source: trunk/examples/widgets/calculator/calculator.cpp@ 16

Last change on this file since 16 was 2, checked in by Dmitry A. Kuminov, 16 years ago

Initially imported qt-all-opensource-src-4.5.1 from Trolltech.
File size: 11.0 KB
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1/****************************************************************************
2**
3** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
4** Contact: Qt Software Information ([email protected])
5**
6** This file is part of the examples of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:LGPL$
9** Commercial Usage
10** Licensees holding valid Qt Commercial licenses may use this file in
11** accordance with the Qt Commercial License Agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and Nokia.
14**
15** GNU Lesser General Public License Usage
16** Alternatively, this file may be used under the terms of the GNU Lesser
17** General Public License version 2.1 as published by the Free Software
18** Foundation and appearing in the file LICENSE.LGPL included in the
19** packaging of this file. Please review the following information to
20** ensure the GNU Lesser General Public License version 2.1 requirements
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23** In addition, as a special exception, Nokia gives you certain
24** additional rights. These rights are described in the Nokia Qt LGPL
25** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
26** package.
27**
28** GNU General Public License Usage
29** Alternatively, this file may be used under the terms of the GNU
30** General Public License version 3.0 as published by the Free Software
31** Foundation and appearing in the file LICENSE.GPL included in the
32** packaging of this file. Please review the following information to
33** ensure the GNU General Public License version 3.0 requirements will be
34** met: http://www.gnu.org/copyleft/gpl.html.
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36** If you are unsure which license is appropriate for your use, please
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40****************************************************************************/
41
42#include <QtGui>
43
44#include <math.h>
45
46#include "button.h"
47#include "calculator.h"
48
49//! [0]
50Calculator::Calculator(QWidget *parent)
51 : QDialog(parent)
52{
53 sumInMemory = 0.0;
54 sumSoFar = 0.0;
55 factorSoFar = 0.0;
56 waitingForOperand = true;
57//! [0]
58
59//! [1]
60 display = new QLineEdit("0");
61//! [1] //! [2]
62 display->setReadOnly(true);
63 display->setAlignment(Qt::AlignRight);
64 display->setMaxLength(15);
65
66 QFont font = display->font();
67 font.setPointSize(font.pointSize() + 8);
68 display->setFont(font);
69//! [2]
70
71//! [4]
72 for (int i = 0; i < NumDigitButtons; ++i) {
73 digitButtons[i] = createButton(QString::number(i), SLOT(digitClicked()));
74 }
75
76 Button *pointButton = createButton(tr("."), SLOT(pointClicked()));
77 Button *changeSignButton = createButton(tr("\261"), SLOT(changeSignClicked()));
78
79 Button *backspaceButton = createButton(tr("Backspace"), SLOT(backspaceClicked()));
80 Button *clearButton = createButton(tr("Clear"), SLOT(clear()));
81 Button *clearAllButton = createButton(tr("Clear All"), SLOT(clearAll()));
82
83 Button *clearMemoryButton = createButton(tr("MC"), SLOT(clearMemory()));
84 Button *readMemoryButton = createButton(tr("MR"), SLOT(readMemory()));
85 Button *setMemoryButton = createButton(tr("MS"), SLOT(setMemory()));
86 Button *addToMemoryButton = createButton(tr("M+"), SLOT(addToMemory()));
87
88 Button *divisionButton = createButton(tr("\367"), SLOT(multiplicativeOperatorClicked()));
89 Button *timesButton = createButton(tr("\327"), SLOT(multiplicativeOperatorClicked()));
90 Button *minusButton = createButton(tr("-"), SLOT(additiveOperatorClicked()));
91 Button *plusButton = createButton(tr("+"), SLOT(additiveOperatorClicked()));
