[Solved] Having trouble using QMdiArea.

chooser

I would really appreciate if somebody could help me with using the QMdiArea class. I'm kind of stumped, why the code below isn't working.

I have no problem displaying subwindows when I add them in the MainWindow::MainWindow() constructor. However, when I try to do this is in a slot function NOTHING appears in the MDI area. What's going on?

Here is the code I am using that isn't doing what I want.
MainWindow.h
@#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

public slots:
void display_images();

private:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H
@

MainWIndow.cpp
@MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);

QPushButton *display_action_button = new QPushButton();

ui->imageDisplayWindowsArea->addSubWindow(display_action_button);
connect(display_action_button, SIGNAL(clicked()), this, SLOT(display_images()));

ui->imageDisplayWindowsArea->cascadeSubWindows();

}

void MainWindow::display_images()
{
QString full_path = "C:\Users\me\Downloads\o-png8.png";

QString qstyle = "background: url";
qstyle.append("(");
qstyle.append(full_path);
qstyle.append(")");

QWidget* imageDisplayWidget = new QWidget();
imageDisplayWidget->setWindowFlags(Qt::Popup);
imageDisplayWidget->setStyleSheet(qstyle);
QPixmap * mypix = new QPixmap(full_path);
int ih = mypix->height();
int iw = mypix->width();
QSize size(iw, ih);
imageDisplayWidget->resize(size);


QMdiSubWindow *subWindow1 = new QMdiSubWindow;
subWindow1->setWidget(imageDisplayWidget);
subWindow1->setWindowTitle("Image Display");
subWindow1->resize(size);
subWindow1->setAttribute(Qt::WA_DeleteOnClose);

ui->imageDisplayWindowsArea->addSubWindow(subWindow1);

}
@

Thanks in advance for any help.

chooser

I believe I resolved my own question. Looks like you have to call the show() method of the subwindow. DUH.

SGaist

Hi and welcome to devnet,

great you found out by yourself !

Could you also update the thread's title so other forum members will know a solution has been found ? :)