now this is a working version of the app with topic disambiguation but it is still not optimal

src/ui/android/res/layout/activity_lexical_entry.xml

@@ -4,49 +4,66 @@
 	android:layout_height="match_parent"
 	android:layout_width="match_parent">
 
-	<RelativeLayout
-		android:layout_height="match_parent"
-		android:layout_width="match_parent">
+	<android.support.v4.widget.DrawerLayout
+		android:id="@+id/drawer_layout"
+		android:layout_width="match_parent"
+		android:layout_height="match_parent">
 
+		<!-- The main content view -->
 		<RelativeLayout
-			android:id="@+id/lexical_header"
-			android:layout_height="wrap_content"
-			android:layout_width="match_parent"
-			android:layout_alignParentTop="true"
-			android:layout_alignParentLeft="true"
-			android:layout_alignParentRight="true"
-			android:padding="8dp"
-			android:background="#C0C0C0">
+			android:layout_height="match_parent"
+			android:layout_width="match_parent">
 
-			<org.grammaticalframework.ui.android.LanguageSelector
-				android:id="@+id/show_language"
+			<RelativeLayout
+				android:id="@+id/lexical_header"
 				android:layout_height="wrap_content"
 				android:layout_width="match_parent"
-				android:layout_alignParentLeft="true"
 				android:layout_alignParentTop="true"
-				android:padding="0dp"/>
+				android:layout_alignParentLeft="true"
+				android:layout_alignParentRight="true"
+				android:padding="8dp"
+				android:background="#C0C0C0">
 
+				<org.grammaticalframework.ui.android.LanguageSelector
+					android:id="@+id/show_language"
+					android:layout_height="wrap_content"
+					android:layout_width="match_parent"
+					android:layout_alignParentLeft="true"
+					android:layout_alignParentTop="true"
+					android:padding="0dp"/>
+
+			</RelativeLayout>
+		
+			<TextView
+				android:id="@+id/lexical_desc"
+				android:layout_width="fill_parent"
+				android:layout_height="wrap_content"
+				android:layout_below="@+id/lexical_header"
+				android:paddingLeft="1dp"
+				android:paddingTop="4dp"
+				android:paddingBottom="2dp"
+				android:textSize="25sp"/>
+
+			<ListView
+				android:layout_width="match_parent"
+				android:layout_height="match_parent"
+				android:layout_below="@id/lexical_desc"
+				android:orientation="vertical"
+				android:paddingLeft="1dp"
+				android:id="@android:id/list" >
+			</ListView>
 		</RelativeLayout>
-	
-		<TextView
-			android:id="@+id/lexical_desc"
-			android:layout_width="fill_parent"
-			android:layout_height="wrap_content"
-			android:layout_below="@+id/lexical_header"
-			android:paddingLeft="1dp"
-			android:paddingTop="4dp"
-			android:paddingBottom="2dp"
-			android:textSize="25sp"/>
 
-		<ListView
-			android:layout_width="match_parent"
+		<!-- The navigation drawer -->
+		<ListView android:id="@+id/topics_list"
+			android:layout_width="250dp"
 			android:layout_height="match_parent"
-			android:layout_below="@id/lexical_desc"
-			android:orientation="vertical"
-			android:paddingLeft="1dp"
-			android:id="@android:id/list" >
-		</ListView>
-	</RelativeLayout>
+			android:layout_gravity="start"
+			android:choiceMode="singleChoice"
+			android:divider="@android:color/transparent"
+			android:dividerHeight="0dp"
+			android:background="#FFFFE0"/>
+	</android.support.v4.widget.DrawerLayout>
 
 	<LinearLayout
 		android:id="@+id/progressBarView" 
@@ -60,4 +77,4 @@
 			android:layout_width="wrap_content"
 			android:layout_height="wrap_content"/>	
 	</LinearLayout>
-</FrameLayout>
+</FrameLayout>

src/ui/android/res/layout/lexical_item.xml

@@ -18,10 +18,10 @@
         android:layout_toRightOf="@id/arrow"
         android:paddingLeft="10dp"
         android:textSize="25sp"/>
-    
+
     <WebView
         android:id="@+id/desc_details"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_below="@id/lexical_desc"/>
-</RelativeLayout>
+</RelativeLayout>

