Merge "Start displaying comments and drafts."

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/CommentApi.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.client.changes;
 
 import com.google.gerrit.client.rpc.NativeMap;
+import com.google.gerrit.client.rpc.RestApi;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gwt.core.client.JsArray;
 import com.google.gwt.user.client.rpc.AsyncCallback;
@@ -23,7 +24,41 @@ public class CommentApi {
 
   public static void comments(PatchSet.Id id,
       AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
-    ChangeApi.revision(id).view("comments").get(cb);
+    revision(id, "comments").get(cb);
+  }
+
+  public static void comment(PatchSet.Id id, String commentId,
+      AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
+    revision(id, "comments").id(commentId).get(cb);
+  }
+
+  public static void drafts(PatchSet.Id id,
+      AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
+    revision(id, "drafts").get(cb);
+  }
+
+  public static void draft(PatchSet.Id id, String draftId,
+      AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
+    revision(id, "drafts").id(draftId).get(cb);
+  }
+
+  public static void createDraft(PatchSet.Id id, CommentInfo content,
+      AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
+    revision(id, "drafts").put(content, cb);
+  }
+
+  public static void updateDraft(PatchSet.Id id, String draftId,
+      CommentInfo content, AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
+    revision(id, "drafts").id(draftId).put(content, cb);
+  }
+
+  public static void deleteDraft(PatchSet.Id id, String draftId,
+      AsyncCallback<NativeMap<JsArray<CommentInfo>>> cb) {
+    revision(id, "drafts").id(draftId).delete(cb);
+  }
+
+  private static RestApi revision(PatchSet.Id id, String type) {
+    return ChangeApi.revision(id).view(type);
   }
 
   private CommentApi() {

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/CodeMirrorDemo.java

@@ -14,15 +14,22 @@
 
 package com.google.gerrit.client.diff;
 
+import com.google.gerrit.client.changes.CommentApi;
+import com.google.gerrit.client.changes.CommentInfo;
 import com.google.gerrit.client.diff.DiffInfo.Region;
 import com.google.gerrit.client.diff.DiffInfo.Span;
 import com.google.gerrit.client.rpc.CallbackGroup;
 import com.google.gerrit.client.rpc.GerritCallback;
+import com.google.gerrit.client.rpc.NativeMap;
 import com.google.gerrit.client.rpc.ScreenLoadCallback;
 import com.google.gerrit.client.ui.Screen;
+import com.google.gerrit.common.changes.Side;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.core.client.JsArray;
 import com.google.gwt.core.client.JsArrayString;
+import com.google.gwt.core.client.Scheduler;
+import com.google.gwt.core.client.Scheduler.ScheduledCommand;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.event.logical.shared.ResizeEvent;
@@ -37,8 +44,13 @@ import net.codemirror.lib.Configuration;
 import net.codemirror.lib.LineCharacter;
 import net.codemirror.lib.ModeInjector;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class CodeMirrorDemo extends Screen {
   private static final int HEADER_FOOTER = 60 + 15 * 2 + 38;
+  private static final JsArrayString EMPTY =
+      JavaScriptObject.createArray().cast();
   private final PatchSet.Id base;
   private final PatchSet.Id revision;
   private final String path;
@@ -47,6 +59,10 @@ public class CodeMirrorDemo extends Screen {
   private CodeMirror cmA;
   private CodeMirror cmB;
   private HandlerRegistration resizeHandler;
+  private JsArray<CommentInfo> published;
+  private JsArray<CommentInfo> drafts;
+  private List<Runnable> resizeCallbacks;
+  private LineMapper mapper;
 
   public CodeMirrorDemo(
       PatchSet.Id base,
@@ -85,7 +101,7 @@ public class CodeMirrorDemo extends Screen {
           new ModeInjector()
             .add(getContentType(diff.meta_a()))
             .add(getContentType(diff.meta_b()))
-            .inject(new ScreenLoadCallback<Void>(CodeMirrorDemo.this){
+            .inject(new ScreenLoadCallback<Void>(CodeMirrorDemo.this) {
               @Override
               protected void preDisplay(Void result) {
                 display(diff);
@@ -93,6 +109,16 @@ public class CodeMirrorDemo extends Screen {
             });
         }
       }));
+    CommentApi.comments(revision,
+        group.add(new GerritCallback<NativeMap<JsArray<CommentInfo>>>() {
+      @Override
+      public void onSuccess(NativeMap<JsArray<CommentInfo>> m) { published = m.get(path); }
+    }));
+    CommentApi.drafts(revision,
+        group.add(new GerritCallback<NativeMap<JsArray<CommentInfo>>>() {
+      @Override
+      public void onSuccess(NativeMap<JsArray<CommentInfo>> m) { drafts = m.get(path); }
+    }));
   }
 
