Find icon in a dialog box

[jk_mk]

Hi,
I have created the following dialog box for finding files. It works correctly as I can find files, but my problem is that I cannot see .png image file included in my directory.Could someone tell me what to change or what to add in my code?

//////////////// window.cpp //////////
@ #include <QtGui>

#include "window.h"

Window::Window(QWidget *parent)
: QDialog(parent)
{

 browseButton = createButton(tr("&Browse..."), SLOT(browse()));

openButton = createButton(tr("&Open"), SLOT(open_file()));

 directoryComboBox = createComboBox(QDir::currentPath());

 directoryLabel = new QLabel(tr("In directory:"));


 QHBoxLayout *buttonsLayout = new QHBoxLayout;
 buttonsLayout->addStretch();

buttonsLayout->addWidget(openButton);

 QGridLayout *mainLayout = new QGridLayout;
 mainLayout->addWidget(directoryLabel, 2, 0);
 mainLayout->addWidget(directoryComboBox, 2, 1);
 mainLayout->addWidget(browseButton, 2, 2);
 mainLayout->addLayout(buttonsLayout, 5, 0, 1, 3);
 setLayout(mainLayout);

 setWindowTitle(tr("Open Files"));
 resize(500, 200);

}

void Window::open_file()
{
/// an 8elw na anoiksw thn eikona me graphicsView
QGraphicsScene * scene = new QGraphicsScene();
scene->addPixmap(QPixmap(QDir::currentPath()));
//graphicsView->setScene(scene);

}

void Window::browse()
{
QString directory = QFileDialog::getExistingDirectory(this,
tr("Open Files"), QDir::currentPath());
if (!directory.isEmpty()) {
directoryComboBox->addItem(directory);
directoryComboBox->setCurrentIndex(directoryComboBox->currentIndex() + 1);
}
}

QPushButton *Window::createButton(const QString &text, const char *member)
{
QPushButton *button = new QPushButton(text);
connect(button, SIGNAL(clicked()), this, member);
return button;
}

QComboBox *Window::createComboBox(const QString &text)
{
QComboBox *comboBox = new QComboBox;
comboBox->setEditable(true);
comboBox->addItem(text);
comboBox->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
return comboBox;
}@

////////////// window.h ////////////////
@#ifndef WINDOW_H
#define WINDOW_H

#include <QDialog>

class QComboBox;
class QDir;
class QLabel;
class QPushButton;

class Window : public QDialog
{
Q_OBJECT

public:
Window(QWidget *parent = 0);

private slots:
void browse();
void open_file();

private:

 QPushButton *createButton(const QString &text, const char *member);
 QComboBox *createComboBox(const QString &text = QString());



 QComboBox *directoryComboBox; 
 QLabel *directoryLabel;
 QPushButton *browseButton;

QPushButton *openButton;

};

#endif@

//////////// main.cpp ////////////
@#include <QApplication>

#include "window.h"

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Window window;
window.show();
return app.exec();
}@

[jk_mk]

I think I have found it. I should have typed:
@ void Window::browse()
{

  QString directory = QFileDialog::getOpenFileName( this , tr("Open File") ,
QDir::currentPath() , tr("Images (*.png *.jpeg *.jpg *.bmp);; bmp (*.bmp);;jpg (*.jpeg *.jpg);;png (*.png)"));

 if (!directory.isEmpty()) {
     directoryComboBox->addItem(directory);
     directoryComboBox->setCurrentIndex(directoryComboBox->currentIndex() + 1);
 }

}@