1 files changed, 92 insertions, 0 deletions
diff --git a/main/src/cgeo/geocaching/maps/ScaleDrawer.java b/main/src/cgeo/geocaching/maps/ScaleDrawer.java
new file mode 100644
index 0000000..fb46408
--- /dev/null
+++ b/main/src/cgeo/geocaching/maps/ScaleDrawer.java
@@ -0,0 +1,92 @@
+package cgeo.geocaching.maps;
+
+import cgeo.geocaching.geopoint.Geopoint;
+import cgeo.geocaching.geopoint.Units;
+import cgeo.geocaching.maps.interfaces.GeoPointImpl;
+import cgeo.geocaching.maps.interfaces.MapViewImpl;
+
+import org.apache.commons.lang3.tuple.ImmutablePair;
+
+import android.app.Activity;
+import android.graphics.BlurMaskFilter;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Typeface;
+import android.util.DisplayMetrics;
+
+public class ScaleDrawer {
+    private static final double SCALE_WIDTH_FACTOR = 1.0 / 2.5;
+
+    private Paint scale = null;
+    private Paint scaleShadow = null;
+    private BlurMaskFilter blur = null;
+    private float pixelDensity = 0;
+
+    public ScaleDrawer(Activity activity) {
+        DisplayMetrics metrics = new DisplayMetrics();
+        activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
+        pixelDensity = metrics.density;
+    }
+
+    static private double keepSignificantDigit(final double distance) {
+        final double scale = Math.pow(10, Math.floor(Math.log10(distance)));
+        return scale * Math.floor(distance / scale);
+    }
+
+    void drawScale(Canvas canvas, MapViewImpl mapView) {
+        final double span = mapView.getLongitudeSpan() / 1e6;
+        final GeoPointImpl center = mapView.getMapViewCenter();
+
+        final int bottom = mapView.getHeight() - 14; // pixels from bottom side of screen
+
+        final Geopoint leftCoords = new Geopoint(center.getLatitudeE6() / 1e6, center.getLongitudeE6() / 1e6 - span / 2);
+        final Geopoint rightCoords = new Geopoint(center.getLatitudeE6() / 1e6, center.getLongitudeE6() / 1e6 + span / 2);
+
+        final ImmutablePair<Double, String> scaled = Units.scaleDistance(leftCoords.distanceTo(rightCoords) * SCALE_WIDTH_FACTOR);
+
+        final double distanceRound = keepSignificantDigit(scaled.left);
+        final double pixels = Math.round((mapView.getWidth() * SCALE_WIDTH_FACTOR / scaled.left) * 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.needsInvertedColors()) {
+            scaleShadow.setColor(0xFF000000);
+            scale.setColor(0xFFFFFFFF);
+        } else {
+            scaleShadow.setColor(0xFFFFFFFF);
+            scale.setColor(0xFF000000);
+        }
+
+        final String formatString = distanceRound >= 1 ? "%.0f" : "%.1f";
+
+        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(formatString, distanceRound) + " " + scaled.right, (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(formatString, distanceRound) + " " + scaled.right, (float) (pixels - (10 * pixelDensity)), (bottom - (10 * pixelDensity)), scale);
+    }
+
+}