2 files changed, 49 insertions, 16 deletions

diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java
index e194ee31..ea90a82e 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/contentassist/ProblemCrossrefProposalProvider.java
@@ -5,39 +5,60 @@
  */
 package tools.refinery.language.ide.contentassist;
 
-import java.util.Objects;
-
+import com.google.inject.Inject;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.xtext.CrossReference;
 import org.eclipse.xtext.GrammarUtil;
 import org.eclipse.xtext.ide.editor.contentassist.ContentAssistContext;
-import org.eclipse.xtext.ide.editor.contentassist.ContentAssistEntry;
 import org.eclipse.xtext.ide.editor.contentassist.IdeCrossrefProposalProvider;
+import org.eclipse.xtext.naming.QualifiedName;
 import org.eclipse.xtext.nodemodel.util.NodeModelUtils;
 import org.eclipse.xtext.resource.IEObjectDescription;
-
-import com.google.inject.Inject;
-
+import org.eclipse.xtext.scoping.IScope;
 import tools.refinery.language.model.problem.Problem;
+import tools.refinery.language.resource.ProblemResourceDescriptionStrategy;
 import tools.refinery.language.resource.ReferenceCounter;
 import tools.refinery.language.utils.ProblemUtil;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Objects;
+
 public class ProblemCrossrefProposalProvider extends IdeCrossrefProposalProvider {
         @Inject
         private ReferenceCounter referenceCounter;
 
         @Override
-        protected ContentAssistEntry createProposal(IEObjectDescription candidate, CrossReference crossRef,
-                        ContentAssistContext context) {
-                if (!shouldCreateProposal(candidate, crossRef, context)) {
-                        return null;
+        protected Iterable<IEObjectDescription> queryScope(IScope scope, CrossReference crossReference,
+                                                                                                           ContentAssistContext context) {
+                var eObjectDescriptionsByName = new HashMap<QualifiedName, List<IEObjectDescription>>();
+                for (var candidate : super.queryScope(scope, crossReference, context)) {
+                        if (isExistingObject(candidate, crossReference, context)) {
+                                // {@code getQualifiedName()} will refer to the full name for objects that are loaded from the global
+                                // scope, but {@code getName()} returns the qualified name that we set in
+                                // {@code ProblemResourceDescriptionStrategy}.
+                                var qualifiedName = candidate.getName();
+                                var candidateList = eObjectDescriptionsByName.computeIfAbsent(qualifiedName,
+                                                ignored -> new ArrayList<>());
+                                candidateList.add(candidate);
+                        }
                 }
-                return super.createProposal(candidate, crossRef, context);
+                var eObjectDescriptions = new ArrayList<IEObjectDescription>();
+                for (var candidates : eObjectDescriptionsByName.values()) {
+                        if (candidates.size() == 1) {
+                                var candidate = candidates.get(0);
+                                if (shouldBeVisible(candidate)) {
+                                        eObjectDescriptions.add(candidate);
+                                }
+                        }
+                }
+                return eObjectDescriptions;
         }
 
-        protected boolean shouldCreateProposal(IEObjectDescription candidate, CrossReference crossRef,
-                        ContentAssistContext context) {
+        protected boolean isExistingObject(IEObjectDescription candidate, CrossReference crossRef,
+                                                                           ContentAssistContext context) {
                 var rootModel = context.getRootModel();
                 var eObjectOrProxy = candidate.getEObjectOrProxy();
                 if (!Objects.equals(rootModel.eResource(), eObjectOrProxy.eResource())) {
@@ -60,6 +81,11 @@ public class ProblemCrossrefProposalProvider extends IdeCrossrefProposalProvider
                 return true;
         }
 
+        protected boolean shouldBeVisible(IEObjectDescription candidate) {
+                var errorPredicate = candidate.getUserData(ProblemResourceDescriptionStrategy.ERROR_PREDICATE);
+                return !ProblemResourceDescriptionStrategy.ERROR_PREDICATE_TRUE.equals(errorPredicate);
+        }
+
         protected EObject getCurrentValue(CrossReference crossRef, ContentAssistContext context) {
                 var value = getCurrentValue(crossRef, context.getCurrentModel());
                 if (value != null) {
diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
index e8f97d51..ae8c70e0 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
@@ -16,6 +16,7 @@ import org.eclipse.xtext.nodemodel.INode;
 import org.eclipse.xtext.nodemodel.util.NodeModelUtils;
 import org.eclipse.xtext.service.OperationCanceledManager;
 import org.eclipse.xtext.util.CancelIndicator;
+import org.jetbrains.annotations.NotNull;
 import tools.refinery.language.model.problem.*;
 import tools.refinery.language.utils.ProblemDesugarer;
 import tools.refinery.language.utils.ProblemUtil;
@@ -94,9 +95,16 @@ public class ProblemSemanticHighlightingCalculator extends DefaultSemanticHighli
         }
 
         protected String[] getHighlightClass(EObject eObject, EReference reference) {
+                boolean isError = ProblemUtil.isError(eObject);
                 if (ProblemUtil.isBuiltIn(eObject)) {
-                        return new String[] { BUILTIN_CLASS };
+                        var className = isError ? ERROR_CLASS : BUILTIN_CLASS;
+                        return new String[] { className };
                 }
+                return getUserDefinedElementHighlightClass(eObject, reference, isError);
+        }
+
+        @NotNull
+        private String[] getUserDefinedElementHighlightClass(EObject eObject, EReference reference, boolean isError) {
                 ImmutableList.Builder<String> classesBuilder = ImmutableList.builder();
                 if (eObject instanceof ClassDeclaration classDeclaration && classDeclaration.isAbstract()) {
                         classesBuilder.add(ABSTRACT_CLASS);
@@ -105,8 +113,7 @@ public class ProblemSemanticHighlightingCalculator extends DefaultSemanticHighli
                                 && desugarer.isContainmentReference(referenceDeclaration)) {
                         classesBuilder.add(CONTAINMENT_CLASS);
                 }
-                if (eObject instanceof PredicateDefinition predicateDefinition
-                                && predicateDefinition.getKind() == PredicateKind.ERROR) {
+                if (isError) {
                         classesBuilder.add(ERROR_CLASS);
                 }
                 if (eObject instanceof Node node) {