core/objectrepeater: add ObjectRepeater

src/core/objectrepeater.hpp

@@ -0,0 +1,86 @@
+#pragma once
+
+#include <qabstractitemmodel.h>
+#include <qobject.h>
+#include <qqmlcomponent.h>
+#include <qqmlintegration.h>
+#include <qtmetamacros.h>
+#include <qtypes.h>
+#include <qvariant.h>
+
+#include "model.hpp"
+
+///! A Repeater / for loop / map for non Item derived objects.
+/// The ObjectRepeater creates instances of the provided delegate for every entry in the
+/// given model, similarly to a [Repeater] but for non visual types.
+///
+/// [Repeater]: https://doc.qt.io/qt-6/qml-qtquick-repeater.html
+class ObjectRepeater: public ObjectModel<QObject> {
+	Q_OBJECT;
+	/// The model providing data to the ObjectRepeater.
+	///
+	/// Currently accepted model types are QML `list<T>` lists, javascript arrays,
+	/// and [QAbstractListModel] derived models, though only one column will be repeated
+	/// from the latter.
+	///
+	/// Note: [ObjectModel] is a [QAbstractListModel] with a single column.
+	///
+	/// [QAbstractListModel]: https://doc.qt.io/qt-6/qabstractlistmodel.html
+	/// [ObjectModel]: ../objectmodel
+	Q_PROPERTY(QVariant model READ model WRITE setModel NOTIFY modelChanged);
+	/// The delegate component to repeat.
+	///
+	/// The delegate is given the same properties as in a Repeater, except `index` which
+	/// is not currently implemented.
+	///
+	/// If the model is a `list<T>` or javascript array, a `modelData` property will be
+	/// exposed containing the entry from the model. If the model is a [QAbstractListModel],
+	/// the roles from the model will be exposed.
+	///
+	/// Note: [ObjectModel] has a single role named `modelData` for compatibility with normal lists.
+	///
+	/// [QAbstractListModel]: https://doc.qt.io/qt-6/qabstractlistmodel.html
+	/// [ObjectModel]: ../objectmodel
+	Q_PROPERTY(QQmlComponent* delegate READ delegate WRITE setDelegate NOTIFY delegateChanged);
+	Q_CLASSINFO("DefaultProperty", "delegate");
+	QML_ELEMENT;
+
+public:
+	explicit ObjectRepeater(QObject* parent = nullptr): ObjectModel(parent) {}
+
+	[[nodiscard]] QVariant model() const;
+	void setModel(QVariant model);
+
+	[[nodiscard]] QQmlComponent* delegate() const;
+	void setDelegate(QQmlComponent* delegate);
+
+signals:
+	void modelChanged();
+	void delegateChanged();
+
+private slots:
+	void onDelegateDestroyed();
+	void onModelDestroyed();
+	void onModelRowsInserted(const QModelIndex& parent, int first, int last);
+	void onModelRowsAboutToBeRemoved(const QModelIndex& parent, int first, int last);
+
+	void onModelRowsMoved(
+	    const QModelIndex& sourceParent,
+	    int sourceStart,
+	    int sourceEnd,
+	    const QModelIndex& destParent,
+	    int destStart
+	);
+
+	void onModelAboutToBeReset();
+
+private:
+	void reloadElements();
+	void insertModelElements(QAbstractItemModel* model, int first, int last);
+	void insertComponent(qsizetype index, const QVariantMap& properties);
+	void removeComponent(qsizetype index);
+
+	QVariant mModel;
+	QAbstractItemModel* itemModel = nullptr;
+	QQmlComponent* mDelegate = nullptr;
+};