Fix a drawing lag during track recording.

For a track with ~2,500 points, the average drawign would take ~30-50ms, now it takes about 20ms (21ms if software clipping is enabled).

Removed all possible congestion points by introducing a blocking queue.

This change includes many fixes, including:
1) Major refactoring and clean up of the overlay, sped up drawing by a factor of 2x
2) Disable software clipping as it was slower by about 5% than w/o clipping and would trigger a bug related to map view spanning
3) Add waypoints synchronization  and fixed a bug related to skipping the first wpt
4) Add a simple unit test

MyTracks/res/values/keys.xml

@@ -38,7 +38,6 @@ limitations under the License.
   <string name="share_url_only_key">shareUrlOnly</string>
   <string name="signal_sampling_frequency_key">signalSamplingFrequency</string>
   <string name="split_frequency_key">splitFrequency</string>
-  <string name="debug_draw_bounds_key">debugDrawBounds</string>
 
   <!-- Preference keys which keep transient state (not user preferences) - DO NOT TRANSLATE -->
   <string name="auto_resume_track_current_retry_key">autoResumeTrackCurrentRetry</string>

MyTracks/src/com/google/android/apps/mytracks/MyTracksMap.java

@@ -50,14 +50,14 @@ import android.provider.Settings;
 import android.speech.tts.TextToSpeech;
 import android.util.Log;
 import android.view.ContextMenu;
-import android.view.ContextMenu.ContextMenuInfo;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.MotionEvent;
 import android.view.SubMenu;
 import android.view.View;
-import android.view.View.OnCreateContextMenuListener;
 import android.view.Window;
+import android.view.ContextMenu.ContextMenuInfo;
+import android.view.View.OnCreateContextMenuListener;
 import android.widget.ImageButton;
 import android.widget.LinearLayout;
 import android.widget.RelativeLayout;
@@ -139,14 +139,16 @@ public class MyTracksMap extends MapActivity
    */
   private HandlerThread updateTrackThread;
 
-  /** Handler for updateTrackThread */
+  /**
+   * Handler for updateTrackThread.
+   */
   private Handler updateTrackHandler;
 
   private MyTracksProviderUtils providerUtils;
  
   /**
    * A runnable that updates the track from the provider (looking for points
-   * added after "lastSeenLocationId".
+   * added after "lastSeenLocationId").
    */
   private final Runnable updateTrackRunnable = new Runnable() {
     @Override
@@ -154,6 +156,7 @@ public class MyTracksMap extends MapActivity
       if (!isATrackSelected()) {
         return;
       }
+      
       readAllNewTrackPoints();
     }
   };
@@ -167,6 +170,7 @@ public class MyTracksMap extends MapActivity
       if (!isATrackSelected()) {
         return;
       }
+      
       mapOverlay.clearPoints();
       firstSeenLocationId = -1;
       lastSeenLocationId = -1;
@@ -192,13 +196,10 @@ public class MyTracksMap extends MapActivity
         cursor = providerUtils.getWaypointsCursor(
             selectedTrackId, 0,
             MyTracksConstants.MAX_DISPLAYED_WAYPOINTS_POINTS);
-        if (cursor != null) {
+        if (cursor != null && cursor.moveToFirst()) {
-          if (cursor.moveToFirst()) {
+          do {
-            do {
+            mapOverlay.addWaypoint(providerUtils.createWaypoint(cursor));
-              Waypoint wpt = providerUtils.createWaypoint(cursor);
+          } while (cursor.moveToNext());
-              mapOverlay.addWaypoint(wpt);
-            } while (cursor.moveToNext());
-          }
         }
       } catch (RuntimeException e) {
         Log.w(MyTracksConstants.TAG, "Caught an unexpected exception.", e);
@@ -212,9 +213,9 @@ public class MyTracksMap extends MapActivity
   };
 
