Index: trunk/src/org/openstreetmap/josm/gui/NavigatableComponent.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/NavigatableComponent.java	(revision 5558)
+++ trunk/src/org/openstreetmap/josm/gui/NavigatableComponent.java	(revision 5560)
@@ -4,5 +4,4 @@
 import static org.openstreetmap.josm.tools.I18n.marktr;
 
-import java.awt.Color;
 import java.awt.Cursor;
 import java.awt.Graphics;
@@ -133,6 +132,22 @@
     }
 
+    /**
+     * Returns the text describing the given distance in the current system of measurement.
+     * @param dist The distance in metres.
+     * @return the text describing the given distance in the current system of measurement.
+     * @since 3406
+     */
     public static String getDistText(double dist) {
         return getSystemOfMeasurement().getDistText(dist);
+    }
+
+    /**
+     * Returns the text describing the given area in the current system of measurement.
+     * @param area The distance in square metres.
+     * @return the text describing the given area in the current system of measurement.
+     * @since 5560
+     */
+    public static String getAreaText(double area) {
+        return getSystemOfMeasurement().getAreaText(area);
     }
 
@@ -1171,4 +1186,9 @@
     }
 
+    /**
+     * Returns the current system of measurement.
+     * @return The current system of measurement (metric system by default).
+     * @since 3490
+     */
     public static SystemOfMeasurement getSystemOfMeasurement() {
         SystemOfMeasurement som = SYSTEMS_OF_MEASUREMENT.get(ProjectionPreference.PROP_SYSTEM_OF_MEASUREMENT.get());
@@ -1178,4 +1198,8 @@
     }
 
+    /**
+     * A system of units used to express length and area measurements.
+     * @since 3406
+     */
     public static class SystemOfMeasurement {
         public final double aValue;
@@ -1185,5 +1209,5 @@
 
         /**
-         * System of measurement. Currently covers only length units.
+         * System of measurement. Currently covers only length (and area) units.
          *
          * If a quantity x is given in m (x_m) and in unit a (x_a) then it translates as
@@ -1197,4 +1221,9 @@
         }
 
+        /**
+         * Returns the text describing the given distance in this system of measurement.
+         * @param dist The distance in metres
+         * @return The text describing the given distance in this system of measurement.
+         */
         public String getDistText(double dist) {
             double a = dist / aValue;
@@ -1207,11 +1236,44 @@
                 return String.format(Locale.US, "%." + (a<10 ? 2 : 1) + "f %s", a, aName);
         }
-    }
-
+
+        /**
+         * Returns the text describing the given area in this system of measurement.
+         * @param area The area in square metres
+         * @return The text describing the given area in this system of measurement.
+         * @since 5560
+         */
+        public String getAreaText(double area) {
+            return getDistText(area)+"\u00b2"; // square
+        }
+    }
+
+    /**
+     * Metric system (international standard).
+     * @since 3406
+     */
     public static final SystemOfMeasurement METRIC_SOM = new SystemOfMeasurement(1, "m", 1000, "km");
+    
+    /**
+     * Chinese system.
+     * @since 3406
+     */
     public static final SystemOfMeasurement CHINESE_SOM = new SystemOfMeasurement(1.0/3.0, "\u5e02\u5c3a" /* chi */, 500, "\u5e02\u91cc" /* li */);
+    
+    /**
+     * Imperial system (British Commonwealth and former British Empire).
+     * @since 3406
+     */
     public static final SystemOfMeasurement IMPERIAL_SOM = new SystemOfMeasurement(0.3048, "ft", 1609.344, "mi");
+    
+    /**
+     * Nautical mile system (navigation, polar exploration).
+     * @since 5549
+     */
     public static final SystemOfMeasurement NAUTICAL_MILE_SOM = new SystemOfMeasurement(185.2, "kbl", 1852, "NM");
 
+    /**
+     * Known systems of measurement.
+     * @since 3406
+     */
     public static final Map<String, SystemOfMeasurement> SYSTEMS_OF_MEASUREMENT;
     static {