#include <QtGui>#include <math.h>#include "button.h"#include "digitdialog.h"Digital::Digital(QWidget *parent)    : QDialog(parent){    display = new QLineEdit("");    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);    for (int i = 0; i < NumDigitButtons; ++i) {	digitButtons[i] = createButton(QString::number(i), digitColor,                                       SLOT(digitClicked()));    }    QGridLayout *mainLayout = new QGridLayout;    mainLayout->setSizeConstraint(QLayout::SetFixedSize);    mainLayout->addWidget(display, 0, 0, 1, 4);    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, 0,1,4);    setLayout(mainLayout);    setWindowTitle(tr("數字"));}bool Digital::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 Digital::digitClicked(){    Button *clickedQButton = qobject_cast<Button *>(sender());    int digitValue = clickedQButton->text().toInt();    display->setText(display->text() + QString::number(digitValue));}Button *Digital::createButton(const QString &text, const QColor &color,                                 const char *member){    Button *button = new Button(text, color);    connect(button, SIGNAL(clicked()), this, member);    return button;}