Started work to produce descriptive output for Properties in preparation for GUI generation

include/openspace/properties/property.h

@@ -200,6 +200,20 @@ public:
 	 */
 	std::string guiName() const;
 
+	/**
+	 * Returns the description for this Property that contains all necessary information
+	 * required for creating a GUI representation. The format of the description is a
+	 * valid Lua table, i.e., it is surrounded by a pair of <code>{</code> and
+	 * <code>}</code> with key,value pairs between. Each value can either be a number, a
+	 * string, a bool, or another table. The general values that every Property must set
+	 * are: <code>Identifier</code>, <code>Name</code>, <code>Type</code>. All other
+	 * values are specific to the type. If a Property does not override this method, an
+	 * empty string is returned.
+	 * \return The descriptive text for the Property that can be used for constructing a
+	 * GUI representation
+	 */
+	virtual std::string description() const;
+
 	/**
 	 * Sets the identifier of the group that this Property belongs to. Property groups can
 	 * be used, for example, by GUI application to visually group different properties,
@@ -274,6 +288,20 @@ public:
     const ghoul::Dictionary& metaData() const;
 
 protected:
+	static const std::string IdentifierKey;
+	static const std::string NameKey;
+	static const std::string TypeKey;
+	static const std::string MetaDataKey;
+
+	/**
+	 * Creates the information for the <code>MetaData</code> key-part of the Lua
+	 * description for the Property. The result can be included as one key-value pair in
+	 * the description text generated by subclasses. Only the metadata curated by the
+	 * Property class is used in this method.
+	 * \return The metadata information text for the property
+	 */
+	std::string generateMetaDataDescription() const;
+
 	/**
 	 * This method must be called by all subclasses whenever the encapsulated value has
 	 * changed and a potential listener has to be informed.

src/properties/property.cpp

@@ -34,7 +34,7 @@ namespace properties {
 namespace {
 	const std::string _loggerCat = "Property";
 	const std::string _metaDataKeyGuiName = "guiName";
-    const std::string _metaDataKeyGroup = "group";
+    const std::string _metaDataKeyGroup = "Group";
     const std::string _metaDataKeyVisible = "isVisible";
     const std::string _metaDataKeyReadOnly = "isReadOnly";
 
@@ -45,7 +45,11 @@ const std::string Property::ViewOptions::Color = "color";
 const std::string Property::ViewOptions::LightPosition = "lightPosition";
 const std::string Property::ViewOptions::PowerScaledCoordinate = "powerScaledCoordinate";
 const std::string Property::ViewOptions::PowerScaledScalar = "powerScaledScalar";
- 
+
+const std::string Property::IdentifierKey = "Identifier";
+const std::string Property::NameKey = "Name";
+const std::string Property::TypeKey = "Type";
+const std::string Property::MetaDataKey = "MetaData";
 
 Property::Property(std::string identifier, std::string guiName)
     : _identifier(std::move(identifier))
@@ -105,6 +109,10 @@ std::string Property::guiName() const {
     return std::move(result);
 }
 
+std::string Property::description() const {
+	return "";
+}
+
 void Property::setGroupIdentifier(std::string groupId) {
     _metaData.setValue(_metaDataKeyGroup, std::move(groupId));
 }
@@ -133,7 +141,6 @@ const ghoul::Dictionary& Property::metaData() const {
 
 void Property::onChange(std::function<void()> callback) {
     _onChangeCallback = std::move(callback);
-
 }
 
 PropertyOwner* Property::owner() const
@@ -151,5 +158,18 @@ void Property::notifyListener() {
 		_onChangeCallback();
 }
 
+std::string Property::generateMetaDataDescription() const {
+	bool isVisible, isReadOnly;
+	_metaData.getValue(_metaDataKeyVisible, isVisible);
+	_metaData.getValue(_metaDataKeyReadOnly, isReadOnly);
+
+	return
+		MetaDataKey + " = {" +
+			_metaDataKeyGroup +   " = '" + groupIdentifier() + "',\n" +
+			_metaDataKeyVisible + " = '" + (isVisible  ? "true" : "false") + "',\n" +
+			_metaDataKeyReadOnly +" = ;" + (isReadOnly ? "true" : "false") + "'\n" +
+		"},";
+}
+
 } // namespace properties
 } // namespace openspace