scoper provider in Java

dsl/org.eclipse.emf.parsley.dsl/src/org/eclipse/emf/parsley/dsl/GenerateEmfParsleyDsl.mwe2

@@ -46,6 +46,9 @@ Workflow {
 			validator = {
 				// composedCheck = "org.eclipse.xtext.validation.NamesAreUniqueValidator"
 			}
+			scopeProvider = {
+				generateXtendStub = false
+			}
 		}
 	}
 }

dsl/org.eclipse.emf.parsley.dsl/src/org/eclipse/emf/parsley/dsl/scoping/EmfParsleyDslScopeProvider.java

@@ -0,0 +1,105 @@
+/**
+ * generated by Xtext 2.10.0-SNAPSHOT
+ */
+package org.eclipse.emf.parsley.dsl.scoping;
+
+import static org.eclipse.xtext.scoping.Scopes.scopedElementsFor;
+import static org.eclipse.xtext.xbase.lib.IterableExtensions.filter;
+
+import java.beans.Introspector;
+import java.util.Objects;
+
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.emf.ecore.EClassifier;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.EReference;
+import org.eclipse.emf.parsley.dsl.model.EmfFeatureAccess;
+import org.eclipse.emf.parsley.dsl.util.EmfParsleyDslModelUtil;
+import org.eclipse.xtext.common.types.JvmGenericType;
+import org.eclipse.xtext.common.types.JvmOperation;
+import org.eclipse.xtext.common.types.JvmType;
+import org.eclipse.xtext.common.types.JvmTypeReference;
+import org.eclipse.xtext.common.types.TypesPackage;
+import org.eclipse.xtext.naming.QualifiedName;
+import org.eclipse.xtext.scoping.IScope;
+import org.eclipse.xtext.scoping.impl.SimpleScope;
+
+/**
+ * This class contains custom scoping description.
+ * 
+ * See
+ * https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#scoping
+ * on how and when to use it.
+ */
+public class EmfParsleyDslScopeProvider extends AbstractEmfParsleyDslScopeProvider {
+	@Override
+	public IScope getScope(final EObject context, final EReference reference) {
+		var scope = createCustomScope(context, reference);
+		if (scope != null) {
+			return scope;
+		}
+		return super.getScope(context, reference);
+	}
+
+	public IScope createCustomScope(final EObject context, final EReference reference) {
+		EClassifier eType = reference.getEType();
+		EClass jvmMember = TypesPackage.eINSTANCE.getJvmMember();
+		if (Objects.equals(eType, jvmMember)) {
+			EmfFeatureAccess containingEmfFeatureAccess = EmfParsleyDslModelUtil
+					.containingEmfFeatureAccess(context);
+			JvmTypeReference parameterType = null;
+			if (containingEmfFeatureAccess != null) {
+				parameterType = containingEmfFeatureAccess.getParameterType();
+			}
+			JvmType type = null;
+			if (parameterType != null) {
+				type = parameterType.getType();
+			}
+			return customScope(type);
+		}
+		return null;
+	}
+
+	protected IScope customScope(final JvmType jvmType) {
+		if (jvmType instanceof JvmGenericType) {
+			// a JvmMember does not have 'name', but 'simpleName'
+			// thus we must also provide a function for computing the
+			// QualifiedName (the default one relies on 'name')
+			JvmGenericType t = (JvmGenericType) jvmType;
+			var jvmOperations = filter(t.getAllFeatures(), JvmOperation.class);
+			var nonStaticOperations = filter(jvmOperations, it -> !it.isStatic());
+			var scopedElementsFor = scopedElementsFor(nonStaticOperations, it -> {
+				if (isGetterMethod(it.getSimpleName())) {
+					return QualifiedName.create(getPropertyNameForGetterMethod(it.getSimpleName()));
+				}
+				return null;
+			});
+			return new SimpleScope(scopedElementsFor);
+		}
+		return null;
+	}
+
+	private boolean isGetterMethod(final String opName) {
+		return getterMethodForNonBoolean(opName) || getterMethodForBoolean(opName);
+	}
+
+	private String getPropertyNameForGetterMethod(final String opName) {
+		if (getterMethodForNonBoolean(opName)) {
+			return Introspector.decapitalize(opName.substring(3));
+		}
+		return Introspector.decapitalize(opName.substring(2));
+	}
+
+	private boolean getterMethodForBoolean(final String opName) {
+		return getterMethodInternal(opName, "is");
+	}
+
+	private boolean getterMethodForNonBoolean(final String opName) {
+		return getterMethodInternal(opName, "get");
+	}
+
+	private boolean getterMethodInternal(final String opName, final String prefix) {
+		return (opName.startsWith(prefix) && opName.length() > prefix.length()
+				&& Character.isUpperCase(opName.charAt(prefix.length())));
+	}
+}