Added clone to these three classes and added more comments.

3 files changed, 51 insertions, 14 deletions

diff --git a/core/java/android/gesture/Gesture.java b/core/java/android/gesture/Gesture.java
index 62330e1..945ebb4 100755
--- a/core/java/android/gesture/Gesture.java
+++ b/core/java/android/gesture/Gesture.java
@@ -34,7 +34,9 @@ import java.util.ArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
- * A gesture can have a single or multiple strokes
+ * A gesture is a hand-drawn shape on a touch screen. It can have one or multiple strokes.
+ * Each stroke is a sequence of timed points. A user-defined gesture can be recognized by 
+ * a GestureLibrary and a built-in alpabet gesture can be recognized by a LetterRecognizer. 
  */
 
 public class Gesture implements Parcelable {
@@ -58,6 +60,19 @@ public class Gesture implements Parcelable {
         mGestureID = GESTURE_ID_BASE + sGestureCount.incrementAndGet();
     }
 
+    @Override
+    public Object clone() {
+        Gesture gesture = new Gesture();
+        gesture.mBoundingBox.set(mBoundingBox.left, mBoundingBox.top, 
+                                        mBoundingBox.right, mBoundingBox.bottom);
+        final int count = mStrokes.size();
+        for (int i = 0; i < count; i++) {
+            GestureStroke stroke = mStrokes.get(i);
+            gesture.mStrokes.add((GestureStroke)stroke.clone());
+        }
+        return gesture;
+    }
+    
     /**
      * @return all the strokes of the gesture
      */
@@ -73,7 +88,7 @@ public class Gesture implements Parcelable {
     }
 
     /**
-     * Add a stroke to the gesture
+     * Adds a stroke to the gesture.
      * 
      * @param stroke
      */
@@ -83,8 +98,8 @@ public class Gesture implements Parcelable {
     }
 
     /**
-     * Get the total length of the gesture. When there are multiple strokes in
-     * the gesture, this returns the sum of the lengths of all the strokes
+     * Calculates the total length of the gesture. When there are multiple strokes in
+     * the gesture, this returns the sum of the lengths of all the strokes.
      * 
      * @return the length of the gesture
      */
@@ -142,7 +157,7 @@ public class Gesture implements Parcelable {
     }
 
     /**
-     * Set the id of the gesture
+     * Sets the id of the gesture.
      * 
      * @param id
      */
@@ -158,7 +173,7 @@ public class Gesture implements Parcelable {
     }
 
     /**
-     * Create a bitmap of the gesture with a transparent background
+     * Creates a bitmap of the gesture with a transparent background.
      * 
      * @param width width of the target bitmap
      * @param height height of the target bitmap
@@ -194,7 +209,7 @@ public class Gesture implements Parcelable {
     }
 
     /**
-     * Create a bitmap of the gesture with a transparent background
+     * Creates a bitmap of the gesture with a transparent background.
      * 
      * @param width
      * @param height
diff --git a/core/java/android/gesture/GesturePoint.java b/core/java/android/gesture/GesturePoint.java
index 3698011..4cb7707 100644
--- a/core/java/android/gesture/GesturePoint.java
+++ b/core/java/android/gesture/GesturePoint.java
@@ -20,7 +20,7 @@ import java.io.DataInputStream;
 import java.io.IOException;
 
 /**
- * A timed point of a gesture stroke
+ * A timed point of a gesture stroke. Multiple points form a stroke.
  */
 
 public class GesturePoint {
@@ -43,4 +43,9 @@ public class GesturePoint {
         final long timeStamp = in.readLong();
         return new GesturePoint(x, y, timeStamp);
     }
+    
+    @Override
+    public Object clone() {
+        return new GesturePoint(x, y, timestamp);
+    }
 }
diff --git a/core/java/android/gesture/GestureStroke.java b/core/java/android/gesture/GestureStroke.java
index 598eb85..68dc5a6 100644
--- a/core/java/android/gesture/GestureStroke.java
+++ b/core/java/android/gesture/GestureStroke.java
@@ -27,7 +27,8 @@ import java.io.DataInputStream;
 import java.util.ArrayList;
 
 /**
- * A gesture stroke started on a touch down and ended on a touch up.
+ * A gesture stroke started on a touch down and ended on a touch up. A stroke
+ * consists of a sequence of timed points. One or multiple strokes form a gesture.
  */
 public class GestureStroke {
     static final float TOUCH_TOLERANCE = 8;
@@ -41,7 +42,7 @@ public class GestureStroke {
     private Path mCachedPath;
 
     /**
-     * Construct a gesture stroke from a list of gesture points
+     * A constructor that constructs a gesture stroke from a list of gesture points.
      * 
      * @param points
      */
@@ -82,7 +83,22 @@ public class GestureStroke {
     }
 
     /**
-     * Draw the gesture with a given canvas and paint
+     * A faster constructor specially for cloning a stroke.
+     */
+    private GestureStroke(RectF bbx, float len, float[] pts, long[] times) {
+        boundingBox = new RectF(bbx.left, bbx.top, bbx.right, bbx.bottom);
+        length = len;
+        points = pts.clone();
+        timestamps = times.clone();
+    }
+    
+    @Override
+    public Object clone() {
+        return new GestureStroke(boundingBox, length, points, timestamps);
+    }
+    
+    /**
+     * Draws the stroke with a given canvas and paint.
      * 
      * @param canvas
      */
@@ -134,7 +150,7 @@ public class GestureStroke {
     }
 
     /**
-     * Convert the stroke to a Path based on the number of points
+     * Converts the stroke to a Path of a given number of points.
      * 
      * @param width the width of the bounding box of the target path
      * @param height the height of the bounding box of the target path
@@ -213,14 +229,15 @@ public class GestureStroke {
     }    
 
     /**
-     * Invalidate the cached path that is used to render the stroke
+     * Invalidates the cached path that is used to render the stroke.
      */
     public void clearPath() {
         if (mCachedPath != null) mCachedPath.rewind();
     }
     
     /**
-     * Compute an oriented bounding box of the stroke
+     * Computes an oriented bounding box of the stroke.
+     * 
      * @return OrientedBoundingBox
      */
     public OrientedBoundingBox computeOrientedBoundingBox() {