core/variants: restructure Variants to match the design of Repeater

src/core/qmlglobal.hpp

@@ -83,12 +83,12 @@ class QuickshellGlobal: public QObject {
 	/// ```qml
 	/// ShellRoot {
 	///   Variants {
-	///     ShellWindow {
-	///       // ...
-	///     }
-	///
 	///     // see Variants for details
-	///     variants: Quickshell.screens.map(screen => ({ screen }))
+	///     variants: Quickshell.screens
+	///     PanelWindow {
+	///       property var modelData
+	///       screen: modelData
+	///     }
 	///   }
 	/// }
 	/// ```

src/core/variants.cpp

@@ -6,6 +6,9 @@
 #include <qlogging.h>
 #include <qobject.h>
 #include <qqmlengine.h>
+#include <qqmllist.h>
+#include <qtmetamacros.h>
+#include <qvariant.h>
 
 #include "reload.hpp"
 
@@ -17,12 +20,18 @@ void Variants::onReload(QObject* oldInstance) {
 		if (old != nullptr) {
 			auto& values = old->instances.values;
 
+			if (variant.canConvert<QVariantMap>()) {
+				auto variantMap = variant.value<QVariantMap>();
+
 				int matchcount = 0;
 				int matchi = 0;
 				int i = 0;
-			for (auto& [valueSet, _]: values) {
+				for (auto& [value, _]: values) {
+					if (!value.canConvert<QVariantMap>()) continue;
+					auto valueSet = value.value<QVariantMap>();
+
 					int count = 0;
-				for (auto& [k, v]: variant.toStdMap()) {
+					for (auto [k, v]: variantMap.asKeyValueRange()) {
 						if (valueSet.contains(k) && valueSet.value(k) == v) {
 							count++;
 						}
@@ -39,6 +48,17 @@ void Variants::onReload(QObject* oldInstance) {
 				if (matchcount > 0) {
 					oldInstance = values.takeAt(matchi).second;
 				}
+			} else {
+				int i = 0;
+				for (auto& [value, _]: values) {
+					if (variant == value) {
+						oldInstance = values.takeAt(i).second;
+						break;
+					}
+
+					i++;
+				}
+			}
 		}
 
 		auto* instance = qobject_cast<Reloadable*>(instanceObj);
@@ -50,9 +70,32 @@ void Variants::onReload(QObject* oldInstance) {
 	this->loaded = true;
 }
 
-void Variants::setVariants(QVariantList variants) {
-	this->mVariants = std::move(variants);
+QVariant Variants::model() const { return QVariant::fromValue(this->mModel); }
+
+void Variants::setModel(const QVariant& model) {
+	if (model.canConvert<QVariantList>()) {
+		this->mModel = model.value<QVariantList>();
+	} else if (model.canConvert<QQmlListReference>()) {
+		auto list = model.value<QQmlListReference>();
+		if (!list.isReadable()) {
+			qWarning() << "Non readable list" << model << "assigned to Variants.model, Ignoring.";
+			return;
+		}
+
+		QVariantList model;
+		auto size = list.count();
+		for (auto i = 0; i < size; i++) {
+			model.push_back(QVariant::fromValue(list.at(i)));
+		}
+
+		this->mModel = std::move(model);
+	} else {
+		qWarning() << "Non list data" << model << "assigned to Variants.model, Ignoring.";
+		return;
+	}
+
 	this->updateVariants();
+	emit this->modelChanged();
 }
 
 void Variants::componentComplete() {
@@ -61,14 +104,14 @@ void Variants::componentComplete() {
 }
 
 void Variants::updateVariants() {
-	if (this->mComponent == nullptr) {
+	if (this->mDelegate == nullptr) {
 		qWarning() << "Variants instance does not have a component specified";
 		return;
 	}
 
 	// clean up removed entries
 	for (auto iter = this->instances.values.begin(); iter < this->instances.values.end();) {
-		if (this->mVariants.contains(iter->first)) {
+		if (this->mModel.contains(iter->first)) {
 			iter++;
 		} else {
 			iter->second->deleteLater();
@@ -76,32 +119,31 @@ void Variants::updateVariants() {
 		}
 	}
 
