qml: Add stub window

Github-Pull: bitcoin-core#5
Rebased-From: e2104f8

Author: hebasto

src/qml/CMakeLists.txt

@@ -10,6 +10,9 @@ qt6_add_qml_module(bitcoin_qml
   STATIC
   SOURCES
     bitcoin.cpp
+  RESOURCE_PREFIX /qt/qml/
+  QML_FILES
+    pages/stub.qml
 )
 
 target_compile_definitions(bitcoin_qml

src/qml/bitcoin.cpp

@@ -52,6 +52,10 @@ int QmlGuiMain(int argc, char* argv[])
     boost::signals2::scoped_connection handler_init_message = ::uiInterface.InitMessage_connect(noui_InitMessage);
 
     QGuiApplication app(argc, argv);
+    QQmlApplicationEngine engine("src/qml/pages/stub.qml");
+    if (engine.rootObjects().isEmpty()) {
+        return EXIT_FAILURE;
+    }
 
     // Parse command-line options. We do this after qt in order to show an error if there are problems parsing these.
     SetupServerArgs(gArgs);

src/qml/pages/stub.qml

@@ -0,0 +1,9 @@
+import QtQuick.Controls
+
+ApplicationWindow {
+    id: appWindow
+    title: "Bitcoin Core TnG"
+    minimumWidth: 750
+    minimumHeight: 450
+    visible: true
+}