   /**
-   * A runnable intended to be posted to the updateTrackThread after the
+   * A runnable intended to be posted to the {@code #updateTrackThread} after
-   * selected track changes. It will post to the ui thread to update the screen
+   * the selected track changes.  It will post to the UI thread to update
-   * elements and move the map to show the selected track.
+   * the screen elements and move the map to show the selected track.
    */
   private final Runnable setSelectedTrackRunnable = new Runnable() {
     @Override
@@ -372,8 +373,6 @@ public class MyTracksMap extends MapActivity
         setSelectedTrack(selectedTrackId);
       }
       updateOptionsButton();
-      mapOverlay.setDrawBounds(preferences.getBoolean(
-          getString(R.string.debug_draw_bounds_key), false));
       preferences.registerOnSharedPreferenceChangeListener(this);
     }
   }
@@ -893,8 +892,7 @@ public class MyTracksMap extends MapActivity
 
   @Override
   public void onSharedPreferenceChanged(
-      final SharedPreferences sharedPreferences,
+      final SharedPreferences sharedPreferences, final String key) {
-      final String key) {
     if (key != null) {
       uiHandler.post(new Runnable() {
         @Override
@@ -918,10 +916,6 @@ public class MyTracksMap extends MapActivity
               mapOverlay.setShowEndMarker(!isRecordingSelected());
               mapView.postInvalidate();
             }
-          } else if (key.equals(getString(R.string.debug_draw_bounds_key))) {
-            mapOverlay.setDrawBounds(
-                sharedPreferences.getBoolean(
-                    getString(R.string.debug_draw_bounds_key), false));
           }
         }
       });
@@ -950,8 +944,8 @@ public class MyTracksMap extends MapActivity
     public void onLocationChanged(Location location) {
       if (location.getProvider().equals(MyTracksConstants.GPS_PROVIDER)) {
         // Recalculate the variation if there was a jump in location > 1km:
-        if (currentLocation == null
+        if (currentLocation == null ||
-            || location.distanceTo(currentLocation) > 1000) {
+            location.distanceTo(currentLocation) > 1000) {
           setVariation(location);
         }
         currentLocation = location;
@@ -1039,8 +1033,8 @@ public class MyTracksMap extends MapActivity
             // Now we already have at least one point, calculate the sampling
             // frequency
             long numTotalPoints = lastStoredLocationId - firstSeenLocationId;
-            samplingFrequency = (int) (1 +
+            samplingFrequency = (int) (1 + numTotalPoints
-                numTotalPoints / MyTracksConstants.TARGET_DISPLAYED_TRACK_POINTS);
+                / MyTracksConstants.TARGET_DISPLAYED_TRACK_POINTS);
           }
 
           providerUtils.fillLocation(cursor, location);
@@ -1052,8 +1046,8 @@ public class MyTracksMap extends MapActivity
           if (numPoints % samplingFrequency == 0 ||
               (!isRecordingSelected() && locationId == lastStoredLocationId) ||
               !MyTracksUtils.isValidLocation(location)) {
-            // Only allocate a new location if it is going to be kept around.
+            // No need to allocate a new location (we can safely reuse the existing).
-            mapOverlay.addLocation(new Location(location));
+            mapOverlay.addLocation(location);
           }
 
           numPoints++;

MyTracks/src/com/google/android/apps/mytracks/MyTracksOverlay.java

@@ -24,16 +24,19 @@ import com.google.android.maps.mytracks.R;
 
 import android.content.Context;
 import android.content.Intent;
+import android.content.res.Resources;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Path;
 import android.graphics.Point;
 import android.graphics.Rect;
-import android.graphics.Region;
 import android.graphics.drawable.Drawable;
 import android.location.Location;
 
 import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
 
 /**
  * A map overlay that displays a "MyLocation" arrow, an error circle, the
@@ -43,7 +46,7 @@ import java.util.ArrayList;
  */
 public class MyTracksOverlay extends Overlay {
 
-  private final Drawable arrow[] = new Drawable[18];
+  private final Drawable[] arrows;
   private final int arrowWidth, arrowHeight;
   private final Drawable statsMarker;
   private final Drawable waypointMarker;
@@ -53,68 +56,89 @@ public class MyTracksOverlay extends Overlay {
   private final Paint selectedTrackPaint;
   private final Paint errorCirclePaint;
   private final Context context;
-  private final ArrayList<Waypoint> waypoints = new ArrayList<Waypoint>();
+  private final List<Waypoint> waypoints;
-  private final ArrayList<Location> points = new ArrayList<Location>(1024);
+  private final List<CachedLocation> points;
+  private final BlockingQueue<CachedLocation> pendingPoints;
 
