qt5: forward window title to nitpicker

This enables Qt5 applications to set a Genode label via 'setWindowTitle'
from within Qt5 applications, and thus, making them identifiable to
other Genode components, like a layout manager.

fixes #3046

repos/libports/include/qt5/qpa_nitpicker/qnitpickerplatformwindow.h

@@ -40,6 +40,8 @@ class QNitpickerPlatformWindow : public QObject, public QPlatformWindow
 	private:
 
 		Genode::Env                     &_env;
+		QString                          _nitpicker_session_label;
+		static QStringList               _nitpicker_session_label_list;
 		Nitpicker::Connection            _nitpicker_session;
 		Framebuffer::Session_client      _framebuffer_session;
 		unsigned char                   *_framebuffer;
@@ -76,6 +78,8 @@ class QNitpickerPlatformWindow : public QObject, public QPlatformWindow
 		Nitpicker::Session::View_handle _create_view();
 		void _adjust_and_set_geometry(const QRect &rect);
 
+		QString _sanitize_label(QString label);
+
 	private Q_SLOTS:
 
 		void _handle_input(unsigned int);
@@ -92,6 +96,8 @@ class QNitpickerPlatformWindow : public QObject, public QPlatformWindow
 		                         Genode::Signal_receiver &signal_receiver,
 		                         int screen_width, int screen_height);
 
+		~QNitpickerPlatformWindow();
+
 	    QWindow *window() const;
 
 	    QPlatformWindow *parent() const;

repos/libports/ports/qt5.hash

@@ -1 +1 @@
-755ed511de17500de4c67cca27cc7d31a65dd2c8
+82600d0dfdfcb7a3693ea2cdd3e5591276e3ae22

repos/libports/src/lib/qt5/patches/qtbase_qwindow_title.patch

@@ -0,0 +1,12 @@
+diff --git a/qtbase/src/widgets/kernel/qwidgetwindow.cpp b/qtbase/src/widgets/kernel/qwidgetwindow.cpp
+index b91fbcf..3221bf3 100644
+--- a/qtbase/src/widgets/kernel/qwidgetwindow.cpp
++++ b/qtbase/src/widgets/kernel/qwidgetwindow.cpp
+@@ -122,6 +122,7 @@ QWidgetWindow::QWidgetWindow(QWidget *widget)
+     : QWindow(*new QWidgetWindowPrivate(), 0)
+     , m_widget(widget)
+ {
++    setTitle(widget->windowTitle());
+     updateObjectName();
+     // Enable QOpenGLWidget/QQuickWidget children if the platform plugin supports it,
+     // and the application developer has not explicitly disabled it.

repos/libports/src/lib/qt5/patches/series

@@ -14,6 +14,7 @@ qtbase_genode.patch
 qtbase_genode_qtscriptclassic.patch
 qtbase_genode_textedit_example.patch
 qtbase_genode_openglwindow_example.patch
+qtbase_qwindow_title.patch
 qtdeclarative_genode.patch
 qtwebkit_genode.patch
 host_tools.patch

repos/libports/src/lib/qt5/qtbase/src/plugins/platforms/nitpicker/qnitpickerplatformwindow.cpp

@@ -27,6 +27,8 @@ QT_BEGIN_NAMESPACE
 
 static const bool qnpw_verbose = false/*true*/;
 
+QStringList QNitpickerPlatformWindow::_nitpicker_session_label_list;
+
 QTouchDevice * QNitpickerPlatformWindow::_init_touch_device()
 {
 	QVector<QWindowSystemInterface::TouchPoint>::iterator i = _touch_points.begin();
@@ -398,12 +400,44 @@ void QNitpickerPlatformWindow::_adjust_and_set_geometry(const QRect &rect)
 	emit framebuffer_changed();
 }
 
+
+QString QNitpickerPlatformWindow::_sanitize_label(QString label)
+{
+	enum { MAX_LABEL = 25 };
+
+	/* remove any occurences of '"' */
+	label.remove("\"");
+
+	/* truncate label and append '..' */
+	if (label.length() > MAX_LABEL) {
+		label.truncate(MAX_LABEL - 2);
+		label.append("..");
+	}
+
+	/* Make sure that the window is distinguishable by the layouter */
+	if (label.isEmpty())
+		label = QString("Untitled Window");
+
+	if (_nitpicker_session_label_list.contains(label))
+		for (unsigned int i = 2; ; i++) {
+			QString versioned_label = label + "." + QString::number(i);
+			if (!_nitpicker_session_label_list.contains(versioned_label)) {
+				label = versioned_label;
+				break;
+			}
+		}
+
+	return label;
+}
+
+
 QNitpickerPlatformWindow::QNitpickerPlatformWindow(Genode::Env &env, QWindow *window,
                                                    Genode::Signal_receiver &signal_receiver,
                                                    int screen_width, int screen_height)
 : QPlatformWindow(window),
   _env(env),
-  _nitpicker_session(env),
+  _nitpicker_session_label(_sanitize_label(window->title())),
+  _nitpicker_session(env, _nitpicker_session_label.toStdString().c_str()),
   _framebuffer_session(_nitpicker_session.framebuffer_session()),
   _framebuffer(0),
   _framebuffer_changed(false),
@@ -425,6 +459,8 @@ QNitpickerPlatformWindow::QNitpickerPlatformWindow(Genode::Env &env, QWindow *wi
 		if (window->transientParent())
 			qDebug() << "QNitpickerPlatformWindow(): child window of" << window->transientParent();
 
+	_nitpicker_session_label_list.append(_nitpicker_session_label);
+
 	_input_session.sigh(_input_signal_dispatcher);
 
 	_nitpicker_session.mode_sigh(_mode_changed_signal_dispatcher);
@@ -448,6 +484,11 @@ QNitpickerPlatformWindow::QNitpickerPlatformWindow(Genode::Env &env, QWindow *wi
 	        Qt::QueuedConnection);
 }
 
+QNitpickerPlatformWindow::~QNitpickerPlatformWindow()
+{
+	_nitpicker_session_label_list.removeOne(_nitpicker_session_label);
+}
+
 QWindow *QNitpickerPlatformWindow::window() const
 {
 	if (qnpw_verbose)