AChart Engine Bar Chart - hide series when scrolling to the right

I am using the excellent AChart engine to create a histogram. All functions work fine, but I have a few things that I cannot solve:

This is my screenshot:

Now there are two things to fix:

1) Hide the series when it scrolls to the right, currently the March series is visible even after 0,0.

2) Gridlines are on top of the chart, but it must be behind the chart.

3) How to display legends in the top right corner instead of the bottom.

here is my code below:

private void openChart(){
        int[] x = { 10,20,30,40,50,60,70,80 };
       // int[] y = { 10,20,30,40,50,60,70 };
        int[] income = { 20,25,27,30,28,35,37,38};
        int[] expense = {22, 27, 29, 28, 26, 30, 33, 34 };
        int[] sample = {22, 27, 29, 28, 26, 30, 33, 34};

        // Creating an  XYSeries for Income
        XYSeries incomeSeries = new XYSeries("Income");
        // Creating an  XYSeries for Expense
        XYSeries expenseSeries = new XYSeries("Expense");
     // Creating an  XYSeries for Expense
        XYSeries sampleseries = new XYSeries("Sample");
        // Adding data to Income and Expense Series
        for(int i=0;i<x.length;i++){
            incomeSeries.add(i,income[i]);
            expenseSeries.add(i,expense[i]);
            sampleseries.add(i,sample[i]);
        }

        // Creating a dataset to hold each series
        XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
        // Adding Income Series to the dataset
        dataset.addSeries(incomeSeries);
        // Adding Expense Series to dataset
        dataset.addSeries(expenseSeries);
        // Adding Expense Series to dataset
        dataset.addSeries(sampleseries);

        // Creating XYSeriesRenderer to customize incomeSeries
        XYSeriesRenderer incomeRenderer = new XYSeriesRenderer();
        incomeRenderer.setColor(Color.rgb(130, 130, 230));
        incomeRenderer.setFillPoints(true);
        incomeRenderer.setLineWidth(2);
        incomeRenderer.setChartValuesTextAlign(Align.CENTER);
        incomeRenderer.setChartValuesTextSize(18);
        incomeRenderer.setDisplayChartValues(true);

        // Creating XYSeriesRenderer to customize expenseSeries
        XYSeriesRenderer expenseRenderer = new XYSeriesRenderer();
        expenseRenderer.setColor(Color.rgb(220, 80, 80));
        expenseRenderer.setFillPoints(true);
        expenseRenderer.setLineWidth(2);
        expenseRenderer.setChartValuesTextAlign(Align.CENTER);
        expenseRenderer.setChartValuesTextSize(18);
        expenseRenderer.setDisplayChartValues(true);

     // Creating XYSeriesRenderer to customize expenseSeries
        XYSeriesRenderer samplseries = new XYSeriesRenderer();
        samplseries.setColor(Color.rgb(120, 40, 40));
        samplseries.setFillPoints(true);
        samplseries.setLineWidth(2);
        samplseries.setChartValuesTextAlign(Align.CENTER);
        samplseries.setChartValuesTextSize(18);
        samplseries.setDisplayChartValues(true);


        // Creating a XYMultipleSeriesRenderer to customize the whole chart
        XYMultipleSeriesRenderer multiRenderer = new XYMultipleSeriesRenderer();
        multiRenderer.setMargins(new int[]{30,50,60,0});
        multiRenderer.setXRoundedLabels(true);
        multiRenderer.setLegendTextSize(24);
        multiRenderer.setZoomRate(0.2f); 
        multiRenderer.setZoomEnabled(false, false); 
        multiRenderer.setBarSpacing(0.3f); 
        multiRenderer.setXAxisMin(-1); 
        multiRenderer.setXAxisMax(5);
        multiRenderer.setYAxisMin(0);
        multiRenderer.setYAxisMax(50);
        multiRenderer.setAxisTitleTextSize(20); 
        multiRenderer.setAxesColor(Color.BLACK); 
        multiRenderer.setGridColor(Color.GRAY); 
        multiRenderer.setShowGridX(true); 
        multiRenderer.setXLabels(0);

        multiRenderer.setPanLimits(new double[] { -1, x.length, 0, x.length});

        multiRenderer.setLabelsColor(Color.BLACK); 
        multiRenderer.setLabelsTextSize(20);  

        multiRenderer.setXLabelsColor(Color.BLACK); 
        multiRenderer.setXTitle("Tests"); 
        multiRenderer.setYLabelsAlign(Align.RIGHT);
        multiRenderer.setYLabelsColor(0, Color.BLACK);
        multiRenderer.setYTitle("Scores");

        for(int i=0; i< x.length;i++){
            multiRenderer.addXTextLabel(i, mMonth[i]);
        }

        // Adding incomeRenderer and expenseRenderer to multipleRenderer
        // Note: The order of adding dataseries to dataset and renderers to multipleRenderer
        // should be same
        multiRenderer.addSeriesRenderer(incomeRenderer);
        multiRenderer.addSeriesRenderer(expenseRenderer);
        multiRenderer.addSeriesRenderer(samplseries);

        // Creating an intent to plot bar chart using dataset and multipleRenderer
        Intent intent = ChartFactory.getBarChartIntent(getBaseContext(), dataset, multiRenderer, Type.DEFAULT);

        // Start Activity
        startActivity(intent);

    }