92
93 Button *squareRootButton = createButton(tr("Sqrt"), SLOT(unaryOperatorClicked()));
94 Button *powerButton = createButton(tr("x\262"), SLOT(unaryOperatorClicked()));
95 Button *reciprocalButton = createButton(tr("1/x"), SLOT(unaryOperatorClicked()));
96 Button *equalButton = createButton(tr("="), SLOT(equalClicked()));
97//! [4]
98
99//! [5]
100 QGridLayout *mainLayout = new QGridLayout;
101//! [5] //! [6]
102 mainLayout->setSizeConstraint(QLayout::SetFixedSize);
103
104 mainLayout->addWidget(display, 0, 0, 1, 6);
105 mainLayout->addWidget(backspaceButton, 1, 0, 1, 2);
106 mainLayout->addWidget(clearButton, 1, 2, 1, 2);
107 mainLayout->addWidget(clearAllButton, 1, 4, 1, 2);
108
109 mainLayout->addWidget(clearMemoryButton, 2, 0);
110 mainLayout->addWidget(readMemoryButton, 3, 0);
111 mainLayout->addWidget(setMemoryButton, 4, 0);
112 mainLayout->addWidget(addToMemoryButton, 5, 0);
113
114 for (int i = 1; i < NumDigitButtons; ++i) {
115 int row = ((9 - i) / 3) + 2;
116 int column = ((i - 1) % 3) + 1;
117 mainLayout->addWidget(digitButtons[i], row, column);
118 }
119
120 mainLayout->addWidget(digitButtons[0], 5, 1);
121 mainLayout->addWidget(pointButton, 5, 2);
122 mainLayout->addWidget(changeSignButton, 5, 3);
123
124 mainLayout->addWidget(divisionButton, 2, 4);
125 mainLayout->addWidget(timesButton, 3, 4);
126 mainLayout->addWidget(minusButton, 4, 4);
127 mainLayout->addWidget(plusButton, 5, 4);
128
129 mainLayout->addWidget(squareRootButton, 2, 5);
130 mainLayout->addWidget(powerButton, 3, 5);
131 mainLayout->addWidget(reciprocalButton, 4, 5);
132 mainLayout->addWidget(equalButton, 5, 5);
133 setLayout(mainLayout);
134
135 setWindowTitle(tr("Calculator"));
136}
137//! [6]
138
139//! [7]
140void Calculator::digitClicked()
141{
142 Button *clickedButton = qobject_cast<Button *>(sender());
143 int digitValue = clickedButton->text().toInt();
144 if (display->text() == "0" && digitValue == 0.0)
145 return;
146
147 if (waitingForOperand) {
148 display->clear();
149 waitingForOperand = false;
150 }
151 display->setText(display->text() + QString::number(digitValue));
152}
153//! [7]
154
155//! [8]
156void Calculator::unaryOperatorClicked()
157//! [8] //! [9]
158{
159 Button *clickedButton = qobject_cast<Button *>(sender());
160 QString clickedOperator = clickedButton->text();
161 double operand = display->text().toDouble();
162 double result = 0.0;
163
164 if (clickedOperator == tr("Sqrt")) {
165 if (operand < 0.0) {
166 abortOperation();
167 return;
168 }
169 result = sqrt(operand);
170 } else if (clickedOperator == tr("x\262")) {
171 result = pow(operand, 2.0);
172 } else if (clickedOperator == tr("1/x")) {
173 if (operand == 0.0) {
174 abortOperation();
175 return;
176 }
177 result = 1.0 / operand;
178 }
179 display->setText(QString::number(result));
180 waitingForOperand = true;
181}
182//! [9]
183
184//! [10]
185void Calculator::additiveOperatorClicked()
186//! [10] //! [11]
187{
188 Button *clickedButton = qobject_cast<Button *>(sender());
189 QString clickedOperator = clickedButton->text();
190 double operand = display->text().toDouble();
191
192//! [11] //! [12]
193 if (!pendingMultiplicativeOperator.isEmpty()) {
194//! [12] //! [13]
195 if (!calculate(operand, pendingMultiplicativeOperator)) {
196 abortOperation();
197 return;
198 }
199 display->setText(QString::number(factorSoFar));
200 operand = factorSoFar;
201 factorSoFar = 0.0;
202 pendingMultiplicativeOperator.clear();
203 }
204
205//! [13] //! [14]
206 if (!pendingAdditiveOperator.isEmpty()) {
207//! [14] //! [15]
208 if (!calculate(operand, pendingAdditiveOperator)) {
209 abortOperation();
210 return;
211 }
212 display->setText(QString::number(sumSoFar));
213 } else {
214 sumSoFar = operand;
215 }
216
217//! [15] //! [16]
218 pendingAdditiveOperator = clickedOperator;
219//! [16] //! [17]
220 waitingForOperand = true;
221}
