How do I get points & draw the route on Googl开发者_运维知识库e maps in Android OS?
An example URL you're going to parse is...
http://maps.googleapis.com/maps/api/directions/xml?origin=52.31,16.71&destination=51.27,6.75&sensor=false
change origin [lat,long] and destination[lat, long] for your purpose
--
points fetching
import java.io.StringReader;
import java.util.ArrayList;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserFactory;
import net.gynsoft.citydusseldorf.lib.HttpClient;
import android.os.Handler;
import com.google.android.maps.GeoPoint;
public class MapRoute
{
private GeoPoint gpSrc = null;
private GeoPoint gpDest = null;
private ArrayList<GeoPoint> alRoute = new ArrayList<GeoPoint>();
private Handler haRoute = new Handler();
public interface RouteListener
{
public void onDetermined(ArrayList<GeoPoint> alPoint);
public void onError();
}
private RouteListener oRoute = null;
public MapRoute(GeoPoint gpSrc,GeoPoint gpDest)
{
this.gpSrc = gpSrc;
this.gpDest = gpDest;
}
public void getPoints(RouteListener oRoute)
{
this.oRoute = oRoute;
new Thread(ruFetch).start();
}
private Runnable ruFetchOk = new Runnable()
{
public void run()
{
oRoute.onDetermined(alRoute);
}
};
private Runnable ruFetchError = new Runnable()
{
public void run()
{
oRoute.onDetermined(alRoute);
}
};
private Runnable ruFetch = new Runnable()
{
public void run()
{
String szUrl = "http://maps.googleapis.com/maps/api/directions/xml";
szUrl += "?origin=" + (gpSrc.getLatitudeE6()/1e6) + "," + (gpSrc.getLongitudeE6()/1e6);
szUrl += "&destination=" + (gpDest.getLatitudeE6()/1e6) + "," + (gpDest.getLongitudeE6()/1e6);
szUrl += "&sensor=true";
HttpClient oHttp = HttpClient.getInstance();
String szXml = oHttp.doGet(szUrl,"");
try
{
XmlPullParserFactory xppfFactory = XmlPullParserFactory.newInstance();
xppfFactory.setNamespaceAware(true);
XmlPullParser xppParses = xppfFactory.newPullParser();
xppParses.setInput(new StringReader(szXml));
int iEventType = xppParses.getEventType();
String szTag = "";
String szText = "";
boolean bStep = false;
int iLat = 0;
int iLong = 0;
while(iEventType != XmlPullParser.END_DOCUMENT)
{
iEventType = xppParses.next();
if(iEventType == XmlPullParser.START_TAG)
{
szTag = xppParses.getName();
if(szTag.equals("step"))
bStep = true;
}
else if(iEventType == XmlPullParser.TEXT)
{
if(szTag.equals("points"))
szText = "";
else
szText = xppParses.getText().trim();
}
else if(iEventType == XmlPullParser.END_TAG)
{
if(xppParses.getName().equals("step"))
{
bStep = false;
}
else if(bStep && xppParses.getName().equals("start_location") || xppParses.getName().equals("end_location"))
{
GeoPoint gpPoint = new GeoPoint(iLat,iLong);
alRoute.add(gpPoint);
}
else if(bStep && xppParses.getName().equals("lat"))
{
iLat = (int)(Double.parseDouble(szText) * 1e6);
}
else if(bStep && xppParses.getName().equals("lng"))
{
iLong = (int)(Double.parseDouble(szText) * 1e6);
}
}
}
}
catch(Exception e)
{
e.printStackTrace();
haRoute.post(ruFetchError);
}
if(alRoute.size() == 0)
haRoute.post(ruFetchError);
else
haRoute.post(ruFetchOk);
}
};
}
--
map overlay
public class MapRouteOverlay extends Overlay
{
private GeoPoint gp1;
private GeoPoint gp2;
private int mode=0;
private int defaultColor;
public MapRouteOverlay(GeoPoint gp1,GeoPoint gp2,int mode) // GeoPoint is a int. (6E)
{
this.gp1 = gp1;
this.gp2 = gp2;
this.mode = mode;
defaultColor = 999; // no defaultColor
}
public MapRouteOverlay(GeoPoint gp1,GeoPoint gp2,int mode, int defaultColor)
{
this.gp1 = gp1;
this.gp2 = gp2;
this.mode = mode;
this.defaultColor = defaultColor;
}
public int getMode()
{
return mode;
}
public boolean draw (Canvas canvas, MapView mapView, boolean shadow, long when)
{
Projection projection = mapView.getProjection();
if (shadow == false)
{
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setDither(true);
Point point = new Point();
projection.toPixels(gp1, point);
if(mode==2)
{
if(defaultColor==999)
{
paint.setColor(Color.RED);
}
else
{
paint.setColor(defaultColor);
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);
}
}
}
return super.draw(canvas, mapView, shadow, when);
}
}
--
how to use it... somewhere in my activity
dEmpty = new BitmapDrawable(Bitmap.createBitmap(1,1,Bitmap.Config.ARGB_8888));
dPin = getResources().getDrawable(R.drawable.pin_map);
private void doDrawPath(GeoPoint gpSrc,GeoPoint gpDest)
{
MapRoute oRoute = new MapRoute(gpSrc,gpDest);
oRoute.getPoints(new RouteListener()
{
@Override
public void onDetermined(ArrayList<GeoPoint> alPoint)
{
GeoPoint oPointA = null;
GeoPoint oPointB = null;
mvMap.getOverlays().clear();
for(int i=1; i<alPoint.size()-1; i++)
{
oPointA = alPoint.get(i-1);
oPointB = alPoint.get(i);
mvMap.getOverlays().add(new MapRouteOverlay(oPointA,oPointB,2,Color.RED));
}
mvMap.getOverlays().add(new MapRoutePinOverlay(alPoint.get(0),dPin));
mvMap.getOverlays().add(new MapRoutePinOverlay(alPoint.get(alPoint.size()-1),dPin));
mvMap.invalidate();
}
@Override
public void onError()
{
}
});
}
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