add flip comma intention

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

@@ -0,0 +1,123 @@
+/*
+ * Copyright 2000-2015 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.openapi.editor.actions;
+
+import com.intellij.codeInsight.intention.IntentionAction;
+import com.intellij.openapi.application.Result;
+import com.intellij.openapi.command.WriteCommandAction;
+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;
+
+public class FlipCommaIntention implements IntentionAction {
+  @NotNull
+  @Override
+  public String getText() {
+    return getFamilyName();
+  }
+
+  @NotNull
+  @Override
+  public String getFamilyName() {
+    return "Flip ','";
+  }
+
+  @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;
+  }
+
+  @Override
+  public void invoke(@NotNull Project project, @NotNull final Editor editor, @NotNull PsiFile file) throws IncorrectOperationException {
+    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(editor, element);
+            }
+          });
+        }
+      }.execute();
+    }
+  }
+
+  @Override
+  public boolean startInWriteAction() {
+    return true;
+  }
+
+  private static void swapAtComma(@NotNull Editor editor, @NotNull PsiElement comma) {
+    PsiElement prev = smartAdvanceAsExpr(comma, false);
+    PsiElement next = smartAdvanceAsExpr(comma, true);
+    if (prev != null && next != null) {
+      boolean caretBeforeComma = editor.getCaretModel().getOffset() <= comma.getTextRange().getStartOffset();
+      PsiElement nextAnchor = next.getPrevSibling();
+      PsiElement prevAnchor = prev.getNextSibling();
+      comma.getParent().addBefore(next, prevAnchor);
+      comma.getParent().addAfter(prev, nextAnchor);
+      next.delete();
+      prev.delete();
+      editor.getCaretModel().moveToOffset(caretBeforeComma ? comma.getTextRange().getStartOffset() : comma.getTextRange().getEndOffset());
+    }
+  }
+
+  private static PsiElement currentCommaElement(@NotNull Editor editor, @NotNull PsiFile file) {
+    PsiElement element;
+    if (!isComma(element = leftElement(editor, file)) && !isComma(element = rightElement(editor, file))) {
+      return null;
+    }
+    return element;
+  }
+
+  @Nullable
+  private static PsiElement leftElement(@NotNull Editor editor, @NotNull PsiFile file) {
+    return file.findElementAt(editor.getCaretModel().getOffset() - 1);
+  }
+
+  @Nullable
+  private static PsiElement rightElement(@NotNull Editor editor, @NotNull PsiFile file) {
+    return file.findElementAt(editor.getCaretModel().getOffset());
+  }
+
+  private static boolean isComma(@Nullable PsiElement element) {
+    return element != null && element.getText().equals(",");
+  }
+
+  @Nullable
+  private static PsiElement smartAdvance(PsiElement element, boolean fwd) {
+    Class[] skipTypes = {PsiWhiteSpace.class, PsiComment.class};
+    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-en/src/intentionDescriptions/FlipCommaIntention/after.sql.template

@@ -0,0 +1 @@
+foo(<spot>b, a)</spot>

platform/platform-resources-en/src/intentionDescriptions/FlipCommaIntention/before.sql.template

@@ -0,0 +1 @@
+foo(<spot>a, b</spot>);

platform/platform-resources-en/src/intentionDescriptions/FlipCommaIntention/description.html

@@ -0,0 +1,5 @@
+<html>
+<body>
+Flips two elements separated by comma.
+</body>
+</html>

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

@@ -411,5 +411,10 @@
     <ui.suitableFontProvider implementation="com.intellij.ui.SuitableFontProviderImpl"/>
 
     <jbProtocolCommand implementation="com.intellij.openapi.project.impl.JBProtocolOpenProjectCommand"/>
+
+    <intentionAction>
+      <className>com.intellij.openapi.editor.actions.FlipCommaIntention</className>
+    </intentionAction>
+    
   </extensions>
 </idea-plugin>