Add SuggestOracle to SearchPanel

Remembering all of the possible search operators is tricky.  Now we
suggest them as the user types.

Change-Id: I17c9dd7fb69bf6a0292fbcf496a8b539308229b9
Signed-off-by: Brad Larson <bklarson@gmail.com>

gerrit-gwtui/src/main/java/com/google/gerrit/client/SearchPanel.java

@@ -27,6 +27,8 @@ import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.Composite;
 import com.google.gwt.user.client.ui.FlowPanel;
+import com.google.gwt.user.client.ui.SuggestBox;
+import com.google.gwt.user.client.ui.SuggestOracle.Suggestion;
 import com.google.gwtexpui.globalkey.client.GlobalKey;
 import com.google.gwtexpui.globalkey.client.KeyCommand;
 
@@ -42,15 +44,22 @@ class SearchPanel extends Composite {
     searchBox = new HintTextBox();
     searchBox.setVisibleLength(70);
     searchBox.setHintText(Gerrit.C.searchHint());
+    final MySuggestionDisplay suggestionDisplay = new MySuggestionDisplay();
     searchBox.addKeyPressHandler(new KeyPressHandler() {
       @Override
       public void onKeyPress(final KeyPressEvent event) {
         if (event.getNativeEvent().getKeyCode() == KeyCodes.KEY_ENTER) {
+          if (!suggestionDisplay.isSuggestionSelected) {
             doSearch();
           }
         }
+      }
     });
 
+    final SuggestBox suggestBox =
+        new SuggestBox(new SearchSuggestOracle(), searchBox, suggestionDisplay);
+    searchBox.setStyleName("gwt-TextBox");
+
     final Button searchButton = new Button(Gerrit.C.searchButton());
     searchButton.addClickHandler(new ClickHandler() {
       @Override
@@ -59,7 +68,7 @@ class SearchPanel extends Composite {
       }
     });
 
-    body.add(searchBox);
+    body.add(suggestBox);
     body.add(searchButton);
   }
 
@@ -106,4 +115,15 @@ class SearchPanel extends Composite {
       Gerrit.display(PageLinks.toChangeQuery(query), QueryScreen.forQuery(query));
     }
   }
+
+  private static class MySuggestionDisplay extends SuggestBox.DefaultSuggestionDisplay {
+    private boolean isSuggestionSelected;
+
+    @Override
+    protected Suggestion getCurrentSelection() {
+      Suggestion currentSelection = super.getCurrentSelection();
+      isSuggestionSelected = currentSelection != null;
+      return currentSelection;
+    }
+  }
 }

gerrit-gwtui/src/main/java/com/google/gerrit/client/SearchSuggestOracle.java

@@ -0,0 +1,140 @@
+// Copyright (C) 2012 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;
+
+import com.google.gwt.user.client.ui.SuggestOracle;
+import com.google.gwtexpui.safehtml.client.HighlightSuggestOracle;
+
+import java.util.ArrayList;
+import java.util.TreeSet;
+
+public class SearchSuggestOracle extends HighlightSuggestOracle {
+  private static final TreeSet<String> suggestions = new TreeSet<String>();
+
+  static {
+    suggestions.add("age:");
+    suggestions.add("age:1week"); // Give an example age
+
+    suggestions.add("change:");
+
+    suggestions.add("owner:");
+    suggestions.add("owner:self");
+    suggestions.add("ownerin:");
+
+    suggestions.add("reviewer:");
+    suggestions.add("reviewer:self");
+    suggestions.add("reviewerin:");
+
+    suggestions.add("commit:");
+    suggestions.add("project:");
+    suggestions.add("branch:");
+    suggestions.add("topic:");
+    suggestions.add("ref:");
+    suggestions.add("tr:");
+    suggestions.add("bug:");
+    suggestions.add("label:");
+    suggestions.add("message:");
+    suggestions.add("file:");
+
+    suggestions.add("has:");
+    suggestions.add("has:draft");
+    suggestions.add("has:star");
+
+    suggestions.add("is:");
+    suggestions.add("is:starred");
+    suggestions.add("is:watched");
+    suggestions.add("is:reviewed");
+    suggestions.add("is:owner");
+    suggestions.add("is:reviewer");
+    suggestions.add("is:open");
+    suggestions.add("is:draft");
+    suggestions.add("is:closed");
+    suggestions.add("is:submitted");
+    suggestions.add("is:merged");
+    suggestions.add("is:abandoned");
+
+    suggestions.add("status:");
+    suggestions.add("status:open");
+    suggestions.add("status:reviewed");
+    suggestions.add("status:submitted");
+    suggestions.add("status:closed");
+    suggestions.add("status:merged");
+    suggestions.add("status:abandoned");
+
+    suggestions.add("AND");
+    suggestions.add("OR");
+    suggestions.add("NOT");
+  }
+
+  @Override
+  public void requestDefaultSuggestions(Request request, Callback done) {
+    final ArrayList<SearchSuggestion> r = new ArrayList<SearchSuggestOracle.SearchSuggestion>();
+    // No text - show some default suggestions.
+    r.add(new SearchSuggestion("status:open", "status:open"));
+    r.add(new SearchSuggestion("age:1week", "age:1week"));
+    if (Gerrit.isSignedIn()) {
+      r.add(new SearchSuggestion("owner:self", "owner:self"));
+    }
+    done.onSuggestionsReady(request, new Response(r));
+  }
+
+  @Override
+  protected void onRequestSuggestions(Request request, Callback done) {
+    final String query = request.getQuery();
+    int lastSpace = query.lastIndexOf(' ');
+    final String lastWord;
+    // NOTE: this method is not called if the query is empty.
+    if (lastSpace == query.length() - 1) {
+      // Starting a new word - don't show suggestions yet.
+      done.onSuggestionsReady(request, null);
+      return;
+    } else if (lastSpace == -1) {
+      lastWord = query;
+    } else {
+      lastWord = query.substring(lastSpace + 1);
+    }
+
+    final ArrayList<SearchSuggestion> r = new ArrayList<SearchSuggestOracle.SearchSuggestion>();
+    for (String suggestion : suggestions.tailSet(lastWord)) {
+      if ((lastWord.length() < suggestion.length()) && suggestion.startsWith(lastWord)) {
+        if (suggestion.contains("self") && !Gerrit.isSignedIn()) {
+          continue;
+        }
+        r.add(new SearchSuggestion(suggestion, query + suggestion.substring(lastWord.length())));
+      }
+    }
+    done.onSuggestionsReady(request, new Response(r));
+  }
+
+  private static class SearchSuggestion implements SuggestOracle.Suggestion {
+    private final String suggestion;
+    private final String fullQuery;
+    public SearchSuggestion(String suggestion, String fullQuery) {
+      this.suggestion = suggestion;
+      // Add a space to the query if it is a complete operation (e.g.
+      // "status:open") so the user can keep on typing.
+      this.fullQuery = fullQuery.endsWith(":") ? fullQuery : fullQuery + " ";
+    }
+    @Override
+    public String getDisplayString() {
+      return suggestion;
+    }
+
+    @Override
+    public String getReplacementString() {
+      return fullQuery;
+    }
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -71,6 +71,9 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   private static final Pattern PAT_LABEL =
       Pattern.compile("^[a-zA-Z][a-zA-Z0-9]*((=|>=|<=)[+-]?|[+-])\\d+$");
 
+  // NOTE: As new search operations are added, please keep the
+  // SearchSuggestOracle up to date.
+
   public static final String FIELD_AGE = "age";
   public static final String FIELD_BRANCH = "branch";
   public static final String FIELD_CHANGE = "change";