examples/widgets/calculator/calculator.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/widgets/calculator/calculator.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,398 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@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]