   private boolean trackDrawingEnabled;
   private int lastHeading = 0;
   private Location myLocation;
   private boolean showEndMarker = true;
-  private boolean drawBounds;
+  // TODO: Remove it completely.  If this is true, drawing is faster by 5%.
+  private boolean alwaysVisible = true;
+  
+  /**
+   * Represents a pre-processed {@code Location} to speed up drawing. 
+   */
+  private static class CachedLocation {
+    public final boolean valid;
+    public final GeoPoint geoPoint;
+    
+    public CachedLocation(Location location) {
+      this.valid = MyTracksUtils.isValidLocation(location);
+      this.geoPoint = valid ? MyTracksUtils.getGeoPoint(location) : null; 
+    }
+  };
   
   public MyTracksOverlay(Context context) {
     this.context = context;
     
+    this.waypoints = new ArrayList<Waypoint>();
+    this.points = new ArrayList<CachedLocation>(256);
+    this.pendingPoints = new ArrayBlockingQueue<CachedLocation>(
+        MyTracksConstants.MAX_DISPLAYED_TRACK_POINTS, true);
+
     // TODO: Can we use a FrameAnimation or similar here rather
     // than individual resources for each arrow direction?
-
+    final Resources resources = context.getResources();
-    arrow[0] = context.getResources().getDrawable(R.drawable.arrow_0);
+    arrows = new Drawable[] {
-    arrow[1] = context.getResources().getDrawable(R.drawable.arrow_20);
+        resources.getDrawable(R.drawable.arrow_0),
-    arrow[2] = context.getResources().getDrawable(R.drawable.arrow_40);
+        resources.getDrawable(R.drawable.arrow_20),
-    arrow[3] = context.getResources().getDrawable(R.drawable.arrow_60);
+        resources.getDrawable(R.drawable.arrow_40),
-    arrow[4] = context.getResources().getDrawable(R.drawable.arrow_80);
+        resources.getDrawable(R.drawable.arrow_60),
-    arrow[5] = context.getResources().getDrawable(R.drawable.arrow_100);
+        resources.getDrawable(R.drawable.arrow_80),
-    arrow[6] = context.getResources().getDrawable(R.drawable.arrow_120);
+        resources.getDrawable(R.drawable.arrow_100),
-    arrow[7] = context.getResources().getDrawable(R.drawable.arrow_140);
+        resources.getDrawable(R.drawable.arrow_120),
-    arrow[8] = context.getResources().getDrawable(R.drawable.arrow_160);
+        resources.getDrawable(R.drawable.arrow_140),
-    arrow[9] = context.getResources().getDrawable(R.drawable.arrow_180);
+        resources.getDrawable(R.drawable.arrow_160),
-    arrow[10] = context.getResources().getDrawable(R.drawable.arrow_200);
+        resources.getDrawable(R.drawable.arrow_180),
-    arrow[11] = context.getResources().getDrawable(R.drawable.arrow_220);
+        resources.getDrawable(R.drawable.arrow_200),
-    arrow[12] = context.getResources().getDrawable(R.drawable.arrow_240);
+        resources.getDrawable(R.drawable.arrow_220),
-    arrow[13] = context.getResources().getDrawable(R.drawable.arrow_260);
+        resources.getDrawable(R.drawable.arrow_240),
-    arrow[14] = context.getResources().getDrawable(R.drawable.arrow_280);
+        resources.getDrawable(R.drawable.arrow_260),
-    arrow[15] = context.getResources().getDrawable(R.drawable.arrow_300);
+        resources.getDrawable(R.drawable.arrow_280),
-    arrow[16] = context.getResources().getDrawable(R.drawable.arrow_320);
+        resources.getDrawable(R.drawable.arrow_300),
-    arrow[17] = context.getResources().getDrawable(R.drawable.arrow_340);
+        resources.getDrawable(R.drawable.arrow_320),
-    arrowWidth = arrow[lastHeading].getIntrinsicWidth();
+        resources.getDrawable(R.drawable.arrow_340)
-    arrowHeight = arrow[lastHeading].getIntrinsicHeight();
+    };
-    for (int i = 0; i <= 17; i++) {
+    arrowWidth = arrows[lastHeading].getIntrinsicWidth();
-      arrow[i].setBounds(0, 0, arrowWidth, arrowHeight);
+    arrowHeight = arrows[lastHeading].getIntrinsicHeight();
+    for (Drawable arrow : arrows) {
+      arrow.setBounds(0, 0, arrowWidth, arrowHeight);
     }
 
