Add some error handling to the QWindowContainer example.

Use a QMainWindow and display errors occurring during loading
QML as well as scene graph errors (for example, failure
to create an Open GL context) in the status bar.

Change-Id: Id9cf190e8a4f40de0f18ab081e2747135221bb88
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>

examples/quick/embeddedinwidgets/main.cpp

@@ -39,35 +39,81 @@
 **
 ****************************************************************************/
 
-#include <QWidget>
+#include <QMainWindow>
 #include <QApplication>
 #include <QVBoxLayout>
 #include <QLineEdit>
+#include <QStatusBar>
+#include <QMenuBar>
+#include <QMenu>
+#include <QAction>
 
+#include <QQmlError>
 #include <QQuickView>
 
-int main(int argc, char **argv)
+class MainWindow : public QMainWindow {
+    Q_OBJECT
+public:
+    MainWindow();
+
+private slots:
+    void quickViewStatusChanged(QQuickView::Status);
+    void sceneGraphError(QQuickWindow::SceneGraphError error, const QString &message);
+
+private:
+    QQuickView *m_quickView;
+};
+
+MainWindow::MainWindow()
+    : m_quickView(new QQuickView)
 {
-    QApplication app(argc, argv);
+    QWidget *centralWidget = new QWidget(this);
+    QVBoxLayout *layout = new QVBoxLayout(centralWidget);
 
-    QWidget rootWidget;
+    m_quickView->setResizeMode(QQuickView::SizeRootObjectToView);
+    connect(m_quickView, SIGNAL(statusChanged(QQuickView::Status)),
+            this, SLOT(quickViewStatusChanged(QQuickView::Status)));
+    connect(m_quickView, SIGNAL(sceneGraphError(QQuickWindow::SceneGraphError,QString)),
+            this, SLOT(sceneGraphError(QQuickWindow::SceneGraphError,QString)));
+    m_quickView->setSource(QUrl(QStringLiteral("qrc:///embeddedinwidgets/main.qml")));
 
-    QVBoxLayout *layout = new QVBoxLayout();
-    rootWidget.setLayout(layout);
-
-    QQuickView *view = new QQuickView();
-    view->setResizeMode(QQuickView::SizeRootObjectToView);
-    view->setSource(QUrl(QStringLiteral("qrc:///embeddedinwidgets/main.qml")));
-
-    QWidget *container = QWidget::createWindowContainer(view);
-    container->setMinimumSize(view->size());
+    QWidget *container = QWidget::createWindowContainer(m_quickView);
+    container->setMinimumSize(m_quickView->size());
     container->setFocusPolicy(Qt::TabFocus);
 
     layout->addWidget(new QLineEdit(QStringLiteral("A QLineEdit")));
     layout->addWidget(container);
     layout->addWidget(new QLineEdit(QStringLiteral("A QLineEdit")));
+    setCentralWidget(centralWidget);
 
-    rootWidget.show();
+    QMenu *fileMenu = menuBar()->addMenu(tr("File"));
+    QAction *quitAction = fileMenu->addAction(tr("Quit"));
+    connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
+}
+
+void MainWindow::quickViewStatusChanged(QQuickView::Status status)
+{
+    if (status == QQuickView::Error) {
+        QStringList errors;
+        foreach (const QQmlError &error, m_quickView->errors())
+            errors.append(error.toString());
+        statusBar()->showMessage(errors.join(QStringLiteral(", ")));
+    }
+}
+
+void MainWindow::sceneGraphError(QQuickWindow::SceneGraphError, const QString &message)
+{
+    statusBar()->showMessage(message);
+}
+
+int main(int argc, char **argv)
+{
+    QApplication app(argc, argv);
+
+    MainWindow mainWindow;
+    mainWindow.show();
 
     return app.exec();
 }
+
+#include "main.moc"