C++ Exercises（三）

// finddialog.h
#ifndef FINDDIALOG_H
#define FINDDIALOG_H
#include <QDialog>
class QCheckBox;
class QLabel;
class QLineEdit;
class QPushButton;


class FindDialog : public QDialog
{
      Q_OBJECT
public:
       FindDialog(QWidget *parent = 0);
signals://声明信号 
        void findNext(const QString &str,Qt::CaseSensitivity cs);
        void findPrev(const QString &str,Qt::CaseSensitivity cs);
private slots://声明槽 
        void findClicked();
        void enableFindButton(const QString &str);
private:
        QLabel *lable;
        QLineEdit *lineEdit;
        QCheckBox *caseCheckBox;
        QCheckBox *backwardCheckBox;
        QPushButton *findBtn;
        QPushButton *closeBtn;
};

#endif

// finddialog.cpp
#include <QtGui>
#include "finddialog.h"

FindDialog::FindDialog(QWidget *parent) : QDialog(parent)
{
   
    this->lable = new QLabel(tr("Find &what:"),this);
    this->lineEdit = new QLineEdit(this);
    lable->setBuddy(lineEdit);
    
    caseCheckBox = new QCheckBox(tr("Match &case"),this);
    backwardCheckBox = new QCheckBox(tr("Search &backward"),this);
    
    findBtn = new QPushButton(tr("&Find"),this);
    findBtn->setDefault(true);
    findBtn->setEnabled(false);
    closeBtn = new QPushButton(tr("Close"),this);
    
    QObject::connect(lineEdit,SIGNAL(textChanged(const QString &)),this,SLOT(enableFindButton(const QString &)));
    QObject::connect(findBtn,SIGNAL(clicked()),this,SLOT(findClicked()));
    QObject::connect(closeBtn,SIGNAL(clicked()),this,SLOT(close()));

    QHBoxLayout *topLeftLayout = new QHBoxLayout;
    topLeftLayout->addWidget(lable);
    topLeftLayout->addWidget(lineEdit);
    
    QVBoxLayout *leftLayout = new QVBoxLayout;
    leftLayout->addLayout(topLeftLayout);
    leftLayout->addWidget(caseCheckBox);
    leftLayout->addWidget(backwardCheckBox);
    
    QVBoxLayout *rightLayout = new QVBoxLayout;
    rightLayout->addWidget(findBtn);
    rightLayout->addWidget(closeBtn);
    rightLayout->addStretch(1);
    
    QHBoxLayout *mainLayout = new QHBoxLayout(this);
    mainLayout->setMargin(11);
    mainLayout->setSpacing(5);
    mainLayout->addLayout(leftLayout);
    mainLayout->addLayout(rightLayout);
    this->setWindowTitle(tr("Find"));
    this->setFixedHeight(sizeHint().height());
}

void FindDialog::findClicked()
{
     QString text = lineEdit->text();
     Qt::CaseSensitivity cs = caseCheckBox->isChecked() ? Qt::CaseSensitive : Qt::CaseInsensitive;

     if(backwardCheckBox->isChecked())
         emit findPrev(text,cs);//发射"向前搜索信号" 
     else
         emit findNext(text,cs);//发射"向后搜索信号" 
}

void FindDialog::enableFindButton(const QString &str)
{
     findBtn->setEnabled(!str.isEmpty());
}

//main.cpp
#include <QApplication>
#include "finddialog.h"

int main(int argc,char *argv[])
{
    QApplication app(argc,argv);
    FindDialog *dialog = new FindDialog;
    dialog->show();
    return app.exec();
}