Initial implementation of "Rename Local Variable" refactoring.

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/AssistContext.java

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/AssistContext.java
diff --git a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/AssistContext.java b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/AssistContext.java
new file mode 100644
index 0000000000000000000000000000000000000000..e42d769313a6e69efbc4b2de9d609308373b8537
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/AssistContext.java
@@ -0,0 +1,129 @@
+package com.google.dart.tools.ui.internal.text.correction;
+
+import com.google.dart.compiler.ast.DartNode;
+import com.google.dart.compiler.ast.DartUnit;
+import com.google.dart.tools.core.dom.NodeFinder;
+import com.google.dart.tools.core.model.CompilationUnit;
+import com.google.dart.tools.ui.internal.text.editor.ASTProvider;
+import com.google.dart.tools.ui.text.dart.IInvocationContext;
+
+import org.eclipse.core.runtime.Assert;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.jface.text.source.TextInvocationContext;
+import org.eclipse.ui.IEditorPart;
+
+public class AssistContext extends TextInvocationContext implements IInvocationContext {
+
+  private final CompilationUnit fCompilationUnit;
+  private final IEditorPart fEditor;
+
+  private DartUnit fASTRoot;
+//  private final SharedASTProvider.WAIT_FLAG fWaitFlag;
+  private final ASTProvider.WAIT_FLAG fWaitFlag;
+  /**
+   * The cached node finder, can be null.
+   */
+  private NodeFinder fNodeFinder;
+
+  /*
+   * Constructor for CorrectionContext.
+   */
+  public AssistContext(CompilationUnit cu, int offset, int length) {
+    this(cu, null, offset, length);
+  }
+
+  public AssistContext(CompilationUnit cu, ISourceViewer sourceViewer, IEditorPart editor,
+      int offset, int length) {
+    this(cu, sourceViewer, editor, offset, length, ASTProvider.WAIT_YES);
+  }
+
+  public AssistContext(CompilationUnit cu, ISourceViewer sourceViewer, int offset, int length) {
+    this(cu, sourceViewer, null, offset, length);
+  }
+
+  public AssistContext(CompilationUnit cu, ISourceViewer sourceViewer, int offset, int length,
+      ASTProvider.WAIT_FLAG waitFlag) {
+    this(cu, sourceViewer, null, offset, length, waitFlag);
+  }
+
+  private AssistContext(CompilationUnit cu, ISourceViewer sourceViewer, IEditorPart editor,
+      int offset, int length, ASTProvider.WAIT_FLAG waitFlag) {
+    super(sourceViewer, offset, length);
+    Assert.isLegal(cu != null);
+    Assert.isLegal(waitFlag != null);
+    fCompilationUnit = cu;
+    fEditor = editor;
+    fWaitFlag = waitFlag;
+  }
+
+  @Override
+  public DartUnit getASTRoot() {
+    if (fASTRoot == null) {
+//      fASTRoot = SharedASTProvider.getAST(fCompilationUnit, fWaitFlag, null);
+      fASTRoot = ASTProvider.getASTProvider().getAST(fCompilationUnit, fWaitFlag, null);
+      // TODO(scheglov) don't know if needed
+//      if (fASTRoot == null) {
+//        // see bug 63554
+//        fASTRoot = ASTResolving.createQuickFixAST(fCompilationUnit, null);
+//      }
+    }
+    return fASTRoot;
+  }
+
+  /**
+   * Returns the compilation unit.
+   * 
+   * @return an <code>CompilationUnit</code>
+   */
+  @Override
+  public CompilationUnit getCompilationUnit() {
+    return fCompilationUnit;
+  }
+
+  @Override
+  public DartNode getCoveredNode() {
+    if (fNodeFinder == null) {
+      fNodeFinder = NodeFinder.find(getASTRoot(), getOffset(), getLength());
+    }
+    return fNodeFinder.getCoveredNode();
+  }
+
+  @Override
+  public DartNode getCoveringNode() {
+    if (fNodeFinder == null) {
+      fNodeFinder = NodeFinder.find(getASTRoot(), getOffset(), getLength());
+    }
+    return fNodeFinder.getCoveringNode();
+  }
+
+  /**
+   * Returns the editor or <code>null</code> if none.
+   * 
+   * @return an <code>IEditorPart</code> or <code>null</code> if none
+   * @since 3.5
+   */
+  public IEditorPart getEditor() {
+    return fEditor;
+  }
+
+  /**
+   * Returns the length.
+   */
+  @Override
+  public int getSelectionLength() {
+    return Math.max(getLength(), 0);
+  }
+
+  /**
+   * Returns the offset.
+   */
+  @Override
+  public int getSelectionOffset() {
+    return getOffset();
+  }
+
+  public void setASTRoot(DartUnit root) {
+    fASTRoot = root;
+  }
+
+}