added north inside position for legend

xchart-demo/src/main/java/com/xeiam/xchart/demo/charts/scatter/ScatterChart02.java

@@ -65,7 +65,7 @@ public class ScatterChart02 implements ExampleChart {
     chart.getStyleManager().setXAxisLogarithmic(true);
 
     // Customize Chart
-    chart.getStyleManager().setLegendPosition(LegendPosition.InsideNW);
+    chart.getStyleManager().setLegendPosition(LegendPosition.InsideN);
 
     // Series
     chart.addSeries("logarithmic data", xData, yData);

xchart/src/main/java/com/xeiam/xchart/StyleManager.java

@@ -41,7 +41,7 @@ public class StyleManager {
 
   public enum LegendPosition {
 
-    OutsideE, InsideNW, InsideNE, InsideSE, InsideSW
+    OutsideE, InsideNW, InsideNE, InsideSE, InsideSW, InsideN
   }
 
   public enum ChartTheme {

xchart/src/main/java/com/xeiam/xchart/internal/chartpart/Legend.java

@@ -146,6 +146,10 @@ public class Legend implements ChartPart {
         xOffset = chartPainter.getPlot().getBounds().getX() + LEGEND_MARGIN;
         yOffset = chartPainter.getPlot().getBounds().getY() + chartPainter.getPlot().getBounds().getHeight() - legendBoxHeight - LEGEND_MARGIN;
         break;
+      case InsideN:
+        xOffset = chartPainter.getPlot().getBounds().getX() + (chartPainter.getPlot().getBounds().getWidth() - legendBoxWidth) / 2 + LEGEND_MARGIN;
+        yOffset = chartPainter.getPlot().getBounds().getY() + LEGEND_MARGIN;
+        break;
 
       default:
         break;