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Diffstat (limited to 'examples/widgets/calculator/calculator.cpp')
| -rw-r--r-- | examples/widgets/calculator/calculator.cpp | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/examples/widgets/calculator/calculator.cpp b/examples/widgets/calculator/calculator.cpp new file mode 100644 index 0000000..9c2ef4a --- /dev/null +++ b/examples/widgets/calculator/calculator.cpp @@ -0,0 +1,398 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QtGui> + +#include <math.h> + +#include "button.h" +#include "calculator.h" + +//! [0] +Calculator::Calculator(QWidget *parent) + : QDialog(parent) +{ + sumInMemory = 0.0; + sumSoFar = 0.0; + factorSoFar = 0.0; + waitingForOperand = true; +//! [0] + +//! [1] + display = new QLineEdit("0"); +//! [1] //! [2] + display->setReadOnly(true); + display->setAlignment(Qt::AlignRight); + display->setMaxLength(15); + + QFont font = display->font(); + font.setPointSize(font.pointSize() + 8); + display->setFont(font); +//! [2] + +//! [4] + for (int i = 0; i < NumDigitButtons; ++i) { + digitButtons[i] = createButton(QString::number(i), SLOT(digitClicked())); + } + + Button *pointButton = createButton(tr("."), SLOT(pointClicked())); + Button *changeSignButton = createButton(tr("\261"), SLOT(changeSignClicked())); + + Button *backspaceButton = createButton(tr("Backspace"), SLOT(backspaceClicked())); + Button *clearButton = createButton(tr("Clear"), SLOT(clear())); + Button *clearAllButton = createButton(tr("Clear All"), SLOT(clearAll())); + + Button *clearMemoryButton = createButton(tr("MC"), SLOT(clearMemory())); + Button *readMemoryButton = createButton(tr("MR"), SLOT(readMemory())); + Button *setMemoryButton = createButton(tr("MS"), SLOT(setMemory())); + Button *addToMemoryButton = createButton(tr("M+"), SLOT(addToMemory())); + + Button *divisionButton = createButton(tr("\367"), SLOT(multiplicativeOperatorClicked())); + Button *timesButton = createButton(tr("\327"), SLOT(multiplicativeOperatorClicked())); + Button *minusButton = createButton(tr("-"), SLOT(additiveOperatorClicked())); + Button *plusButton = createButton(tr("+"), SLOT(additiveOperatorClicked())); + + Button *squareRootButton = createButton(tr("Sqrt"), SLOT(unaryOperatorClicked())); + Button *powerButton = createButton(tr("x\262"), SLOT(unaryOperatorClicked())); + Button *reciprocalButton = createButton(tr("1/x"), SLOT(unaryOperatorClicked())); + Button *equalButton = createButton(tr("="), SLOT(equalClicked())); +//! [4] + +//! [5] + QGridLayout *mainLayout = new QGridLayout; +//! [5] //! [6] + 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")); +} +//! [6] + +//! [7] +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)); +} +//! [7] + +//! [8] +void Calculator::unaryOperatorClicked() +//! [8] //! [9] +{ + 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; +} +//! [9] + +//! [10] +void Calculator::additiveOperatorClicked() +//! [10] //! [11] +{ + Button *clickedButton = qobject_cast<Button *>(sender()); + QString clickedOperator = clickedButton->text(); + double operand = display->text().toDouble(); + +//! [11] //! [12] + if (!pendingMultiplicativeOperator.isEmpty()) { +//! [12] //! [13] + if (!calculate(operand, pendingMultiplicativeOperator)) { + abortOperation(); + return; + } + display->setText(QString::number(factorSoFar)); + operand = factorSoFar; + factorSoFar = 0.0; + pendingMultiplicativeOperator.clear(); + } + +//! [13] //! [14] + if (!pendingAdditiveOperator.isEmpty()) { +//! [14] //! [15] + if (!calculate(operand, pendingAdditiveOperator)) { + abortOperation(); + return; + } + display->setText(QString::number(sumSoFar)); + } else { + sumSoFar = operand; + } + +//! [15] //! [16] + pendingAdditiveOperator = clickedOperator; +//! [16] //! [17] + waitingForOperand = true; +} +//! [17] + +//! [18] +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; +} +//! [18] + +//! [20] +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; +} +//! [20] + +//! [22] +void Calculator::pointClicked() +{ + if (waitingForOperand) + display->setText("0"); + if (!display->text().contains(".")) + display->setText(display->text() + tr(".")); + waitingForOperand = false; +} +//! [22] + +//! [24] +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); +} +//! [24] + +//! [26] +void Calculator::backspaceClicked() +{ + if (waitingForOperand) + return; + + QString text = display->text(); + text.chop(1); + if (text.isEmpty()) { + text = "0"; + waitingForOperand = true; + } + display->setText(text); +} +//! [26] + +//! [28] +void Calculator::clear() +{ + if (waitingForOperand) + return; + + display->setText("0"); + waitingForOperand = true; +} +//! [28] + +//! [30] +void Calculator::clearAll() +{ + sumSoFar = 0.0; + factorSoFar = 0.0; + pendingAdditiveOperator.clear(); + pendingMultiplicativeOperator.clear(); + display->setText("0"); + waitingForOperand = true; +} +//! [30] + +//! [32] +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(); +} +//! [32] +//! [34] +Button *Calculator::createButton(const QString &text, const char *member) +{ + Button *button = new Button(text); + connect(button, SIGNAL(clicked()), this, member); + return button; +} +//! [34] + +//! [36] +void Calculator::abortOperation() +{ + clearAll(); + display->setText(tr("####")); +} +//! [36] + +//! [38] +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; +} +//! [38] |