cgOverlayScale.java

package carnero.cgeo.mapcommon;

import android.app.Activity;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.Typeface;
import android.util.DisplayMetrics;
import carnero.cgeo.cgBase;
import carnero.cgeo.cgSettings;
import carnero.cgeo.mapinterfaces.GeoPointImpl;
import carnero.cgeo.mapinterfaces.MapProjectionImpl;
import carnero.cgeo.mapinterfaces.OverlayBase;
import carnero.cgeo.mapinterfaces.MapViewImpl;

public class cgOverlayScale implements OverlayBase {
	private cgSettings settings = null;
    private Paint scale = null;
    private Paint scaleShadow = null;
	private BlurMaskFilter blur = null;
	private float pixelDensity = 0l;
	private double pixels = 0d;
	private int bottom = 0;
	private double distance = 0d;
	private double distanceRound = 0d;
	private String units = null;

    public cgOverlayScale(Activity activity, cgSettings settingsIn) {
		settings = settingsIn;

		DisplayMetrics metrics = new DisplayMetrics();
		activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
		pixelDensity = metrics.density;
	}

	@Override
	public void drawOverlayBitmap(Canvas canvas, Point drawPosition,
			MapProjectionImpl projection, byte drawZoomLevel) {
		// TODO Auto-generated method stub
		
	}

	@Override
    public void draw(Canvas canvas, MapViewImpl mapView, boolean shadow) {
		//super.draw(canvas, mapView, shadow);

		final double span = mapView.getLongitudeSpan() / 1e6;
		final GeoPointImpl center = mapView.getMapViewCenter();

		pixels = mapView.getWidth() / 2; // pixels related to following latitude span
		bottom = mapView.getHeight() - 14; // pixels from bottom side of screen
		distance = cgBase.getDistance((center.getLatitudeE6() / 1e6), ((center.getLongitudeE6() / 1e6) - (span /2)), (center.getLatitudeE6() / 1e6), ((center.getLongitudeE6() / 1e6) + (span /2)));
		distance = distance / 2;
		distanceRound = 0d;

		if(settings.units == cgSettings.unitsImperial) {
			distance *= cgBase.kmInMiles;

			if (distance > 100) { // 100+ mi > 1xx mi
				distanceRound = Math.floor(distance / 100) * 100;
				units = "mi";
			} else if (distance > 10) { // 10 - 100 mi > 1x mi
				distanceRound = Math.floor(distance / 10) * 10;
				units = "mi";
			} else if (distance > 1) { // 1 - 10 mi > 1.x mi
				distanceRound = Math.floor(distance);
				units = "mi";
			} else if (distance > 0.1) { // 0.1 mi - 1.0 mi > 1xx ft
				distance *= 5280;
				distanceRound = Math.floor(distance / 100) * 100;
				units = "ft";
			} else { // 1 - 100 ft > 1x ft
				distance *= 5280;
				distanceRound = Math.round(distance / 10) * 10;
				units = "ft";
			}
		} else {
			if (distance > 100) { // 100+ km > 1xx km
				distanceRound = Math.floor(distance / 100) * 100;
				units = "km";
			} else if (distance > 10) { // 10 - 100 km > 1x km
				distanceRound = Math.floor(distance / 10) * 10;
				units = "km";
			} else if (distance > 1) { // 1 - 10 km > 1.x km
				distanceRound = Math.floor(distance);
				units = "km";
			} else if (distance > 0.1) { // 100 m - 1 km > 1xx m
				distance *= 1000;
				distanceRound = Math.floor(distance / 100) * 100;
				units = "m";
			} else { // 1 - 100 m > 1x m
				distance *= 1000;
				distanceRound = Math.round(distance / 10) * 10;
				units = "m";
			}
		}

		pixels = Math.round((pixels / distance) * distanceRound);

		if (blur == null) {
			blur = new BlurMaskFilter(3, BlurMaskFilter.Blur.NORMAL);
		}

		if (scaleShadow == null) {
			scaleShadow = new Paint();
			scaleShadow.setAntiAlias(true);
			scaleShadow.setStrokeWidth(4 * pixelDensity);
			scaleShadow.setMaskFilter(blur);
			scaleShadow.setTextSize(14 * pixelDensity);
			scaleShadow.setTypeface(Typeface.DEFAULT_BOLD);
		}

		if (scale == null) {
			scale = new Paint();
			scale.setAntiAlias(true);
			scale.setStrokeWidth(2 * pixelDensity);
			scale.setTextSize(14 * pixelDensity);
			scale.setTypeface(Typeface.DEFAULT_BOLD);
		}

		if (mapView.isSatellite()) {
			scaleShadow.setColor(0xFF000000);
			scale.setColor(0xFFFFFFFF);
		} else {
			scaleShadow.setColor(0xFFFFFFFF);
			scale.setColor(0xFF000000);
		}

		canvas.drawLine(10, bottom, 10, (bottom - (8 * pixelDensity)), scaleShadow);
		canvas.drawLine((int)(pixels + 10), bottom, (int)(pixels + 10), (bottom - (8 * pixelDensity)), scaleShadow);
		canvas.drawLine(8, bottom, (int)(pixels + 12), bottom, scaleShadow);
		canvas.drawText(String.format("%.0f", distanceRound) + " " + units, (float)(pixels - (10 * pixelDensity)), (bottom - (10 * pixelDensity)), scaleShadow);

		canvas.drawLine(11, bottom, 11, (bottom - (6 * pixelDensity)), scale);
		canvas.drawLine((int)(pixels + 9), bottom, (int)(pixels + 9), (bottom - (6 * pixelDensity)), scale);
		canvas.drawLine(10, bottom, (int)(pixels + 10), bottom, scale);
		canvas.drawText(String.format("%.0f", distanceRound) + " " + units, (float)(pixels - (10 * pixelDensity)), (bottom - (10 * pixelDensity)), scale);
    }
}