练习93

#include <QtGui>  #include  "finddialog.h"     FindDialog::FindDialog(QWidget *parent)          : QDialog(parent)  {          label =  new  QLabel(tr( "Find &what:" ));          lineEdit =  new  QLineEdit;          label->setBuddy(lineEdit);            caseCheckBox =  new  QCheckBox(tr( "Match &case" ));          backwardCheckBox =  new  QCheckBox(tr( "Search &backford" ));            findButton =  new  QPushButton(tr( "&Find" ));          findButton->setDefault( true );          findButton->setEnabled( false );            closeButton =  new  QPushButton(tr( "Close" ));            connect(lineEdit, SIGNAL(textChanged( const  QString&)),  this , SLOT(enableFindButton( const  QString&)));          connect(findButton, SIGNAL(clicked()),  this , SLOT(findClicked()));          connect(closeButton, SIGNAL(clicked()),  this , SLOT(close()));            QHBoxLayout *topLeftLayout =  new  QHBoxLayout;          topLeftLayout->addWidget(label);          topLeftLayout->addWidget(lineEdit);            QVBoxLayout *leftLayout =  new  QVBoxLayout;          leftLayout->addLayout(topLeftLayout);          leftLayout->addWidget(caseCheckBox);          leftLayout->addWidget(backwardCheckBox);            QVBoxLayout *rightLayout =  new  QVBoxLayout;          rightLayout->addWidget(findButton);          rightLayout->addWidget(closeButton);          rightLayout->addStretch();            QHBoxLayout *mainLayout =  new  QHBoxLayout;          mainLayout->addLayout(leftLayout);          mainLayout->addLayout(rightLayout);          setLayout(mainLayout);            setWindowTitle(tr( "Find" ));          setFixedHeight(sizeHint().height());  }    FindDialog::~FindDialog()  {    }    void  FindDialog::findClicked()  {          QString text = lineEdit->text();          Qt::CaseSensitivity cs = caseCheckBox->isChecked() ? Qt::CaseInsensitive : Qt::CaseSensitive;           if (backwardCheckBox->isChecked()) {                  emit findPrevious(text, cs);          }  else  {                  emit findNext(text, cs);          }  }    void  FindDialog::enableFindButton( const  QString &text)  {          findButton->setEnabled(!text.isEmpty());  }