Question

How to connect markers in Google map API using just java, i.e., without using asp.net, php or any other language? I am just a beginner. I have multiple markers on my map which are showing the corresponding places in Google android project.

Answer 1

Create your own Overlay class (instead of using the ItemizedOverlay that’s used to show markers) and implement the draw() method to paint the lines. Add this overlay to your MapView before adding the normal overlay you use to show the markers like so:

mMapView.getOverlays().add(mPathOverlay);
mMapView.getOverlays().add(mMarkersOverlay);

A PathOverlay class can look like this. The positions would be the positions of your markers, already converted to GeoPoints.

public class PathOverlay extends Overlay {

    private List<GeoPoint> mPositions;
    private Path mPath;
    private Paint mPathPaint;
    private Point mHelperPoint = new Point();

    public PathOverlay(List<GeoPoint> positions) {
        mPositions = positions;
        mPath = new Path();
        mPathPaint = new Paint();
        mPathPaint.setColor(0xDDA4C639);
        mPathPaint.setStyle(Paint.Style.STROKE);
        // add more path styling here
    }

    @Override
    public void draw(Canvas canvas, MapView mapView, boolean shadow) {
        if (shadow) {
            return; // path has no shadow
        }
        mPath.reset();
        boolean start = true;
        Point prev = new Point();
        for (Position p : mPositions) {
            mapView.getProjection().toPixels(p.geoPoint, mHelperPoint);
            if (start) {
                mPath.moveTo(mHelperPoint.x, mHelperPoint.y);
                prev.set(mHelperPoint.x, mHelperPoint.y);
                start = false;
            } else {
                int dx = prev.x - mHelperPoint.x;
                int dy = prev.y - mHelperPoint.y;
                mPath.lineTo(mHelperPoint.x, mHelperPoint.y);
                prev.set(mHelperPoint.x, mHelperPoint.y);
            }
        }
        canvas.drawPath(mPath, mPathPaint);
    }
}