基于嵌入式linux计算器的实现

沈阳航空航天大学课程设计报告 附 录

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(\ if (!display->text().contains(\

display->setText(display->text() + tr(\ waitingForOperand = false; } //! [22] //! [24]

-19-

沈阳航空航天大学课程设计报告 附 录

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 = \

waitingForOperand = true; }

display->setText(text); } //! [26] //! [28]

void Calculator::clear()

-20-

沈阳航空航天大学课程设计报告 附 录

{

if (waitingForOperand) return;

display->setText(\ waitingForOperand = true; } //! [28] //! [30]

void Calculator::clearAll() {

sumSoFar = 0.0; factorSoFar = 0.0;

pendingAdditiveOperator.clear(); pendingMultiplicativeOperator.clear(); display->setText(\ waitingForOperand = true; } //! [30] //! [32]

void Calculator::clearMemory() {

sumInMemory = 0.0; }

void Calculator::readMemory() {

display->setText(QString::number(sumInMemory));

-21-

沈阳航空航天大学课程设计报告 附 录

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(\

-22-