preselect final fields on constructor generation (IDEA-78512)

java/java-impl/src/com/intellij/codeInsight/generation/GenerateConstructorHandler.java

@@ -134,6 +134,32 @@ public class GenerateConstructorHandler extends GenerateMembersHandlerBase {
     return members;
   }
 
+  @Override
+  protected MemberChooser<ClassMember> createMembersChooser(ClassMember[] members,
+                                                            boolean allowEmptySelection,
+                                                            boolean copyJavadocCheckbox,
+                                                            Project project) {
+    final MemberChooser<ClassMember> chooser = super.createMembersChooser(members, allowEmptySelection, copyJavadocCheckbox, project);
+    final List<ClassMember> preselection = preselect(members);
+    if (!preselection.isEmpty()) {
+      chooser.selectElements(preselection.toArray(new ClassMember[preselection.size()]));
+    }
+    return chooser;
+  }
+
+  protected static List<ClassMember> preselect(ClassMember[] members) {
+    final List<ClassMember> preselection = new ArrayList<ClassMember>();
+    for (ClassMember member : members) {
+      if (member instanceof PsiFieldMember) {
+        final PsiField psiField = ((PsiFieldMember)member).getElement();
+        if (psiField != null && psiField.hasModifierProperty(PsiModifier.FINAL)) {
+          preselection.add(member);
+        }
+      }
+    }
+    return preselection;
+  }
+
   @NotNull
   protected List<? extends GenerationInfo> generateMemberPrototypes(PsiClass aClass, ClassMember[] members) throws IncorrectOperationException {
     List<PsiMethod> baseConstructors = new ArrayList<PsiMethod>();

java/java-impl/src/com/intellij/codeInsight/generation/GenerateMembersHandlerBase.java

@@ -183,15 +183,23 @@ public abstract class GenerateMembersHandlerBase implements CodeInsightActionHan
 
   @Nullable
   protected ClassMember[] chooseMembers(ClassMember[] members, boolean allowEmptySelection, boolean copyJavadocCheckbox, Project project) {
-    MemberChooser<ClassMember> chooser = new MemberChooser<ClassMember>(members, allowEmptySelection, true, project);
-    chooser.setTitle(myChooserTitle);
-    chooser.setCopyJavadocVisible(copyJavadocCheckbox);
+    MemberChooser<ClassMember> chooser = createMembersChooser(members, allowEmptySelection, copyJavadocCheckbox, project);
     chooser.show();
     myToCopyJavaDoc = chooser.isCopyJavadoc();
     final List<ClassMember> list = chooser.getSelectedElements();
     return list == null ? null : list.toArray(new ClassMember[list.size()]);
   }
 
+  protected MemberChooser<ClassMember> createMembersChooser(ClassMember[] members,
+                                                            boolean allowEmptySelection,
+                                                            boolean copyJavadocCheckbox,
+                                                            Project project) {
+    MemberChooser<ClassMember> chooser = new MemberChooser<ClassMember>(members, allowEmptySelection, true, project);
+    chooser.setTitle(myChooserTitle);
+    chooser.setCopyJavadocVisible(copyJavadocCheckbox);
+    return chooser;
+  }
+
   @NotNull
   protected List<? extends GenerationInfo> generateMemberPrototypes(PsiClass aClass, ClassMember[] members) throws IncorrectOperationException {
     ArrayList<GenerationInfo> array = new ArrayList<GenerationInfo>();

java/java-tests/testData/codeInsight/generateConstructor/afterFinalFieldPreselection.java

@@ -0,0 +1,11 @@
+class Test {
+    private int a;
+    private final int b;
+    private int c;
+    private final int d;
+
+    Test(int b, int d) {
+        this.b = b;
+        this.d = d;
+    }
+}

java/java-tests/testData/codeInsight/generateConstructor/beforeFinalFieldPreselection.java

@@ -0,0 +1,6 @@
+class Test {
+    private int a;
+    private final int b;
+    private int c;
+    private final int d;
+}

java/java-tests/testSrc/com/intellij/codeInsight/GenerateConstructorTest.java

@@ -10,6 +10,8 @@ import com.intellij.psi.codeStyle.CodeStyleSettings;
 import com.intellij.psi.codeStyle.CodeStyleSettingsManager;
 import com.intellij.testFramework.LightCodeInsightTestCase;
 
+import java.util.List;
+
 public class GenerateConstructorTest extends LightCodeInsightTestCase {
   public void testAbstractClass() throws Exception { doTest(); }
   public void testPackageLocalClass() throws Exception { doTest(); }
@@ -38,6 +40,22 @@ public class GenerateConstructorTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testFinalFieldPreselection() throws Exception {
+    String name = getTestName(false);
+    configureByFile("/codeInsight/generateConstructor/before" + name + ".java");
+    new GenerateConstructorHandler() {
+      @Override
+      protected ClassMember[] chooseMembers(ClassMember[] members,
+                                            boolean allowEmptySelection,
+                                            boolean copyJavadocCheckbox,
+                                            Project project) {
+        final List<ClassMember> preselection = GenerateConstructorHandler.preselect(members);
+        return preselection.toArray(new ClassMember[preselection.size()]);
+      }
+    }.invoke(getProject(), getEditor(), getFile());
+    checkResultByFile("/codeInsight/generateConstructor/after" + name +".java");
+  }
+
   private void doTest() throws Exception {
     String name = getTestName(false);
     configureByFile("/codeInsight/generateConstructor/before" +