LT-22822: Don't display autogenerated Natural Classes

DistFiles/Language Explorer/Configuration/Grammar/areaConfiguration.xml

@@ -439,7 +439,9 @@
 					<recordList owner="MorphologicalData" property="Phonemes"/>
 		</clerk>
 				<clerk id="naturalClasses">
-					<recordList owner="MorphologicalData" property="NaturalClasses"/>
+					<recordList owner="MorphologicalData" property="NaturalClasses">
+					  <dynamicloaderinfo assemblyPath="MorphologyEditorDll.dll" class="SIL.FieldWorks.XWorks.MorphologyEditor.NaturalClassRecordList"/>
+					</recordList>
 				</clerk>
 				<clerk id="environments">
 					<recordList owner="MorphologicalData" property="Environments"/>

Src/LexText/Morphology/AffixRuleFormulaControl.cs

@@ -841,7 +841,9 @@ public override void SetMappingNaturalClass(SelectionHelper sel = null)
 			var natClasses = new HashSet<ICmObject>();
 			foreach (var nc in m_cache.LangProject.PhonologicalDataOA.NaturalClassesOS)
 			{
-				if (nc.ClassID == PhNCFeaturesTags.kClassId)
+				// Rule mappings only allow feature-based, user-defined natural classes
+				// to be selected.
+				if (nc is IPhNCFeatures featNC && IsFeatureBasedNCUserDefined(featNC))
 					natClasses.Add(nc);
 			}
 			var selectedNc = DisplayChooser(MEStrings.ksRuleNCOpt, MEStrings.ksRuleNCChooserLink,

Src/LexText/Morphology/AffixRuleFormulaSlice.cs

@@ -62,7 +62,11 @@ public bool OnMappingSetNaturalClass(object args)
 		public bool OnDisplayMappingJumpToNaturalClass(object commandObject, ref XCore.UIItemDisplayProperties display)
 		{
 			CheckDisposed();
-			bool enable = AffixRuleFormulaControl.IsNCIndexCurrent;
+			// Note that a mapping's Natural Class is always feature-based.
+			// For feature-based NCs, we only want to allow jumping to the NC
+			// if it is user-defined.
+			var mapping = AffixRuleFormulaControl.CurrentObject as IMoModifyFromInput;
+			bool enable = mapping != null && RuleFormulaControl.IsFeatureBasedNCUserDefined(mapping.ModificationRA);
 			display.Enabled = enable;
 			display.Visible = enable;
 			return true;

Src/LexText/Morphology/MorphologyEditorDllTests/NaturalClassRecordListTests.cs

@@ -0,0 +1,64 @@
+// Copyright (c) 2026 SIL International
+// This software is licensed under the LGPL, version 2.1 or later
+// (http://www.gnu.org/licenses/lgpl-2.1.html)
+
+using System.Collections.Generic;
+using System.Linq;
+using NUnit.Framework;
+using SIL.LCModel;
+
+namespace SIL.FieldWorks.XWorks.MorphologyEditor
+{
+	/// <summary>
+	/// Tests to confirm that <see cref="NaturalClassRecordList"/> includes every
+	/// natural class except a feature-based one generated automatically for a rule.
+	/// </summary>
+	[TestFixture]
+	public class NaturalClassRecordListTests : RuleFormulaVcTestBase
+	{
+		private IEnumerable<int> NCRecordList(params ICmObject[] natClasses)
+		{
+			return NaturalClassRecordList.ExcludeAutoGenerated(
+				natClasses.Select(nc => nc.Hvo), Cache);
+		}
+		[Test]
+		public void AutoGeneratedClass_IsExcluded()
+		{
+			IPhNCFeatures natClass = AddAutoGeneratedFeatureNaturalClass("s to n",
+				new Dictionary<string, string> { { "vd", "+" } });
+
+			// Since the only NC is autogenerated, the NC record list should be empty
+			Assert.That(NCRecordList(natClass), Is.Empty);
+		}
+
+		[Test]
+		public void NamedFeatureClass_IsIncluded()
+		{
+			IPhNCFeatures natClass = AddFeatureNaturalClass("Voiced", "Vd",
+				new Dictionary<string, string> { { "vd", "+" } });
+
+			Assert.That(NCRecordList(natClass), Is.EqualTo(new[] { natClass.Hvo }));
+		}
+
+		/// <summary>
+		/// A feature-based class the user creates starts with no name, so an unnamed class must
+		/// be included for the user to be able to name it.
+		/// </summary>
+		[Test]
+		public void UnnamedFeatureClass_IsIncluded()
+		{
+			IPhNCFeatures natClass = AddFeatureNaturalClass(null, null,
+				new Dictionary<string, string> { { "vd", "+" } });
+
+			Assert.That(NCRecordList(natClass), Is.EqualTo(new[] { natClass.Hvo }));
+		}
+
+		[Test]
+		public void SegmentClass_IsIncluded()
+		{
+			IPhNCSegments natClass = AddSegmentNaturalClass("Vowels", "V");
+
+			Assert.That(NCRecordList(natClass), Is.EqualTo(new[] { natClass.Hvo }));
+		}
+	}
+}

Src/LexText/Morphology/MorphologyEditorDllTests/RuleFormulaControlNaturalClassNameTests.cs

@@ -21,56 +21,62 @@ public class RuleFormulaControlNaturalClassNameTests : RuleFormulaVcTestBase
 		[Test]
 		public void NoClass_IsNotUserDefined()
 		{
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(null), Is.False);
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(null), Is.False);
 		}
 
