SIGNAL and SLOT Problem

[RHMK]

Hi
I 'm a beginner in QT.
My class's slots in my code do not work!!


test.cpp:

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

#include <QHBoxLayout>
#include <QVBoxLayout>
#include "test.h"

FindDialog::FindDialog(	QWidget *parent): QDialog(parent)
{
	label = new QLabel(tr("Find &what:"));
	lineEdit = new QLineEdit;
	label->setBuddy(lineEdit);

	caseCheckBox = new QCheckBox(tr("Mach &case"));
	backwardCheckBox = new QCheckBox(tr("Search &backward"));

	findButton = new QPushButton(tr("&Find"));
	findButton->setDefault(true);
	findButton->setEnabled(false);

	closeButton = new QPushButton(tr("Close"));

	connect(lineEdit,SIGNAL(textChanged(const QString &)),this,SLOT(this->enableFindButton(const QString &)));
	connect(findButton , SIGNAL(clicked()),this,SLOT(this->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("Search"));
	setFixedHeight(sizeHint().height());
}

void FindDialog::findClicked()
{
	QString text = lineEdit->text();
	Qt::CaseSensitivity cs = caseCheckBox->isChecked() ? Qt::CaseSensitive : Qt::CaseInsensitive;
	if (backwardCheckBox->isChecked()) {
		emit findPrevious(text,cs);
	} else {
		emit findNext(text,cs);
	}
}

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

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test.h:

#ifndef FINDDIALOG_H
#define FINDDIALOG_H
 
#include <QtGui>
#include <QDialog>
 
#include <QCheckBox>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
 
class FindDialog : public QDialog
{
	Q_OBJECT
 
public :
	FindDialog(QWidget *parent = 0);
 
signals:
	void findNext(const QString &str , Qt::CaseSensitivity cs);
	void findPrevious(const QString &str , Qt::CaseSensitivity cs);
 
private:
	QLabel *label;
	QLineEdit *lineEdit;
	QCheckBox *caseCheckBox;
	QCheckBox *backwardCheckBox;
	QPushButton *findButton;
	QPushButton *closeButton;
 
private slots:
	void findClicked();
	void enableFindButton(const QString &text);
 
};
#endif

#ifndef FINDDIALOG_H
#define FINDDIALOG_H

#include <QtGui>
#include <QDialog>

#include <QCheckBox>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>

class FindDialog : public QDialog
{
	Q_OBJECT

public :
	FindDialog(QWidget *parent = 0);

signals:
	void findNext(const QString &str , Qt::CaseSensitivity cs);
	void findPrevious(const QString &str , Qt::CaseSensitivity cs);

private:
	QLabel *label;
	QLineEdit *lineEdit;
	QCheckBox *caseCheckBox;
	QCheckBox *backwardCheckBox;
	QPushButton *findButton;
	QPushButton *closeButton;

private slots:
	void findClicked();
	void enableFindButton(const QString &text);

};
#endif

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main.cpp:

#include <QApplication>
#include "test.h"
 
int main(int argc,char *argv[])
{
	QApplication app(argc,argv);
	FindDialog *fd = new FindDialog;
	fd->show();
	return app.exec();
}

#include <QApplication>
#include "test.h"

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

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Please help me about this.
Thanks