Introduces Configurable::Device and implements it for the Electron.

Configurable::Device covers devices that have user-facing configuration options, listing them and accepting them.

Configurable/Configurable.hpp

@@ -0,0 +1,76 @@
+//
+//  Configurable.h
+//  Clock Signal
+//
+//  Created by Thomas Harte on 17/11/2017.
+//  Copyright © 2017 Thomas Harte. All rights reserved.
+//
+
+#ifndef Configurable_h
+#define Configurable_h
+
+#include <map>
+#include <string>
+#include <vector>
+
+namespace Configurable {
+
+/*!
+	The Option class hierarchy provides a way for components, machines, etc, to provide a named
+	list of typed options to which they can respond.
+*/
+struct Option {
+	std::string long_name;
+	std::string short_name;
+	virtual ~Option() {}
+
+	Option(const std::string &long_name, const std::string &short_name) : long_name(long_name), short_name(short_name) {}
+};
+
+struct BooleanOption: public Option {
+	BooleanOption(const std::string &long_name, const std::string &short_name) : Option(long_name, short_name) {}
+};
+
+struct ListOption: public Option {
+	std::vector<std::string> options;
+	ListOption(const std::string &long_name, const std::string &short_name, const std::vector<std::string> &options) : Option(long_name, short_name), options(options) {}
+};
+
+/*!
+	Selections are responses to Options.
+*/
+struct Selection {
+	virtual ~Selection() {}
+};
+
+struct BooleanSelection: public Selection {
+	bool value;
+	BooleanSelection(bool value) : value(value) {}
+};
+
+struct ListSelection: public Selection {
+	std::string value;
+	ListSelection(const std::string value) : value(value) {}
+};
+
+using SelectionSet = std::map<std::string, std::unique_ptr<Selection>>;
+
+/*!
+	A Configuratble provides the options that it responds to and allows selections to be set.
+*/
+struct Device {
+	virtual std::vector<std::unique_ptr<Option>> get_options() = 0;
+	virtual void set_selections(const SelectionSet &selection_by_option) = 0;
+	virtual SelectionSet get_accurate_selections() = 0;
+	virtual SelectionSet get_user_friendly_selections() = 0;
+};
+
+template <typename T> T *selection(const Configurable::SelectionSet &selections_by_option, const std::string &name) {
+	auto selection = selections_by_option.find(name);
+	if(selection == selections_by_option.end()) return nullptr;
+	return dynamic_cast<T *>(selection->second.get());
+}
+
+}
+
+#endif /* Configurable_h */