   @Override
@@ -105,6 +131,15 @@ public class CodeMirrorDemo extends Screen {
       cmB.refresh();
     }
     Window.enableScrolling(false);
+    Scheduler.get().scheduleDeferred(new ScheduledCommand() {
+      @Override
+      public void execute() {
+        for (Runnable r : resizeCallbacks) {
+          r.run();
+        }
+        resizeCallbacks = null;
+      }
+    });
   }
 
   @Override
@@ -129,6 +164,14 @@ public class CodeMirrorDemo extends Screen {
     cmA = displaySide(diff.meta_a(), diff.text_a(), diffTable.getCmA());
     cmB = displaySide(diff.meta_b(), diff.text_b(), diffTable.getCmB());
     render(diff);
+    resizeCallbacks = new ArrayList<Runnable>();
+    renderComments(published, false);
+    renderComments(drafts, true);
+    published = null;
+    drafts = null;
+    mapper = null;
+
+    // TODO: Probably need horizontal resize
     resizeHandler = Window.addResizeHandler(new ResizeHandler() {
       @Override
       public void onResize(ResizeEvent event) {
@@ -159,40 +202,36 @@ public class CodeMirrorDemo extends Screen {
       .set("styleSelectedText", true)
       .set("value", contents);
     final CodeMirror cm = CodeMirror.create(ele, cfg);
-    cm.setWidth("100%");
     cm.setHeight(Window.getClientHeight() - HEADER_FOOTER);
     return cm;
   }
 
   private void render(DiffInfo diff) {
     JsArray<Region> regions = diff.content();
-    int lineA = 0, lineB = 0;
+    mapper = new LineMapper();
     for (int i = 0; i < regions.length(); i++) {
       Region current = regions.get(i);
-      if (current.ab() != null) {
-        lineA += current.ab().length();
-        lineB += current.ab().length();
-      } else if (current.a() == null && current.b() != null) {
-        int delta = current.b().length();
-        insertEmptyLines(cmA, lineA, delta);
-        lineB = colorLines(cmB, lineB, delta);
-      } else if (current.a() != null && current.b() == null) {
-        int delta = current.a().length();
-        insertEmptyLines(cmB, lineB, delta);
-        lineA = colorLines(cmA, lineA, delta);
-      } else {
-        JsArrayString currentA = current.a();
-        JsArrayString currentB = current.b();
+      int origLineA = mapper.getLineA();
+      int origLineB = mapper.getLineB();
+      if (current.ab() != null) { // Common
+        // TODO: Handle skips.
+        mapper.appendCommon(current.ab().length());
+      } else { // Insert, Delete or Edit
+        JsArrayString currentA = current.a() == null ? EMPTY : current.a();
+        JsArrayString currentB = current.b() == null ? EMPTY : current.b();
         int aLength = currentA.length();
         int bLength = currentB.length();
-        int origLineA = lineA;
-        int origLineB = lineB;
-        lineA = colorLines(cmA, lineA, aLength);
-        lineB = colorLines(cmB, lineB, bLength);
-        if (aLength < bLength) {
-          insertEmptyLines(cmA, lineA, bLength - aLength);
-        } else if (aLength > bLength) {
-          insertEmptyLines(cmB, lineB, aLength - bLength);
+        colorLines(cmA, origLineA, aLength);
+        colorLines(cmB, origLineB, bLength);
+        mapper.appendCommon(Math.min(aLength, bLength));
+        if (aLength < bLength) { // Edit with insertion
+          int insertCnt = bLength - aLength;
+          insertEmptyLines(cmA, mapper.getLineA(), insertCnt);
+          mapper.appendInsert(insertCnt);
+        } else if (aLength > bLength) { // Edit with deletion
+          int deleteCnt = aLength - bLength;
+          insertEmptyLines(cmB, mapper.getLineB(), deleteCnt);
+          mapper.appendDelete(deleteCnt);
         }
         markEdit(cmA, currentA, current.edit_a(), origLineA);
         markEdit(cmB, currentB, current.edit_b(), origLineB);
@@ -200,25 +239,44 @@ public class CodeMirrorDemo extends Screen {
     }
   }
 