src/ui/android/res/menu/main.xml

@@ -1,6 +1,8 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android" >
 	<item android:id="@+id/input_mode"
           android:title="@string/keyboard_input"/>
+	<item android:id="@+id/topics"
+          android:title="@string/topics"/>
 	<item android:id="@+id/help"
           android:title="@string/help"/>
 </menu>

src/ui/android/res/values/strings.xml

@@ -29,4 +29,8 @@
     
     <string name="search_hint">Search word:</string>
     <string name="search_description">Search for words in the lexicon</string>
+    
+    <string name="topics">Topics</string>
+    <string name="topics_open">Open topics</string>
+    <string name="topics_close">Close topics</string>
 </resources>

src/ui/android/src/org/grammaticalframework/ui/android/AlternativesActivity.java

@@ -5,19 +5,30 @@ import java.util.*;
 import android.app.Activity;
 import android.app.ListActivity;
 import android.content.Context;
+import android.content.res.Configuration;
 import android.os.AsyncTask;
 import android.os.Bundle;
-import android.view.LayoutInflater;
+import android.view.*;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
+import android.view.MenuItem;
+import android.view.LayoutInflater;
 import android.webkit.WebView;
+import android.widget.BaseAdapter;
+import android.widget.ListAdapter;
 import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.RelativeLayout;
 import android.widget.TextView;
+import android.widget.CheckBox;
+import android.widget.CompoundButton;
+import android.widget.ListView;
+import android.widget.AdapterView;
 import android.util.Log;
+import android.support.v4.widget.DrawerLayout;
+import android.support.v4.app.ActionBarDrawerToggle;
 
 import org.grammaticalframework.pgf.*;
 import org.grammaticalframework.ui.android.LanguageSelector.OnLanguageSelectedListener;
@@ -28,6 +39,9 @@ public class AlternativesActivity extends ListActivity {
 	private LanguageSelector mShowLanguageView;
 	private View mProgressBarView = null;
 	private AlternativesAdapter mAdapter = null;
+	private DrawerLayout mDrawerLayout;
+	private ListView mDrawerList;
+	private ActionBarDrawerToggle mDrawerToggle;
 
 	/** Called when the activity is first created. */
 	@Override
@@ -64,23 +78,44 @@ public class AlternativesActivity extends ListActivity {
                 }.execute();
             }
         });
-	    
+
+		mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
+		mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
+		                                          R.drawable.ic_drawer,
+		                                          R.string.topics_open,
+		                                          R.string.topics_close);
+		mDrawerLayout.setDrawerListener(mDrawerToggle);
+
+		getActionBar().setDisplayHomeAsUpEnabled(true);
+        getActionBar().setHomeButtonEnabled(true);
+
 	    TextView descrView = (TextView) findViewById(R.id.lexical_desc);
 
-		String authority = getIntent().getData().getAuthority();
-		String source = getIntent().getData().getQueryParameter("source");
-		List analyses = new ArrayList();
-		for (String an : getIntent().getData().getQueryParameters("alternative")) {
-			analyses.add(Expr.readExpr(an));
-		}
-		descrView.setText(source);
+	    if (getIntent().getData() != null) {
+			String authority = getIntent().getData().getAuthority();
+			String source = getIntent().getData().getQueryParameter("source");
 
-		mAdapter = new AlternativesAdapter(this, authority, analyses);
+			List analyses = new ArrayList();
+			for (String an : getIntent().getData().getQueryParameters("alternative")) {
+				analyses.add(Expr.readExpr(an));
+			}
+			descrView.setText(source);
+			
+			mAdapter = new AlternativesAdapter(this, authority, analyses);
+		} else {
+	        mDrawerLayout.openDrawer(Gravity.LEFT);
+
+	        mAdapter = new AlternativesAdapter(this, Translator.WORDS);
+		}
+
+		expandedView = null;
 		setListAdapter(mAdapter);
-        expandedView = null;
+
+		mDrawerList = (ListView) findViewById(R.id.topics_list);
+		mDrawerList.setAdapter(mAdapter.getTopicsAdapter());
 
 	    mProgressBarView = findViewById(R.id.progressBarView);
-     }
+    }
 
 	@Override
 	protected void onResume() {
@@ -98,7 +133,7 @@ public class AlternativesActivity extends ListActivity {
 	}
 
 	private View expandedView;
-	
+
 	private void collapse() {
 		if (expandedView == null)
 			return;
@@ -182,22 +217,183 @@ public class AlternativesActivity extends ListActivity {
 		expandedView = view;
 	}
 
