Initial implementation of "Rename Local Variable" refactoring.

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/internal/corext/refactoring/util/ResourceUtil.java

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/internal/corext/refactoring/util/ResourceUtil.java
diff --git a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/internal/corext/refactoring/util/ResourceUtil.java b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/internal/corext/refactoring/util/ResourceUtil.java
new file mode 100644
index 0000000000000000000000000000000000000000..2c30db1d76399d07f87e038896aa214d00f19520
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/internal/corext/refactoring/util/ResourceUtil.java
@@ -0,0 +1,59 @@
+package com.google.dart.tools.internal.corext.refactoring.util;
+
+import com.google.dart.tools.core.model.CompilationUnit;
+import com.google.dart.tools.core.model.DartElement;
+import com.google.dart.tools.core.model.OpenableElement;
+
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IResource;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ResourceUtil {
+
+  public static IFile getFile(CompilationUnit cu) {
+    IResource resource = cu.getResource();
+    if (resource != null && resource.getType() == IResource.FILE) {
+      return (IFile) resource;
+    } else {
+      return null;
+    }
+  }
+
+  public static IFile[] getFiles(CompilationUnit[] cus) {
+    List<IResource> files = new ArrayList<IResource>(cus.length);
+    for (int i = 0; i < cus.length; i++) {
+      IResource resource = cus[i].getResource();
+      if (resource != null && resource.getType() == IResource.FILE) {
+        files.add(resource);
+      }
+    }
+    return files.toArray(new IFile[files.size()]);
+  }
+
+  public static IResource getResource(Object o) {
+    if (o instanceof IResource) {
+      return (IResource) o;
+    }
+    if (o instanceof DartElement) {
+      return getResource((DartElement) o);
+    }
+    return null;
+  }
+
+  //----- other ------------------------------
+
+  private static IResource getResource(DartElement element) {
+    if (element.getElementType() == DartElement.COMPILATION_UNIT) {
+      return ((CompilationUnit) element).getResource();
+    } else if (element instanceof OpenableElement) {
+      return element.getResource();
+    } else {
+      return null;
+    }
+  }
+
+  private ResourceUtil() {
+  }
+}