frontend: Add utilities

src/frontend/select_files_dialog.h

@@ -0,0 +1,29 @@
+// Copyright 2020 threeSD Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <QDialog>
+
+class QWidget;
+
+namespace Ui {
+class SelectFilesDialog;
+}
+
+class SelectFilesDialog : public QDialog {
+    Q_OBJECT
+
+public:
+    explicit SelectFilesDialog(QWidget* parent, bool source_is_dir, bool destination_is_dir);
+    ~SelectFilesDialog() override;
+
+    std::pair<QString, QString> GetResults() const;
+
+private:
+    std::unique_ptr<Ui::SelectFilesDialog> ui;
+    bool source_is_dir;      // Whether Source should be a directory
+    bool destination_is_dir; // Whether Destination should be a directory
+};