IDEA-153614 (Flip ',' (comma) generates invalid code)

java/java-impl/src/com/intellij/codeInsight/intention/impl/JavaFlipper.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.intellij.codeInsight.intention.impl;
+
+import com.intellij.openapi.editor.actions.FlipCommaIntention;
+import com.intellij.psi.*;
+import com.intellij.psi.util.PsiTreeUtil;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class JavaFlipper implements FlipCommaIntention.Flipper {
+
+  @Override
+  public boolean flip(PsiElement left, PsiElement right) {
+    if (left instanceof PsiVariable && right instanceof PsiVariable) {
+      final PsiElement first = left.getFirstChild();
+      if (!(first instanceof PsiModifierList)) {
+        return false;
+      }
+      final PsiElement child = PsiTreeUtil.skipSiblingsForward(first, PsiWhiteSpace.class);
+      if (!(child instanceof PsiTypeElement)) {
+        return false;
+      }
+      final PsiElement last = child.getNextSibling();
+      if (!(last instanceof PsiWhiteSpace)) {
+        return false;
+      }
+      final PsiElement anchor = right.getFirstChild();
+      if (!(anchor instanceof PsiIdentifier)) {
+        return false;
+      }
+      final PsiElement semiColon = right.getLastChild();
+      if (!(semiColon instanceof PsiJavaToken)) {
+        return false;
+      }
+      right.addRangeBefore(first, last, anchor);
+      left.deleteChildRange(first, last);
+      left.add(semiColon);
+      semiColon.delete();
+      final PsiElement copy = left.copy();
+      left.replace(right);
+      right.replace(copy);
+      return true;
+    }
+    return false;
+  }
+}

java/java-tests/testData/codeInsight/flipComma/afterMultiVar.java

@@ -0,0 +1,5 @@
+// "Flip ','" "true"
+class MultiVar {
+
+  private int b,<caret> a;
+}

java/java-tests/testData/codeInsight/flipComma/beforeMultiVar.java

@@ -0,0 +1,8 @@
+// "Flip ','" "true"
+
+class MultiVar {
+
+  void m() {
+    int a,<caret> b;
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/intention/FlipCommaIntentionTest.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.intellij.codeInsight.intention;
+
+import com.siyeh.ipp.IPPTestCase;
+
+/**
+ * @author Bas Leijdekkers
+ */
+public class FlipCommaIntentionTest extends IPPTestCase {
+
+  public void test() throws Exception {
+    doTest("class C {\n" +
+           "    int a,/*_Flip ','*/ b;" +
+           "}",
+           "class C {\n" +
+           "    int b, a;\n" +
+           "}");
+  }
+}

platform/lang-impl/src/com/intellij/openapi/editor/actions/FlipCommaIntention.java

@@ -16,18 +16,15 @@
 package com.intellij.openapi.editor.actions;
 
 import com.intellij.codeInsight.intention.IntentionAction;
-import com.intellij.openapi.application.Result;
-import com.intellij.openapi.command.WriteCommandAction;
+import com.intellij.lang.Language;
+import com.intellij.lang.LanguageExtension;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.project.Project;
 import com.intellij.psi.PsiComment;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiWhiteSpace;
-import com.intellij.psi.impl.source.PostprocessReformattingAspect;
 import com.intellij.psi.util.PsiTreeUtil;
-import com.intellij.util.IncorrectOperationException;
-import com.intellij.util.ObjectUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -47,23 +44,14 @@ public class FlipCommaIntention implements IntentionAction {
   @Override
   public boolean isAvailable(@NotNull Project project, @NotNull Editor editor, @NotNull PsiFile file) {
     PsiElement comma = currentCommaElement(editor, file);
-    return comma != null && smartAdvanceAsExpr(comma, true) != null && smartAdvance(comma, false) != null;
+    return comma != null && smartAdvance(comma, true) != null && smartAdvance(comma, false) != null;
   }
 
