feat: add hard reload signal and wrap root object

src/cpp/rootwrapper.cpp

@@ -0,0 +1,64 @@
+#include "rootwrapper.hpp"
+#include <cstdlib>
+#include <utility>
+
+#include <qlogging.h>
+#include <qobject.h>
+#include <qqmlcomponent.h>
+#include <qqmlengine.h>
+#include <qurl.h>
+
+#include "shell.hpp"
+
+RootWrapper::RootWrapper(QUrl rootUrl):
+    QObject(nullptr), rootUrl(std::move(rootUrl)), engine(this) {
+	this->reloadGraph();
+
+	if (this->activeRoot == nullptr) {
+		qCritical() << "could not create scene graph, exiting";
+		exit(-1); // NOLINT
+	}
+}
+
+void RootWrapper::reloadGraph() {
+	if (this->activeRoot != nullptr) {
+		this->engine.clearComponentCache();
+	}
+
+	auto component = QQmlComponent(&this->engine, this->rootUrl);
+	auto* obj = component.beginCreate(this->engine.rootContext());
+	if (obj == nullptr) {
+		qWarning() << "failed to create root component";
+		return;
+	}
+
+	auto* qtsobj = qobject_cast<QtShell*>(obj);
+	if (qtsobj == nullptr) {
+		qWarning() << "root component was not a QtShell";
+		delete obj;
+		return;
+	}
+
+	component.completeCreate();
+
+	if (this->activeRoot != nullptr) {
+		this->activeRoot->deleteLater();
+		this->activeRoot = nullptr;
+	}
+
+	this->activeRoot = qtsobj;
+}
+
+void RootWrapper::changeRoot(QtShell* newRoot) {
+	if (this->activeRoot != nullptr) {
+		QObject::disconnect(this->destroyConnection);
+		this->activeRoot->deleteLater();
+	}
+
+	if (newRoot != nullptr) {
+		this->activeRoot = newRoot;
+		QObject::connect(this->activeRoot, &QtShell::destroyed, this, &RootWrapper::destroy);
+	}
+}
+
+void RootWrapper::destroy() { this->deleteLater(); }