-    private class AlternativesAdapter extends ArrayAdapter<Expr> {
-		private String mAuthority;
+	private class Topic {
+		public String name;
+		public Expr expr;
+		public boolean isChecked;
+		public boolean isAvailable;
+		
+		public Topic(String name, Expr expr) {
+			this.name        = name;
+			this.expr        = expr;
+			this.isChecked   = false;
+			this.isAvailable = true;
+		}
+	}
 
-    	public AlternativesAdapter(Context context, String authority, List<Expr> data) {
-    		super(context, android.R.layout.simple_list_item_1, data);
-    		mAuthority = authority;
-    	}
+	private class AlternativesAdapter extends BaseAdapter implements ListAdapter {
+		/**
+		 * Contains the list of objects that represent the alternatives
+		 */
+		private List<Expr> mAlternatives;
+
+		private Context mContext;
+
+		// A copy of the original mAlternatives array, initialized from and then used instead as soon as
+		// a topic filtering is applied. mAlternatives will then only contain the filtered values.
+		private ArrayList<Expr> mOriginalAlternatives;
+
+		private LayoutInflater mInflater;
+
+		private String mAuthority;
+		
+		/**
+		 * A list of lists of topics. Each element in this list contains
+		 * the list of topics for the correponding item in 
+		 * mAlternatives/mOriginalAlternatives
+		 */
+		private List<List<Topic>> mTopics;
+
+		private Map<String,Topic> mTopicMap;
+		private Topic[] mAllTopics;
+		private Topic[] mOriginalAllTopics;
+
+		private Topic mOtherTopic;
+		private Topic mSourceTopic;
+
+		private TopicsAdapter mTopicsAdapter;
+
+		public AlternativesAdapter(Context context, String authority, List<Expr> alternatives) {
+			mContext = context;
+			mAuthority = authority;
+			mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+			mAlternatives = alternatives;
+
+			boolean addOther = false;
+			mTopics = new ArrayList<List<Topic>>();
+			mTopicMap = new TreeMap<String,Topic>();
+			for (Expr e : mAlternatives) {
+				List<Topic> topics = new ArrayList<Topic>();
+				for (Expr topicExpr : mTranslator.getTopicsOf(e)) {
+					String name = mTranslator.linearizeSource(topicExpr);
+					String key  = name.toLowerCase();
+					Topic topic = mTopicMap.get(key);
+					if (topic == null) {
+						topic = new Topic(name, topicExpr);
+						mTopicMap.put(key,topic);
+					}
+					topics.add(topic);
+				}
+				mTopics.add(topics);
+
+				if (topics.size() == 0)
+					addOther = true;
+			}
+
+			int i = 0;
+			mAllTopics = new Topic[mTopicMap.size() + (addOther ? 1 : 0)];
+			for (Map.Entry<String,Topic> entry : mTopicMap.entrySet()) {
+				mAllTopics[i++] = entry.getValue();
+			}
+			if (addOther) {
+				Expr topicExpr = Expr.readExpr("other_1_A");
+				String name = mTranslator.linearizeSource(topicExpr);
+				mOtherTopic = new Topic(name, topicExpr);
+				mAllTopics[i++] = mOtherTopic;
+			}
+
+			mOriginalAllTopics = mAllTopics;
+
+			mTopicsAdapter = new TopicsAdapter();
+		}
+
+		public AlternativesAdapter(Context context, String authority) {
+			mContext = context;
+			mAuthority = authority;
+			mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+			mAlternatives = null;
+
+			mTopics = null;
+
+			int i = 0;
+			mTopicMap = new TreeMap<String,Topic>();
+			for (Expr topicExpr : mTranslator.getTopicsOf(null)) {
+				String name = mTranslator.linearizeSource(topicExpr);
+				String key  = name.toLowerCase();
+				Topic topic = mTopicMap.get(key);
+				if (topic == null) {
+					topic = new Topic(name, topicExpr);
+					mTopicMap.put(key,topic);
+				}
+			}
+			mAllTopics = new Topic[mTopicMap.size()];
+			for (Map.Entry<String,Topic> entry : mTopicMap.entrySet()) {
+				mAllTopics[i++] = entry.getValue();
+			}
+
+			mOriginalAllTopics = mAllTopics;
+
+			mTopicsAdapter = new TopicsAdapter();
+		}
+
+		/**
+		 * Returns the context associated with this array adapter. The context is used
+		 * to create views from the resource passed to the constructor.
+		 *
+		 * @return The Context associated with this adapter.
+		 */
+		public Context getContext() {
+			return mContext;
+		}
+
+		public String getAuthority() {
+			return mAuthority;
+		}
+
+		/**
+		 * {@inheritDoc}
+		 */
+		public int getCount() {
+			if (mAlternatives == null)
+				return 0;
+			else
+				return mAlternatives.size();
+		}
+
+		/**
+		 * {@inheritDoc}
+		 */
+		public Expr getItem(int position) {
+			return mAlternatives.get(position);
+		}
+
+		/**
+		 * Returns the position of the specified item in the array.
+		 *
+		 * @param item The item to retrieve the position of.
+		 *
+		 * @return The position of the specified item.
+		 */
+		public int getPosition(Expr item) {
+			if (mAlternatives == null)
+				return -1;
+			else
+				return mAlternatives.indexOf(item);
+		}
+
+		/**
+		 * {@inheritDoc}
+		 */
+		public long getItemId(int position) {
+			return position;
+		}
 