-  private void insertEmptyLines(CodeMirror cm, int line, int cnt) {
-    Element div = DOM.createDiv();
-    div.setClassName(diffTable.style.padding());
-    div.getStyle().setHeight(cnt, Unit.EM);
-    Configuration config = Configuration.create()
-        .set("coverGutter", true)
-        .set("above", line == 0);
-    cm.addLineWidget(line == 0 ? 0 : (line - 1), div, config);
+  private void renderComments(JsArray<CommentInfo> comments, boolean isDraft) {
+    Configuration config = Configuration.create().set("coverGutter", true);
+    for (int i = 0; comments != null && i < comments.length(); i++) {
+      CommentInfo info = comments.get(i);
+      Side mySide = info.side();
+      CodeMirror cm = mySide == Side.PARENT ? cmA : cmB;
+      CodeMirror other = otherCM(cm);
+      final CommentBox box = new CommentBox(info.author(), info.updated(),
+          info.message(), isDraft);
+      int line = info.line() - 1; // CommentInfo is 1-based, but CM is 0-based
+      diffTable.add(box);
+      cm.addLineWidget(line, box.getElement(), config);
+      int lineToPad = mapper.lineOnOther(mySide, line);
+      // Estimated height at 21px, fixed by deferring after display
+      final Element paddingOtherside = addPaddingWidget(other,
+          diffTable.style.padding(), lineToPad,
+          21, Unit.PX);
+      Runnable callback = new Runnable() {
+        @Override
+        public void run() {
+          paddingOtherside.getStyle().setHeight(
+              box.getOffsetHeight(), Unit.PX);
+        }
+      };
+      resizeCallbacks.add(callback);
+      box.setOpenCloseHandler(callback);
+    }
   }
 
-  private int colorLines(CodeMirror cm, int line, int cnt) {
-    for (int i = 0; i < cnt; i++) {
-      cm.addLineClass(line + i, LineClassWhere.WRAP, diffTable.style.diff());
-    }
-    return line + cnt;
+  private CodeMirror otherCM(CodeMirror me) {
+    return me == cmA ? cmB : cmA;
   }
 
   private void markEdit(CodeMirror cm, JsArrayString lines,
       JsArray<Span> edits, int startLine) {
+    if (edits == null) {
+      return;
+    }
     EditIterator iter = new EditIterator(lines, startLine);
     Configuration diffOpt = Configuration.create()
         .set("className", diffTable.style.diff())
@@ -246,8 +304,32 @@ public class CodeMirrorDemo extends Screen {
     }
   }
 
-  public Runnable doScroll(final CodeMirror cm) {
-    final CodeMirror other = cm == cmA ? cmB : cmA;
+  private void colorLines(CodeMirror cm, int line, int cnt) {
+    for (int i = 0; i < cnt; i++) {
+      cm.addLineClass(line + i, LineClassWhere.WRAP, diffTable.style.diff());
+    }
+  }
+
+  private void insertEmptyLines(CodeMirror cm, int nextLine, int cnt) {
+    // -1 to compensate for the line we went past when this method is called.
+    addPaddingWidget(cm, diffTable.style.padding(), nextLine - 1,
+        cnt, Unit.EM);
+  }
+
+  private Element addPaddingWidget(CodeMirror cm, String style, int line,
+      int height, Unit unit) {
+    Element div = DOM.createDiv();
+    div.setClassName(style);
+    div.getStyle().setHeight(height, unit);
+    Configuration config = Configuration.create()
+        .set("coverGutter", true)
+        .set("above", line == -1);
+    cm.addLineWidget(line == -1 ? 0 : line, div, config);
+    return div;
+  }
+
+  private Runnable doScroll(final CodeMirror cm) {
+    final CodeMirror other = otherCM(cm);
     return new Runnable() {
       public void run() {
         cm.scrollToY(other.getScrollInfo().getTop());

