Settings variable abstract base, additional validation, and reading/writing JSON

scwx-qt/source/scwx/qt/settings/settings_variable_base.hpp

@@ -0,0 +1,76 @@
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include <boost/json/object.hpp>
+
+namespace scwx
+{
+namespace qt
+{
+namespace settings
+{
+
+/**
+ * @brief Settings Variable base class
+ */
+class SettingsVariableBase
+{
+protected:
+   explicit SettingsVariableBase(const std::string& name);
+   ~SettingsVariableBase();
+
+public:
+   SettingsVariableBase(const SettingsVariableBase&)            = delete;
+   SettingsVariableBase& operator=(const SettingsVariableBase&) = delete;
+
+   SettingsVariableBase(SettingsVariableBase&&) noexcept;
+   SettingsVariableBase& operator=(SettingsVariableBase&&) noexcept;
+
+   std::string name() const;
+
+   /**
+    * Sets the current value of the settings variable to default.
+    */
+   virtual void SetValueToDefault() = 0;
+
+   /**
+    * Sets the current value of the settings variable to the staged value.
+    */
+   virtual void Commit() = 0;
+
+   /**
+    * Reads the value from the JSON object. If the read value is out of range,
+    * the value is set to the minimum or maximum. If the read value fails
+    * validation, the value is set to default.
+    *
+    * @param json JSON object to read
+    *
+    * @return true if the read value is valid, false if the value was modified.
+    */
+   virtual bool ReadValue(const boost::json::object& json) = 0;
+
+   /**
+    * Writes the current value to the JSON object.
+    *
+    * @param json JSON object to write
+    */
+   virtual void WriteValue(boost::json::object& json) const = 0;
+
+protected:
+   friend bool  operator==(const SettingsVariableBase& lhs,
+                          const SettingsVariableBase& rhs);
+   virtual bool Equals(const SettingsVariableBase& o) const;
+
+private:
+   class Impl;
+   std::unique_ptr<Impl> p;
+};
+
+bool operator==(const SettingsVariableBase& lhs,
+                const SettingsVariableBase& rhs);
+
+} // namespace settings
+} // namespace qt
+} // namespace scwx