-    statsMarker = context.getResources().getDrawable(R.drawable.ylw_pushpin);
+    statsMarker = resources.getDrawable(R.drawable.ylw_pushpin);
     markerWidth = statsMarker.getIntrinsicWidth();
     markerHeight = statsMarker.getIntrinsicHeight();
     statsMarker.setBounds(0, 0, markerWidth, markerHeight);
 
-    startMarker = context.getResources().getDrawable(R.drawable.green_dot);
+    startMarker = resources.getDrawable(R.drawable.green_dot);
     startMarker.setBounds(0, 0, markerWidth, markerHeight);
 
-    endMarker = context.getResources().getDrawable(R.drawable.red_dot);
+    endMarker = resources.getDrawable(R.drawable.red_dot);
     endMarker.setBounds(0, 0, markerWidth, markerHeight);
 
-    waypointMarker =
+    waypointMarker = resources.getDrawable(R.drawable.blue_pushpin);
-        context.getResources().getDrawable(R.drawable.blue_pushpin);
     waypointMarker.setBounds(0, 0, markerWidth, markerHeight);
 
     selectedTrackPaint = new Paint();
-    selectedTrackPaint.setColor(context.getResources().getColor(R.color.red));
+    selectedTrackPaint.setColor(resources.getColor(R.color.red));
     selectedTrackPaint.setStrokeWidth(3);
     selectedTrackPaint.setStyle(Paint.Style.STROKE);
     selectedTrackPaint.setAntiAlias(true);
 
     errorCirclePaint = new Paint();
-    errorCirclePaint.setColor(context.getResources().getColor(R.color.blue));
+    errorCirclePaint.setColor(resources.getColor(R.color.blue));
     errorCirclePaint.setStyle(Paint.Style.STROKE);
     errorCirclePaint.setStrokeWidth(3);
     errorCirclePaint.setAlpha(127);
@@ -124,35 +148,47 @@ public class MyTracksOverlay extends Overlay {
   /**
    * Add a location to the map overlay.
    * 
-   * NOTE: this method takes ownership of this location and may change it.
+   * NOTE: This method doesn't take ownership of the given location, so it is
+   * safe to reuse the same location while calling this method.
    *
-   * @param l the location to add
+   * @param l the location to add.
    */
   public void addLocation(Location l) {
-    if (l != null) {
+    // Queue up in the pending queue until it's merged with {@code #points}.
-      synchronized (points) {
+    pendingPoints.offer(new CachedLocation(l));
-        points.add(l);
+  }
+
+  public void addWaypoint(Waypoint wpt) {
+    if (wpt != null && wpt.getLocation() != null) {
+      synchronized (waypoints) {
+        waypoints.add(wpt);
       }
     }
   }
   
-  public void addWaypoint(Waypoint wpt) {
-    waypoints.add(wpt);
-  }
-
   public int getNumLocations() {
     synchronized (points) {
-      return points.size();
+      return points.size() + pendingPoints.size();
     }
   }
 
-  public void clearWaypoints() {
+  // Visible for testing.
-    waypoints.clear();
+  int getNumWaypoints() {
+    synchronized (waypoints) {
+      return waypoints.size();
+    }
   }
   
   public void clearPoints() {
     synchronized (points) {
       points.clear();
+      pendingPoints.clear();
+    }
+  }
+
+  public void clearWaypoints() {
+    synchronized (waypoints) {
+      waypoints.clear();
     }
   }
 
