am b6d99b7d: Modify how GestureLibrary stores its data. The XML format is now replaced by a more efficient binary format which should speed up saving/loading. The format is very similar to the one used by the letters recognizer. The format is documented in GestureLibrary.java.

Merge commit 'b6d99b7d17fd1bb1326a70744bd01be5d1586487'

* commit 'b6d99b7d17fd1bb1326a70744bd01be5d1586487':
  Modify how GestureLibrary stores its data. The XML format is now replaced by a more efficient binary format which should speed up saving/loading. The format is very similar to the one used by the letters recognizer. The format is documented in GestureLibrary.java.

10 files changed, 288 insertions, 278 deletions

diff --git a/tests/sketch/AndroidManifest.xml b/tests/sketch/AndroidManifest.xml
index 1f4333c..78df234 100755
--- a/tests/sketch/AndroidManifest.xml
+++ b/tests/sketch/AndroidManifest.xml
@@ -14,25 +14,34 @@
      limitations under the License.
 -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-      package="com.android.gesture.example"
-      android:versionCode="1"
-      android:versionName="1.0.0">
-      <uses-permission android:name="android.permission.READ_CONTACTS" />
-      <application android:icon="@drawable/icon" android:label="@string/app_name">
-        <activity android:name="com.android.gesture.example.GestureEntry"
-                  android:label="@string/app_name">
+    package="com.android.gesture.example"
+    android:versionCode="1"
+    android:versionName="1.0.0">
+
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
+    <uses-permission android:name="android.permission.WRITE_SDCARD" />
+
+    <application android:icon="@drawable/icon" android:label="@string/app_name">
+
+        <activity
+            android:name="com.android.gesture.example.GestureEntry"
+            android:label="@string/app_name">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
         <activity android:name="com.android.gesture.example.GestureLibViewer"/>
-        <activity android:name="com.android.gesture.example.ContactListGestureOverlay"
-                  android:label="@string/overlay_name">
+
+        <activity
+            android:name="com.android.gesture.example.ContactListGestureOverlay"
+            android:label="@string/overlay_name">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
     </application>
 </manifest> 
diff --git a/tests/sketch/src/com/android/gesture/Gesture.java b/tests/sketch/src/com/android/gesture/Gesture.java
index 44711ca..d5dcc65 100755
--- a/tests/sketch/src/com/android/gesture/Gesture.java
+++ b/tests/sketch/src/com/android/gesture/Gesture.java
@@ -23,12 +23,17 @@ import android.graphics.Path;
 import android.graphics.RectF;
 import android.os.Parcel;
 import android.os.Parcelable;
-
-import org.xmlpull.v1.XmlSerializer;
+import android.util.Log;
 
 import java.io.IOException;
+import java.io.DataOutputStream;
+import java.io.DataInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ByteArrayInputStream;
 import java.util.ArrayList;
 
+import static com.android.gesture.GestureConstants.LOG_TAG;
+
 /**
  * A gesture can have a single or multiple strokes
  */
@@ -149,10 +154,12 @@ public class Gesture implements Parcelable {
      * @return the bitmap
      */
     public Bitmap toBitmap(int width, int height, int edge, int numSample, int color) {
-        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
-        Canvas canvas = new Canvas(bitmap);
+        final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        final Canvas canvas = new Canvas(bitmap);
+
         canvas.translate(edge, edge);
-        Paint paint = new Paint();
+
+        final Paint paint = new Paint();
         paint.setAntiAlias(BITMAP_RENDERING_ANTIALIAS);
         paint.setDither(BITMAP_RENDERING_DITHER);
         paint.setColor(color);
@@ -182,10 +189,12 @@ public class Gesture implements Parcelable {
      * @return the bitmap
      */
     public Bitmap toBitmap(int width, int height, int edge, int color) {
-        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
-        Canvas canvas = new Canvas(bitmap);
+        final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        final Canvas canvas = new Canvas(bitmap);
+
         canvas.translate(edge, edge);
-        Paint paint = new Paint();
+
+        final Paint paint = new Paint();
         paint.setAntiAlias(BITMAP_RENDERING_ANTIALIAS);
         paint.setDither(BITMAP_RENDERING_DITHER);
         paint.setColor(color);
@@ -193,53 +202,44 @@ public class Gesture implements Parcelable {
         paint.setStrokeJoin(Paint.Join.ROUND);
         paint.setStrokeCap(Paint.Cap.ROUND);
         paint.setStrokeWidth(BITMAP_RENDERING_WIDTH);
-        ArrayList<GestureStroke> strokes = mStrokes;
-        int count = strokes.size();
+
+        final ArrayList<GestureStroke> strokes = mStrokes;
+        final int count = strokes.size();
+
         for (int i = 0; i < count; i++) {
-            GestureStroke stroke = strokes.get(i);
-            stroke.draw(canvas, paint);
+            strokes.get(i).draw(canvas, paint);
         }
 
