m_addValues != NO ) {
141 double proX = m_elements[i].proX( VERTICAL_BAR );
142 double proY = m_elements[i].proY( VERTICAL_BAR );
143 if ( proX < 0 || proY < 0 ) {
144 proX = x / width;
145 proY = y / height;
146 }
147 label = valueLabel( label, m_elements[i].value(), total );
148 CanvasText *text = new CanvasText( i, label, m_font, m_canvas );
149 text->setColor( m_elements[i].labelColor() );
150 text->setX( proX * width );
151 text->setY( proY * height );
152 text->setZ( 1 );
153 text->show();
154 m_elements[i].setProX( VERTICAL_BAR, proX );
155 m_elements[i].setProY( VERTICAL_BAR, proY );
156 }
157 x += prowidth;
158 }
159 }
160}
161
162
163void ChartForm::drawHorizontalBarChart(
164 const double scales[], double total, int count )
165{
166 double width = m_canvas->width();
167 double height = m_canvas->height();
168 int proheight = int(height / count);
169 int y = 0;
170 QPen pen;
171 pen.setStyle( NoPen );
172
173 for ( int i = 0; i < MAX_ELEMENTS; ++i ) {
174 if ( m_elements[i].isValid() ) {
175 int extent = int(scales[i]);
176 QCanvasRectangle *rect = new QCanvasRectangle(
177 0, y, extent, proheight, m_canvas );
178 rect->setBrush( QBrush( m_elements[i].valueColor(),
179 BrushStyle(m_elements[i].valuePattern()) ) );
180 rect->setPen( pen );
181 rect->setZ( 0 );
182 rect->show();
183 QString label = m_elements[i].label();
184 if ( !label.isEmpty() || m_addValues != NO ) {
185 double proX = m_elements[i].proX( HORIZONTAL_BAR );
186 double proY = m_elements[i].proY( HORIZONTAL_BAR );
187 if ( proX < 0 || proY < 0 ) {
188 proX = 0;
189 proY = y / height;
190 }
191 label = valueLabel( label, m_elements[i].value(), total );
192 CanvasText *text = new CanvasText( i, label, m_font, m_canvas );
193 text->setColor( m_elements[i].labelColor() );
194 text->setX( proX * width );
195 text->setY( proY * height );
196 text->setZ( 1 );
197 text->show();
198 m_elements[i].setProX( HORIZONTAL_BAR, proX );
199 m_elements[i].setProY( HORIZONTAL_BAR, proY );
200 }
201 y += proheight;
202 }
203 }
204}
205
206
207QString ChartForm::valueLabel(
208 const QString& label, double value, double total )
209{
210 if ( m_addValues == NO )
211 return label;
212
213 QString newLabel = label;
214 if ( !label.isEmpty() )
215 if ( m_chartType == VERTICAL_BAR )
216 newLabel += '\n';
217 else
218 newLabel += ' ';
219 if ( m_addValues == YES )
220 newLabel += QString::number( value, 'f', m_decimalPlaces );
221 else if ( m_addValues == AS_PERCENTAGE )
222 newLabel += QString::number( (value / total) * 100, 'f', m_decimalPlaces )
223 + '%';
224 return newLabel;
225}
226
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