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/CommentBox.java

@@ -0,0 +1,141 @@
+//Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.diff;
+
+import com.google.gerrit.client.AvatarImage;
+import com.google.gerrit.client.FormatUtil;
+import com.google.gerrit.client.account.AccountInfo;
+import com.google.gwt.core.client.GWT;
+import com.google.gwt.dom.client.Element;
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.event.shared.HandlerRegistration;
+import com.google.gwt.resources.client.CssResource;
+import com.google.gwt.uibinder.client.UiBinder;
+import com.google.gwt.uibinder.client.UiField;
+import com.google.gwt.user.client.ui.Composite;
+import com.google.gwt.user.client.ui.HTMLPanel;
+import com.google.gwt.user.client.ui.Widget;
+
+import java.sql.Timestamp;
+
+/** An HtmlPanel holding the DialogBox to display a comment */
+class CommentBox extends Composite {
+  interface Binder extends UiBinder<HTMLPanel, CommentBox> {}
+  private static Binder uiBinder = GWT.create(Binder.class);
+
+  interface CommentBoxStyle extends CssResource {
+    String open();
+    String close();
+  }
+
+  private HandlerRegistration headerClick;
+  private Runnable clickCallback;
+
+  @UiField
+  Widget header;
+
+  @UiField
+  AvatarImage avatar;
+
+  @UiField
+  Element name;
+
+  @UiField
+  Element summary;
+
+  @UiField
+  Element date;
+
+  @UiField
+  Element contentPanel;
+
+  @UiField
+  Element contentPanelMessage;
+
+  @UiField
+  CommentBoxStyle style;
+
+  CommentBox(AccountInfo author, Timestamp when, String message,
+      boolean isDraft) {
+    initWidget(uiBinder.createAndBindUi(this));
+    // TODO: Format the comment box differently based on whether isDraft
+    // is true.
+    setAuthorNameText(author);
+    date.setInnerText(FormatUtil.shortFormatDayTime(when));
+    setMessageText(message);
+    setOpen(false);
+  }
+
+  @Override
+  protected void onLoad() {
+    super.onLoad();
+
+    headerClick = header.addDomHandler(new ClickHandler() {
+      @Override
+      public void onClick(ClickEvent event) {
+        setOpen(!isOpen());
+        if (clickCallback != null) {
+          clickCallback.run();
+        }
+      }
+    }, ClickEvent.getType());
+  }
+
+  void setOpenCloseHandler(final Runnable callback) {
+    clickCallback = callback;
+  }
+
+  @Override
+  protected void onUnload() {
+    super.onUnload();
+
+    if (headerClick != null) {
+      headerClick.removeHandler();
+      headerClick = null;
+    }
+  }
+
+  private void setAuthorNameText(AccountInfo author) {
+    // TODO: Set avatar's display to none if we get a 404.
+    avatar = new AvatarImage(author, 26);
+    name.setInnerText(FormatUtil.name(author));
+  }
+
+  private void setMessageText(String message) {
+    if (message == null) {
+      message = "";
+    } else {
+      message = message.trim();
+    }
+    summary.setInnerText(message);
+    // TODO: Change to use setInnerHtml
+    contentPanelMessage.setInnerText(message);
+  }
+
+  private void setOpen(boolean open) {
+    if (open) {
+      removeStyleName(style.close());
+      addStyleName(style.open());
+    } else {
+      removeStyleName(style.open());
+      addStyleName(style.close());
+    }
+  }
+
+  private boolean isOpen() {
+    return getStyleName().contains(style.open());
+  }
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/CommentBox.ui.xml

