Initial support for 'Extract temp' - only when single expression selected

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/actions/ExtractLocalAction.java

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/actions/ExtractLocalAction.java
diff --git a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/actions/ExtractLocalAction.java b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/actions/ExtractLocalAction.java
new file mode 100644
index 0000000000000000000000000000000000000000..874a880030568ff1e05b6dedf58eb2e43281cec3
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/actions/ExtractLocalAction.java
@@ -0,0 +1,59 @@
+package com.google.dart.tools.ui.actions;
+
+import com.google.dart.tools.internal.corext.refactoring.RefactoringAvailabilityTester;
+import com.google.dart.tools.internal.corext.refactoring.code.ExtractLocalRefactoring;
+import com.google.dart.tools.ui.internal.actions.ActionUtil;
+import com.google.dart.tools.ui.internal.actions.SelectionConverter;
+import com.google.dart.tools.ui.internal.refactoring.ExtractLocalWizard;
+import com.google.dart.tools.ui.internal.refactoring.RefactoringMessages;
+import com.google.dart.tools.ui.internal.refactoring.RefactoringSaveHelper;
+import com.google.dart.tools.ui.internal.refactoring.actions.RefactoringStarter;
+import com.google.dart.tools.ui.internal.text.DartHelpContextIds;
+import com.google.dart.tools.ui.internal.text.editor.DartEditor;
+import com.google.dart.tools.ui.internal.text.editor.DartTextSelection;
+
+import org.eclipse.jface.text.ITextSelection;
+import org.eclipse.ui.PlatformUI;
+
+/**
+ * Extracts an expression into a new local variable and replaces all occurrences of the expression
+ * with the local variable.
+ */
+public class ExtractLocalAction extends SelectionDispatchAction {
+
+  private final DartEditor editor;
+
+  public ExtractLocalAction(DartEditor editor) {
+    super(editor.getEditorSite());
+    this.editor = editor;
+    setText(RefactoringMessages.ExtractLocalAction_label);
+    setEnabled(SelectionConverter.getInputAsCompilationUnit(editor) != null);
+    PlatformUI.getWorkbench().getHelpSystem().setHelp(this, DartHelpContextIds.EXTRACT_LOCAL_ACTION);
+  }
+
+  @Override
+  public void run(ITextSelection selection) {
+    if (!ActionUtil.isEditable(editor)) {
+      return;
+    }
+    ExtractLocalRefactoring refactoring = new ExtractLocalRefactoring(
+        SelectionConverter.getInputAsCompilationUnit(editor),
+        selection.getOffset(),
+        selection.getLength());
+    new RefactoringStarter().activate(
+        new ExtractLocalWizard(refactoring),
+        getShell(),
+        RefactoringMessages.ExtractLocalAction_dialog_title,
+        RefactoringSaveHelper.SAVE_NOTHING);
+  }
+
+  @Override
+  public void selectionChanged(DartTextSelection selection) {
+    setEnabled(RefactoringAvailabilityTester.isExtractLocalAvailable(selection));
+  }
+
+  @Override
+  public void selectionChanged(ITextSelection selection) {
+    setEnabled(editor != null && SelectionConverter.getInputAsCompilationUnit(editor) != null);
+  }
+}