         return bitmap;
     }
 
-    /**
-     * Save the gesture as XML
-     * 
-     * @param namespace
-     * @param serializer
-     * @throws IOException
-     */
-    void toXML(String namespace, XmlSerializer serializer) throws IOException {
-        serializer.startTag(namespace, GestureConstants.XML_TAG_GESTURE);
-        serializer.attribute(namespace, GestureConstants.XML_TAG_ID, Long.toString(mGestureID));
-        ArrayList<GestureStroke> strokes = mStrokes;
-        int count = strokes.size();
+    void serialize(DataOutputStream out) throws IOException {
+        final ArrayList<GestureStroke> strokes = mStrokes;
+        final int count = strokes.size();
+
+        // Write gesture ID
+        out.writeLong(mGestureID);
+        // Write number of strokes
+        out.writeInt(count);
+
         for (int i = 0; i < count; i++) {
-            GestureStroke stroke = strokes.get(i);
-            stroke.toXML(namespace, serializer);
+            strokes.get(i).serialize(out);
         }
-        serializer.endTag(namespace, GestureConstants.XML_TAG_GESTURE);
     }
 
-    /**
-     * Create the gesture from a string
-     * 
-     * @param str
-     */
-    public void createFromString(String str) {
-        int startIndex = 0;
-        int endIndex;
-        while ((endIndex =
-                str.indexOf(GestureConstants.STRING_GESTURE_DELIIMITER, startIndex + 1)) != -1) {
-            String token = str.substring(startIndex, endIndex);
-            if (startIndex > 0) { // stroke tokens
-                addStroke(GestureStroke.createFromString(token));
-            } else { // id token
-                mGestureID = Long.parseLong(token);
-            }
-            startIndex = endIndex + 1;
+    static Gesture deserialize(DataInputStream in) throws IOException {
+        final Gesture gesture = new Gesture();
+
+        // Gesture ID
+        gesture.mGestureID = in.readLong();
+        // Number of strokes
+        final int count = in.readInt();
+
+        for (int i = 0; i < count; i++) {
+            gesture.addStroke(GestureStroke.deserialize(in));
         }
+
+        return gesture;
     }
 
     /**
@@ -247,12 +247,14 @@ public class Gesture implements Parcelable {
      */
     @Override
     public String toString() {
-        StringBuilder str = new StringBuilder();
+        final StringBuilder str = new StringBuilder();
         str.append(mGestureID);
-        ArrayList<GestureStroke> strokes = mStrokes;
-        int count = strokes.size();
+
+        final ArrayList<GestureStroke> strokes = mStrokes;
+        final int count = strokes.size();
+
         for (int i = 0; i < count; i++) {
-            GestureStroke stroke = strokes.get(i);
+            final GestureStroke stroke = strokes.get(i);
             str.append(GestureConstants.STRING_GESTURE_DELIIMITER);
             str.append(stroke.toString());
         }
@@ -262,9 +264,24 @@ public class Gesture implements Parcelable {
 
     public static final Parcelable.Creator<Gesture> CREATOR = new Parcelable.Creator<Gesture>() {
         public Gesture createFromParcel(Parcel in) {
-            String str = in.readString();
-            Gesture gesture = new Gesture();
-            gesture.createFromString(str);
+            Gesture gesture = null;
+            final long gestureID = in.readLong();
+
+            final DataInputStream inStream = new DataInputStream(
+                    new ByteArrayInputStream(in.createByteArray()));
+
+            try {
+                gesture = deserialize(inStream);
+            } catch (IOException e) {
+                Log.e(LOG_TAG, "Error reading Gesture from parcel:", e);
+            } finally {
+                GestureUtilities.closeStream(inStream);
+            }
+
+            if (gesture != null) {
+                gesture.mGestureID = gestureID;
+            }
+
             return gesture;
         }
 
@@ -273,35 +290,31 @@ public class Gesture implements Parcelable {
         }
     };
 