@@ -183,27 +219,13 @@ public class MyTracksOverlay extends Overlay {
   }
 
   private void drawWaypoints(Canvas canvas, MapView mapView) {
-    ArrayList<Waypoint> currentWaypoints = waypoints;
+    synchronized (waypoints) {;
-    for (int i = 1; i < currentWaypoints.size(); i++) {
+      for (Waypoint wpt : waypoints) {
-      Waypoint wpt = currentWaypoints.get(i);
+        Location loc = wpt.getLocation();
-      if (wpt == null) {
+        drawElement(canvas, mapView, MyTracksUtils.getGeoPoint(loc),
-        continue;
+            wpt.getType() == Waypoint.TYPE_STATISTICS ? statsMarker
+                : waypointMarker, -(markerWidth / 2) + 3, -markerHeight);
       }
-      Location loc = wpt.getLocation();
-      if (loc == null) {
-        continue;
-      }
-      GeoPoint geoPoint = MyTracksUtils.getGeoPoint(loc);
-      Point pt = new Point();
-      mapView.getProjection().toPixels(geoPoint, pt);
-      canvas.save();
-      canvas.translate(pt.x - (markerWidth / 2) + 3, pt.y - (markerHeight));
-      if (wpt.getType() == Waypoint.TYPE_STATISTICS) {
-        statsMarker.draw(canvas);
-      } else {
-        waypointMarker.draw(canvas);
-      }
-      canvas.restore();
     }
   }
 
@@ -213,16 +235,9 @@ public class MyTracksOverlay extends Overlay {
       return;
     }
 
-    GeoPoint geoPoint = new GeoPoint(
+    Point pt = drawElement(canvas, mapView,
-        (int) (myLocation.getLatitude() * 1E6),
+        MyTracksUtils.getGeoPoint(myLocation), arrows[lastHeading],
-        (int) (myLocation.getLongitude() * 1E6));
+        -(arrowWidth / 2) + 3, -(arrowHeight / 2));
-    Point pt = new Point();
-    mapView.getProjection().toPixels(geoPoint, pt);
-    canvas.save();
-    canvas.translate(pt.x - (arrowWidth / 2), pt.y - (arrowHeight / 2));
-    arrow[lastHeading].draw(canvas);
-    canvas.restore();
-
     // Draw the error circle:
     float radius =
         mapView.getProjection().metersToEquatorPixels(myLocation.getAccuracy());
@@ -230,170 +245,92 @@ public class MyTracksOverlay extends Overlay {
   }
 
   private void drawTrack(Canvas canvas, MapView mapView) {
-    Path path;
-    Point pt = new Point();
-    Location lastValidLocation;
-    int locLon = 0, locLat = 0;
     GeoPoint firstGeoPoint = null;
-    boolean lastLocValid;
+    GeoPoint lastGeoPoint = null;
 
-    // Get the current viewing window:
+    // Get the current viewing window.
-    int w = mapView.getLongitudeSpan();
+    Rect viewRect = null;
-    int h = mapView.getLatitudeSpan();
+    if (!alwaysVisible) {
-    int cx = mapView.getMapCenter().getLongitudeE6();
+      int w = mapView.getLongitudeSpan();
-    int cy = mapView.getMapCenter().getLatitudeE6();
+      int h = mapView.getLatitudeSpan();
-    Rect viewRect = new Rect(cx - w, cy - h, cx + w, cy + h);
+      int cx = mapView.getMapCenter().getLongitudeE6();
-
+      int cy = mapView.getMapCenter().getLatitudeE6();
-    // Global bounding box, including points not visible
+      viewRect = new Rect(cx - w / 2, cy - h / 2, cx + w / 2, cy + h / 2);
-    int allMinLat, allMinLon, allMaxLat, allMaxLon;
+    }
     
+    final Path path = new Path();
+    final Point pt = new Point();
     synchronized (points) {
+      // Merge the pending points with the list of cached locations. 
+      pendingPoints.drainTo(points);
+      
       int numPoints = points.size();
       if (numPoints < 2) {
         return;
       }
-
-      GeoPoint geoPoint;
-      Location loc;
-      int minLon, maxLon, minLat, maxLat;
-      lastValidLocation = points.get(0);
-      int lastLocLon = allMinLon = allMaxLon = (int) (lastValidLocation.getLongitude() * 1E6);
-      int lastLocLat = allMinLat = allMaxLat = (int) (lastValidLocation.getLatitude() * 1E6);
-      lastLocValid = MyTracksUtils.isValidLocation(lastValidLocation);
-      boolean lastLocVisible = false;
-      path = new Path();
-
-      // Loop over track points:
       path.incReserve(numPoints);
-      for (int i = 1; i < numPoints; i++) {
-        loc = points.get(i);
 