222//! [17]
223
224//! [18]
225void Calculator::multiplicativeOperatorClicked()
226{
227 Button *clickedButton = qobject_cast<Button *>(sender());
228 QString clickedOperator = clickedButton->text();
229 double operand = display->text().toDouble();
230
231 if (!pendingMultiplicativeOperator.isEmpty()) {
232 if (!calculate(operand, pendingMultiplicativeOperator)) {
233 abortOperation();
234 return;
235 }
236 display->setText(QString::number(factorSoFar));
237 } else {
238 factorSoFar = operand;
239 }
240
241 pendingMultiplicativeOperator = clickedOperator;
242 waitingForOperand = true;
243}
244//! [18]
245
246//! [20]
247void Calculator::equalClicked()
248{
249 double operand = display->text().toDouble();
250
251 if (!pendingMultiplicativeOperator.isEmpty()) {
252 if (!calculate(operand, pendingMultiplicativeOperator)) {
253 abortOperation();
254 return;
255 }
256 operand = factorSoFar;
257 factorSoFar = 0.0;
258 pendingMultiplicativeOperator.clear();
259 }
260 if (!pendingAdditiveOperator.isEmpty()) {
261 if (!calculate(operand, pendingAdditiveOperator)) {
262 abortOperation();
263 return;
264 }
265 pendingAdditiveOperator.clear();
266 } else {
267 sumSoFar = operand;
268 }
269
270 display->setText(QString::number(sumSoFar));
271 sumSoFar = 0.0;
272 waitingForOperand = true;
273}
274//! [20]
275
276//! [22]
277void Calculator::pointClicked()
278{
279 if (waitingForOperand)
280 display->setText("0");
281 if (!display->text().contains("."))
282 display->setText(display->text() + tr("."));
283 waitingForOperand = false;
284}
285//! [22]
286
287//! [24]
288void Calculator::changeSignClicked()
289{
290 QString text = display->text();
291 double value = text.toDouble();
292
293 if (value > 0.0) {
294 text.prepend(tr("-"));
295 } else if (value < 0.0) {
296 text.remove(0, 1);
297 }
298 display->setText(text);
299}
300//! [24]
301
302//! [26]
303void Calculator::backspaceClicked()
304{
305 if (waitingForOperand)
306 return;
307
308 QString text = display->text();
309 text.chop(1);
310 if (text.isEmpty()) {
311 text = "0";
312 waitingForOperand = true;
313 }
314 display->setText(text);
315}
316//! [26]
317
318//! [28]
319void Calculator::clear()
320{
321 if (waitingForOperand)
322 return;
323
324 display->setText("0");
325 waitingForOperand = true;
326}
327//! [28]
328
329//! [30]
330void Calculator::clearAll()
331{
332 sumSoFar = 0.0;
333 factorSoFar = 0.0;
334 pendingAdditiveOperator.clear();
335 pendingMultiplicativeOperator.clear();
336 display->setText("0");
337 waitingForOperand = true;
338}
339//! [30]
340
341//! [32]
342void Calculator::clearMemory()
343{
344 sumInMemory = 0.0;
345}
346
347void Calculator::readMemory()
348{
349 display->setText(QString::number(sumInMemory));
350 waitingForOperand = true;
351}
352
353void Calculator::setMemory()
354{
355 equalClicked();
356 sumInMemory = display->text().toDouble();
357}
358
359void Calculator::addToMemory()
360{
361 equalClicked();
362 sumInMemory += display->text().toDouble();
363}
364//! [32]
365//! [34]
366Button *Calculator::createButton(const QString &text, const char *member)
367{
368 Button *button = new Button(text);
369 connect(button, SIGNAL(clicked()), this, member);
370 return button;
371}
372//! [34]
373
374//! [36]
375void Calculator::abortOperation()
376{
377 clearAll();
378 display->setText(tr("####"));
379}
380//! [36]
381
382//! [38]
383bool Calculator::calculate(double rightOperand, const QString &pendingOperator)
384{
385 if (pendingOperator == tr("+")) {
386 sumSoFar += rightOperand;
387 } else if (pendingOperator == tr("-")) {
388 sumSoFar -= rightOperand;
389 } else if (pendingOperator == tr("\327")) {
390 factorSoFar *= rightOperand;
391 } else if (pendingOperator == tr("\367")) {
392 if (rightOperand == 0.0)
393 return false;
394 factorSoFar /= rightOperand;
395 }
396 return true;
397}
398//! [38]
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