   @Override
-  public void invoke(@NotNull Project project, @NotNull final Editor editor, @NotNull PsiFile file) throws IncorrectOperationException {
+  public void invoke(@NotNull Project project, @NotNull final Editor editor, @NotNull PsiFile file) {
     final PsiElement element = currentCommaElement(editor, file);
     if (element != null) {
-      new WriteCommandAction(project, file) {
-        protected void run(@NotNull Result result) throws Throwable {
-          PostprocessReformattingAspect.getInstance(getProject()).disablePostprocessFormattingInside(new Runnable() {
-            @Override
-            public void run() {
-              swapAtComma(element);
-            }
-          });
-        }
-      }.execute();
+      swapAtComma(element);
     }
   }
 
@@ -73,15 +61,37 @@ public class FlipCommaIntention implements IntentionAction {
   }
 
   private static void swapAtComma(@NotNull PsiElement comma) {
-    PsiElement prev = smartAdvanceAsExpr(comma, false);
-    PsiElement next = smartAdvanceAsExpr(comma, true);
+    PsiElement prev = smartAdvance(comma, false);
+    PsiElement next = smartAdvance(comma, true);
     if (prev != null && next != null) {
+      if (Flipper.tryFlip(prev, next)) {
+        return;
+      }
       PsiElement copy = prev.copy();
       prev.replace(next);
       next.replace(copy);
     }
   }
 
+  public interface Flipper {
+    LanguageExtension<Flipper> EXTENSION = new LanguageExtension<>("com.intellij.flipCommaIntention.flipper");
+
+    /**
+     * @return true, if elements were flipped; false, if default flip implementation should be used.
+     */
+    boolean flip(PsiElement left, PsiElement right);
+
+    static boolean tryFlip(PsiElement left, PsiElement right) {
+      final Language language = left.getLanguage();
+      for (Flipper handler : EXTENSION.allForLanguage(language)) {
+        if (handler.flip(left, right)) {
+          return true;
+        }
+      }
+      return false;
+    }
+  }
+
   private static PsiElement currentCommaElement(@NotNull Editor editor, @NotNull PsiFile file) {
     PsiElement element;
     if (!isComma(element = leftElement(editor, file)) && !isComma(element = rightElement(editor, file))) {
@@ -110,9 +120,4 @@ public class FlipCommaIntention implements IntentionAction {
     return fwd ? PsiTreeUtil.skipSiblingsForward(element, skipTypes)
                : PsiTreeUtil.skipSiblingsBackward(element, skipTypes);
   }
-
-  @Nullable
-  static private PsiElement smartAdvanceAsExpr(PsiElement element, boolean fwd) {
-    return ObjectUtils.tryCast(smartAdvance(element, fwd), PsiElement.class);
-  }
 }

platform/platform-resources/src/META-INF/LangExtensionPoints.xml

@@ -751,6 +751,11 @@
             implements="com.intellij.codeInsight.editorActions.moveLeftRight.MoveElementLeftRightHandler"/>
     </extensionPoint>
 
+    <extensionPoint name="flipCommaIntention.flipper" beanClass="com.intellij.lang.LanguageExtensionPoint">
+      <with attribute="implementationClass"
+            implements="com.intellij.openapi.editor.actions.FlipCommaIntention.Flipper"/>
+    </extensionPoint>
+
     <extensionPoint name="fileLookupInfoProvider" interface="com.intellij.psi.file.FileLookupInfoProvider"/>
 
     <extensionPoint name="idIndexer" beanClass="com.intellij.openapi.fileTypes.FileTypeExtensionPoint">

resources/src/META-INF/IdeaPlugin.xml

@@ -1114,7 +1114,8 @@
     <statementUpDownMover implementation="com.intellij.codeInsight.editorActions.moveUpDown.CaseBlockMover" id="caseBlock"
                           order="before statement"/>
     <moveLeftRightHandler language="JAVA" implementationClass="com.intellij.codeInsight.editorActions.moveLeftRight.JavaMoveLeftRightHandler"/>
-    
+    <flipCommaIntention.flipper language="JAVA" implementationClass="com.intellij.codeInsight.intention.impl.JavaFlipper"/>
+
     <fileType.fileViewProviderFactory filetype="CLASS" implementationClass="com.intellij.psi.ClassFileViewProviderFactory"/>
 
     <editorFileSwapper implementation="com.intellij.codeEditor.JavaEditorFileSwapper"/>