     	public View getView(int position, View convertView, ViewGroup parent) {
 			final Expr expr = getItem(position);
 
 			if (mAuthority.equals(Translator.WORDS)) {
 				if (convertView == null) {
-					LayoutInflater inflater = (LayoutInflater) 
-							getContext().getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
-		            convertView = inflater.inflate(R.layout.lexical_item, null);
+		            convertView = mInflater.inflate(R.layout.lexical_item, null);
 		        }
 
 		        TextView descView = (TextView)
@@ -221,9 +417,7 @@ public class AlternativesActivity extends ListActivity {
 				});
 			} else if (mAuthority.equals(Translator.SENTENCES)) {
 				if (convertView == null) {
-					LayoutInflater inflater = (LayoutInflater) 
-							getContext().getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
-		            convertView = inflater.inflate(R.layout.alternative_item, null);
+		            convertView = mInflater.inflate(R.layout.alternative_item, null);
 
 		            View treeView = (View) convertView.findViewById(R.id.desc_details);
 		    		((RelativeLayout) convertView).removeView(treeView);
@@ -283,5 +477,192 @@ public class AlternativesActivity extends ListActivity {
 
 			return convertView;
 	    }
+	    
+	    public boolean areAllItemsEnabled() {
+			return true;
+		}
+		
+		public boolean isEnabled(int position) {
+			return true;
+		}
+		
+		public TopicsAdapter getTopicsAdapter() {
+			return mTopicsAdapter;
+		}
+		
+		void filterOnTopics(List<Topic> selected_topics) {
+			if (mSourceTopic != null && !selected_topics.contains(mSourceTopic))
+				mAlternatives = null;
+
+			if (mAlternatives == null) {
+				if (selected_topics.size() == 0)
+					return;
+
+				mSourceTopic = selected_topics.get(0);
+				mAlternatives = mTranslator.getTopicWords(mSourceTopic.expr);
+				
+				mTopics = new ArrayList<List<Topic>>();
+				for (Expr e : mAlternatives) {
+					List<Topic> topics = new ArrayList<Topic>();
+					for (Expr topicExpr : mTranslator.getTopicsOf(e)) {
+						String name = mTranslator.linearizeSource(topicExpr);
+						String key  = name.toLowerCase();
+						topics.add(mTopicMap.get(key));
+					}
+					mTopics.add(topics);
+				}
+			}
+
+			if (mOriginalAlternatives == null) {
+				mOriginalAlternatives = new ArrayList<Expr>(mAlternatives);
+            }
+
+			mAlternatives = new ArrayList<Expr>();
+			List<List<Expr>> topics = new ArrayList<List<Expr>>();
+
+			for (Topic topic : mOriginalAllTopics) {
+				topic.isAvailable = false;
+			}
+
+			int count = 0;
+            for (int i = 0; i < mOriginalAlternatives.size(); i++) {
+				boolean match = true;
+				for (Topic topic : selected_topics) {
+					if (topic == mOtherTopic) {
+						if (mTopics.get(i).size() > 0) {
+							match = false;
+							break;
+						}
+					} else if (!mTopics.get(i).contains(topic)) {
+						match = false;
+						break;
+					}
+				}
+				if (match) {
+					mAlternatives.add(mOriginalAlternatives.get(i));
+					if (mTopics.get(i).size() == 0) {
+						if (!mOtherTopic.isAvailable)
+							count++;
+						mOtherTopic.isAvailable = true;
+					} else {
+						for (Topic topic : mTopics.get(i)) {
+							if (!topic.isAvailable)
+								count++;
+							topic.isAvailable = true;
+						}
+					}
+				}
+			}
+
+			int i = 0;
+			mAllTopics = new Topic[count];
+			for (Topic topic : mOriginalAllTopics) {
+				if (topic.isAvailable)
+					mAllTopics[i++] = topic;
+			}
+
+			notifyDataSetChanged();