-        boolean locValid = MyTracksUtils.isValidLocation(loc);
+      // Whether to start a new segment on new valid and visible point.
-        boolean locVisible = false;
+      boolean newSegment = true;
-        if (locValid) {
+      boolean lastVisible = false;
-          locLon = (int) (loc.getLongitude() * 1E6);
+      // Loop over track points:
-          locLat = (int) (loc.getLatitude() * 1E6);
+      for (CachedLocation loc : points) {
-
+        // Check if valid, if not then indicate a new segment.
-          if (firstGeoPoint == null) {
+        if (!loc.valid) {
-            // Found the starting point
+          newSegment = true;
-            firstGeoPoint = new GeoPoint(locLat, locLon);
+          continue;
-          }
+        }
-
+        
-          // If both the current and previous locations were valid
+        final GeoPoint geoPoint = loc.geoPoint;
-          if (lastLocValid) {
+        if (firstGeoPoint == null) {
-            lastValidLocation = loc;
+          // Found the starting point.
-  
+          firstGeoPoint = geoPoint;
-            // Get the bounding box of the segment about to be drawn
+        }
-            if (locLon > lastLocLon) {
+        lastGeoPoint = geoPoint;
-              minLon = lastLocLon;
+
-              maxLon = locLon;
+        // Check if break the existing segment.
-            } else {
+        boolean visible = alwaysVisible || viewRect.contains(
-              minLon = locLon;
+            geoPoint.getLongitudeE6(), geoPoint.getLatitudeE6());
-              maxLon = lastLocLon;
+        if (!visible && !lastVisible) {
-            }
+          // So this is a point outside view not connected to a visible one.
-            if (locLat > lastLocLat) {
+          newSegment = true;
-              minLat = lastLocLat;
+        }
-              maxLat = locLat;
+        lastVisible = visible;
-            } else {
+        
-              minLat = locLat;
+        // Either move to beginning of a new segment or continue the old one.
-              maxLat = lastLocLat;
+        mapView.getProjection().toPixels(geoPoint, pt);
-            }
+        if (newSegment) {
-
+          path.moveTo(pt.x, pt.y);
-            if (drawBounds) {
+          newSegment = false;
-              allMaxLat = Math.max(allMaxLat, maxLat);
+        } else {
-              allMinLat = Math.min(allMinLat, minLat);
+          path.lineTo(pt.x, pt.y);
-              allMaxLon = Math.max(allMaxLon, maxLon);
-              allMinLon = Math.min(allMinLon, minLon);
-            }
-
-            // See if that bounding box intersects the viewable bounding box
-            // Assume that if it does, the location is visible
-            locVisible = viewRect.intersects(minLon, minLat, maxLon, maxLat);
-            if (locVisible) {
-              // If the previous point wasn't drawn, start at its position
-              if (!lastLocVisible) {
-                geoPoint = new GeoPoint(lastLocLat, lastLocLon);
-                mapView.getProjection().toPixels(geoPoint, pt);
-                path.moveTo(pt.x, pt.y);
-              }
-  
-              // Draw a line to the new point
-              geoPoint = new GeoPoint(locLat, locLon);
-              mapView.getProjection().toPixels(geoPoint, pt);
-              path.lineTo(pt.x, pt.y);
-            }
-          }
         }
-        lastLocLon = locLon;
-        lastLocLat = locLat;
-        lastLocValid = locValid;
-        lastLocVisible = locVisible;
       }
     }
-
     canvas.drawPath(path, selectedTrackPaint);
 
-    if (drawBounds) {
+    // Draw the "End" marker.
-      drawBoundingBox(canvas, mapView,
+    if (showEndMarker && lastGeoPoint != null) {
-          allMinLat, allMinLon, allMaxLat, allMaxLon);
+      drawElement(canvas, mapView, lastGeoPoint, endMarker, -markerWidth / 2,
-    }
+          -markerHeight);
-
-    // Draw the "End" marker:
-    if (showEndMarker && lastValidLocation != null) {
-      canvas.save();
-      GeoPoint geoPoint = MyTracksUtils.getGeoPoint(lastValidLocation);
-      mapView.getProjection().toPixels(geoPoint, pt);
-      canvas.translate(pt.x - (markerWidth / 2), pt.y - markerHeight);
-      endMarker.draw(canvas);
-      canvas.restore();
     }
     
