screens: make screen list changes not recreate QuickshellScreenInfos

Fixes Variants recreating windows on existing screens and causing flickering.

src/core/qmlglobal.cpp

@@ -120,17 +120,31 @@ void QuickshellGlobal::setWatchFiles(bool watchFiles) { // NOLINT
 
 void QuickshellGlobal::updateScreens() {
 	auto screens = QGuiApplication::screens();
-	this->mScreens.resize(screens.size());
+	auto newScreens = QList<QuickshellScreenInfo*>();
 
-	for (auto i = 0; i < screens.size(); i++) {
-		if (this->mScreens[i] != nullptr) {
-			this->mScreens[i]->screen = nullptr;
-			this->mScreens[i]->setParent(nullptr); // delete if not owned by the js engine
+	for (auto* newScreen: screens) {
+		for (auto i = 0; i < this->mScreens.length(); i++) {
+			auto* oldScreen = this->mScreens[i];
+			if (newScreen == oldScreen->screen) {
+				newScreens.push_back(oldScreen);
+				this->mScreens.remove(i);
+				goto next;
+			}
 		}
 
-		this->mScreens[i] = new QuickshellScreenInfo(this, screens[i]);
+		{
+			auto* si = new QuickshellScreenInfo(this, newScreen);
+			QQmlEngine::setObjectOwnership(si, QQmlEngine::CppOwnership);
+			newScreens.push_back(si);
+		}
+	next:;
 	}
 
+	for (auto* oldScreen: this->mScreens) {
+		oldScreen->deleteLater();
+	}
+
+	this->mScreens = newScreens;
 	emit this->screensChanged();
 }
 

src/core/qmlscreen.cpp

@@ -109,3 +109,21 @@ void QuickshellScreenInfo::screenDestroyed() {
 	this->screen = nullptr;
 	this->dangling = true;
 }
+
+QDebug operator<<(QDebug debug, const QuickshellScreenInfo* screen) {
+	if (screen == nullptr) {
+		debug.nospace() << "QuickshellScreenInfo(nullptr)";
+		return debug;
+	}
+
+	debug.nospace() << screen->metaObject()->className() << '(' << static_cast<const void*>(screen)
+	                << ", screen=" << screen->screen << ')';
+
+	return debug;
+}
+
+QString QuickshellScreenInfo::toString() const {
+	QString str;
+	QDebug(&str) << this;
+	return str;
+}

src/core/qmlscreen.hpp

@@ -1,9 +1,12 @@
 #pragma once
 
+#include <qdebug.h>
 #include <qnamespace.h>
 #include <qobject.h>
+#include <qqmlinfo.h>
 #include <qqmlintegration.h>
 #include <qscreen.h>
+#include <qtclasshelpermacros.h>
 #include <qtmetamacros.h>
 #include <qtypes.h>
 
@@ -55,6 +58,8 @@ public:
 	[[nodiscard]] Qt::ScreenOrientation orientation() const;
 	[[nodiscard]] Qt::ScreenOrientation primaryOrientation() const;
 
+	[[nodiscard]] Q_INVOKABLE QString toString() const;
+
 	QScreen* screen;
 
 private:
@@ -71,3 +76,5 @@ signals:
 private slots:
 	void screenDestroyed();
 };
+
+QDebug operator<<(QDebug debug, const QuickshellScreenInfo* screen);

src/core/variants.cpp

@@ -46,6 +46,8 @@ void Variants::onReload(QObject* oldInstance) {
 		if (instance != nullptr) instance->onReload(oldInstance);
 		else Reloadable::reloadChildrenRecursive(instanceObj, oldInstance);
 	}
+
+	this->loaded = true;
 }
 
 void Variants::setVariants(QVariantList variants) {
@@ -108,6 +110,11 @@ void Variants::updateVariants() {
 
 			instance->setParent(this);
 			this->instances.insert(variant, instance);
+
+			if (this->loaded) {
+				if (auto* reloadable = qobject_cast<Reloadable*>(instance)) reloadable->onReload(nullptr);
+				else Reloadable::reloadChildrenRecursive(instance, nullptr);
+			}
 		}
 
 	outer:;

src/core/variants.hpp

@@ -53,4 +53,5 @@ private:
 	QQmlComponent* mComponent = nullptr;
 	QVariantList mVariants;
 	AwfulMap<QVariantMap, QObject*> instances;
+	bool loaded = false;
 };