Question

I using class Overlay to marker place on map.. I want show infomation of place when i click icon on map (show atm_name and atm_address).
I tried method onTap but it show all infomation of all icon when i click.
Which method should I use to solved my problem.. Help me.
Sorry i use english not good

My Code:

public class atm_markerATM extends Overlay{

    Double lat;
    Double lng;
    Context ct;
    String atm_name;
    String atm_address;

    @Override
    public void draw(Canvas canvas, MapView mapView, boolean shadow) {
        Projection projection = mapView.getProjection();
        if (shadow == false) {
            Double latitude = lat*1E6;
            Double longitude = lng*1E6;
            GeoPoint geoPoint;
            geoPoint = new GeoPoint(latitude.intValue(),longitude.intValue());

            // Convert the location to screen pixelats
            Point point = new Point();
            projection.toPixels(geoPoint, point);

            // Setup the paint
            Paint paint = new Paint();

            Bitmap mBitmap = BitmapFactory.decodeResource(ct.getResources(), R.drawable.hoe);
            canvas.drawBitmap(mBitmap, point.x-8, point.y-38, paint);
        }
        super.draw(canvas, mapView, shadow);
    }

    @Override
    public boolean onTap(GeoPoint point, MapView mapView) {
        return false;
    }

    public void setLocation(Double lat, Double lng, Context ct, String name, String address) {
        this.lat = lat;
        this.lng = lng;
        this.ct = ct;
        this.atm_name = name;
        this.atm_address = address;
    }
}

Answer 1

I’ve used OnTap in my Overlay and it works well.

In my Draw method I populate a ArrayList of objects which represent the displayed entity (ATM in your case). Each of these object has a latitude and longitude value.

In onTap I compare the tapped point with the lat/long of each of the object in my ArrayList (populated during Draw). If the tap hits a point in close proximity to an object then I can display it’s details.

I have some source code which I can post up at some point if this sounds like the way you want to go.

[Edit] Here is the source code which I’ve hacked out the bits you will need. Note that there are some references to bubbleLayouts etc which you won’t need but it’s easier to leave them in.

Note that there is always more than one way to do just about anything – this may not be the best way but it works for me 😉

import java.util.ArrayList;
import java.util.Iterator;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.RectF;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.Projection;
import com.google.android.maps.MapView.LayoutParams;
import com.google.android.maps.Overlay;

public class EnhancedStationOverlay extends Overlay {

private MapView _mapView;
private Context _context;
private LinearLayout _bubbleLayout;
private int _defaultMarker;
private ArrayList<station> _stationLocations;
private ArrayList<station> _displayedStations;

// private RectF debugHitRect = new RectF();

public EnhancedStationOverlay(int defaultMarker, MapView mapView, LinearLayout bubbleLayout, ArrayList<station> stationList) {
    _stationLocations = stationList;
    _mapView = mapView;
    _context = mapView.getContext();
    _bubbleLayout = bubbleLayout;
    _defaultMarker = defaultMarker;
}

public boolean onTap(GeoPoint p, MapView mapView) {

    station tappedStation = FetchTappedStation(mapView, p);

    if (tappedStation != null) {

        // Display Bubble containing Location Details
    }

    return true;
}

@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {

    Projection projection = mapView.getProjection();
    super.draw(canvas, mapView, shadow);

    // Need to resolve top, bottom, left and right coordinates in relation to the map

    // Height & Width
    int latSpan = mapView.getLatitudeSpan();
    int lngSpan = mapView.getLongitudeSpan();

    // Centre Point
    GeoPoint mapCenter = mapView.getMapCenter();

    // Left and Right
    int mapLeftGeo = mapCenter.getLongitudeE6() - (lngSpan / 2);
    int mapRightGeo = mapCenter.getLongitudeE6() + (lngSpan / 2);

    // Top and Bottom
    int mapTopGeo = mapCenter.getLatitudeE6() - (latSpan / 2);
    int mapBottomGeo = mapCenter.getLatitudeE6() + (latSpan / 2);

    if (shadow != false) {
        // Create an empty ArrayList
        _displayedStations = new ArrayList<station>();

        // Loop through stations
        for (station currentStation : _stationLocations) {

            // Resolve current station location to a GeoPoint
            GeoPoint point = new GeoPoint((int) currentStation.getLatitude(), (int) currentStation.getLongitude());

            // Determine whether it falls within the screens view of the map
            if ((point.getLatitudeE6() > mapTopGeo && point.getLatitudeE6() < mapBottomGeo)
                    && (point.getLongitudeE6() > mapLeftGeo && point.getLongitudeE6() < mapRightGeo)) {

                // Yes it does - configure and place marker (pushpin)
                Point myPoint = new Point();
                projection.toPixels(point, myPoint);

                Bitmap stationMarker = BitmapFactory.decodeResource(_context.getResources(), _defaultMarker);
                canvas.drawBitmap(stationMarker, myPoint.x - 15, myPoint.y - 30, null);

                // Add this location to the collection of displayed locations
                _displayedStations.add(currentStation);
            }
        }
    }
}

private station FetchTappedStation(MapView mapView, GeoPoint geo) {

    // As in Draw() - Need to resolve top, bottom, left and right coordinates in relation to the map (could refactor this)
    int latSpan = mapView.getLatitudeSpan();
    int lngSpan = mapView.getLongitudeSpan();
    GeoPoint mapCenter = mapView.getMapCenter();
    int mapLeftGeo = mapCenter.getLongitudeE6() - (lngSpan / 2);
    int mapRightGeo = mapCenter.getLongitudeE6() + (lngSpan / 2);
    int mapTopGeo = mapCenter.getLatitudeE6() - (latSpan / 2);
    int mapBottomGeo = mapCenter.getLatitudeE6() + (latSpan / 2);

    // Track which MapLocation was hit…if any
    station hitMapLocation = null;

    RectF hitTestRecr = new RectF();
    Point screenCoords = new Point();
    Point tappedCoords = new Point();

    Iterator<station> iterator = _displayedStations.iterator();

    // Iterate over displayed stations...
    while (iterator.hasNext()) {
        station testLocation = iterator.next();

        // Translate MapLocation lat/long to screen coordinates
        GeoPoint test = new GeoPoint((int) testLocation.getLatitude(), (int) testLocation.getLongitude());

        Projection projection = mapView.getProjection();
        projection.toPixels(test, screenCoords);

        if (screenCoords.x != 0 && screenCoords.y != 0) {
            // Create a 'hit testing' rectangle
            hitTestRecr.set(-20, -50, 20, 15);

            // Next, offset the Rectangle 'surround' current location’s
            // icon on the screen.
            hitTestRecr.offset(screenCoords.x, screenCoords.y);

            // Finally test for match between ‘hit’ Rectangle and
            // location clicked by the user.
            // If a hit occurred, then we stop processing and return the
            // result;
            projection.toPixels(geo, tappedCoords);
            if (hitTestRecr.contains(tappedCoords.x, tappedCoords.y)) {
                hitMapLocation = testLocation;
                break;
            }
        }

    }

    return hitMapLocation;
}

}