-    /**
-     * Build a gesture from a byte array
-     * 
-     * @param bytes
-     * @return the gesture
-     */
-    static Gesture buildFromArray(byte[] bytes) {
-        String str = new String(bytes);
-        Gesture gesture = new Gesture();
-        gesture.createFromString(str);
-        return gesture;
-    }
-
-    /**
-     * Save a gesture to a byte array
-     * 
-     * @param stroke
-     * @return the byte array
-     */
-    static byte[] saveToArray(Gesture stroke) {
-        String str = stroke.toString();
-        return str.getBytes();
-    }
-
     public void writeToParcel(Parcel out, int flags) {
-        out.writeString(toString());
+        out.writeLong(mGestureID);
+
+        boolean result = false;
+        final ByteArrayOutputStream byteStream =
+                new ByteArrayOutputStream(GestureConstants.IO_BUFFER_SIZE);
+        final DataOutputStream outStream = new DataOutputStream(byteStream);
+
+        try {
+            serialize(outStream);
+            result = true;
+        } catch (IOException e) {
+            Log.e(LOG_TAG, "Error writing Gesture to parcel:", e);
+        } finally {
+            GestureUtilities.closeStream(outStream);
+            GestureUtilities.closeStream(byteStream);
+        }
+
+        if (result) {
+            out.writeByteArray(byteStream.toByteArray());
+        }
     }
 
     public int describeContents() {
-        return CONTENTS_FILE_DESCRIPTOR;
+        return 0;
     }
 }
+
diff --git a/tests/sketch/src/com/android/gesture/GestureConstants.java b/tests/sketch/src/com/android/gesture/GestureConstants.java
index cb64791..c0f2f3d 100644
--- a/tests/sketch/src/com/android/gesture/GestureConstants.java
+++ b/tests/sketch/src/com/android/gesture/GestureConstants.java
@@ -17,16 +17,13 @@
 package com.android.gesture;
 
 interface GestureConstants {
-    static final String XML_TAG_LIBRARY = "library";
-    static final String XML_TAG_ENTRY = "entry";
-    static final String XML_TAG_GESTURE = "gesture";
-    static final String XML_TAG_STROKE = "stroke";
-    static final String XML_TAG_ID = "id";
-    static final String XML_TAG_NAME = "name";
     static final String STRING_GESTURE_DELIIMITER = "#";
     static final String STRING_STROKE_DELIIMITER = ",";
+
     static final int STROKE_STRING_BUFFER_SIZE = 1024;
     static final int STROKE_POINT_BUFFER_SIZE = 100; // number of points
-    static final int IO_BUFFER_SIZE = 8 * 1024; // 8K
-    String LOG_TAG = "GestureLibrary";
+
+    static final int IO_BUFFER_SIZE = 32 * 1024; // 32K
+
+    static final String LOG_TAG = "Gestures";
 }
diff --git a/tests/sketch/src/com/android/gesture/GestureLibrary.java b/tests/sketch/src/com/android/gesture/GestureLibrary.java
index 915b840..eba6069 100644
--- a/tests/sketch/src/com/android/gesture/GestureLibrary.java
+++ b/tests/sketch/src/com/android/gesture/GestureLibrary.java
@@ -16,16 +16,8 @@
 
 package com.android.gesture;
 
-import android.util.Config;
 import android.util.Log;
-import android.util.Xml;
-import android.util.Xml.Encoding;
-
-import org.xml.sax.Attributes;
-import org.xml.sax.ContentHandler;
-import org.xml.sax.Locator;
-import org.xml.sax.SAXException;
-import org.xmlpull.v1.XmlSerializer;
+import android.os.SystemClock;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
@@ -33,10 +25,12 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.PrintWriter;
+import java.io.DataOutputStream;
+import java.io.DataInputStream;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Set;
+import java.util.Map;
 
 import static com.android.gesture.GestureConstants.LOG_TAG;
 