     // Draw the "Start" marker:
     if (firstGeoPoint != null) {
-      mapView.getProjection().toPixels(firstGeoPoint, pt);
+      drawElement(canvas, mapView, firstGeoPoint, startMarker, -markerWidth / 2,
-      canvas.save();
+          -markerHeight);
-      canvas.translate(pt.x - (markerWidth / 2), pt.y - markerHeight);
-      startMarker.draw(canvas);
-      canvas.restore();
     }
   }
   
-  private void drawBoundingBox(Canvas canvas, MapView mapView, int allMinLat,
+  private Point drawElement(Canvas canvas, MapView mapView, GeoPoint geoPoint,
-      int allMinLon, int allMaxLat, int allMaxLon) {
+      Drawable element, int offsetX, int offsetY) {
-    // Transform coordinates
+    Point pt = new Point();
-    GeoPoint maxPoint = new GeoPoint(allMaxLat, allMaxLon);
+    mapView.getProjection().toPixels(geoPoint, pt);
-    GeoPoint minPoint = new GeoPoint(allMinLat, allMinLon);
-    Point minPt = new Point();
-    Point maxPt = new Point();
-    mapView.getProjection().toPixels(minPoint, minPt);
-    mapView.getProjection().toPixels(maxPoint, maxPt);
-    Rect allBounds = new Rect(minPt.x, minPt.y, maxPt.x, maxPt.y);
-
-    // Prepare a green paint
-    Paint boundingBoxPaint = new Paint();
-    boundingBoxPaint.setColor(context.getResources().getColor(R.color.green));
-    boundingBoxPaint.setStrokeWidth(2);
-    boundingBoxPaint.setStyle(Paint.Style.STROKE);
-    boundingBoxPaint.setAntiAlias(true);
-
-    // Disable clipping
     canvas.save();
-    canvas.clipRect(Float.NEGATIVE_INFINITY, Float.NEGATIVE_INFINITY,
+    canvas.translate(pt.x + offsetX, pt.y + offsetY);
-                    Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY,
+    element.draw(canvas);
-                    Region.Op.REPLACE);
-
-    // Draw the bounding box
-    canvas.drawRect(allBounds, boundingBoxPaint);
-
-    // Re-enable clipping
     canvas.restore();
-  }
+    return pt;
-
-  @Override
-  public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
-      long when) {
-    draw(canvas, mapView, shadow);
-    return false;
   }
 
   /**
@@ -436,20 +373,22 @@ public class MyTracksOverlay extends Overlay {
     final Location tapLocation = MyTracksUtils.getLocation(p);
     double dmin = Double.MAX_VALUE;
     Waypoint waypoint = null;
-    for (int i = 0; i < waypoints.size(); i++) {
+    synchronized (waypoints) {
-      final Location waypointLocation = waypoints.get(i).getLocation();
+      for (int i = 0; i < waypoints.size(); i++) {
-      if (waypointLocation == null) {
+        final Location waypointLocation = waypoints.get(i).getLocation();
-        continue;
+        if (waypointLocation == null) {
-      }
+          continue;
-      final double d = waypointLocation.distanceTo(tapLocation);
+        }
-      if (d < dmin) {
+        final double d = waypointLocation.distanceTo(tapLocation);
-        dmin = d;
+        if (d < dmin) {
-        waypoint = waypoints.get(i);
+          dmin = d;
+          waypoint = waypoints.get(i);
+        }
       }
     }
 
-    if (waypoint != null
+    if (waypoint != null &&
-        && dmin < 15000000 / Math.pow(2, mapView.getZoomLevel())) {
+        dmin < 15000000 / Math.pow(2, mapView.getZoomLevel())) {
       Intent intent = new Intent(context, MyTracksWaypointDetails.class);
       intent.putExtra("waypointid", waypoint.getId());
       context.startActivity(intent);
@@ -457,8 +396,4 @@ public class MyTracksOverlay extends Overlay {
     }
     return super.onTap(p, mapView);
   }
-
-  public void setDrawBounds(boolean drawBounds) {
-    this.drawBounds = drawBounds;
-  }
 }