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+Copyright (C) 2013 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+<ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'
+    xmlns:g='urn:import:com.google.gwt.user.client.ui'
+    xmlns:c='urn:import:com.google.gerrit.client'>
+  <ui:style type='com.google.gerrit.client.diff.CommentBox.CommentBoxStyle'>
+    .commentBox {
+      background-color: #e5ecf9;
+      border: 1px solid black;
+    }
+    .table {
+      width: 100%;
+      cursor: pointer;
+      table-layout: fixed;
+    }
+    .summary {
+      width: 60%;
+    }
+    .summaryText {
+      color: #777;
+      height: 1em;
+      max-width: 80%;
+      overflow: hidden;
+      padding-bottom: 1px;
+      text-overflow: ellipsis;
+      white-space: nowrap;
+    }
+    .open .summaryText {
+      display: none;
+    }
+    .date {
+      width: 25%;
+      text-align: right;
+    }
+    .close .contentPanel {
+      display: none;
+    }
+    .message {
+      margin: 5px;
+    }
+  </ui:style>
+  <g:HTMLPanel styleName='{style.commentBox}'>
+    <g:HTMLPanel ui:field='header'>
+    <table class='{style.table}'>
+      <tr>
+        <td><c:AvatarImage ui:field='avatar' /></td>
+        <td ui:field='name'></td>
+        <td class='{style.summary}'>
+          <div ui:field='summary' class='{style.summaryText}'></div>
+        </td>
+        <td ui:field='date' class='{style.date}'></td>
+      </tr>
+    </table>
+    </g:HTMLPanel>
+    <div ui:field='contentPanel' class='{style.contentPanel}'>
+      <div><p ui:field='contentPanelMessage' class='{style.message}'></p></div>
+      <div>
+        <button ui:field='reply'><ui:msg>Reply ...</ui:msg></button>
+        <button ui:field='replyDone'><ui:msg>Reply 'Done'</ui:msg></button>
+      </div>
+    </div>
+  </g:HTMLPanel>
+</ui:UiBinder>

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DiffTable.java

@@ -15,12 +15,13 @@
 package com.google.gerrit.client.diff;
 
 import com.google.gwt.core.client.GWT;
-import com.google.gwt.dom.client.DivElement;
+import com.google.gwt.dom.client.Element;
 import com.google.gwt.resources.client.CssResource;
 import com.google.gwt.uibinder.client.UiBinder;
 import com.google.gwt.uibinder.client.UiField;
 import com.google.gwt.user.client.ui.Composite;
 import com.google.gwt.user.client.ui.HTMLPanel;
+import com.google.gwt.user.client.ui.Widget;
 
 /**
  * A table with one row and two columns to hold the two CodeMirrors displaying
@@ -37,10 +38,10 @@ class DiffTable extends Composite {
   }
 
   @UiField
-  DivElement cmA;
+  Element cmA;
 
   @UiField
-  DivElement cmB;
+  Element cmB;
 
   @UiField
   LineStyle style;
@@ -49,12 +50,15 @@ class DiffTable extends Composite {
     initWidget(uiBinder.createAndBindUi(this));
   }
 
-  DivElement getCmA() {
+  Element getCmA() {
     return cmA;
   }
 
-  DivElement getCmB() {
+  Element getCmB() {
     return cmB;
   }
 
+  void add(Widget widget) {
+    ((HTMLPanel) getWidget()).add(widget);
+  }
 }

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DiffTable.ui.xml

@@ -24,6 +24,13 @@ limitations under the License.
       padding: 0;
       overflow: hidden;
     }
+    .table {
+      width: 100%;
+      table-layout: fixed;
+    }
+    .a, .b {
+      width: 50%;
+    }
     .a .diff,
     .a .diff .CodeMirror-linenumber {
       background-color: #fee;
@@ -52,10 +59,10 @@ limitations under the License.
     }
   </ui:style>
   <g:HTMLPanel styleName='{style.difftable}'>
-    <table>
+    <table class='{style.table}'>
       <tr>
-        <td><div ui:field='cmA' class='{style.a}'></div></td>
-        <td><div ui:field='cmB' class='{style.b}'></div></td>
+        <td ui:field='cmA' class='{style.a}'></td>
+        <td ui:field='cmB' class='{style.b}'></td>
       </tr>
     </table>
   </g:HTMLPanel>

