reload: encapsulate each engine generation more

src/core/CMakeLists.txt

@@ -17,6 +17,7 @@ qt_add_library(quickshell-core STATIC
 	panelinterface.cpp
 	popupwindow.cpp
 	singleton.cpp
+	generation.cpp
 )
 
 set_source_files_properties(main.cpp PROPERTIES COMPILE_DEFINITIONS GIT_REVISION="${GIT_REVISION}")

src/core/generation.cpp

@@ -0,0 +1,53 @@
+#include "generation.hpp"
+
+#include <qcontainerfwd.h>
+#include <qcoreapplication.h>
+#include <qhash.h>
+#include <qobject.h>
+#include <qqmlcontext.h>
+#include <qqmlengine.h>
+#include <qtimer.h>
+
+#include "plugin.hpp"
+#include "reload.hpp"
+
+static QHash<QQmlEngine*, EngineGeneration*> g_generations; // NOLINT
+
+EngineGeneration::EngineGeneration() { g_generations.insert(&this->engine, this); }
+
+EngineGeneration::~EngineGeneration() {
+	g_generations.remove(&this->engine);
+	if (this->root != nullptr) this->root->deleteLater();
+}
+
+void EngineGeneration::onReload(EngineGeneration* old) {
+	auto* app = QCoreApplication::instance();
+	QObject::connect(&this->engine, &QQmlEngine::quit, app, &QCoreApplication::quit);
+	QObject::connect(&this->engine, &QQmlEngine::exit, app, &QCoreApplication::exit);
+
+	this->root->onReload(old == nullptr ? nullptr : old->root);
+	this->singletonRegistry.onReload(old == nullptr ? nullptr : &old->singletonRegistry);
+
+	delete old;
+
+	if (old != nullptr) {
+		QTimer::singleShot(0, [this]() {
+			QuickshellPlugin::runOnReload();
+			PostReloadHook::postReloadTree(this->root);
+		});
+	} else {
+		QuickshellPlugin::runOnReload();
+		PostReloadHook::postReloadTree(this->root);
+	}
+}
+
+EngineGeneration* EngineGeneration::findObjectGeneration(QObject* object) {
+	while (object != nullptr) {
+		auto* context = QQmlEngine::contextForObject(object);
+		if (auto* generation = g_generations.value(context->engine())) {
+			return generation;
+		}
+	}
+
+	return nullptr;
+}

src/core/generation.hpp

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <qobject.h>
+#include <qtclasshelpermacros.h>
+
+#include "shell.hpp"
+#include "singleton.hpp"
+
+class EngineGeneration {
+public:
+	explicit EngineGeneration();
+	~EngineGeneration();
+	Q_DISABLE_COPY_MOVE(EngineGeneration);
+
+	// assumes root has been initialized, consumes old generation
+	void onReload(EngineGeneration* old);
+
+	static EngineGeneration* findObjectGeneration(QObject* object);
+
+	QQmlEngine engine;
+	ShellRoot* root = nullptr;
+	SingletonRegistry singletonRegistry;
+};

src/core/rootwrapper.cpp

@@ -2,21 +2,17 @@
 #include <cstdlib>
 #include <utility>
 
-#include <qcoreapplication.h>
 #include <qdir.h>
 #include <qfileinfo.h>
 #include <qlogging.h>
 #include <qobject.h>
 #include <qqmlcomponent.h>
 #include <qqmlengine.h>
-#include <qtimer.h>
 #include <qurl.h>
 
-#include "plugin.hpp"
+#include "generation.hpp"
 #include "qmlglobal.hpp"
-#include "reload.hpp"
 #include "shell.hpp"
-#include "singleton.hpp"
 #include "watcher.hpp"
 
 RootWrapper::RootWrapper(QString rootPath)
@@ -29,7 +25,7 @@ RootWrapper::RootWrapper(QString rootPath)
 
 	this->reloadGraph(true);
 
-	if (this->root == nullptr) {
+	if (this->generation == nullptr) {
 		qCritical() << "could not create scene graph, exiting";
 		exit(-1); // NOLINT
 	}
@@ -37,31 +33,32 @@ RootWrapper::RootWrapper(QString rootPath)
 
 RootWrapper::~RootWrapper() {
 	// event loop may no longer be running so deleteLater is not an option
-	delete this->root;
+	if (this->generation != nullptr) {
+		delete this->generation->root;
+		this->generation->root = nullptr;
+	}
+
+	delete this->generation;
 }
 
 void RootWrapper::reloadGraph(bool hard) {
-	auto* oldEngine = this->engine;
-	this->engine = new QQmlEngine(this);
+	auto* generation = new EngineGeneration();
 
-	auto* app = QCoreApplication::instance();
-	QObject::connect(this->engine, &QQmlEngine::quit, app, &QCoreApplication::quit);
-	QObject::connect(this->engine, &QQmlEngine::exit, app, &QCoreApplication::exit);
-
-	if (this->root != nullptr) {
+	// todo: move into EngineGeneration
+	if (this->generation != nullptr) {
 		QuickshellSettings::reset();
-		SingletonRegistry::instance()->flip();
 	}
 
 	QDir::setCurrent(this->originalWorkingDirectory);
 
-	auto component = QQmlComponent(this->engine, QUrl::fromLocalFile(this->rootPath));
+	auto component = QQmlComponent(&generation->engine, QUrl::fromLocalFile(this->rootPath));
 
