show reference to implementation for attributes

src/main/java/org/jastadd/tooling/aspect/ImplementationAnnotator.java

+package org.jastadd.tooling.aspect;
+
+
+import com.intellij.codeInspection.ProblemHighlightType;
+import com.intellij.lang.annotation.AnnotationHolder;
+import com.intellij.lang.annotation.Annotator;
+import com.intellij.lang.annotation.HighlightSeverity;
+import com.intellij.lang.jvm.annotation.JvmAnnotationConstantValue;
+import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.impl.java.stubs.index.JavaMethodNameIndex;
+import com.intellij.psi.search.GlobalSearchScope;
+import org.jastadd.tooling.aspect.psi.JastAddAspectAttributeName;
+import org.jastadd.tooling.java.JavaSyntaxHighlighter;
+import org.jetbrains.annotations.NotNull;
+
+import static org.jastadd.tooling.java.GeneratedCodeUtil.getNavigationUrlFromFileLocation;
+
+public class ImplementationAnnotator implements Annotator {
+
+  @Override
+  public void annotate(@NotNull final PsiElement element, @NotNull AnnotationHolder holder) {
+
+    if (!(element instanceof JastAddAspectAttributeName nameElement)) {
+      return;
+    }
+
+    for (var method : JavaMethodNameIndex.getInstance().get(nameElement.getText(), element.getProject(), GlobalSearchScope.allScope(element.getProject()))) {
+      for (var annotation : method.getAnnotations()) {
+        String fqn = annotation.getQualifiedName();
+        if (fqn != null && fqn.endsWith("ASTNodeAnnotation.Source")) {
+          for (var attribute : annotation.getAttributes()) {
+            if (attribute.getAttributeName().equals("declaredAt")) {
+              JvmAnnotationConstantValue value = (JvmAnnotationConstantValue) attribute.getAttributeValue();
+              if (value != null) {
+                Object originalReference = value.getConstantValue();
+                String fileName = element.getContainingFile().getVirtualFile().getPath();
+                int lineNumber = StringUtil.offsetToLineNumber(element.getContainingFile().getText(), element.getTextOffset()) + 1; // lines start with 0 in JetBrains
+                String reference = fileName + ":" + lineNumber;
+                if (originalReference != null && reference.equals(originalReference.toString())) {
+                  String methodFileName = method.getContainingFile().getVirtualFile().getPath();
+                  int methodLineNumber = StringUtil.offsetToLineNumber(method.getContainingFile().getText(), method.getTextOffset()) + 1; // lines start with 0 in JetBrains
+                  String methodNavigationUrl = getNavigationUrlFromFileLocation(methodFileName + ":" + methodLineNumber);
+
+                  holder.newAnnotation(HighlightSeverity.INFORMATION, "JastAdd definition")
+                    .range(element.getTextRange())
+                    .highlightType(ProblemHighlightType.INFORMATION)
+                    .textAttributes(JavaSyntaxHighlighter.IMPLEMENTED_ATTRIBUTE_DEFINITION)
+                    .tooltip(methodNavigationUrl)
+                    .create();
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+}

src/main/java/org/jastadd/tooling/java/JavaSyntaxHighlighter.java

@@ -23,6 +23,8 @@ public class JavaSyntaxHighlighter extends SyntaxHighlighterBase {
     createTextAttributesKey("INTERNAL_API_USE", DefaultLanguageHighlighterColors.HIGHLIGHTED_REFERENCE);
   public static final TextAttributesKey ATTRIBUTE_CALL =
     createTextAttributesKey("ATTRIBUTE_CALL", DefaultLanguageHighlighterColors.HIGHLIGHTED_REFERENCE);
+  public static final TextAttributesKey IMPLEMENTED_ATTRIBUTE_DEFINITION =
+    createTextAttributesKey("IMPLEMENTED_ATTRIBUTE_DEFINITION", DefaultLanguageHighlighterColors.HIGHLIGHTED_REFERENCE);
   public static final TextAttributesKey INTERTYPE_DECL_USE =
     createTextAttributesKey("INTERTYPE_DECL_USE", DefaultLanguageHighlighterColors.HIGHLIGHTED_REFERENCE);
 

src/main/resources/META-INF/plugin.xml

@@ -92,6 +92,8 @@
         <lang.foldingBuilder language="JastAddAspect" implementationClass="org.jastadd.tooling.aspect.AspectFoldingBuilder"/>
 
         <lang.psiStructureViewFactory language="JastAddAspect" implementationClass="org.jastadd.tooling.aspect.AspectStructureViewFactory"/>
+
+        <annotator language="JastAddAspect" implementationClass="org.jastadd.tooling.aspect.ImplementationAnnotator"/>
     </extensions>
 
     <actions>