@@ -44,10 +38,28 @@ import static com.android.gesture.GestureConstants.LOG_TAG;
  * GestureLibrary maintains gesture examples and makes predictions on a new
  * gesture
  */
+//
+//    File format for GestureLibrary:
+//
+//                Nb. bytes   Java type   Description
+//                -----------------------------------
+//    Header
+//                2 bytes     short       File format version number
+//                4 bytes     int         Number of entries
+//    Entry
+//                X bytes     UTF String  Entry name
+//                4 bytes     int         Number of gestures
+//    Gesture
+//                8 bytes     long        Gesture ID
+//                4 bytes     int         Number of strokes
+//    Stroke
+//                4 bytes     int         Number of points
+//    Point
+//                4 bytes     float       X coordinate of the point
+//                4 bytes     float       Y coordinate of the point
+//                8 bytes     long        Time stamp
+//
 public class GestureLibrary {
-
-    private static final String NAMESPACE = "";
-
     public static final int SEQUENCE_INVARIANT = 1;
     // when SEQUENCE_SENSITIVE is used, only single stroke gestures are currently allowed
     public static final int SEQUENCE_SENSITIVE = 2;
@@ -56,12 +68,16 @@ public class GestureLibrary {
     public static final int ORIENTATION_INVARIANT = 1;
     public static final int ORIENTATION_SENSITIVE = 2;
 
+    private static final short FILE_FORMAT_VERSION = 1;
+
+    private static final boolean PROFILE_LOADING_SAVING = false;
+
     private int mSequenceType = SEQUENCE_SENSITIVE;
     private int mOrientationStyle = ORIENTATION_SENSITIVE;
 
     private final String mGestureFileName;
 
-    private final HashMap<String, ArrayList<Gesture>> mEntryName2gestures =
+    private final HashMap<String, ArrayList<Gesture>> mNamedGestures =
             new HashMap<String, ArrayList<Gesture>>();
 
     private Learner mClassifier;
@@ -104,7 +120,7 @@ public class GestureLibrary {
      * @return a set of strings
      */
     public Set<String> getGestureEntries() {
-        return mEntryName2gestures.keySet();
+        return mNamedGestures.keySet();
     }
 
     /**
@@ -128,10 +144,10 @@ public class GestureLibrary {
         if (entryName == null || entryName.length() == 0) {
             return;
         }
-        ArrayList<Gesture> gestures = mEntryName2gestures.get(entryName);
+        ArrayList<Gesture> gestures = mNamedGestures.get(entryName);
         if (gestures == null) {
             gestures = new ArrayList<Gesture>();
-            mEntryName2gestures.put(entryName, gestures);
+            mNamedGestures.put(entryName, gestures);
         }
         gestures.add(gesture);
         mClassifier.addInstance(Instance.createInstance(mSequenceType, gesture, entryName));
@@ -146,7 +162,7 @@ public class GestureLibrary {
      * @param gesture
      */
     public void removeGesture(String entryName, Gesture gesture) {
-        ArrayList<Gesture> gestures = mEntryName2gestures.get(entryName);
+        ArrayList<Gesture> gestures = mNamedGestures.get(entryName);
         if (gestures == null) {
             return;
         }
@@ -155,7 +171,7 @@ public class GestureLibrary {
 
         // if there are no more samples, remove the entry automatically
         if (gestures.isEmpty()) {
-            mEntryName2gestures.remove(entryName);
+            mNamedGestures.remove(entryName);
         }
 
         mClassifier.removeInstance(gesture.getID());
@@ -169,7 +185,7 @@ public class GestureLibrary {
      * @param entryName the entry name
      */
     public void removeEntireEntry(String entryName) {
-        mEntryName2gestures.remove(entryName);
+        mNamedGestures.remove(entryName);
         mClassifier.removeInstances(entryName);
         mChanged = true;
     }
@@ -181,7 +197,7 @@ public class GestureLibrary {
      * @return the list of gestures that is under this name
      */
     public ArrayList<Gesture> getGestures(String entryName) {
-        ArrayList<Gesture> gestures = mEntryName2gestures.get(entryName);
+        ArrayList<Gesture> gestures = mNamedGestures.get(entryName);
         if (gestures != null) {
             return new ArrayList<Gesture>(gestures);
         } else {
@@ -197,8 +213,8 @@ public class GestureLibrary {
             return true;
         }
 
-        boolean result= false;
-        PrintWriter writer = null;
+        boolean result = false;
+        DataOutputStream out = null;
 
         try {
             File file = new File(mGestureFileName);
@@ -208,40 +224,48 @@ public class GestureLibrary {
                 }
             }
 
-            writer = new PrintWriter(new BufferedOutputStream(new FileOutputStream(
-                    mGestureFileName), GestureConstants.IO_BUFFER_SIZE));
+            long start;
+            if (PROFILE_LOADING_SAVING) {
+                start = SystemClock.elapsedRealtime();
+            }
+
+            final HashMap<String, ArrayList<Gesture>> maps = mNamedGestures;
+
+            out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file),
+                    GestureConstants.IO_BUFFER_SIZE));
+            // Write version number
+            out.writeShort(FILE_FORMAT_VERSION);
+            // Write number of entries
+            out.writeInt(maps.size());
 