-	auto* obj = component.beginCreate(this->engine->rootContext());
+	auto* obj = component.beginCreate(generation->engine.rootContext());
 
 	if (obj == nullptr) {
 		qWarning() << component.errorString().toStdString().c_str();
 		qWarning() << "failed to create root component";
+		delete generation;
 		return;
 	}
 
@@ -69,31 +66,19 @@ void RootWrapper::reloadGraph(bool hard) {
 	if (newRoot == nullptr) {
 		qWarning() << "root component was not a Quickshell.ShellRoot";
 		delete obj;
+		delete generation;
 		return;
 	}
 
+	generation->root = newRoot;
+
 	component.completeCreate();
 
-	auto* oldRoot = this->root;
-	this->root = newRoot;
+	generation->onReload(hard ? nullptr : this->generation);
+	if (hard) delete this->generation;
+	this->generation = generation;
 
-	this->root->onReload(hard ? nullptr : oldRoot);
-
-	if (oldRoot != nullptr) {
-		oldRoot->deleteLater();
-
-		QTimer::singleShot(0, [this, newRoot]() {
-			if (this->root == newRoot) {
-				QuickshellPlugin::runOnReload();
-				PostReloadHook::postReloadTree(this->root);
-			}
-		});
-	} else {
-		PostReloadHook::postReloadTree(newRoot);
-		QuickshellPlugin::runOnReload();
-	}
-
-	delete oldEngine;
+	qInfo() << "Configuration Loaded";
 
 	this->onWatchFilesChanged();
 }

src/core/rootwrapper.hpp

@@ -6,7 +6,7 @@
 #include <qtmetamacros.h>
 #include <qurl.h>
 
-#include "shell.hpp"
+#include "generation.hpp"
 #include "watcher.hpp"
 
 class RootWrapper: public QObject {
@@ -25,8 +25,7 @@ private slots:
 
 private:
 	QString rootPath;
-	QQmlEngine* engine = nullptr;
-	ShellRoot* root = nullptr;
+	EngineGeneration* generation = nullptr;
 	FiletreeWatcher* configWatcher = nullptr;
 	QString originalWorkingDirectory;
 };

src/core/singleton.cpp

@@ -7,58 +7,48 @@
 #include <qqmlengine.h>
 #include <qurl.h>
 
+#include "generation.hpp"
 #include "reload.hpp"
 
 void Singleton::componentComplete() {
 	auto* context = QQmlEngine::contextForObject(this);
 
 	if (context == nullptr) {
-		qWarning() << "not registering singleton not created in the qml context:" << this;
+		qWarning() << "Not registering singleton not created in the qml context:" << this;
 		return;
 	}
 
 	auto url = context->baseUrl();
 
 	if (this->parent() != nullptr || context->contextObject() != this) {
-		qWarning() << "tried to register singleton" << this
+		qWarning() << "Tried to register singleton" << this
 		           << "which is not the root component of its file" << url;
 		return;
 	}
 
-	SingletonRegistry::instance()->install(url, this);
+	auto* generation = EngineGeneration::findObjectGeneration(this);
+
+	if (generation == nullptr) {
+		qWarning() << "Tried to register singleton" << this
+		           << "which has no associated engine generation" << url;
+		return;
+	}
+
+	generation->singletonRegistry.registerSingleton(url, this);
 	this->ReloadPropagator::componentComplete();
 }
 
-SingletonRegistry::~SingletonRegistry() {
-	delete this->previousRegistry;
-	delete this->currentRegistry;
-}
-
-void SingletonRegistry::install(const QUrl& url, Singleton* singleton) {
-	QObject* old = nullptr;
-
-	if (this->previousRegistry != nullptr) {
-		old = this->previousRegistry->value(url);
+void SingletonRegistry::registerSingleton(const QUrl& url, Singleton* singleton) {
+	if (this->registry.contains(url)) {
+		qWarning() << "Tried to register singleton twice for the same file" << url;
+		return;
 	}
 
-	if (this->currentRegistry == nullptr) {
-		this->currentRegistry = new QMap<QUrl, QObject*>();
+	this->registry.insert(url, singleton);
+}
+
+void SingletonRegistry::onReload(SingletonRegistry* old) {
+	for (auto [url, singleton]: this->registry.asKeyValueRange()) {
+		singleton->onReload(old == nullptr ? nullptr : old->registry.value(url));
 	}
-
-	this->currentRegistry->insert(url, singleton);
-	singleton->onReload(old);
-}
-
-void SingletonRegistry::flip() {
-	delete this->previousRegistry;
-	this->previousRegistry = this->currentRegistry;
-	this->currentRegistry = nullptr;
-}
-
-SingletonRegistry* SingletonRegistry::instance() {
-	static SingletonRegistry* instance = nullptr; // NOLINT
-	if (instance == nullptr) {
-		instance = new SingletonRegistry();
-	}
-	return instance;
 }

src/core/singleton.hpp

@@ -21,15 +21,10 @@ public:
 class SingletonRegistry {
 public:
 	SingletonRegistry() = default;
-	~SingletonRegistry();
-	Q_DISABLE_COPY_MOVE(SingletonRegistry);
 
-	void install(const QUrl& url, Singleton* singleton);
-	void flip();
-
-	static SingletonRegistry* instance();
+	void registerSingleton(const QUrl& url, Singleton* singleton);
+	void onReload(SingletonRegistry* old);
 
 private:
-	QMap<QUrl, QObject*>* previousRegistry = nullptr;
-	QMap<QUrl, QObject*>* currentRegistry = nullptr;
+	QMap<QUrl, Singleton*> registry;
 };