+		}
+	}
+
+    private class TopicsAdapter extends BaseAdapter implements ListAdapter {
+    	public TopicsAdapter() {
+    	}
+
+		public Context getContext() {
+			return mAdapter.getContext();
+		}
+
+		public int getCount() {
+			return mAdapter.mAllTopics.length;
+		}
+
+		public Topic getItem(int position) {
+			return mAdapter.mAllTopics[position];
+		}
+
+		public int getPosition(Topic topic) {
+			for (int i = 0; i < mAdapter.mAllTopics.length; i++) {
+				if (mAdapter.mAllTopics[i] == topic)
+					return i;
+			}
+			return -1;
+		}
+
+		public long getItemId(int position) {
+			return position;
+		}
+
+		// Shame on you Google this class should not have been here
+		// but unfortuantely CheckBox.setChecked doesn't work and here
+		// we need a workarround. Since the class is there now it is also
+		// used to implement OnClickListener.
+		private class TopicCheckBox extends CheckBox implements OnClickListener {
+			private Topic mTopic;
+			
+			public TopicCheckBox(Context context, Topic topic) {
+				super(context);
+				mTopic = topic;
+				setOnClickListener(this);
+			}
+
+			@Override
+			public boolean isChecked() {
+				if (mTopic == null)
+					return false;
+				else
+					return mTopic.isChecked;
+			}
+
+			@Override
+			public void onClick(View view) {
+				mTopic.isChecked = !mTopic.isChecked;
+				filterOnTopics();
+				notifyDataSetChanged();
+			}
+		}
+
+		private void filterOnTopics() {
+			List<Topic> selected_topics = new ArrayList<Topic>();
+			for (int i = 0; i < getCount(); i++) {
+				Topic topic = getItem(i);
+				if (topic.isChecked)
+					selected_topics.add(topic);
+			}
+			mAdapter.filterOnTopics(selected_topics);
+		}
+
+    	public View getView(int position, View convertView, ViewGroup parent) {
+			Topic entry = getItem(position);
+
+			CheckBox checkBox = new TopicCheckBox(getContext(), entry);
+			checkBox.setText(entry.name);
+			checkBox.setTextSize(25);
+			checkBox.setTextColor(android.graphics.Color.parseColor("#808080"));
+			return checkBox;
+	    }
+    }
+
+    @Override
+    protected void onPostCreate(Bundle savedInstanceState) {
+        super.onPostCreate(savedInstanceState);
+        // Sync the toggle state after onRestoreInstanceState has occurred.
+        mDrawerToggle.syncState();
+    }
+
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+        mDrawerToggle.onConfigurationChanged(newConfig);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        // Pass the event to ActionBarDrawerToggle, if it returns
+        // true, then it has handled the app icon touch event
+        if (mDrawerToggle.onOptionsItemSelected(item)) {
+          return true;
+        }
+        return super.onOptionsItemSelected(item);
     }
 }

src/ui/android/src/org/grammaticalframework/ui/android/MainActivity.java

@@ -191,8 +191,8 @@ public class MainActivity extends Activity {
 	        	editor.commit();
 
 	            return true;
-	        case R.id.semantic_graph: {
-	        	Intent myIntent = new Intent(MainActivity.this, SemanticGraphActivity.class);
+	        case R.id.topics: {
+	        	Intent myIntent = new Intent(MainActivity.this, AlternativesActivity.class);
             	MainActivity.this.startActivity(myIntent);
 	        	return true;
 	        }

src/ui/android/src/org/grammaticalframework/ui/android/Translator.java

@@ -338,11 +338,26 @@ public class Translator {
     	if (s == null)
     		s = "% ";     // make sure that we return something
 	