-            final XmlSerializer serializer = Xml.newSerializer();
-            serializer.setOutput(writer);
-            serializer.startDocument(Encoding.ISO_8859_1.name(), null);
-            serializer.startTag(NAMESPACE, GestureConstants.XML_TAG_LIBRARY);
+            for (Map.Entry<String, ArrayList<Gesture>> entry : maps.entrySet()) {
+                final String key = entry.getKey();
+                final ArrayList<Gesture> examples = entry.getValue();
+                final int count = examples.size();
 
-            final HashMap<String, ArrayList<Gesture>> maps = mEntryName2gestures;
+                // Write entry name
+                out.writeUTF(key);
+                // Write number of examples for this entry
+                out.writeInt(count);
 
-            for (String key : maps.keySet()) {
-                ArrayList<Gesture> examples = maps.get(key);
-                // save an entry
-                serializer.startTag(NAMESPACE, GestureConstants.XML_TAG_ENTRY);
-                serializer.attribute(NAMESPACE, GestureConstants.XML_TAG_NAME, key);
-                int count = examples.size();
                 for (int i = 0; i < count; i++) {
-                    Gesture gesture = examples.get(i);
-                    // save each gesture in the entry
-                    gesture.toXML(NAMESPACE, serializer);
+                    examples.get(i).serialize(out);
                 }
-                serializer.endTag(NAMESPACE, GestureConstants.XML_TAG_ENTRY);
             }
 
-            serializer.endTag(NAMESPACE, GestureConstants.XML_TAG_LIBRARY);
-            serializer.endDocument();
-            serializer.flush();
+            out.flush();
+
+            if (PROFILE_LOADING_SAVING) {
+                long end = SystemClock.elapsedRealtime();
+                Log.d(LOG_TAG, "Saving gestures library = " + (end - start) + " ms");
+            }
 
             mChanged = false;
             result = true;
         } catch (IOException ex) {
             Log.d(LOG_TAG, "Failed to save gestures:", ex);
         } finally {
-            GestureUtilities.closeStream(writer);
+            GestureUtilities.closeStream(out);
         }
 
         return result;
@@ -255,17 +279,30 @@ public class GestureLibrary {
 
         final File file = new File(mGestureFileName);
         if (file.exists()) {
-            BufferedInputStream in = null;
+            DataInputStream in = null;
             try {
-                if (Config.DEBUG) {
-                    Log.v(LOG_TAG, "Load from " + mGestureFileName);
+                in = new DataInputStream(new BufferedInputStream(
+                        new FileInputStream(mGestureFileName), GestureConstants.IO_BUFFER_SIZE));
+
+                long start;
+                if (PROFILE_LOADING_SAVING) {
+                    start = SystemClock.elapsedRealtime();
+                }
+
+                // Read file format version number
+                final short versionNumber = in.readShort();
+                switch (versionNumber) {
+                    case 1:
+                        readFormatV1(in);
+                        break;
                 }
-                in = new BufferedInputStream(new FileInputStream(
-                        mGestureFileName), GestureConstants.IO_BUFFER_SIZE);
-                Xml.parse(in, Encoding.ISO_8859_1, new CompactInkHandler());
+
+                if (PROFILE_LOADING_SAVING) {
+                    long end = SystemClock.elapsedRealtime();
+                    Log.d(LOG_TAG, "Loading gestures library = " + (end - start) + " ms");
+                }
+
                 result = true;
-            } catch (SAXException ex) {
-                Log.d(LOG_TAG, "Failed to load gestures:", ex);
             } catch (IOException ex) {
                 Log.d(LOG_TAG, "Failed to load gestures:", ex);
             } finally {
@@ -276,69 +313,28 @@ public class GestureLibrary {
         return result;
     }
 