 		/// <summary>
-		/// The check answers whether a class carries a name the user gave it, and an unnamed
-		/// class carries none. Set Phonological Features relies on that answer to keep
-		/// offering feature edits on unnamed classes (LT-22576).
+		/// A user defined class can have no name, while an auto-generated one will always have
+		/// a generated name. Check that if the class has no name, it is flagged as user defined.
 		/// </summary>
 		[Test]
-		public void ClassWithNoName_IsNotUserDefined()
+		public void ClassWithNoName_IsUserDefined()
 		{
 			IPhNCFeatures natClass = AddFeatureNaturalClass(null, "Vd",
 				new FeatVals { { "vd", "+" } });
 
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.False,
-				"an unnamed class carries no name the user gave it");
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True,
+				"an unnamed class must be user defined");
 		}
 
+		/// <summary>
+		/// A user defined class can have an empty name, while an auto-generated one will always
+		/// have a nonempty generated name. Check that if the class's name is empty,
+		/// it is flagged as user defined.
+		/// </summary>
 		[Test]
-		public void ClassWithAnEmptyName_IsNotUserDefined()
+		public void ClassWithAnEmptyName_IsUserDefined()
 		{
 			IPhNCFeatures natClass = AddFeatureNaturalClass(string.Empty, "Vd",
 				new FeatVals { { "vd", "+" } });
 
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.False,
-				"an empty name is not a name the user gave the class");
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True,
+				"a class with an empty name must be user defined");
 		}
 
 		[Test]
 		public void ClassNamedForARule_IsNotUserDefined()
 		{
-			IPhNCFeatures natClass = AddRuleNamedFeatureNaturalClass("s to n",
+			IPhNCFeatures natClass = AddAutoGeneratedFeatureNaturalClass("s to n",
 				new FeatVals { { "vd", "+" } });
 
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.False);
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.False);
 		}
 
 		/// <summary>
-		/// Projects hold rule-generated names that carry a prefix ahead of the generated text, so
-		/// the generated text is recognised wherever it sits in the name.
+		/// If a project contains a NC whose name was generated but a user has added text before
+		/// or after the generated name, it is user defined.
 		/// </summary>
 		[Test]
-		public void ClassNamedForARuleBehindAPrefix_IsNotUserDefined()
+		public void ClassNamedForARuleWithUserAssignedPrefixOrPostfix_IsUserDefined()
 		{
 			IPhNCFeatures natClass = AddFeatureNaturalClass(null, null,
 				new FeatVals { { "vd", "+" } });
 			natClass.Name.SetUserWritingSystem("Phonemes s and t - "
 				+ string.Format(MEStrings.ksRuleNCFeatsName, "s to n"));
-
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.False);
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True);
+			natClass.Name.SetUserWritingSystem(string.Format(MEStrings.ksRuleNCFeatsName, "s to n")
+				+ " - phonemes s and t");
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True);
 		}
 
 		[Test]
@@ -79,7 +85,7 @@ public void NamedClass_IsUserDefined()
 			IPhNCFeatures natClass = AddFeatureNaturalClass("Voiced", "Vd",
 				new FeatVals { { "vd", "+" } });
 
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.True);
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True);
 		}
 
 		/// <summary>
@@ -101,16 +107,52 @@ public void ClassNamedInAnAnalysisWritingSystemOtherThanTheUserOne_IsUserDefined
 				"the name must reach the check through the analysis writing system, "
 				+ "not through a placeholder");
 
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.True);
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True);
 		}
 
 		[Test]
 		public void NamedClassWithNoFeatures_IsUserDefined()
 		{
 			IPhNCFeatures natClass = AddFeatureNaturalClass("Voiced", "Vd", new FeatVals());
 
-			Assert.That(RuleFormulaControl.IsFeatureBasedNCNameUserDefined(natClass), Is.True,
+			Assert.That(RuleFormulaControl.IsFeatureBasedNCUserDefined(natClass), Is.True,
 				"a name qualifies a class whatever it carries for features");
 		}
+
+		/// <summary>
+		/// No class is neither user defined nor auto-generated.
+		/// </summary>
+		[Test]
+		public void NullClass_IsNotAutoGenerated()
+		{
+			Assert.That(RuleFormulaControl.IsAutoGeneratedNaturalClass(null), Is.False);
+		}
+
+		/// <summary>
+		/// A translation may put the rule name first, leaving no generated text before the
+		/// placeholder. Its generated names are still recognized, but ordinary names are not.
+		/// </summary>
+		[Test]
+		public void FormatStartingWithRuleName_RecognisesGeneratedName()
+		{
+			const string format = "{0} rule: created automatically";
+
+			Assert.That(RuleFormulaControl.IsAutoGeneratedName(string.Format(format, "s to n"), format),
+				Is.True, "a name generated from the format is recognized");
+			Assert.That(RuleFormulaControl.IsAutoGeneratedName("Voiced", format), Is.False,
+				"an empty stub before the rule name must not match every name");
+		}
+
+		/// <summary>
+		/// A translation lacking the rule name placeholder must not break recognition; no name
+		/// counts as generated from it.
+		/// </summary>
+		[Test]
+		public void FormatWithoutPlaceholder_RecognisesNothing()
+		{
+			const string format = "Created automatically for rule";
+
+			Assert.That(RuleFormulaControl.IsAutoGeneratedName(format, format), Is.False);
+		}
 	}
 }