Initial implementation of "Rename Local Variable" refactoring.

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

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/DartCorrectionAssistant.java
diff --git a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/DartCorrectionAssistant.java b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/DartCorrectionAssistant.java
new file mode 100644
index 0000000000000000000000000000000000000000..dbab066cae252c31de74485a4e9ac0ad1350ea1d
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/DartCorrectionAssistant.java
@@ -0,0 +1,352 @@
+package com.google.dart.tools.ui.internal.text.correction;
+
+import com.google.dart.tools.core.model.CompilationUnit;
+import com.google.dart.tools.core.model.DartElement;
+import com.google.dart.tools.ui.internal.text.editor.ASTProvider;
+
+import org.eclipse.core.runtime.Assert;
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.DefaultInformationControl;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IInformationControl;
+import org.eclipse.jface.text.IInformationControlCreator;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.Position;
+import org.eclipse.jface.text.contentassist.ContentAssistEvent;
+import org.eclipse.jface.text.contentassist.ICompletionListener;
+import org.eclipse.jface.text.contentassist.ICompletionProposal;
+import org.eclipse.jface.text.quickassist.IQuickAssistAssistant;
+import org.eclipse.jface.text.quickassist.QuickAssistAssistant;
+import org.eclipse.jface.text.source.Annotation;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.IWorkbenchPreferenceConstants;
+import org.eclipse.ui.PlatformUI;
+import org.eclipse.ui.texteditor.IDocumentProvider;
+import org.eclipse.ui.texteditor.ITextEditor;
+
+public class DartCorrectionAssistant extends QuickAssistAssistant {
+
+//  public static int collectQuickFixableAnnotations(ITextEditor editor, int invocationLocation,
+//      boolean goToClosest, ArrayList<Annotation> resultingAnnotations) throws BadLocationException {
+//    IAnnotationModel model = DartUI.getDocumentProvider().getAnnotationModel(
+//        editor.getEditorInput());
+//    if (model == null) {
+//      return invocationLocation;
+//    }
+//
+//    ensureUpdatedAnnotations(editor);
+//
+//    Iterator<Annotation> iter = model.getAnnotationIterator();
+//    if (goToClosest) {
+//      IRegion lineInfo = getRegionOfInterest(editor, invocationLocation);
+//      if (lineInfo == null) {
+//        return invocationLocation;
+//      }
+//      int rangeStart = lineInfo.getOffset();
+//      int rangeEnd = rangeStart + lineInfo.getLength();
+//
+//      ArrayList<Annotation> allAnnotations = new ArrayList<Annotation>();
+//      ArrayList<Position> allPositions = new ArrayList<Position>();
+//      int bestOffset = Integer.MAX_VALUE;
+//      while (iter.hasNext()) {
+//        Annotation annot = iter.next();
+//        if (DartCorrectionProcessor.isQuickFixableType(annot)) {
+//          Position pos = model.getPosition(annot);
+//          if (pos != null && isInside(pos.offset, rangeStart, rangeEnd)) { // inside our range?
+//            allAnnotations.add(annot);
+//            allPositions.add(pos);
+//            bestOffset = processAnnotation(annot, pos, invocationLocation, bestOffset);
+//          }
+//        }
+//      }
+//      if (bestOffset == Integer.MAX_VALUE) {
+//        return invocationLocation;
+//      }
+//      for (int i = 0; i < allPositions.size(); i++) {
+//        Position pos = allPositions.get(i);
+//        if (isInside(bestOffset, pos.offset, pos.offset + pos.length)) {
+//          resultingAnnotations.add(allAnnotations.get(i));
+//        }
+//      }
+//      return bestOffset;
+//    } else {
+//      while (iter.hasNext()) {
+//        Annotation annot = iter.next();
+//        if (DartCorrectionProcessor.isQuickFixableType(annot)) {
+//          Position pos = model.getPosition(annot);
+//          if (pos != null && isInside(invocationLocation, pos.offset, pos.offset + pos.length)) {
+//            resultingAnnotations.add(annot);
+//          }
+//        }
+//      }
+//      return invocationLocation;
+//    }
+//  }
+
+  /**
+   * Computes and returns the invocation offset given a new position, the initial offset and the
+   * best invocation offset found so far.
+   * <p>
+   * The closest offset to the left of the initial offset is the best. If there is no offset on the
+   * left, the closest on the right is the best.