-    private class CompactInkHandler implements ContentHandler {
-        final StringBuilder mBuffer = new StringBuilder(GestureConstants.STROKE_STRING_BUFFER_SIZE);
-
-        String mEntryName;
-
-        Gesture mCurrentGesture = null;
-        ArrayList<Gesture> mGestures;
-
-        CompactInkHandler() {
-        }
-
-        public void characters(char[] ch, int start, int length) {
-            mBuffer.append(ch, start, length);
-        }
-
-        public void endDocument() {
-        }
-
-        public void endElement(String uri, String localName, String qName) {
-            if (localName.equals(GestureConstants.XML_TAG_ENTRY)) {
-                mEntryName2gestures.put(mEntryName, mGestures);
-                mGestures = null;
-            } else if (localName.equals(GestureConstants.XML_TAG_GESTURE)) {
-                mGestures.add(mCurrentGesture);
-                mClassifier.addInstance(Instance.createInstance(mSequenceType,
-                        mCurrentGesture, mEntryName));
-                mCurrentGesture = null;
-            } else if (localName.equals(GestureConstants.XML_TAG_STROKE)) {
-                mCurrentGesture.addStroke(GestureStroke.createFromString(mBuffer.toString()));
-                mBuffer.setLength(0);
+    private void readFormatV1(DataInputStream in) throws IOException {
+        final Learner classifier = mClassifier;
+        final HashMap<String, ArrayList<Gesture>> namedGestures = mNamedGestures;
+        namedGestures.clear();
+
+        // Number of entries in the library
+        final int entriesCount = in.readInt();
+
+        for (int i = 0; i < entriesCount; i++) {
+            // Entry name
+            final String name = in.readUTF();
+            // Number of gestures
+            final int gestureCount = in.readInt();
+
+            final ArrayList<Gesture> gestures = new ArrayList<Gesture>(gestureCount);
+            for (int j = 0; j < gestureCount; j++) {
+                final Gesture gesture = Gesture.deserialize(in);
+                gestures.add(gesture);
+                classifier.addInstance(Instance.createInstance(mSequenceType, gesture, name));
             }
-        }
-
-        public void endPrefixMapping(String prefix) {
-        }
-
-        public void ignorableWhitespace(char[] ch, int start, int length) {
-        }
-
-        public void processingInstruction(String target, String data) {
-        }
-
-        public void setDocumentLocator(Locator locator) {
-        }
-
-        public void skippedEntity(String name) {
-        }
-
-        public void startDocument() {
-        }
-
-        public void startElement(String uri, String localName, String qName, Attributes attributes) {
-            if (localName.equals(GestureConstants.XML_TAG_ENTRY)) {
-                mGestures = new ArrayList<Gesture>();
-                mEntryName = attributes.getValue(NAMESPACE, GestureConstants.XML_TAG_NAME);
-            } else if (localName.equals(GestureConstants.XML_TAG_GESTURE)) {
-                mCurrentGesture = new Gesture();
-                mCurrentGesture.setID(Long.parseLong(attributes.getValue(NAMESPACE,
-                        GestureConstants.XML_TAG_ID)));
-            }
-        }
 
-        public void startPrefixMapping(String prefix, String uri) {
+            namedGestures.put(name, gestures);
         }
     }
 }
diff --git a/tests/sketch/src/com/android/gesture/GesturePoint.java b/tests/sketch/src/com/android/gesture/GesturePoint.java
index 81e59a4..560f893 100644
--- a/tests/sketch/src/com/android/gesture/GesturePoint.java
+++ b/tests/sketch/src/com/android/gesture/GesturePoint.java
@@ -16,6 +16,9 @@
 
 package com.android.gesture;
 
+import java.io.DataInputStream;
+import java.io.IOException;
+
 /**
  * A timed point of a gesture stroke
  */
@@ -31,4 +34,13 @@ public class GesturePoint {
         this.y = y;
         timestamp = t;
     }
+
+    static GesturePoint deserialize(DataInputStream in) throws IOException {
+        // Read X and Y
+        final float x = in.readFloat();
+        final float y = in.readFloat();
+        // Read timestamp
+        final long timeStamp = in.readLong();
+        return new GesturePoint(x, y, timeStamp);
+    }
 }
diff --git a/tests/sketch/src/com/android/gesture/GestureStroke.java b/tests/sketch/src/com/android/gesture/GestureStroke.java
index c2ebc17..79b42fe 100644
--- a/tests/sketch/src/com/android/gesture/GestureStroke.java
+++ b/tests/sketch/src/com/android/gesture/GestureStroke.java
@@ -22,9 +22,9 @@ import android.graphics.Paint;
 import android.graphics.Path;
 import android.graphics.RectF;
 
-import org.xmlpull.v1.XmlSerializer;
-
 import java.io.IOException;
+import java.io.DataOutputStream;
+import java.io.DataInputStream;
 import java.util.ArrayList;
 
 /**
@@ -167,57 +167,35 @@ public class GestureStroke {
         return path;
     }
 