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/LineMapper.java

@@ -0,0 +1,148 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.diff;
+
+import com.google.gerrit.common.changes.Side;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/** Helper class to handle calculations involving line gaps. */
+class LineMapper {
+  private int lineA;
+  private int lineB;
+  private List<LineGap> lineMapAtoB;
+  private List<LineGap> lineMapBtoA;
+
+  LineMapper() {
+    lineMapAtoB = new ArrayList<LineGap>();
+    lineMapBtoA = new ArrayList<LineGap>();
+  }
+
+  int getLineA() {
+    return lineA;
+  }
+
+  int getLineB() {
+    return lineB;
+  }
+
+  void appendCommon(int numLines) {
+    lineA += numLines;
+    lineB += numLines;
+  }
+
+  void appendInsert(int numLines) {
+    int origLineB = lineB;
+    lineB += numLines;
+    int bAheadOfA = lineB - lineA;
+    lineMapAtoB.add(new LineGap(lineA, lineA, bAheadOfA));
+    lineMapBtoA.add(new LineGap(origLineB, lineB - 1, -bAheadOfA));
+  }
+
+  void appendDelete(int numLines) {
+    int origLineA = lineA;
+    lineA += numLines;
+    int aAheadOfB = lineA - lineB;
+    lineMapAtoB.add(new LineGap(origLineA, lineA - 1, -aAheadOfB));
+    lineMapBtoA.add(new LineGap(lineB, lineB, aAheadOfB));
+  }
+
+  /**
+   * Helper method to retrieve the line number on the other side.
+   *
+   * Given a line number on one side, performs a binary search in the lineMap
+   * to find the corresponding LineGap record.
+   *
+   * A LineGap records gap information from the start of an actual gap up to
+   * the start of the next gap. In the following example,
+   * lineMapAtoB will have LineGap: {start: 1, end: 1, delta: 3}
+   * (end doesn't really matter here, as the binary search only looks at start)
+   * lineMapBtoA will have LineGap: {start: 1, end: 3, delta: -3}
+   * These LineGaps control lines between 1 and 5.
+   *
+   * The "delta" is computed as the number to add on our side to get the line
+   * number on the other side given a line after the actual gap, so the result
+   * will be (line + delta). All lines within the actual gap (1 to 3) are
+   * considered corresponding to the last line above the region on the other
+   * side, which is 0 in this case. For these lines, we do (end + delta).
+   *
+   * For example, to get the line number on the left corresponding to 1 on the
+   * right (lineOnOther(REVISION, 1)), the method looks up in lineMapBtoA,
+   * finds the "delta" to be -3, and returns 3 + (-3) = 0 since 1 falls in the
+   * actual gap. On the other hand, the line corresponding to 5 on the right
+   * will be 5 + (-3) = 2, since 5 is in the region after the gap (but still
+   * controlled by the current LineGap).
+   *
+   * PARENT REVISION
+   *   0   |   0
+   *   -   |   1 \                      \
+   *   -   |   2 | Actual insertion gap |
+   *   -   |   3 /                      | Region controlled by one LineGap
+   *   1   |   4   <- delta = 4 - 1 = 3 |
+   *   2   |   5                        /
+   *   -   |   6
+   *      ...
+   */
+  int lineOnOther(Side mySide, int line) {
+    List<LineGap> lineGaps = mySide == Side.PARENT ? lineMapAtoB : lineMapBtoA;
+    // Create a dummy LineGap for the search.
+    int ret = Collections.binarySearch(lineGaps, new LineGap(line));
+    if (ret == -1) {
+      return line;
+    } else {
+      LineGap lookup = lineGaps.get(0 <= ret ? ret : -ret - 2);
+      int end = lookup.end;
+      int delta = lookup.delta;
+      if (lookup.start <= line && line <= end) { // Line falls within gap
+        return end + delta;
+      } else { // Line after gap
+        return line + delta;
+      }
+    }
+  }
+
+  /**
+   * Helper class to record line gap info and assist in calculation of line
+   * number on the other side.
+   *
+   * For a mapping from A to B, where A is the side with an insertion:
+   * @field start The start line of the insertion in A.
+   * @field end The exclusive end line of the insertion in A.
+   * @field delta The offset added to A to get the line number in B calculated
+   *              from end.
+   */
+  private static class LineGap implements Comparable<LineGap> {
+    private final int start;
+    private final int end;
+    private final int delta;
+
+    private LineGap(int start, int end, int delta) {
+      this.start = start;
+      this.end = end;
+      this.delta = delta;
+    }
+
+    private LineGap(int line) {
+      this(line, 0, 0);
+    }
+
+    @Override
+    public int compareTo(LineGap o) {
+      return start - o.start;
+    }
+  }
+}

gerrit-gwtui/src/main/java/net/codemirror/lib/CodeMirror.java

@@ -66,9 +66,18 @@ public class CodeMirror extends JavaScriptObject {
     this.addLineClass(line, where, lineClass);
   }-*/;
 