+   * </p>
+   * 
+   * @param newOffset the offset to look at
+   * @param invocationLocation the invocation location
+   * @param bestOffset the current best offset
+   * @return -1 is returned if the given offset is not closer or the new best offset
+   */
+  private static int computeBestOffset(int newOffset, int invocationLocation, int bestOffset) {
+    if (newOffset <= invocationLocation) {
+      if (bestOffset > invocationLocation) {
+        return newOffset; // closest was on the right, prefer on the left
+      } else if (bestOffset <= newOffset) {
+        return newOffset; // we are closer or equal
+      }
+      return -1; // further away
+    }
+
+    if (newOffset <= bestOffset) {
+      return newOffset; // we are closer or equal
+    }
+
+    return -1; // further away
+  }
+
+  private static void ensureUpdatedAnnotations(ITextEditor editor) {
+    Object inputElement = editor.getEditorInput().getAdapter(DartElement.class);
+    if (inputElement instanceof CompilationUnit) {
+      ASTProvider.getASTProvider().getAST((CompilationUnit) inputElement,
+          ASTProvider.WAIT_ACTIVE_ONLY, null);
+    }
+  }
+
+  private static IRegion getRegionOfInterest(ITextEditor editor, int invocationLocation)
+      throws BadLocationException {
+    IDocumentProvider documentProvider = editor.getDocumentProvider();
+    if (documentProvider == null) {
+      return null;
+    }
+    IDocument document = documentProvider.getDocument(editor.getEditorInput());
+    if (document == null) {
+      return null;
+    }
+    return document.getLineInformationOfOffset(invocationLocation);
+  }
+
+  private static boolean isInside(int offset, int start, int end) {
+    return offset == start || offset == end || offset > start && offset < end; // make sure to handle 0-length ranges
+  }
+
+  private static int processAnnotation(Annotation annot, Position pos, int invocationLocation,
+      int bestOffset) {
+    int posBegin = pos.offset;
+    int posEnd = posBegin + pos.length;
+    if (isInside(invocationLocation, posBegin, posEnd)) { // covers invocation location?
+      return invocationLocation;
+    } else if (bestOffset != invocationLocation) {
+      int newClosestPosition = computeBestOffset(posBegin, invocationLocation, bestOffset);
+      if (newClosestPosition != -1) {
+        if (newClosestPosition != bestOffset) { // new best
+          // TODO(scheglov) restore this later
+//          if (DartCorrectionProcessor.hasCorrections(annot)) { // only jump to it if there are proposals
+//            return newClosestPosition;
+//          }
+        }
+      }
+    }
+    return bestOffset;
+  }
+
+  private ITextViewer fViewer;
+
+  private final ITextEditor fEditor;
+
+  private Position fPosition;
+
+  private Annotation[] fCurrentAnnotations;
+
+  private QuickAssistLightBulbUpdater fLightBulbUpdater;
+
+  private boolean fIsCompletionActive;
+
+  /*
+   * @see org.eclipse.jface.text.quickassist.QuickAssistAssistant#showPossibleQuickAssists()
+   * 
+   * @since 3.2
+   */
+
+  private boolean fIsProblemLocationAvailable;
+
+  public DartCorrectionAssistant(ITextEditor editor) {
+    super();
+    Assert.isNotNull(editor);
+    fEditor = editor;
+
+    DartCorrectionProcessor processor = new DartCorrectionProcessor(this);
+
+    setQuickAssistProcessor(processor);
+    enableColoredLabels(PlatformUI.getPreferenceStore().getBoolean(
+        IWorkbenchPreferenceConstants.USE_COLORED_LABELS));
+
+    setInformationControlCreator(getInformationControlCreator());
+
+    addCompletionListener(new ICompletionListener() {
+      @Override
+      public void assistSessionEnded(ContentAssistEvent event) {
+        fIsCompletionActive = false;
+      }
+
+      @Override
+      public void assistSessionStarted(ContentAssistEvent event) {
+        fIsCompletionActive = true;
+      }
+
+      @Override
+      public void selectionChanged(ICompletionProposal proposal, boolean smartToggle) {
+      }
+    });
+  }
+
+  /**
+   * Returns the annotations at the current offset
+   * 
+   * @return the annotations at the offset
+   */
+  public Annotation[] getAnnotationsAtOffset() {
+    return fCurrentAnnotations;
+  }
+
+  public IEditorPart getEditor() {
+    return fEditor;
+  }
+
+  @Override
+  public void install(ISourceViewer sourceViewer) {
+    super.install(sourceViewer);
+    fViewer = sourceViewer;
+
+    fLightBulbUpdater = new QuickAssistLightBulbUpdater(fEditor, sourceViewer);
+    fLightBulbUpdater.install();
+  }
+
+  /**
+   * @return <code>true</code> if a problem exist on the current line and the completion was not
+   *         invoked at the problem location
+   * @since 3.4
+   */
+  public boolean isProblemLocationAvailable() {
+    return fIsProblemLocationAvailable;
+  }
+
+  /**
+   * Returns true if the last invoked completion was called with an updated offset.
