Merge pull request #1456 from Kellermorph/terminal-potential

Terminal: rename potential separation to function separation

sources/conductorproperties.cpp

@@ -851,6 +851,32 @@ void ConductorProperties::applyChanges(const ConductorProperties &before,
 		singleLineProperties.setPhasesCount(slp_after.phasesCount());
 }
 
+/**
+	@brief ConductorProperties::applyTensionProtocolChange
+	Copy into this the voltage / protocol when it differs between before
+	and after, and leave every other attribute as it is. This is the one
+	property a function separated terminal element lets through
+	(@see Conductor::functionSeparatedConductors): the voltage /
+	protocol describes the electrical node itself, while the text, the
+	function, the wire color... describe one side of the separation and
+	stay local to it.
+
+	Both arguments describe one edit -- what was shown to the user, and
+	what the user made of it -- so that only an edit which really
+	changed the voltage / protocol passes it on. Passing the far wire's
+	own properties as @a before instead would make every edit overwrite
+	its voltage: the two sides differ on that field just as often as
+	not, so the comparison would hold no matter what was edited.
+	@param before : the properties as they were shown to the user
+	@param after : the properties after the user's edit
+*/
+void ConductorProperties::applyTensionProtocolChange(const ConductorProperties &before,
+						     const ConductorProperties &after)
+{
+	if (before.m_tension_protocol != after.m_tension_protocol)
+		m_tension_protocol = after.m_tension_protocol;
+}
+
 /**
 	@brief ConductorProperties::defaultProperties
 	@return the default properties stored in the setting file