-	if (getTargetLanguage().getLangCode().equals("cmn-Hans-CN") ||
-	    getTargetLanguage().getLangCode().equals("ja-JP") ||
-	    getTargetLanguage().getLangCode().equals("th-TH"))
-	    return implode(s) ;
-	else return s ;
+		if (getTargetLanguage().getLangCode().equals("cmn-Hans-CN") ||
+		    getTargetLanguage().getLangCode().equals("ja-JP") ||
+		    getTargetLanguage().getLangCode().equals("th-TH"))
+		  return implode(s);
+		else
+		  return s;
+    }
+
+    public String linearizeSource(Expr expr) {
+    	Concr targetLang = getSourceConcr();
+    	String s = targetLang.linearize(expr);
+    	if (s == null)
+    		s = "% ";     // make sure that we return something
+	
+		if (getTargetLanguage().getLangCode().equals("cmn-Hans-CN") ||
+		    getTargetLanguage().getLangCode().equals("ja-JP") ||
+		    getTargetLanguage().getLangCode().equals("th-TH"))
+		  return implode(s);
+		else
+		  return s;
     }
 
     public Object[] bracketedLinearize(Expr expr) {
@@ -443,15 +458,34 @@ public class Translator {
 		}
 	}
 
-    private Expr getTopicWords(Expr lemma) {
-		StringBuilder sbuilder = new StringBuilder();
+    public List<Expr> getTopicWords(Expr lemma) {
+		TripleResult res = null;
+		List<Expr> words = new ArrayList<Expr>();
 		try {
-			TripleResult res = mSGManager.queryTriple(null, topic_pred, lemma);
+			res = mSGManager.queryTriple(null, topic_pred, lemma);
+			while (res.hasNext()) {
+				words.add(res.getSubject());
+			}
+		} catch (IOException e) {
+			// nothing
+		} catch (SGError e) {
+			// nothing
+		} finally {
+			if (res != null)
+				res.close();
+		}
+		return words;
+	}
+
+    private Expr getTopicWordsHtml(Expr lemma) {
+		StringBuilder sbuilder = new StringBuilder();
+		TripleResult res = null;
+		try {
+			res = mSGManager.queryTriple(null, topic_pred, lemma);
 			Map<String,Uri.Builder> map = new TreeMap<String,Uri.Builder>();
 			while (res.hasNext()) {
 				updateWordsMap(res.getSubject(), map);
 			}
-			res.close();
 
 			StringBuilder builder = new StringBuilder();
 			buildWordsHtml(map, builder);
@@ -460,6 +494,9 @@ public class Translator {
 			// nothing
 		} catch (SGError e) {
 			// nothing
+		} finally {
+			if (res != null)
+				res.close();
 		}
 		return null;
 	}
@@ -483,9 +520,9 @@ public class Translator {
 			Expr e = new Expr("MkDocument", 
 			                  def,
 			                  new Expr("Inflection"+cat,lemma),
-			                  getTopicWords(lemma));
+			                  getTopicWordsHtml(lemma));
 			String html =
-				"<html><head><meta charset=\"UTF-8\"/><style>a {color: gray;}</style></head><body>" +
+				"<html><head><meta charset=\"UTF-8\"/><style>a {color: #808080;}</style></head><body>" +
 				targetLang.linearize(e) +
 				"</body>";
 			return html;
@@ -495,7 +532,26 @@ public class Translator {
 			return null;
 		}
 	}
-	
+
+    public List<Expr> getTopicsOf(Expr lemma) {
+		TripleResult res = null;
+		List<Expr> topics = new ArrayList<Expr>();
+		try {
+			res = mSGManager.queryTriple(lemma, topic_pred, null);
+			while (res.hasNext()) {
+				topics.add(res.getObject());
+			}
+		} catch (IOException e) {
+			// nothing
+		} catch (SGError e) {
+			// nothing
+		} finally {
+			if (res != null)
+				res.close();
+		}
+		return topics;
+	}
+
 	private static String escapeHtml(CharSequence text) {
 		StringBuilder out = new StringBuilder();