--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/chart/MinMaxStepNaviChartStepper.java	Tue Jul 17 19:48:18 2018 +0200
@@ -0,0 +1,80 @@
+/** Copyright (C) 2017 by Bundesanstalt für Gewässerkunde
+ * Software engineering by
+ *  Björnsen Beratende Ingenieure GmbH
+ *  Dr. Schumacher Ingenieurbüro für Wasser und Umwelt
+ *
+ * This file is Free Software under the GNU AGPL (>=v3)
+ * and comes with ABSOLUTELY NO WARRANTY! Check out the
+ * documentation coming with Dive4Elements River for details.
+ */
+package org.dive4elements.river.client.client.ui.chart;
+
+/**
+ * 'Old' stepping behaviour of the navi chart, as used by WINFO and Fixierungsanalyse.
+ *
+ * @author Gernot Belger
+ */
+public class MinMaxStepNaviChartStepper implements INaviChartStepper {
+
+    private double currentKm;
+    private final double minKm;
+    private final double maxKm;
+    private final double step;
+
+    public MinMaxStepNaviChartStepper(final double minKm, final double maxKm, final double step) {
+        this.minKm = minKm;
+        this.maxKm = maxKm;
+        this.step = step;
+
+        this.currentKm = minKm;
+    }
+
+    @Override
+    public double getCurrentKm() {
+        return this.currentKm;
+    }
+
+    @Override
+    public double stepForward() {
+
+        if (this.currentKm >= this.maxKm)
+            this.currentKm = this.maxKm;
+        else {
+            // Why this math?
+            double newVal = this.currentKm * 100;
+            newVal += this.step / 10;
+            this.currentKm = (double) Math.round(newVal) / 100;
+        }
+
+        return this.currentKm;
+    }
+
+    @Override
+    public double stepBackward() {
+
+        if (this.currentKm <= this.minKm)
+            this.currentKm = this.minKm;
+        else {
+            // Why this math?
+            double newVal = this.currentKm * 100;
+            newVal -= this.step / 10;
+
+            this.currentKm = ((double) Math.round(newVal) / 100);
+        }
+
+        return this.currentKm;
+    }
+
+    @Override
+    public double setValidCurrentKm(final double userInput) {
+
+        if (userInput > this.maxKm)
+            this.currentKm = this.maxKm;
+        else if (userInput < this.minKm)
+            this.currentKm = this.minKm;
+        else
+            this.currentKm = userInput;
+
+        return this.currentKm;
+    }
+}
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