[welcome] More QML support

- start of a class to hold configuration information; this can
   later be substituted into the WelcomeViewStep and filled from
   setConfigurationMap()

In the example application:
 - register the Config type

src/modules/welcome/CMakeLists.txt

@@ -41,5 +41,12 @@ calamares_add_plugin( welcome
     SHARED_LIB
 )
 
-add_executable( welcomeqmltest qmlmain.cpp )
-target_link_libraries( welcomeqmltest calamaresui )
+add_executable( welcomeqmltest qmlmain.cpp Config.cpp )
+target_link_libraries( welcomeqmltest PRIVATE calamaresui Qt5::Core )
+set_target_properties( welcomeqmltest
+    PROPERTIES
+        ENABLE_EXPORTS TRUE
+        RUNTIME_OUTPUT_NAME welcomeqmltest
+)
+calamares_automoc( welcomeqmltest )
+calamares_autouic( welcomeqmltest )

src/modules/welcome/Config.cpp

@@ -0,0 +1,27 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Config.h"
+
+Config::Config()
+{
+}
+
+Config::~Config()
+{
+}

src/modules/welcome/Config.h

@@ -0,0 +1,40 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
+ *
+ *   Calamares is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Calamares is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef WELCOME_CONFIG_H
+#define WELCOME_CONFIG_H
+
+#include <QObject>
+#include <QUrl>
+
+class Config : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY( QUrl helpUrl READ helpUrl WRITE setHelpUrl )
+public:
+    Config();
+    virtual ~Config();
+
+    QUrl helpUrl() const { return m_helpUrl; }
+    void setHelpUrl( const QUrl& url ) { m_helpUrl = url; }
+
+private:
+    QUrl m_helpUrl;
+};
+
+#endif

src/modules/welcome/qmlmain.cpp

@@ -16,6 +16,8 @@
 
 #include "utils/Logger.h"
 
+#include "Config.h"
+
 int main(int argc, char **argv)
 {
     QApplication a( argc, argv );
@@ -46,6 +48,14 @@ int main(int argc, char **argv)
     mw.resize( QSize( 400, 400 ) );
     mw.show();
 
+    Config cnf;
+    if ( argc > 1 )
+    {
+        cnf.setHelpUrl( QUrl( argv[1] ) );
+    }
+
+    qmlRegisterType< Config >( "io.calamares.modules.welcome", 1, 0, "Config" );
+
     qqw.setSource( QUrl::fromLocalFile("../src/modules/welcome/welcome.qml") );
 
     return a.exec();

src/modules/welcome/welcome.qml

@@ -1,4 +1,5 @@
 import QtQuick 2.0;
+import io.calamares.modules.welcome 1.0;
 
 Rectangle {
     width: 200;