-    /**
-     * Save the gesture stroke as XML
-     * 
-     * @param namespace
-     * @param serializer
-     * @throws IOException
-     */
-    void toXML(String namespace, XmlSerializer serializer) throws IOException {
-        serializer.startTag(namespace, GestureConstants.XML_TAG_STROKE);
-        serializer.text(toString());
-        serializer.endTag(namespace, GestureConstants.XML_TAG_STROKE);
+    void serialize(DataOutputStream out) throws IOException {
+        final float[] pts = points;
+        final long[] times = timestamps;
+        final int count = points.length;
+
+        // Write number of points
+        out.writeInt(count / 2);
+
+        for (int i = 0; i < count; i += 2) {
+            // Write X
+            out.writeFloat(pts[i]);
+            // Write Y
+            out.writeFloat(pts[i + 1]);
+            // Write timestamp
+            out.writeLong(times[i / 2]);
+        }
     }
 
-    /**
-     * Create a gesture stroke from a string
-     * 
-     * @param str
-     * @return the gesture stroke
-     */
-    public static GestureStroke createFromString(String str) {
-        final ArrayList<GesturePoint> points = new ArrayList<GesturePoint>(
-                GestureConstants.STROKE_POINT_BUFFER_SIZE);
-
-        int endIndex;
-        int startIndex = 0;
-
-        while ((endIndex =
-                str.indexOf(GestureConstants.STRING_STROKE_DELIIMITER, startIndex + 1)) != -1) {
-
-            // parse x
-            String token = str.substring(startIndex, endIndex);
-            float x = Float.parseFloat(token);
-            startIndex = endIndex + 1;
-
-            // parse y
-            endIndex = str.indexOf(GestureConstants.STRING_STROKE_DELIIMITER, startIndex + 1);
-            token = str.substring(startIndex, endIndex);
-            float y = Float.parseFloat(token);
-            startIndex = endIndex + 1;
-
-            // parse t
-            endIndex = str.indexOf(GestureConstants.STRING_STROKE_DELIIMITER, startIndex + 1);
-            token = str.substring(startIndex, endIndex);
-            long time = Long.parseLong(token);
-            startIndex = endIndex + 1;
-
-            points.add(new GesturePoint(x, y, time));
+    static GestureStroke deserialize(DataInputStream in) throws IOException {
+        // Number of points
+        final int count = in.readInt();
+
+        final ArrayList<GesturePoint> points = new ArrayList<GesturePoint>(count);
+        for (int i = 0; i < count; i++) {
+            points.add(GesturePoint.deserialize(in));
         }
 
         return new GestureStroke(points);
-    }
+    }    
 
     /**
      * Convert the stroke to string
diff --git a/tests/sketch/src/com/android/gesture/GestureUtilities.java b/tests/sketch/src/com/android/gesture/GestureUtilities.java
index 92de987..6d73c2d 100755
--- a/tests/sketch/src/com/android/gesture/GestureUtilities.java
+++ b/tests/sketch/src/com/android/gesture/GestureUtilities.java
@@ -18,6 +18,7 @@ package com.android.gesture;
 
 import android.graphics.RectF;
 import android.graphics.Matrix;
+import android.util.Log;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -42,7 +43,7 @@ final class GestureUtilities {
             try {
                 stream.close();
             } catch (IOException e) {
-                android.util.Log.e(LOG_TAG, "Could not close stream", e);
+                Log.e(LOG_TAG, "Could not close stream", e);
             }
         }
     }
@@ -56,24 +57,25 @@ final class GestureUtilities {
         float sx = targetPatchSize / rect.width();
         float sy = targetPatchSize / rect.height();
         float scale = sx < sy ? sx : sy;
-        android.graphics.Matrix trans = new android.graphics.Matrix();
+
+        Matrix trans = new Matrix();
         trans.setScale(scale, scale);
-        android.graphics.Matrix translate1 = new android.graphics.Matrix();
-        translate1.setTranslate(-rect.centerX(), -rect.centerY());
-        trans.preConcat(translate1);
-        android.graphics.Matrix translate2 = new android.graphics.Matrix();
-        translate2.setTranslate(targetPatchSize / 2, targetPatchSize / 2);
-        trans.postConcat(translate2);
-
-        ArrayList<GestureStroke> strokes = gesture.getStrokes();
-        int count = strokes.size();
+        trans.preTranslate(-rect.centerX(), -rect.centerY());
+        trans.postTranslate(targetPatchSize / 2, targetPatchSize / 2);
+
+        final ArrayList<GestureStroke> strokes = gesture.getStrokes();
+        final int count = strokes.size();
+
         int size;
         float xpos;
         float ypos;
+
         for (int index = 0; index < count; index++) {
-            GestureStroke stroke = strokes.get(index);
+            final GestureStroke stroke = strokes.get(index);
             size = stroke.points.length;
-            float[] pts = new float[size];
+
+            final float[] pts = new float[size];
+
             trans.mapPoints(pts, 0, stroke.points, 0, size / 2);
             float segmentEndX = -1;
             float segmentEndY = -1;
diff --git a/tests/sketch/src/com/android/gesture/Instance.java b/tests/sketch/src/com/android/gesture/Instance.java
index b2e030e..502a0fa 100755
--- a/tests/sketch/src/com/android/gesture/Instance.java
+++ b/tests/sketch/src/com/android/gesture/Instance.java
@@ -16,6 +16,8 @@
 
