Switch to CMake for Qt build

src/qt/main.cpp

@@ -1,5 +1,7 @@
-#include <QApplication>
+#include <QGuiApplication>
 #include <QQmlApplicationEngine>
+#include <iostream>
+#include <string>
 
 #include <caml/mlvalues.h>
 #include <caml/callback.h>
@@ -9,14 +11,38 @@ void load_caml(char *argv[])
     caml_main(argv);
 }
 
+void print_closure(const std::string &closure_name) {
+    value * closure_f = caml_named_value(closure_name.c_str());
+    if (closure_f == nullptr) {
+        std::cerr << "ERROR: Unreachable closure " << closure_name << "\n";
+        return;
+    }
+
+    const char *str = String_val(caml_callback(*closure_f, Val_unit));
+    std::cout <<  closure_name << ": " << str << "\n";
+}
+
+
 int main(int argc, char *argv[])
 {
-    QApplication app(argc, argv);
+    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+    QGuiApplication app(argc, argv);
 
     QQmlApplicationEngine engine;
-    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
+    const QUrl url(QStringLiteral("qrc:/main.qml"));
+    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
+                     &app, [url](QObject *obj, const QUrl &objUrl) {
+        if (!obj && url == objUrl)
+            QCoreApplication::exit(-1);
+    }, Qt::QueuedConnection);
+    engine.load(url);
 
     load_caml(argv);
 
+    std::cout << "test std::cout" << "\n";
+    std::cerr << "test std::cerr" << "\n";
+    print_closure("name");
+    print_closure("version");
+
     return app.exec();
 }