title: How to clear displayed route on google map?
body: <p>In my android app i am displaying route b/w current_location and user selected near theater by clicking "Get directions" Button but when user select another theater new route also displaying but old route is not clearing.i tried in several ways but i am unable to do. i tried with mapOverlays.clear(); which clearing entire map which i dont want.even i tried {mapOverlays.remove(ol1); mapView.postInvalidate();}its not clearing route please help me:following is the code:</p>
  
  <p>MyOverLay.java</p>
  
  <pre><code>public class MyOverLay extends Overlay 
  { 
      private GeoPoint gp1; 
      private GeoPoint gp2; 
      private int mode=0; 
      Context mContext;
  
      public MyOverLay(GeoPoint gp1,GeoPoint gp2,int mode) 
      { 
          this.gp1 = gp1; 
          this.gp2 = gp2; 
          this.mode = mode; 
      }  
      public int getMode() 
      { 
          return mode; 
      } 
  
      @Override 
      public boolean draw (Canvas canvas, MapView mapView, boolean shadow, long when) 
      { 
          Projection projection = mapView.getProjection(); 
          Log.d("shadow", ""+shadow);
          if (shadow== false) 
          { 
              Paint paint = new Paint(); 
              paint.setAntiAlias(true); 
              Point point = new Point(); 
              projection.toPixels(gp1, point); 
              if(mode==1) // start point
              { 
                      paint.setColor(Color.BLUE); 
              } 
              else if(mode==2) // mode=2,path 
              { 
                  paint.setColor(Color.BLUE); 
                  Point point2 = new Point(); 
                  projection.toPixels(gp2, point2); 
                  paint.setStrokeWidth(5); 
                  paint.setAlpha(120); 
                  canvas.drawLine(point.x, point.y, point2.x,point2.y, paint); 
              } 
              else if(mode==3)   /* mode=3&amp;#65306;end */ 
              { 
                  /* the last path */ 
                  Point point2 = new Point(); 
                  projection.toPixels(gp2, point2); 
                  paint.setStrokeWidth(5); 
                  paint.setAlpha(120); 
                  canvas.drawLine(point.x, point.y, point2.x,point2.y, paint); 
                  /* end point */
              } 
          } 
          return super.draw(canvas, mapView, shadow, when); 
      } 
  }
  </code></pre>
  
  <p>HelloItemizedOverlay.java</p>
  
  <pre><code>public class HelloItemizedOverlay extends ItemizedOverlay&lt;OverlayItem&gt; {
      WebViewDemo viewDemo;
      GeoPoint curret_point;
  
      private ArrayList&lt;OverlayItem&gt; mOverlays = new ArrayList&lt;OverlayItem&gt;();
      Context mContext;
  
     //some methods
  
      public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
          super(boundCenterBottom(defaultMarker));
          mContext = context;
          viewDemo=(WebViewDemo)context;
      }
  
      //When user taps theater icon this alert box pop ups.which contains 'Get directions' Button
      @Override
      protected boolean onTap(int index) { 
           WebViewDemo.MyOverLayItem item = (WebViewDemo.MyOverLayItem) mOverlays.get(index);
          AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
          viewDemo.desc_lat=item.getPoint().getLatitudeE6();
          viewDemo.desc_lng=item.getPoint().getLongitudeE6();
          dialog.setTitle(item.getTitle());
          dialog.setMessage(item.getSnippet());
          dialog.setPositiveButton("Get directions", new DialogInterface.OnClickListener() {
              public void onClick(DialogInterface dialog, int which) {
                  viewDemo.showDrections();
              }
          });
          dialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
  
              public void onClick(DialogInterface dialog, int which) {
                  dialog.dismiss();
              }
          });
          dialog.show();
          return true;
      }
  }
  </code></pre>
  
  <p>Main part of WebViewDemo Map Activity:</p>
  
  <p>WebViewDemo.java</p>
  
  <pre><code>public class WebViewDemo extends MapActivity {
  
  public double current_latitude, current_langitude;
  Overlay ol1;
  MapView mapView;
  GeoPoint destGeoPoint;
  HttpClient httpClient;
  HttpPost postRequest;
  HttpResponse response;
  BufferedReader reader;
  String sResponse, result;
  StringBuilder s;
  JSONObject jsonObject;
  public String lat = null, lng = null;
  int desc_lat,desc_lng;
  
  public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  .....
  mapView = (MapView) findViewById(R.id.mapview);
  mapOverlays = mapView.getOverlays();
  /**Here i am getting current_latitude, current_langitude using Location Manager
  and displaying it on map.and making Web Service request to google and displaying near theaters also.*/
  ..
  }//onCreate end
  
  // *For displaying route b/w current location and User selected Theaters when Get directions Button clicked (in HelloItemizedOverlay class). 
  
  public void showDrections() {
  
          try {
                        //Here i am trying  to clear previous path. 
              if(ol1!=null){
                  mapOverlays.remove(ol1);
                  mapView.postInvalidate();
                  mapView.invalidate();
              }
              double l1 = desc_lat/1E6;
              double l2 = desc_lng/1E6;
              destGeoPoint = new GeoPoint(desc_lat,desc_lng);
              httpClient = new DefaultHttpClient();
              postRequest = new HttpPost(
                      "http://maps.googleapis.com/maps/api/directions/json?origin="
                              + current_latitude
                              + ","
                              + current_langitude
                              + "&amp;destination="
                              + l1
                              + ","
                              + l2
                              + "&amp;sensor=true&amp;optimize=true&amp;alternatives=false");
              response = httpClient.execute(postRequest);
              reader = new BufferedReader(new InputStreamReader(response
                      .getEntity().getContent(), "UTF-8"));// getting response
              sResponse = null;
              s = new StringBuilder();
              while ((sResponse = reader.readLine()) != null) {
                  s = s.append(sResponse);
              }
              result = s.toString().trim();
              jsonObject = new JSONObject(result);
  
              JSONArray jsonRouteArray = jsonObject.getJSONArray("routes");
              JSONObject overview_poly = jsonRouteArray.getJSONObject(0).getJSONObject("overview_polyline");
              String points = overview_poly.getString("points");
              List&lt;GeoPoint&gt; _geopoints = decodePoly(points);
              GeoPoint gp1;
              GeoPoint gp2;
              gp2 = _geopoints.get(0);
              for (int i = 1; i &lt; _geopoints.size(); i++) // the last one  would be crash
              {
                  gp1 = gp2;
                  gp2 = _geopoints.get(i);
                  ol1 = new MyOverLay(gp1, gp2, 2);
                  mapOverlays.add(ol1);
              }
              mapView.postInvalidate();
              dialog.cancel();
          } catch (JSONException je) {
              Toast.makeText(this, "Unable to Show The Route", Toast.LENGTH_LONG).show();
              Log.d("showDirectins() JSON ERROR", ""+je);
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
  private List&lt;GeoPoint&gt; decodePoly(String encoded) {
  //this method is used to decode the route points which are coming from web service and convert them into GeoPoints
  }
  
  }
  </code></pre>
  
  <p>Please Suggest me code changes if required.</p>