+   * 
+   * @return <code> true</code> if the last invoked completion was called with an updated offset.
+   */
+  public boolean isUpdatedOffset() {
+    return fPosition != null;
+  }
+
+  /**
+   * Show completions at caret position. If current position does not contain quick fixes look for
+   * next quick fix on same line by moving from left to right and restarting at end of line if the
+   * beginning of the line is reached.
+   * 
+   * @see IQuickAssistAssistant#showPossibleQuickAssists()
+   */
+  @Override
+  public String showPossibleQuickAssists() {
+    // TODO(scheglov) enable later
+//    boolean isReinvoked = false;
+//    fIsProblemLocationAvailable = false;
+//
+//    if (fIsCompletionActive) {
+//      if (isUpdatedOffset()) {
+//        isReinvoked = true;
+//        restorePosition();
+//        hide();
+//        fIsProblemLocationAvailable = true;
+//      }
+//    }
+//
+//    fPosition = null;
+//    fCurrentAnnotations = null;
+//
+//    if (fViewer == null || fViewer.getDocument() == null) {
+//      // Let superclass deal with this
+//      return super.showPossibleQuickAssists();
+//    }
+//
+//    ArrayList<Annotation> resultingAnnotations = new ArrayList<Annotation>(20);
+//    try {
+//      Point selectedRange = fViewer.getSelectedRange();
+//      int currOffset = selectedRange.x;
+//      int currLength = selectedRange.y;
+//      boolean goToClosest = currLength == 0 && !isReinvoked;
+//
+//      int newOffset = collectQuickFixableAnnotations(fEditor, currOffset, goToClosest,
+//          resultingAnnotations);
+//      if (newOffset != currOffset) {
+//        storePosition(currOffset, currLength);
+//        fViewer.setSelectedRange(newOffset, 0);
+//        fViewer.revealRange(newOffset, 0);
+//        fIsProblemLocationAvailable = true;
+//        if (fIsCompletionActive) {
+//          hide();
+//        }
+//      }
+//    } catch (BadLocationException e) {
+//      DartToolsPlugin.log(e);
+//    }
+//    fCurrentAnnotations = resultingAnnotations.toArray(new Annotation[resultingAnnotations.size()]);
+
+    return super.showPossibleQuickAssists();
+  }
+
+  @Override
+  public void uninstall() {
+    if (fLightBulbUpdater != null) {
+      fLightBulbUpdater.uninstall();
+      fLightBulbUpdater = null;
+    }
+    super.uninstall();
+  }
+
+  /*
+   * @see org.eclipse.jface.text.contentassist.ContentAssistant#possibleCompletionsClosed()
+   */
+  @Override
+  protected void possibleCompletionsClosed() {
+    super.possibleCompletionsClosed();
+    restorePosition();
+  }
+
+  private IInformationControlCreator getInformationControlCreator() {
+    return new IInformationControlCreator() {
+      @Override
+      public IInformationControl createInformationControl(Shell parent) {
+        // TODO(scheglov) not sure what exactly message
+        return new DefaultInformationControl(parent,
+            "DartToolsPlugin.getAdditionalInfoAffordanceString()");
+//        return new DefaultInformationControl(parent,
+//            DartToolsPlugin.getAdditionalInfoAffordanceString());
+      }
+    };
+  }
+
+  private void restorePosition() {
+    if (fPosition != null && !fPosition.isDeleted() && fViewer.getDocument() != null) {
+      fViewer.setSelectedRange(fPosition.offset, fPosition.length);
+      fViewer.revealRange(fPosition.offset, fPosition.length);
+    }
+    fPosition = null;
+  }
+
+  private void storePosition(int currOffset, int currLength) {
+    fPosition = new Position(currOffset, currLength);
+  }
+}