-	for (auto iter = this->mVariants.begin(); iter < this->mVariants.end(); iter++) {
-		auto& variantObj = *iter;
-		if (!variantObj.canConvert<QVariantMap>()) {
-			qWarning() << "value passed to Variants is not an object and will be ignored:" << variantObj;
-		} else {
-			auto variant = variantObj.value<QVariantMap>();
-
-			for (auto iter2 = this->mVariants.begin(); iter2 < iter; iter2++) {
-				if (*iter2 == variantObj) {
+	for (auto iter = this->mModel.begin(); iter < this->mModel.end(); iter++) {
+		auto& variant = *iter;
+		for (auto iter2 = this->mModel.begin(); iter2 < iter; iter2++) {
+			if (*iter2 == variant) {
 				qWarning() << "same value specified twice in Variants, duplicates will be ignored:"
-					           << variantObj;
+				           << variant;
 				goto outer;
 			}
 		}
 
+		{
 			if (this->instances.contains(variant)) {
 				continue; // we dont need to recreate this one
 			}
 
-			auto* instance = this->mComponent->createWithInitialProperties(
-			    variant,
-			    QQmlEngine::contextForObject(this->mComponent)
+			auto variantMap = QVariantMap();
+			variantMap.insert("modelData", variant);
+
+			auto* instance = this->mDelegate->createWithInitialProperties(
+			    variantMap,
+			    QQmlEngine::contextForObject(this->mDelegate)
 			);
 
 			if (instance == nullptr) {
-				qWarning() << this->mComponent->errorString().toStdString().c_str();
+				qWarning() << this->mDelegate->errorString().toStdString().c_str();
 				qWarning() << "failed to create variant with object" << variant;
 				continue;
 			}

src/core/variants.hpp

@@ -8,7 +8,9 @@
 #include <qqmlcomponent.h>
 #include <qqmlparserstatus.h>
 #include <qtmetamacros.h>
+#include <qvariant.h>
 
+#include "doc.hpp"
 #include "reload.hpp"
 
 // extremely inefficient map
@@ -22,39 +24,54 @@ public:
 	QList<QPair<K, V>> values;
 };
 
-///! Creates instances of a component based on a given set of variants.
+///! Creates instances of a component based on a given model.
 /// Creates and destroys instances of the given component when the given property changes.
 ///
+/// `Variants` is similar to [Repeater] except it is for *non Item* objects, and acts as
+/// a reload scope.
+///
+/// Each non duplicate value passed to [model](#prop.model) will create a new instance of
+/// [delegate](#prop.delegate) with its `modelData` property set to that value.
+///
 /// See [Quickshell.screens] for an example of using `Variants` to create copies of a window per
 /// screen.
 ///
 /// > [!WARNING] BUG: Variants currently fails to reload children if the variant set is changed as
 /// > it is instantiated. (usually due to a mutation during variant creation)
 ///
+/// [Repeater]: https://doc.qt.io/qt-6/qml-qtquick-repeater.html
 /// [Quickshell.screens]: ../quickshell#prop.screens
 class Variants: public Reloadable {
 	Q_OBJECT;
-	/// The component to create instances of
-	Q_PROPERTY(QQmlComponent* component MEMBER mComponent);
+	/// The component to create instances of.
+	///
+	/// The delegate should define a `modelData` property that will be popuplated with a value
+	/// from the [model](#prop.model).
+	Q_PROPERTY(QQmlComponent* delegate MEMBER mDelegate);
 	/// The list of sets of properties to create instances with.
 	/// Each set creates an instance of the component, which are updated when the input sets update.
-	Q_PROPERTY(QList<QVariant> variants MEMBER mVariants WRITE setVariants);
-	Q_CLASSINFO("DefaultProperty", "component");
+	QSDOC_PROPERTY_OVERRIDE(QList<QVariant> model READ model WRITE setModel NOTIFY modelChanged);
+	QSDOC_HIDE Q_PROPERTY(QVariant model READ model WRITE setModel NOTIFY modelChanged);
+	Q_CLASSINFO("DefaultProperty", "delegate");
 	QML_ELEMENT;
 
 public:
 	explicit Variants(QObject* parent = nullptr): Reloadable(parent) {}
 
 	void onReload(QObject* oldInstance) override;
-
 	void componentComplete() override;
 
+	[[nodiscard]] QVariant model() const;
+	void setModel(const QVariant& model);
+
+signals:
+	void modelChanged();
+
 private:
-	void setVariants(QVariantList variants);
 	void updateVariants();
 
-	QQmlComponent* mComponent = nullptr;
-	QVariantList mVariants;
-	AwfulMap<QVariantMap, QObject*> instances;
+	QQmlComponent* mDelegate = nullptr;
+	QVariantList mModel;
+	AwfulMap<QVariant, QObject*> instances;
 	bool loaded = false;
 };