Start: Recreate start as a QtWidgets-based app

Removes all Start network access and dependency on Chromium for rendering. Written
entirely in C++ (no HTML, CSS, JS, etc.).

src/Mod/CleanStart/App/DisplayedFilesModel.h

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/****************************************************************************
+ *                                                                          *
+ *   Copyright (c) 2024 The FreeCAD Project Association AISBL               *
+ *                                                                          *
+ *   This file is part of FreeCAD.                                          *
+ *                                                                          *
+ *   FreeCAD is free software: you can redistribute it and/or modify it     *
+ *   under the terms of the GNU Lesser General Public License as            *
+ *   published by the Free Software Foundation, either version 2.1 of the   *
+ *   License, or (at your option) any later version.                        *
+ *                                                                          *
+ *   FreeCAD is distributed in the hope that it will be useful, but         *
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of             *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU       *
+ *   Lesser General Public License for more details.                        *
+ *                                                                          *
+ *   You should have received a copy of the GNU Lesser General Public       *
+ *   License along with FreeCAD. If not, see                                *
+ *   <https://www.gnu.org/licenses/>.                                       *
+ *                                                                          *
+ ***************************************************************************/
+
+#ifndef FREECAD_CLEANSTART_DISPLAYEDFILESMODEL_H
+#define FREECAD_CLEANSTART_DISPLAYEDFILESMODEL_H
+
+#include <QAbstractListModel>
+#include <Base/Parameter.h>
+#include <QtQml/QQmlTypeInfo>
+
+#include "../CleanStartGlobal.h"
+
+namespace CleanStart
+{
+
+enum class DisplayedFilesModelRoles
+{
+    baseName = Qt::UserRole + 1,
+    image,
+    size,
+    author,
+    creationTime,
+    modifiedTime,
+    description,
+    company,
+    license,
+    path
+};
+
+using FileStats = std::map<DisplayedFilesModelRoles, std::string>;
+
+/// A model for displaying a list of files including a thumbnail or icon, plus various file statistics.
+class CleanStartExport DisplayedFilesModel: public QAbstractListModel
+{
+    Q_OBJECT
+public:
+    explicit DisplayedFilesModel(QObject* parent = nullptr);
+
+    int rowCount(const QModelIndex& parent = QModelIndex()) const override;
+
+    QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
+
+    void addFile(const QString &filePath);
+
+    void clear();
+
+protected:
+    /// For communication with QML, define the text version of each role name defined in the
+    /// DisplayedFilesModelRoles enumeration
+    QHash<int, QByteArray> roleNames() const override;
+
+    /// Destroy and recreate the cache of info about the files. Should be connected to a signal
+    /// indicating when some piece of information about the files has changed. Does NOT generate
+    /// a new list of files, only re-caches the existing ones.
+    void reCacheFileInfo();
+
+private:
+
+    std::vector<FileStats> _fileInfoCache;
+    QMap<QString, QByteArray> _imageCache;
+};
+
+}  // namespace CleanStart
+
+#endif  // FREECAD_CLEANSTART_DISPLAYEDFILESMODEL_H