QGridLayout and QScrollArea

fotte

Hi, i am new to QT and i'm trying to have a gridlayout within a scrollarea. But somehow i can't get it to work the way i intent it to.

I intend to create my own widget, which has two push buttons, and a certain minimum size (i'm not quite sure what size it should have in the end. something around 512x256 i guess).

One button opens a filedialog and the user can choose a directory, and all images in that directory are shown in a gridlayout which is within a scroll area.

I subclassed the QWidget and my code looks like this:
@ ...
{
/// create an initial main layout
main_layout = new QGridLayout();
setLayout(main_layout);

/// create a scrollarea for the top widget
top_scroll = new QScrollArea;

/// create a top and bottom widget
/// bottom -> Holds all the controls
bottom_widget = new QWidget();
top_widget = new QWidget(top_scroll);

/// create new layout for the bottom widgets
bottom_layout = new QHBoxLayout(bottom_widget);
top_layout = new QGridLayout(top_widget);

/// associate the scroll area with the top-widget
top_scroll->setWidget(top_widget);

open = new QPushButton(QIcon(), tr("Open"));
clear = new QPushButton(QIcon(), tr("Clear"));

/// connect the buttons to their respective symbols
connect(open, SIGNAL(clicked()), this, SLOT(openFileDialog()));

bottom_layout->addWidget(open);
bottom_layout->addWidget(clear);
top_widget->setLayout(top_layout);
bottom_widget->setLayout(bottom_layout);
main_layout->addWidget(top_scroll, 0, 0);
main_layout->addWidget(bottom_widget,1,0);

@
later i add widgets to like this:

@ QLabel *lab = new QLabel();
lab->setPixmpa(pix);
lab->setFixedSize(128,128);
top_layout->addWidget(lab)
@

But nothing is shown in the scrollarea.

I tried adding the scrollarea and the layout after i inserted the labels:

@
QLabel *lab = new QLabel();
lab->setPixmpa(pix);
lab->setFixedSize(128,128);
top_layout->addWidget(lab);
top_widget->setLayout(top_layout);
top_scroll->setWidget(top_widget);
@

but that did not do the trick.
Can you point me in the right direction?

EDIT:
I use this widget in the following way: (maybe I got it wrong here?)

@MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
ui->gridLayout->addWidget(new imagePreviewer(this));
}@