java: handle { after if/while statement condition and insert new block statement if needed

java/java-impl/src/com/intellij/codeInsight/editorActions/JavaTypedHandler.java

@@ -18,6 +18,8 @@ package com.intellij.codeInsight.editorActions;
 import com.intellij.codeInsight.AutoPopupController;
 import com.intellij.codeInsight.CodeInsightSettings;
 import com.intellij.codeInsight.completion.JavaClassReferenceCompletionContributor;
+import com.intellij.codeInsight.editorActions.smartEnter.JavaSmartEnterProcessor;
+import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.editor.EditorModificationUtil;
 import com.intellij.openapi.editor.ex.EditorEx;
@@ -125,11 +127,18 @@ public class JavaTypedHandler extends TypedHandlerDelegate {
       if (iterator.atEnd() || iterator.getTokenType() == JavaTokenType.RBRACKET || iterator.getTokenType() == JavaTokenType.EQ) {
         return Result.CONTINUE;
       }
-      PsiDocumentManager.getInstance(project).commitDocument(editor.getDocument());
+      Document doc = editor.getDocument();
+      PsiDocumentManager.getInstance(project).commitDocument(doc);
       final PsiElement leaf = file.findElementAt(offset);
       if (PsiTreeUtil.getParentOfType(leaf, PsiArrayInitializerExpression.class, false, PsiCodeBlock.class, PsiMember.class) != null) {
         return Result.CONTINUE;
       }
+      PsiElement st = leaf != null ? leaf.getParent() : null;
+      if (CodeInsightSettings.getInstance().AUTOINSERT_PAIR_BRACKET && isRparenth(leaf) &&
+          (st instanceof PsiWhileStatement || st instanceof PsiIfStatement) && noBody(st, doc)) {
+        new JavaSmartEnterProcessor().process(project, editor, file);
+        return Result.STOP;
+      }
       if (PsiTreeUtil.getParentOfType(leaf, PsiCodeBlock.class, false, PsiMember.class) != null) {
         EditorModificationUtil.insertStringAtCaret(editor, "{");
         TypedHandler.indentOpenedBrace(project, editor);
@@ -140,6 +149,24 @@ public class JavaTypedHandler extends TypedHandlerDelegate {
     return Result.CONTINUE;
   }
 
+  private static boolean noBody(@NotNull PsiElement statement, @NotNull Document doc) {
+    PsiStatement block = statement instanceof PsiWhileStatement ? ((PsiWhileStatement)statement).getBody() : ((PsiIfStatement)statement).getThenBranch();
+    PsiExpression condition = PsiTreeUtil.getChildOfType(statement, PsiExpression.class);
+    return !(block instanceof PsiBlockStatement) && (block == null || startLine(doc, block) != startLine(doc, statement) || condition == null);
+  }
+
+  private static boolean isRparenth(@Nullable PsiElement leaf) {
+    if (leaf == null) return false;
+    if (leaf.getNode().getElementType() == JavaTokenType.RPARENTH) return true;
+    PsiElement next = PsiTreeUtil.nextVisibleLeaf(leaf);
+    if (next == null) return false;
+    return next.getNode().getElementType() == JavaTokenType.RPARENTH;
+  }
+
+  private static int startLine(@NotNull Document doc, @NotNull PsiElement psiElement) {
+    return doc.getLineNumber(psiElement.getTextRange().getStartOffset());
+  }
+
   @Override
   public Result charTyped(final char c, final Project project, @NotNull final Editor editor, @NotNull final PsiFile file) {
     if (myJavaLTTyped) {

java/java-tests/testData/codeInsight/typing/fixIfByBrace_after.java

@@ -0,0 +1,7 @@
+class C {
+  boolean f() {
+      if (f()) {
+          <caret>
+      }
+  }
+}

java/java-tests/testData/codeInsight/typing/fixIfByBrace_before.java

@@ -0,0 +1,5 @@
+class C {
+  boolean f() {
+    if (f()<caret>)
+  }
+}

java/java-tests/testData/codeInsight/typing/fixWhileByBrace_after.java

@@ -0,0 +1,7 @@
+class C {
+  boolean f() {
+      while (f()) {
+          <caret>
+      }
+  }
+}

java/java-tests/testData/codeInsight/typing/fixWhileByBrace_before.java

@@ -0,0 +1,5 @@
+class C {
+  boolean f() {
+    while (f()<caret>)
+  }
+}

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

@@ -74,6 +74,14 @@ public class JavaTypingTest extends LightPlatformCodeInsightFixtureTestCase {
     myFixture.checkResultByFile(getTestName(true) + "_after.java");
   }
 
+  public void testFixIfByBrace() {
+    doTest('{');
+  }
+
+  public void testFixWhileByBrace() {
+    doTest('{');
+  }
+  
   private void doTest(char c) {
     myFixture.configureByFile(getTestName(true) + "_before.java");
     myFixture.type(c);