-  public final native void addLineWidget(int line, Element node,
+  public final native void addWidget(LineCharacter pos, Element node,
+      boolean scrollIntoView) /*-{
+    this.addWidget(pos, node, scrollIntoView);
+  }-*/;
+
+  public final native LineWidget addLineWidget(int line, Element node,
       Configuration options) /*-{
-    this.addLineWidget(line, node, options);
+    return this.addLineWidget(line, node, options);
+  }-*/;
+
+  public final native int lineAtHeight(int height) /*-{
+    return this.lineAtHeight(height);
   }-*/;
 
   public final native CodeMirrorDoc getDoc() /*-{

gerrit-gwtui/src/main/java/net/codemirror/lib/LineWidget.java

@@ -0,0 +1,31 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package net.codemirror.lib;
+
+import com.google.gwt.core.client.JavaScriptObject;
+
+/** LineWidget objects used within CodeMirror. */
+public class LineWidget extends JavaScriptObject {
+  public static LineWidget create() {
+    return createObject().cast();
+  }
+
+  public final native void clear() /*-{ this.clear(); }-*/;
+  public final native void changed() /*-{ this.changed(); }-*/;
+  public final native JavaScriptObject getLine() /*-{ return this.line; }-*/;
+
+  protected LineWidget() {
+  }
+}

gerrit-gwtui/src/test/java/com/google/gerrit/client/diff/LineMapperTest.java

@@ -0,0 +1,91 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.diff;
+
+import static org.junit.Assert.assertEquals;
+
+import com.google.gerrit.common.changes.Side;
+
+import org.junit.Test;
+
+/** Unit tests for LineMapper */
+public class LineMapperTest {
+
+  @Test
+  public void testAppendCommon() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendCommon(10);
+    assertEquals(10, mapper.getLineA());
+    assertEquals(10, mapper.getLineB());
+  }
+
+  @Test
+  public void testAppendInsert() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendInsert(10);
+    assertEquals(0, mapper.getLineA());
+    assertEquals(10, mapper.getLineB());
+  }
+
+  @Test
+  public void testAppendDelete() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendDelete(10);
+    assertEquals(10, mapper.getLineA());
+    assertEquals(0, mapper.getLineB());
+  }
+
+  @Test
+  public void testFindInCommon() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendCommon(10);
+    assertEquals(9, mapper.lineOnOther(Side.PARENT, 9));
+  }
+
+  @Test
+  public void testFindAfterCommon() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendCommon(10);
+    assertEquals(10, mapper.lineOnOther(Side.PARENT, 10));
+  }
+
+  @Test
+  public void testFindInInsertGap() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendInsert(10);
+    assertEquals(-1, mapper.lineOnOther(Side.REVISION, 9));
+  }
+
+  @Test
+  public void testFindAfterInsertGap() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendInsert(10);
+    assertEquals(0, mapper.lineOnOther(Side.REVISION, 10));
+  }
+
+  @Test
+  public void testFindInDeleteGap() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendDelete(10);
+    assertEquals(-1, mapper.lineOnOther(Side.PARENT, 9));
+  }
+
+  @Test
+  public void testFindAfterDeleteGap() {
+    LineMapper mapper = new LineMapper();
+    mapper.appendDelete(10);
+    assertEquals(0, mapper.lineOnOther(Side.PARENT, 10));
+  }
+}

lib/codemirror/BUCK

@@ -1,6 +1,8 @@
-VERSION = '3.13'
-SHA1 = '7a83ae686d75afd30bb152d7683f2dc27e59ea82'
-URL = 'http://codemirror.net/codemirror-%s.zip' % VERSION
+include_defs('//lib/maven.defs')
+
+VERSION = 'bb73aeacb8'
+SHA1 = '3bc9c92b97210135bc83fca7a2bd5f3c4aab496a'
+URL = GERRIT + 'net/codemirror/codemirror-%s.zip' % VERSION
 
 prebuilt_jar(
   name = 'codemirror',