IDEA-50625 Safe delete doesn't remove class when its only usage is in an unused import in a groovy file

java/java-impl/src/com/intellij/refactoring/safeDelete/ImportSearcher.java

@@ -0,0 +1,43 @@
+/*
+ * 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.refactoring.safeDelete;
+
+import com.intellij.openapi.extensions.ExtensionPointName;
+import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @author Max Medvedev
+ */
+public abstract class ImportSearcher {
+  private static final ExtensionPointName<ImportSearcher> EP_NAME = ExtensionPointName.create("com.intellij.safeDelete.importChecker");
+
+  /**
+   * @return found import or null
+   */
+  @Nullable
+  public abstract PsiElement findImport(PsiElement element);
+
+  @Nullable
+  public static PsiElement getImport(PsiElement element) {
+    for (ImportSearcher searcher : EP_NAME.getExtensions()) {
+      PsiElement anImport = searcher.findImport(element);
+      if (anImport != null) return anImport;
+    }
+
+    return null;
+  }
+}

java/java-impl/src/com/intellij/refactoring/safeDelete/JavaImportSearcher.java

@@ -0,0 +1,36 @@
+/*
+ * 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.refactoring.safeDelete;
+
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.PsiImportList;
+import com.intellij.psi.PsiJavaFile;
+import com.intellij.psi.util.PsiTreeUtil;
+
+/**
+ * @author Max Medvedev
+ */
+public class JavaImportSearcher extends ImportSearcher {
+  @Override
+  public PsiElement findImport(PsiElement element) {
+    final PsiFile containingFile = element.getContainingFile();
+    if (containingFile instanceof PsiJavaFile) {
+      return PsiTreeUtil.getParentOfType(element, PsiImportList.class, true);
+    }
+    return null;
+  }
+}

java/java-impl/src/com/intellij/refactoring/safeDelete/JavaSafeDeleteProcessor.java

@@ -329,13 +329,17 @@ public class JavaSafeDeleteProcessor extends SafeDeleteProcessorDelegateBase {
             }
           }
           LOG.assertTrue(element.getTextRange() != null);
-          usages.add(new SafeDeleteReferenceJavaDeleteUsageInfo(element, psiClass, parent instanceof PsiImportStatement));
+          usages.add(new SafeDeleteReferenceJavaDeleteUsageInfo(element, psiClass, isInImport(element)));
         }
         return true;
       }
     });
   }
 
+  private static boolean isInImport(PsiElement element) {
+    return ImportSearcher.getImport(element) != null;
+  }
+
   private static boolean containsOnlyPrivates(final PsiClass aClass) {
     final PsiField[] fields = aClass.getFields();
     for (PsiField field : fields) {

java/java-impl/src/com/intellij/refactoring/safeDelete/usageInfo/SafeDeleteReferenceJavaDeleteUsageInfo.java

@@ -15,11 +15,10 @@
  */
 package com.intellij.refactoring.safeDelete.usageInfo;
 
-import com.intellij.util.IncorrectOperationException;
-import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiImportStatementBase;
-import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.psi.PsiElement;
+import com.intellij.refactoring.safeDelete.ImportSearcher;
+import com.intellij.util.IncorrectOperationException;
 
 /**
  * @author yole
@@ -31,19 +30,26 @@ public class SafeDeleteReferenceJavaDeleteUsageInfo extends SafeDeleteReferenceS
     super(element, referencedElement, isSafeDelete);
   }
 
-  public SafeDeleteReferenceJavaDeleteUsageInfo(final PsiElement element, final PsiElement referencedElement, final int startOffset, final int endOffset,
+  public SafeDeleteReferenceJavaDeleteUsageInfo(final PsiElement element,
+                                                final PsiElement referencedElement,
+                                                final int startOffset,
+                                                final int endOffset,
                                                 final boolean isNonCodeUsage,
                                                 final boolean isSafeDelete) {
     super(element, referencedElement, startOffset, endOffset, isNonCodeUsage, isSafeDelete);
   }
 
   public void deleteElement() throws IncorrectOperationException {
-    if(isSafeDelete()) {
+    if (isSafeDelete()) {
       PsiElement element = getElement();
       LOG.assertTrue(element != null);
-      PsiImportStatementBase importStatement = PsiTreeUtil.getParentOfType(element, PsiImportStatementBase.class);
-      if (importStatement != null) importStatement.delete();
-      else element.delete();
+      PsiElement importStatement = ImportSearcher.getImport(element);
+      if (importStatement != null) {
+        importStatement.delete();
+      }
+      else {
+        element.delete();
+      }
     }
   }
 }