MyTracksTest/src/com/google/android/apps/mytracks/MyTracksOverlayTest.java

@@ -0,0 +1,133 @@
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * 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.android.apps.mytracks;
+
+import com.google.android.apps.mytracks.content.Waypoint;
+import com.google.android.maps.MapView;
+
+import android.graphics.Canvas;
+import android.location.Location;
+import android.test.AndroidTestCase;
+
+/**
+ * Tests for the MyTracks map overlay.
+ * 
+ * @author Bartlomiej Niechwiej
+ */
+public class MyTracksOverlayTest extends AndroidTestCase {
+  private Canvas canvas;
+  private MyTracksOverlay myTracksOverlay;
+  private MapView mockView;
+  
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    canvas = new Canvas();
+    myTracksOverlay = new MyTracksOverlay(getContext());
+    // TODO: add real mock view and enable track drawing.
+    mockView = null;
+  }
+
+  public void testAddLocation() throws Exception {
+    Location location = new Location("gps");
+    location.setLatitude(10);
+    location.setLongitude(20);
+    myTracksOverlay.addLocation(location);
+    assertEquals(1, myTracksOverlay.getNumLocations());
+    
+    location.setLatitude(20);
+    location.setLongitude(30);
+    myTracksOverlay.addLocation(location);
+    assertEquals(2, myTracksOverlay.getNumLocations());
+    
+    // Draw and make sure that we don't lose any point.
+    myTracksOverlay.draw(canvas, mockView, false);
+    assertEquals(2, myTracksOverlay.getNumLocations());
+    myTracksOverlay.draw(canvas, mockView, true);
+    assertEquals(2, myTracksOverlay.getNumLocations());
+  }
+  
+  public void testClearPoints() throws Exception {
+    Location location = new Location("gps");
+    location.setLatitude(10);
+    location.setLongitude(20);
+    myTracksOverlay.addLocation(location);
+    assertEquals(1, myTracksOverlay.getNumLocations());
+    myTracksOverlay.clearPoints();
+    assertEquals(0, myTracksOverlay.getNumLocations());
+
+    // Same after drawing on canvas.
+    final int locations = 100;
+    for (int i = 0; i < locations; ++i) {
+      myTracksOverlay.addLocation(location);
+    }
+    assertEquals(locations, myTracksOverlay.getNumLocations());
+    myTracksOverlay.draw(canvas, mockView, false);
+    myTracksOverlay.draw(canvas, mockView, true);
+    myTracksOverlay.clearPoints();
+    assertEquals(0, myTracksOverlay.getNumLocations());
+  }
+
+  public void testAddWaypoint() throws Exception {
+    Location location = new Location("gps");
+    location.setLatitude(10);
+    location.setLongitude(20);
+    Waypoint waypoint = new Waypoint();
+    waypoint.setLocation(location);
+    myTracksOverlay.addWaypoint(waypoint);
+    assertEquals(1, myTracksOverlay.getNumWaypoints());
+    
+    final int waypoints = 10;
+    for (int i = 0; i < waypoints; ++i) {
+      waypoint = new Waypoint();
+      waypoint.setLocation(location);
+      myTracksOverlay.addWaypoint(waypoint);
+    }
+    assertEquals(1 + waypoints, myTracksOverlay.getNumWaypoints());
+  }
+
+  public void testClearWaypoints() throws Exception {
+    Location location = new Location("gps");
+    location.setLatitude(10);
+    location.setLongitude(20);
+    Waypoint waypoint = new Waypoint();
+    waypoint.setLocation(location);
+    myTracksOverlay.addWaypoint(waypoint);
+    assertEquals(1, myTracksOverlay.getNumWaypoints());
+    myTracksOverlay.clearWaypoints();
+    assertEquals(0, myTracksOverlay.getNumWaypoints());
+  }
+  
+  public void testDrawing() {
+    Location location = new Location("gps");
+    location.setLatitude(10);
+    for (int i = 0; i < 40; ++i) {
+      location.setLongitude(20 + i);
+      Waypoint waypoint = new Waypoint();
+      waypoint.setLocation(location);
+      myTracksOverlay.addWaypoint(waypoint);
+    }
+    for (int i = 0; i < 100; ++i) {
+      location = new Location("gps");
+      location.setLatitude(50 + i);
+      location.setLongitude(150 - i);
+      myTracksOverlay.addLocation(location);
+    }
+    
+    myTracksOverlay.draw(canvas, mockView, false);
+    myTracksOverlay.draw(canvas, mockView, true);
+  }
+}