apply some intellij fixes

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

@@ -72,13 +72,13 @@ public class AspectColorSettingsPage implements ColorSettingsPage {
 
   @NotNull
   @Override
-  public AttributesDescriptor[] getAttributeDescriptors() {
+  public AttributesDescriptor @NotNull [] getAttributeDescriptors() {
     return DESCRIPTORS;
   }
 
   @NotNull
   @Override
-  public ColorDescriptor[] getColorDescriptors() {
+  public ColorDescriptor @NotNull [] getColorDescriptors() {
     return ColorDescriptor.EMPTY_ARRAY;
   }
 

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

@@ -131,7 +131,7 @@ public class AspectSyntaxHighlighter extends SyntaxHighlighterBase {
 
   @NotNull
   @Override
-  public TextAttributesKey[] getTokenHighlights(IElementType tokenType) {
+  public TextAttributesKey @NotNull [] getTokenHighlights(IElementType tokenType) {
     if (javaKeywords.contains(tokenType) || jastAddKeywords.contains(tokenType)) {
       return KEYWORD_KEYS;
     } else if (keywordLiterals.contains(tokenType)) {

src/main/java/org/jastadd/tooling/aspect/parser/AspectParserDefinition.java

@@ -56,17 +56,17 @@ public class AspectParserDefinition implements ParserDefinition {
   }
 
   @Override
-  public IFileElementType getFileNodeType() {
+  public @NotNull IFileElementType getFileNodeType() {
     return FILE;
   }
 
   @Override
-  public PsiFile createFile(FileViewProvider viewProvider) {
+  public @NotNull PsiFile createFile(@NotNull FileViewProvider viewProvider) {
     return new AspectFile(viewProvider);
   }
 
   @Override
-  public SpaceRequirements spaceExistenceTypeBetweenTokens(ASTNode left, ASTNode right) {
+  public @NotNull SpaceRequirements spaceExistenceTypeBetweenTokens(ASTNode left, ASTNode right) {
     return SpaceRequirements.MAY;
   }
 

src/main/java/org/jastadd/tooling/grammar/GrammarChooseByNameContributor.java

@@ -3,6 +3,7 @@ package org.jastadd.tooling.grammar;
 import com.intellij.navigation.ChooseByNameContributor;
 import com.intellij.navigation.NavigationItem;
 import com.intellij.openapi.project.Project;
+import com.intellij.psi.PsiElement;
 import org.jastadd.tooling.grammar.psi.GrammarTypeDecl;
 import org.jetbrains.annotations.NotNull;
 
@@ -28,8 +29,13 @@ public class GrammarChooseByNameContributor implements ChooseByNameContributor {
   @Override
   public NavigationItem @NotNull [] getItemsByName(String name, String pattern, Project project, boolean includeNonProjectItems) {
     // TODO: include non project items
-    List<GrammarTypeDecl> typeDecls = GrammarUtil.findTypeDecl(project, name);
-    return typeDecls.toArray(new NavigationItem[0]);
+
+    List<NavigationItem> items = new ArrayList<>();
+    for (PsiElement typeDecl : GrammarUtil.findTypeDecl(project, name)) {
+      items.add((NavigationItem) typeDecl);
+    }
+
+    return items.toArray(new NavigationItem[0]);
   }
 
 }

src/main/java/org/jastadd/tooling/grammar/GrammarColorSettingsPage.java

@@ -13,6 +13,7 @@ import org.jetbrains.annotations.Nullable;
 import javax.swing.*;
 import java.util.Map;
 
+@SuppressWarnings("DialogTitleCapitalization")
 public class GrammarColorSettingsPage implements ColorSettingsPage {
 
   private static final AttributesDescriptor[] DESCRIPTORS = new AttributesDescriptor[]{

src/main/java/org/jastadd/tooling/grammar/GrammarFormattingModelBuilder.java

@@ -3,7 +3,6 @@ package org.jastadd.tooling.grammar;
 import com.intellij.formatting.*;
 import com.intellij.lang.ASTNode;
 import com.intellij.openapi.util.TextRange;
-import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.codeStyle.CodeStyleSettings;
 import com.intellij.psi.codeStyle.CommonCodeStyleSettings;

src/main/java/org/jastadd/tooling/grammar/GrammarLineMarkerProvider.java

@@ -28,7 +28,7 @@ public class GrammarLineMarkerProvider extends RelatedItemLineMarkerProvider {
 
     Optional<PsiClass> classOptional = asReferenceToTypeDecl(element.getParent());
 
-    if (classOptional.isEmpty()) {
+    if (!classOptional.isPresent()) {
       return;
     }
 

src/main/java/org/jastadd/tooling/grammar/GrammarStructureViewModel.java

@@ -16,7 +16,7 @@ public class GrammarStructureViewModel extends StructureViewModelBase implements
   }
 
   @NotNull
-  public Sorter[] getSorters() {
+  public Sorter @NotNull [] getSorters() {
     return new Sorter[]{Sorter.ALPHA_SORTER};
   }
 

src/main/java/org/jastadd/tooling/grammar/GrammarUtil.java

@@ -76,7 +76,7 @@ public class GrammarUtil {
 
   public static Optional<PsiClass> asReferenceToTypeDecl(@NotNull final PsiElement element) {
 
-    // Ensure the Psi Element is an reference
+    // Ensure the Psi Element is a reference
     if (!(element instanceof PsiJavaCodeReferenceElement)) {
       return Optional.empty();
     }

src/main/java/org/jastadd/tooling/grammar/parser/GrammarParserDefinition.java

@@ -55,17 +55,17 @@ public class GrammarParserDefinition implements ParserDefinition {
   }
 
   @Override
-  public IFileElementType getFileNodeType() {
+  public @NotNull IFileElementType getFileNodeType() {
     return FILE;
   }
 
   @Override
-  public PsiFile createFile(FileViewProvider viewProvider) {
+  public @NotNull PsiFile createFile(@NotNull FileViewProvider viewProvider) {
     return new GrammarFile(viewProvider);
   }
 
   @Override
-  public SpaceRequirements spaceExistenceTypeBetweenTokens(ASTNode left, ASTNode right) {
+  public @NotNull SpaceRequirements spaceExistenceTypeBetweenTokens(ASTNode left, ASTNode right) {
     return SpaceRequirements.MAY;
   }