<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Qt 4.2: calculator.cpp Example File (widgets/calculator/calculator.cpp)</title> <link href="classic.css" rel="stylesheet" type="text/css" /> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td align="left" valign="top" width="32"><a href="http://www.trolltech.com/products/qt"><img src="images/qt-logo.png" align="left" width="32" height="32" border="0" /></a></td> <td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> · <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a> · <a href="functions.html"><font color="#004faf">Functions</font></a></td> <td align="right" valign="top" width="230"><a href="http://www.trolltech.com"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></a></td></tr></table><h1 align="center">calculator.cpp Example File<br /><sup><sup>widgets/calculator/calculator.cpp</sup></sup></h1> <pre> /**************************************************************************** ** ** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved. ** ** This file is part of the example classes of the Qt Toolkit. ** ** This file may be used under the terms of the GNU General Public ** License version 2.0 as published by the Free Software Foundation ** and appearing in the file LICENSE.GPL included in the packaging of ** this file. Please review the following information to ensure GNU ** General Public Licensing requirements will be met: ** http:<span class="comment">//www.trolltech.com/products/qt/opensource.html</span> ** ** If you are unsure which license is appropriate for your use, please ** review the following information: ** http:<span class="comment">//www.trolltech.com/products/qt/licensing.html or contact the</span> ** sales department at sales@trolltech.com. ** ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ** ****************************************************************************/ #include <QtGui> #include <math.h> #include "button.h" #include "calculator.h" Calculator::Calculator(QWidget *parent) : QDialog(parent) { sumInMemory = 0.0; sumSoFar = 0.0; factorSoFar = 0.0; waitingForOperand = true; display = new QLineEdit("0"); display->setReadOnly(true); display->setAlignment(Qt::AlignRight); display->setMaxLength(15); display->installEventFilter(this); QFont font = display->font(); font.setPointSize(font.pointSize() + 8); display->setFont(font); QColor digitColor(150, 205, 205); QColor backspaceColor(225, 185, 135); QColor memoryColor(100, 155, 155); QColor operatorColor(155, 175, 195); for (int i = 0; i < NumDigitButtons; ++i) { digitButtons[i] = createButton(QString::number(i), digitColor, SLOT(digitClicked())); } pointButton = createButton(tr("."), digitColor, SLOT(pointClicked())); changeSignButton = createButton(tr("\261"), digitColor, SLOT(changeSignClicked())); backspaceButton = createButton(tr("Backspace"), backspaceColor, SLOT(backspaceClicked())); clearButton = createButton(tr("Clear"), backspaceColor, SLOT(clear())); clearAllButton = createButton(tr("Clear All"), backspaceColor.light(120), SLOT(clearAll())); clearMemoryButton = createButton(tr("MC"), memoryColor, SLOT(clearMemory())); readMemoryButton = createButton(tr("MR"), memoryColor, SLOT(readMemory())); setMemoryButton = createButton(tr("MS"), memoryColor, SLOT(setMemory())); addToMemoryButton = createButton(tr("M+"), memoryColor, SLOT(addToMemory())); divisionButton = createButton(tr("\367"), operatorColor, SLOT(multiplicativeOperatorClicked())); timesButton = createButton(tr("\327"), operatorColor, SLOT(multiplicativeOperatorClicked())); minusButton = createButton(tr("-"), operatorColor, SLOT(additiveOperatorClicked())); plusButton = createButton(tr("+"), operatorColor, SLOT(additiveOperatorClicked())); squareRootButton = createButton(tr("Sqrt"), operatorColor, SLOT(unaryOperatorClicked())); powerButton = createButton(tr("x\262"), operatorColor, SLOT(unaryOperatorClicked())); reciprocalButton = createButton(tr("1/x"), operatorColor, SLOT(unaryOperatorClicked())); equalButton = createButton(tr("="), operatorColor.light(120), SLOT(equalClicked())); QGridLayout *mainLayout = new QGridLayout; mainLayout->setSizeConstraint(QLayout::SetFixedSize); mainLayout->addWidget(display, 0, 0, 1, 6); mainLayout->addWidget(backspaceButton, 1, 0, 1, 2); mainLayout->addWidget(clearButton, 1, 2, 1, 2); mainLayout->addWidget(clearAllButton, 1, 4, 1, 2); mainLayout->addWidget(clearMemoryButton, 2, 0); mainLayout->addWidget(readMemoryButton, 3, 0); mainLayout->addWidget(setMemoryButton, 4, 0); mainLayout->addWidget(addToMemoryButton, 5, 0); for (int i = 1; i < NumDigitButtons; ++i) { int row = ((9 - i) / 3) + 2; int column = ((i - 1) % 3) + 1; mainLayout->addWidget(digitButtons[i], row, column); } mainLayout->addWidget(digitButtons[0], 5, 1); mainLayout->addWidget(pointButton, 5, 2); mainLayout->addWidget(changeSignButton, 5, 3); mainLayout->addWidget(divisionButton, 2, 4); mainLayout->addWidget(timesButton, 3, 4); mainLayout->addWidget(minusButton, 4, 4); mainLayout->addWidget(plusButton, 5, 4); mainLayout->addWidget(squareRootButton, 2, 5); mainLayout->addWidget(powerButton, 3, 5); mainLayout->addWidget(reciprocalButton, 4, 5); mainLayout->addWidget(equalButton, 5, 5); setLayout(mainLayout); setWindowTitle(tr("Calculator")); } bool Calculator::eventFilter(QObject *target, QEvent *event) { if (target == display) { if (event->type() == QEvent::MouseButtonPress || event->type() == QEvent::MouseButtonDblClick || event->type() == QEvent::MouseButtonRelease || event->type() == QEvent::ContextMenu) { QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event); if (mouseEvent->buttons() & Qt::LeftButton) { QPalette newPalette = palette(); newPalette.setColor(QPalette::Base, display->palette().color(QPalette::Text)); newPalette.setColor(QPalette::Text, display->palette().color(QPalette::Base)); display->setPalette(newPalette); } else { display->setPalette(palette()); } return true; } } return QDialog::eventFilter(target, event); } void Calculator::digitClicked() { Button *clickedButton = qobject_cast<Button *>(sender()); int digitValue = clickedButton->text().toInt(); if (display->text() == "0" && digitValue == 0.0) return; if (waitingForOperand) { display->clear(); waitingForOperand = false; } display->setText(display->text() + QString::number(digitValue)); } void Calculator::unaryOperatorClicked() { Button *clickedButton = qobject_cast<Button *>(sender()); QString clickedOperator = clickedButton->text(); double operand = display->text().toDouble(); double result = 0.0; if (clickedOperator == tr("Sqrt")) { if (operand < 0.0) { abortOperation(); return; } result = sqrt(operand); } else if (clickedOperator == tr("x\262")) { result = pow(operand, 2.0); } else if (clickedOperator == tr("1/x")) { if (operand == 0.0) { abortOperation(); return; } result = 1.0 / operand; } display->setText(QString::number(result)); waitingForOperand = true; } void Calculator::additiveOperatorClicked() { Button *clickedButton = qobject_cast<Button *>(sender()); QString clickedOperator = clickedButton->text(); double operand = display->text().toDouble(); if (!pendingMultiplicativeOperator.isEmpty()) { if (!calculate(operand, pendingMultiplicativeOperator)) { abortOperation(); return; } display->setText(QString::number(factorSoFar)); operand = factorSoFar; factorSoFar = 0.0; pendingMultiplicativeOperator.clear(); } if (!pendingAdditiveOperator.isEmpty()) { if (!calculate(operand, pendingAdditiveOperator)) { abortOperation(); return; } display->setText(QString::number(sumSoFar)); } else { sumSoFar = operand; } pendingAdditiveOperator = clickedOperator; waitingForOperand = true; } void Calculator::multiplicativeOperatorClicked() { Button *clickedButton = qobject_cast<Button *>(sender()); QString clickedOperator = clickedButton->text(); double operand = display->text().toDouble(); if (!pendingMultiplicativeOperator.isEmpty()) { if (!calculate(operand, pendingMultiplicativeOperator)) { abortOperation(); return; } display->setText(QString::number(factorSoFar)); } else { factorSoFar = operand; } pendingMultiplicativeOperator = clickedOperator; waitingForOperand = true; } void Calculator::equalClicked() { double operand = display->text().toDouble(); if (!pendingMultiplicativeOperator.isEmpty()) { if (!calculate(operand, pendingMultiplicativeOperator)) { abortOperation(); return; } operand = factorSoFar; factorSoFar = 0.0; pendingMultiplicativeOperator.clear(); } if (!pendingAdditiveOperator.isEmpty()) { if (!calculate(operand, pendingAdditiveOperator)) { abortOperation(); return; } pendingAdditiveOperator.clear(); } else { sumSoFar = operand; } display->setText(QString::number(sumSoFar)); sumSoFar = 0.0; waitingForOperand = true; } void Calculator::pointClicked() { if (waitingForOperand) display->setText("0"); if (!display->text().contains(".")) display->setText(display->text() + tr(".")); waitingForOperand = false; } void Calculator::changeSignClicked() { QString text = display->text(); double value = text.toDouble(); if (value > 0.0) { text.prepend(tr("-")); } else if (value < 0.0) { text.remove(0, 1); } display->setText(text); } void Calculator::backspaceClicked() { if (waitingForOperand) return; QString text = display->text(); text.chop(1); if (text.isEmpty()) { text = "0"; waitingForOperand = true; } display->setText(text); } void Calculator::clear() { if (waitingForOperand) return; display->setText("0"); waitingForOperand = true; } void Calculator::clearAll() { sumSoFar = 0.0; factorSoFar = 0.0; pendingAdditiveOperator.clear(); pendingMultiplicativeOperator.clear(); display->setText("0"); waitingForOperand = true; } void Calculator::clearMemory() { sumInMemory = 0.0; } void Calculator::readMemory() { display->setText(QString::number(sumInMemory)); waitingForOperand = true; } void Calculator::setMemory() { equalClicked(); sumInMemory = display->text().toDouble(); } void Calculator::addToMemory() { equalClicked(); sumInMemory += display->text().toDouble(); } Button *Calculator::createButton(const QString &text, const QColor &color, const char *member) { Button *button = new Button(text, color); connect(button, SIGNAL(clicked()), this, member); return button; } void Calculator::abortOperation() { clearAll(); display->setText(tr("####")); } bool Calculator::calculate(double rightOperand, const QString &pendingOperator) { if (pendingOperator == tr("+")) { sumSoFar += rightOperand; } else if (pendingOperator == tr("-")) { sumSoFar -= rightOperand; } else if (pendingOperator == tr("\327")) { factorSoFar *= rightOperand; } else if (pendingOperator == tr("\367")) { if (rightOperand == 0.0) return false; factorSoFar /= rightOperand; } return true; }</pre> <p /><address><hr /><div align="center"> <table width="100%" cellspacing="0" border="0"><tr class="address"> <td width="30%">Copyright © 2006 <a href="trolltech.html">Trolltech</a></td> <td width="40%" align="center"><a href="trademarks.html">Trademarks</a></td> <td width="30%" align="right"><div align="right">Qt 4.2.1</div></td> </tr></table></div></address></body> </html>