IDEA-81079: surround with notnull checks on selection

java/java-impl/src/com/intellij/codeInsight/generation/surroundWith/JavaExpressionSurroundDescriptor.java

@@ -41,7 +41,8 @@ public class JavaExpressionSurroundDescriptor implements SurroundDescriptor {
       new JavaWithNotSurrounder(),
       new JavaWithNotInstanceofSurrounder(),
       new JavaWithIfExpressionSurrounder(),
-      new JavaWithIfElseExpressionSurrounder()
+      new JavaWithIfElseExpressionSurrounder(),
+      new JavaWithNullCheckSurrounder()
   };
 
   @NotNull public PsiElement[] getElementsToSurround(PsiFile file, int startOffset, int endOffset) {

java/java-impl/src/com/intellij/codeInsight/generation/surroundWith/JavaWithNullCheckSurrounder.java

@@ -0,0 +1,66 @@
+
+/*
+ * Copyright 2000-2012 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.generation.surroundWith;
+
+import com.intellij.codeInsight.CodeInsightUtilBase;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.TextRange;
+import com.intellij.psi.*;
+import com.intellij.psi.codeStyle.CodeStyleManager;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.IncorrectOperationException;
+import org.jetbrains.annotations.NonNls;
+
+class JavaWithNullCheckSurrounder extends JavaExpressionSurrounder{
+  public boolean isApplicable(PsiExpression expr) {
+    PsiType type = expr.getType();
+    if (type instanceof PsiPrimitiveType) return false;
+    if (!expr.isPhysical()) return false;
+    if (expr.getParent() instanceof PsiExpressionStatement) return false;
+    PsiElement parent = PsiTreeUtil.getParentOfType(expr, PsiExpressionStatement.class);
+    if (parent == null) return false;
+    final PsiElement element = parent.getParent();
+    if (!(element instanceof PsiCodeBlock) && !(JspPsiUtil.isInJspFile(element)  && element instanceof PsiFile)) return false;
+    return true;
+  }
+
+  public TextRange surroundExpression(Project project, Editor editor, PsiExpression expr) throws IncorrectOperationException {
+    PsiManager manager = expr.getManager();
+    PsiElementFactory factory = JavaPsiFacade.getInstance(manager.getProject()).getElementFactory();
+    CodeStyleManager codeStyleManager = CodeStyleManager.getInstance(project);
+
+    @NonNls String text = "if(a != null){\nst;\n}";
+    PsiIfStatement ifStatement = (PsiIfStatement)factory.createStatementFromText(text, null);
+    ifStatement = (PsiIfStatement)codeStyleManager.reformat(ifStatement);
+
+    ((PsiBinaryExpression)ifStatement.getCondition()).getLOperand().replace(expr);
+
+    PsiExpressionStatement statement = PsiTreeUtil.getParentOfType(expr, PsiExpressionStatement.class);
+    String oldText = statement.getText();
+    ifStatement = (PsiIfStatement)statement.replace(ifStatement);
+    PsiCodeBlock block = ((PsiBlockStatement)ifStatement.getThenBranch()).getCodeBlock();
+    block = CodeInsightUtilBase.forcePsiPostprocessAndRestoreElement(block);
+    PsiElement replace = block.getStatements()[0].replace(factory.createStatementFromText(oldText, block));
+    int offset = replace.getTextRange().getEndOffset();
+    return new TextRange(offset, offset);
+  }
+
+  public String getTemplateDescription() {
+    return "if (expr != null) {...}";
+  }
+}

java/java-tests/testData/codeInsight/generation/surroundWith/java/SurroundWithNotNullCheck.java

@@ -0,0 +1,10 @@
+
+class Test {
+  String foo() {
+    return null;
+  }
+  
+  void bar() {
+    <selection>foo()</selection>.toLowerCase()
+  }
+}

java/java-tests/testData/codeInsight/generation/surroundWith/java/SurroundWithNotNullCheck_after.java

@@ -0,0 +1,12 @@
+
+class Test {
+  String foo() {
+    return null;
+  }
+  
+  void bar() {
+      if (foo() != null) {
+          foo().toLowerCase()<caret>
+      }
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/generation/surroundWith/JavaSurroundWithTest.java

@@ -139,6 +139,17 @@ public class JavaSurroundWithTest extends LightCodeInsightTestCase {
     }
   }
 
+  public void testSurroundWithNotNullCheck() {
+    final TemplateManagerImpl templateManager = (TemplateManagerImpl)TemplateManager.getInstance(getProject());
+    templateManager.setTemplateTesting(true);
+    try {
+      doTest(getTestName(false), new JavaWithNullCheckSurrounder());
+    }
+    finally {
+      templateManager.setTemplateTesting(false);
+    }
+  }
+
   private void doTest(@NotNull String fileName, final Surrounder surrounder) {
     configureByFile(BASE_PATH + fileName + ".java");
     SurroundWithHandler.invoke(getProject(), getEditor(), getFile(), surrounder);