 package com.android.gesture;
 
+import android.graphics.Matrix;
+
 /**
  * An instance represents a sample if the label is available or a query if the
  * label is null.
@@ -47,10 +49,12 @@ class Instance {
     private void normalize() {
         float[] sample = vector;
         float sum = 0;
+
         int size = sample.length;
         for (int i = 0; i < size; i++) {
             sum += sample[i] * sample[i];
         }
+
         float magnitude = (float) Math.sqrt(sum);
         for (int i = 0; i < size; i++) {
             sample[i] /= magnitude;
@@ -100,12 +104,11 @@ class Instance {
             }
         }
 
-        android.graphics.Matrix m = new android.graphics.Matrix();
+        Matrix m = new Matrix();
         m.setTranslate(-center[0], -center[1]);
-        android.graphics.Matrix rotation = new android.graphics.Matrix();
-        rotation.setRotate(adjustment);
-        m.postConcat(rotation);
+        m.postRotate(adjustment);
         m.mapPoints(pts);
+
         return pts;
     }
 
diff --git a/tests/sketch/src/com/android/gesture/LetterRecognizer.java b/tests/sketch/src/com/android/gesture/LetterRecognizer.java
index 086aedf..981c416 100644
--- a/tests/sketch/src/com/android/gesture/LetterRecognizer.java
+++ b/tests/sketch/src/com/android/gesture/LetterRecognizer.java
@@ -21,7 +21,6 @@ import android.content.res.Resources;
 import android.util.Log;
 
 import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
 import java.io.DataInputStream;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -29,9 +28,9 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 
-public class LetterRecognizer {
-    private static final String LOG_TAG = "LetterRecognizer";
+import static com.android.gesture.GestureConstants.LOG_TAG;
 
+public class LetterRecognizer {
     public final static int LATIN_LOWERCASE = 0;
 
     private SigmoidUnit[] mHiddenLayer;
@@ -41,7 +40,7 @@ public class LetterRecognizer {
 
     private final int mPatchSize;
     
-    static final String GESTURE_FILE_NAME = "letters.xml";
+    static final String GESTURE_FILE_NAME = "letters.gestures";
 
     private GestureLibrary mGestureLibrary; 
     private final static int ADJUST_RANGE = 3;
@@ -151,7 +150,8 @@ public class LetterRecognizer {
         LetterRecognizer classifier = null;
 
         try {
-            in = new DataInputStream(new BufferedInputStream(resources.openRawResource(resourceID)));
+            in = new DataInputStream(new BufferedInputStream(resources.openRawResource(resourceID),
+                    GestureConstants.IO_BUFFER_SIZE));
 
             final int iCount = in.readInt();
             final int hCount = in.readInt();
diff --git a/tests/sketch/src/com/android/gesture/example/GestureEntry.java b/tests/sketch/src/com/android/gesture/example/GestureEntry.java
index 03a26da..53ba481 100644
--- a/tests/sketch/src/com/android/gesture/example/GestureEntry.java
+++ b/tests/sketch/src/com/android/gesture/example/GestureEntry.java
@@ -49,7 +49,7 @@ public class GestureEntry extends Activity {
     private static final String PARCEL_KEY = "gesture";
 
     static final String GESTURE_FILE_NAME = Environment.getExternalStorageDirectory().getAbsolutePath()
-            + File.separator + "gestureEntry.xml";
+            + File.separator + "demo_library.gestures";
 
     private static final int DIALOG_NEW_ENTRY = 1;