when add points dynamicly, scale is changeing,

[kscorpio]

when add points dynamicly, scale is changeing. so visually, all the points are in the screen , the distance between became smaller, i need the visual effects like electrocardiogram or Oscilloscope

1 when the screen is not full (in x direction), the point add to screen from right
2 when the screen is full (in x direction), the point add to screen from right and a point disappear from left

the same to :#263
code like this:

   //! Y
   ChartDataSet * currentDataSet=self.scaleView.data.dataSets[0];
   NSInteger xIndex= currentDataSet.valueCount;
   ChartDataEntry * entry=[[ChartDataEntry alloc] initWithValue:yVal xIndex:xIndex];
   [currentDataSet addEntry:entry];
   //! X
   NSArray * xVal=_scaleView.data.xValsObjc;
   double lastX=[xVal.lastObject doubleValue];
   lastX +=0.1;
   [_scaleView.data addXValue:[NSString stringWithFormat:@"%f",lastX]];

   //!
   [self.scaleView notifyDataSetChanged];
   [self.scaleView moveViewToX:xIndex+1];

[kscorpio]

same to :#263