fix heatmap tooltip

uk/ac/sanger/artemis/components/BasePlot.java

@@ -985,45 +985,43 @@ public class BasePlot extends Plot
     if(offset < 1) 
       offset = 0;
 
-    final int get_values_return_count =
+    final int nvalues =
       getBaseAlgorithm().getValueCount();
     
     int xpos = getPointPosition(event.getPoint().x);
-    
-    //getXCoordinate(getWidthInBases(),
-    //                          offset, event.getPoint().x);
-    
     String tt = Integer.toString(xpos);
     
-    NumberFormat df= NumberFormat.getNumberInstance();
+    NumberFormat df = NumberFormat.getNumberInstance();
     df.setMaximumFractionDigits(2);
     
-    float ypos;
-    for(int value_index = 0; value_index < get_values_return_count;
-        ++value_index)
-    {
-       ypos = getYCoordinate(step_size, getWindowSize(),
-                             offset, value_array_array[value_index], 
-                             xpos);
-       tt = tt + ", " + df.format(ypos);
-    }
- 
+    for(int i = 0; i < nvalues; ++i)
+      tt += ", " + df.format(
+           getYCoordinate(step_size, getWindowSize(),
+               offset, value_array_array[i], xpos));
+
     if(lines != null)
     {
       // if heat map display column number
       String plotType = lines[0].getPlotType();
       if(plotType.equals(LineAttributes.PLOT_TYPES[2]))
       {
-        final int graph_height = super.getSize().height -
+        final int graph_height = getSize().height -
                   getLabelHeight() - getScaleHeight() - 2;
-        
-        float hgt = ((float)graph_height/(float)lines.length);
+
+        int hgt = graph_height/value_array_array.length;
         float mousePos = (float) (event.getPoint().getY()- 
                   getLabelHeight() - getScaleHeight() - 2.f );
 
         int plotNumber = Math.round(( mousePos / hgt )+.5f);
         if(plotNumber < 1)
           plotNumber = 1;
+        else if(plotNumber > value_array_array.length)
+          plotNumber = value_array_array.length;
+        
+        if(nvalues > 5)
+          tt = Integer.toString(xpos)+", "+df.format(
+              getYCoordinate(step_size, getWindowSize(),
+              offset, value_array_array[plotNumber-1], xpos));
         
         tt = "Plot number : "+plotNumber+"\n"+tt;
       }