Initial implementation of "Rename Local Variable" refactoring.

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

Index: editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/proposals/LinkedNamesAssistProposal.java
diff --git a/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/proposals/LinkedNamesAssistProposal.java b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/proposals/LinkedNamesAssistProposal.java
new file mode 100644
index 0000000000000000000000000000000000000000..b633f841f15a9da563fb165f7d5b985a35245453
--- /dev/null
+++ b/editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/correction/proposals/LinkedNamesAssistProposal.java
@@ -0,0 +1,269 @@
+package com.google.dart.tools.ui.internal.text.correction.proposals;
+
+import com.google.dart.compiler.ast.DartIdentifier;
+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.internal.corext.dom.LinkedNodeFinder;
+import com.google.dart.tools.internal.corext.refactoring.util.Messages;
+import com.google.dart.tools.ui.DartPluginImages;
+import com.google.dart.tools.ui.DartToolsPlugin;
+import com.google.dart.tools.ui.internal.text.correction.AssistContext;
+import com.google.dart.tools.ui.internal.text.correction.CorrectionCommandHandler;
+import com.google.dart.tools.ui.internal.text.correction.CorrectionMessages;
+import com.google.dart.tools.ui.internal.text.correction.ICommandAccess;
+import com.google.dart.tools.ui.internal.text.editor.ASTProvider;
+import com.google.dart.tools.ui.internal.text.editor.DartEditor;
+import com.google.dart.tools.ui.internal.text.editor.EditorHighlightingSynchronizer;
+import com.google.dart.tools.ui.text.dart.IDartCompletionProposal;
+import com.google.dart.tools.ui.text.dart.IInvocationContext;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.DocumentEvent;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.contentassist.ICompletionProposalExtension2;
+import org.eclipse.jface.text.contentassist.ICompletionProposalExtension6;
+import org.eclipse.jface.text.contentassist.IContextInformation;
+import org.eclipse.jface.text.link.LinkedModeModel;
+import org.eclipse.jface.text.link.LinkedModeUI;
+import org.eclipse.jface.text.link.LinkedModeUI.ExitFlags;
+import org.eclipse.jface.text.link.LinkedModeUI.IExitPolicy;
+import org.eclipse.jface.text.link.LinkedPosition;
+import org.eclipse.jface.text.link.LinkedPositionGroup;
+import org.eclipse.jface.viewers.StyledCellLabelProvider;
+import org.eclipse.jface.viewers.StyledString;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.VerifyEvent;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.texteditor.link.EditorLinkedModeUI;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+/**
+ * A template proposal.
+ */
+public class LinkedNamesAssistProposal implements IDartCompletionProposal,
+    ICompletionProposalExtension2, ICompletionProposalExtension6, ICommandAccess {
+
+  /**
+   * An exit policy that skips Backspace and Delete at the beginning and at the end of a linked
+   * position, respectively. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=183925 .
+   */
+  public static class DeleteBlockingExitPolicy implements IExitPolicy {
+    private final IDocument fDocument;
+
+    public DeleteBlockingExitPolicy(IDocument document) {
+      fDocument = document;
+    }
+
+    @Override
+    public ExitFlags doExit(LinkedModeModel model, VerifyEvent event, int offset, int length) {
+      if (length == 0 && (event.character == SWT.BS || event.character == SWT.DEL)) {
+        LinkedPosition position = model.findPosition(new LinkedPosition(fDocument, offset, 0,
+            LinkedPositionGroup.NO_STOP));
+        if (position != null) {
+          if (event.character == SWT.BS) {
+            if (offset - 1 < position.getOffset()) {
+              //skip backspace at beginning of linked position
+              event.doit = false;
+            }
+          } else /* event.character == SWT.DEL */{
+            if (offset + 1 > position.getOffset() + position.getLength()) {
+              //skip delete at end of linked position
+              event.doit = false;
+            }
+          }
+        }
+      }
+
+      return null; // don't change behavior
+    }
+  }
+
+  public static final String ASSIST_ID = "org.eclipse.jdt.ui.correction.renameInFile.assist"; //$NON-NLS-1$
+
+  private final DartIdentifier fNode;
+  private final IInvocationContext fContext;
+  private final String fLabel;
+  private final String fValueSuggestion;
+  private int fRelevance;
+
+  public LinkedNamesAssistProposal(IInvocationContext context, DartIdentifier node) {
+    this(CorrectionMessages.LinkedNamesAssistProposal_description, context, node, null);
+  }
+
+  public LinkedNamesAssistProposal(String label, IInvocationContext context, DartIdentifier node,
+      String valueSuggestion) {
+    fLabel = label;
+    fNode = node;
+    fContext = context;
+    fValueSuggestion = valueSuggestion;
+    fRelevance = 8;
+  }
+
+  @Override
+  public void apply(IDocument document) {
+    // can't do anything
+  }
+
+  @Override
+  public void apply(ITextViewer viewer, char trigger, int stateMask, int offset) {
+    try {
+      Point seletion = viewer.getSelectedRange();
+
+      // get full ast
+      DartUnit root = ASTProvider.getASTProvider().getAST(fContext.getCompilationUnit(),
+          ASTProvider.WAIT_YES, null);
+
+      DartNode nameNode = NodeFinder.perform(root, fNode.getSourceInfo().getOffset(),
+          fNode.getSourceInfo().getLength());
+      final int pos = fNode.getSourceInfo().getOffset();
+
+      DartNode[] sameNodes;
+      if (nameNode instanceof DartIdentifier) {
+        sameNodes = LinkedNodeFinder.findByNode(root, (DartIdentifier) nameNode);
+      } else {
+        sameNodes = new DartNode[] {nameNode};
+      }
+
+      // sort for iteration order, starting with the node @ offset
+      Arrays.sort(sameNodes, new Comparator<DartNode>() {
+
+        @Override
+        public int compare(DartNode o1, DartNode o2) {
+          return rank(o1) - rank(o2);
+        }
+
+        /**
+         * Returns the absolute rank of an <code>DartNode</code>. Nodes preceding
+         * <code>offset</code> are ranked last.
