FilledLineActivity.java

package com.xxmassdeveloper.mpchartexample;

import android.content.Intent;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.WindowManager;

import com.github.mikephil.charting.charts.LineChart;
import com.github.mikephil.charting.components.Legend;
import com.github.mikephil.charting.components.XAxis;
import com.github.mikephil.charting.components.YAxis;
import com.github.mikephil.charting.data.Entry;
import com.github.mikephil.charting.data.LineData;
import com.github.mikephil.charting.data.LineDataSet;
import com.github.mikephil.charting.formatter.IFillFormatter;
import com.github.mikephil.charting.interfaces.dataprovider.LineDataProvider;
import com.github.mikephil.charting.interfaces.datasets.ILineDataSet;
import com.xxmassdeveloper.mpchartexample.notimportant.DemoBase;

import java.util.ArrayList;

/**
 * This works by inverting the background and desired "fill" color. First, we draw the fill color
 * that we want between the lines as the actual background of the chart. Then, we fill the area
 * above the highest line and the area under the lowest line with the desired background color.
 *
 * This method makes it look like we filled the area between the lines, but really we are filling
 * the area OUTSIDE the lines!
 */
@SuppressWarnings("SameParameterValue")
public class FilledLineActivity extends DemoBase {

    private LineChart chart;
    private final int fillColor = Color.argb(150, 51, 181, 229);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_linechart_noseekbar);

        setTitle("FilledLineActivity");

        chart = findViewById(R.id.chart1);
        chart.setBackgroundColor(Color.WHITE);
        chart.setGridBackgroundColor(fillColor);
        chart.setDrawGridBackground(true);

        chart.setDrawBorders(true);

        // no description text
        chart.getDescription().setEnabled(false);

        // if disabled, scaling can be done on x- and y-axis separately
        chart.setPinchZoom(false);

        Legend l = chart.getLegend();
        l.setEnabled(false);

        XAxis xAxis = chart.getXAxis();
        xAxis.setEnabled(false);

        YAxis leftAxis = chart.getAxisLeft();
        leftAxis.setAxisMaximum(900f);
        leftAxis.setAxisMinimum(-250f);
        leftAxis.setDrawAxisLine(false);
        leftAxis.setDrawZeroLine(false);
        leftAxis.setDrawGridLines(false);

        chart.getAxisRight().setEnabled(false);

        // add data
        setData(100, 60);

        chart.invalidate();
    }

    private void setData(int count, float range) {

        ArrayList<Entry> values1 = new ArrayList<>();

        for (int i = 0; i < count; i++) {
            float val = (float) (Math.random() * range) + 50;
            values1.add(new Entry(i, val));
        }

        ArrayList<Entry> values2 = new ArrayList<>();

        for (int i = 0; i < count; i++) {
            float val = (float) (Math.random() * range) + 450;
            values2.add(new Entry(i, val));
        }

        LineDataSet set1, set2;

        if (chart.getData() != null &&
                chart.getData().getDataSetCount() > 0) {
            set1 = (LineDataSet) chart.getData().getDataSetByIndex(0);
            set2 = (LineDataSet) chart.getData().getDataSetByIndex(1);
            set1.setValues(values1);
            set2.setValues(values2);
            chart.getData().notifyDataChanged();
            chart.notifyDataSetChanged();
        } else {
            // create a dataset and give it a type
            set1 = new LineDataSet(values1, "DataSet 1");

            set1.setAxisDependency(YAxis.AxisDependency.LEFT);
            set1.setColor(Color.rgb(255, 241, 46));
            set1.setDrawCircles(false);
            set1.setLineWidth(2f);
            set1.setCircleRadius(3f);
            set1.setFillAlpha(255);
            set1.setDrawFilled(true);
            set1.setFillColor(Color.WHITE);
            set1.setHighLightColor(Color.rgb(244, 117, 117));
            set1.setDrawCircleHole(false);
            set1.setFillFormatter(new IFillFormatter() {
                @Override
                public float getFillLinePosition(ILineDataSet dataSet, LineDataProvider dataProvider) {
                    // change the return value here to better understand the effect
                    // return 0;
                    return chart.getAxisLeft().getAxisMinimum();
                }
            });

            // create a dataset and give it a type
            set2 = new LineDataSet(values2, "DataSet 2");
            set2.setAxisDependency(YAxis.AxisDependency.LEFT);
            set2.setColor(Color.rgb(255, 241, 46));
            set2.setDrawCircles(false);
            set2.setLineWidth(2f);
            set2.setCircleRadius(3f);
            set2.setFillAlpha(255);
            set2.setDrawFilled(true);
            set2.setFillColor(Color.WHITE);
            set2.setDrawCircleHole(false);
            set2.setHighLightColor(Color.rgb(244, 117, 117));
            set2.setFillFormatter(new IFillFormatter() {
                @Override
                public float getFillLinePosition(ILineDataSet dataSet, LineDataProvider dataProvider) {
                    // change the return value here to better understand the effect
                    // return 600;
                    return chart.getAxisLeft().getAxisMaximum();
                }
            });

            ArrayList<ILineDataSet> dataSets = new ArrayList<>();
            dataSets.add(set1); // add the data sets
            dataSets.add(set2);

            // create a data object with the data sets
            LineData data = new LineData(dataSets);
            data.setDrawValues(false);

            // set data
            chart.setData(data);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.only_github, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {
            case R.id.viewGithub: {
                Intent i = new Intent(Intent.ACTION_VIEW);
                i.setData(Uri.parse("https://github.com/PhilJay/MPAndroidChart/blob/master/MPChartExample/src/com/xxmassdeveloper/mpchartexample/FilledLineActivity.java"));
                startActivity(i);
                break;
            }
        }

        return true;
    }

    @Override
    public void saveToGallery() { /* Intentionally left empty */ }
}