RouteOverlay.java

package direction.json;

import java.util.Iterator;
import java.util.List;

import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Point;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.Projection;

public class RouteOverlay extends Overlay {
	/** GeoPoints representing this routePoints. **/
	private final List<GeoPoint> routePoints;
	/** Colour to paint routePoints. **/
	private int colour;
	/** Alpha setting for route overlay. **/
	private static final int ALPHA = 120;
	/** Stroke width. **/
	private static final float STROKE = 4.5f;
	/** Route path. **/
	private final Path path;
	/** Point to draw with. **/
	private final Point p;
	/** Paint for path. **/
	private final Paint paint;

	/**
	 * Public constructor.
	 * 
	 * @param route
	 *            Route object representing the route.
	 * @param defaultColour
	 *            default colour to draw route in.
	 */

	public RouteOverlay(final Route route, final int defaultColour) {
		super();
		routePoints = route.getPoints();
		colour = defaultColour;
		path = new Path();
		p = new Point();
		paint = new Paint();
	}

	@Override
	public final void draw(final Canvas c, final MapView mv,
			final boolean shadow) {
		super.draw(c, mv, shadow);

		paint.setColor(colour);
		paint.setAlpha(ALPHA);
		paint.setAntiAlias(true);
		paint.setStrokeWidth(STROKE);
		paint.setStyle(Paint.Style.STROKE);

		redrawPath(mv);
		c.drawPath(path, paint);
	}

	/**
	 * Set the colour to draw this route's overlay with.
	 * 
	 * @param c
	 *            Int representing colour.
	 */
	public final void setColour(final int c) {
		colour = c;
	}

	/**
	 * Clear the route overlay.
	 */
	public final void clear() {
		routePoints.clear();
	}

	/**
	 * Recalculate the path accounting for changes to the projection and
	 * routePoints.
	 * 
	 * @param mv
	 *            MapView the path is drawn to.
	 */

	private void redrawPath(final MapView mv) {
		final Projection prj = mv.getProjection();
		path.rewind();
		final Iterator<GeoPoint> it = routePoints.iterator();
		prj.toPixels(it.next(), p);
		path.moveTo(p.x, p.y);
		while (it.hasNext()) {
			prj.toPixels(it.next(), p);
			path.lineTo(p.x, p.y);
		}
		path.setLastPoint(p.x, p.y);
	}

}