+         * 
+         * @param node the node to compute the rank for
+         * @return the rank of the node with respect to the invocation offset
+         */
+        private int rank(DartNode node) {
+          int relativeRank = node.getSourceInfo().getOffset() + node.getSourceInfo().getLength()
+              - pos;
+          if (relativeRank < 0) {
+            return Integer.MAX_VALUE + relativeRank;
+          } else {
+            return relativeRank;
+          }
+        }
+
+      });
+
+      IDocument document = viewer.getDocument();
+      LinkedPositionGroup group = new LinkedPositionGroup();
+      for (int i = 0; i < sameNodes.length; i++) {
+        DartNode elem = sameNodes[i];
+        group.addPosition(new LinkedPosition(document, elem.getSourceInfo().getOffset(),
+            elem.getSourceInfo().getLength(), i));
+      }
+
+      LinkedModeModel model = new LinkedModeModel();
+      model.addGroup(group);
+      model.forceInstall();
+      if (fContext instanceof AssistContext) {
+        IEditorPart editor = ((AssistContext) fContext).getEditor();
+        if (editor instanceof DartEditor) {
+          model.addLinkingListener(new EditorHighlightingSynchronizer((DartEditor) editor));
+        }
+      }
+
+      LinkedModeUI ui = new EditorLinkedModeUI(model, viewer);
+      ui.setExitPolicy(new DeleteBlockingExitPolicy(document));
+      ui.setExitPosition(viewer, offset, 0, LinkedPositionGroup.NO_STOP);
+      ui.enter();
+
+      if (fValueSuggestion != null) {
+        document.replace(nameNode.getSourceInfo().getOffset(),
+            nameNode.getSourceInfo().getLength(), fValueSuggestion);
+        IRegion selectedRegion = ui.getSelectedRegion();
+        seletion = new Point(selectedRegion.getOffset(), fValueSuggestion.length());
+      }
+
+      viewer.setSelectedRange(seletion.x, seletion.y); // by default full word is selected, restore original selection
+
+    } catch (BadLocationException e) {
+      DartToolsPlugin.log(e);
+    }
+  }
+
+  @Override
+  public String getAdditionalProposalInfo() {
+    return CorrectionMessages.LinkedNamesAssistProposal_proposalinfo;
+  }
+
+  @Override
+  public String getCommandId() {
+    return ASSIST_ID;
+  }
+
+  @Override
+  public IContextInformation getContextInformation() {
+    return null;
+  }
+
+  @Override
+  public String getDisplayString() {
+    String shortCutString = CorrectionCommandHandler.getShortCutString(getCommandId());
+    if (shortCutString != null) {
+      return Messages.format(CorrectionMessages.ChangeCorrectionProposal_name_with_shortcut,
+          new String[] {fLabel, shortCutString});
+    }
+    return fLabel;
+  }
+
+  @Override
+  public Image getImage() {
+    return DartPluginImages.get(DartPluginImages.IMG_CORRECTION_LINKED_RENAME);
+  }
+
+  @Override
+  public int getRelevance() {
+    return fRelevance;
+  }
+
+  @Override
+  public Point getSelection(IDocument document) {
+    return null;
+  }
+
+  @Override
+  public StyledString getStyledDisplayString() {
+    StyledString str = new StyledString(fLabel);
+
+    String shortCutString = CorrectionCommandHandler.getShortCutString(getCommandId());
+    if (shortCutString != null) {
+      String decorated = Messages.format(
+          CorrectionMessages.ChangeCorrectionProposal_name_with_shortcut, new String[] {
+              fLabel, shortCutString});
+      return StyledCellLabelProvider.styleDecoratedString(decorated, StyledString.QUALIFIER_STYLER,
+          str);
+    }
+    return str;
+  }
+
+  @Override
+  public void selected(ITextViewer textViewer, boolean smartToggle) {
+  }
+
+  public void setRelevance(int relevance) {
+    fRelevance = relevance;
+  }
+
+  @Override
+  public void unselected(ITextViewer textViewer) {
+  }
+
+  @Override
+  public boolean validate(IDocument document, int offset, DocumentEvent event) {
+    return false;
+  }
+}