DemoBase.java

package com.sp.mpandroidchart;

import android.Manifest;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.graphics.Typeface;
import android.os.Bundle;
import android.support.annotation.Nullable;

//import com.google.android.material.snackbar.Snackbar;


import android.view.View;
import android.widget.Toast;

import com.github.mikephil.charting.charts.Chart;
import com.sp.mpandroidchart.R;

/**
 * Base class of all Activities of the Demo Application.
 *
 * @author Philipp Jahoda
 */
public abstract class DemoBase extends Activity  {

    protected final String[] months = new String[] {
            "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Okt", "Nov", "Dec"
    };

    protected final String[] parties = new String[] {
            "Party A", "Party B", "Party C", "Party D", "Party E", "Party F", "Party G", "Party H",
            "Party I", "Party J", "Party K", "Party L", "Party M", "Party N", "Party O", "Party P",
            "Party Q", "Party R", "Party S", "Party T", "Party U", "Party V", "Party W", "Party X",
            "Party Y", "Party Z"
    };

    private static final int PERMISSION_STORAGE = 0;

    protected Typeface tfRegular;
    protected Typeface tfLight;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        tfRegular = Typeface.createFromAsset(getAssets(), "OpenSans-Regular.ttf");
        tfLight = Typeface.createFromAsset(getAssets(), "OpenSans-Light.ttf");
    }

    protected float getRandom(float range, float start) {
        return (float) (Math.random() * range) + start;
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        overridePendingTransition(R.anim.move_left_in_activity, R.anim.move_right_out_activity);
    }

//    @Override
//    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
//        if (requestCode == PERMISSION_STORAGE) {
//            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//                saveToGallery();
//            } else {
//                Toast.makeText(getApplicationContext(), "Saving FAILED!", Toast.LENGTH_SHORT)
//                        .show();
//            }
//        }
//    }

//    protected void requestStoragePermission(View view) {
//        if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
//            Snackbar.make(view, "Write permission is required to save image to gallery", Snackbar.LENGTH_INDEFINITE)
//                    .setAction(android.R.string.ok, new View.OnClickListener() {
//                        @Override
//                        public void onClick(View v) {
//                            ActivityCompat.requestPermissions(DemoBase.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, PERMISSION_STORAGE);
//                        }
//                    }).show();
//        } else {
//            Toast.makeText(getApplicationContext(), "Permission Required!", Toast.LENGTH_SHORT)
//                    .show();
//            ActivityCompat.requestPermissions(DemoBase.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, PERMISSION_STORAGE);
//        }
//    }

    protected void saveToGallery(Chart chart, String name) {
        if (chart.saveToGallery(name + "_" + System.currentTimeMillis(), 70))
            Toast.makeText(getApplicationContext(), "Saving SUCCESSFUL!",
                    Toast.LENGTH_SHORT).show();
        else
            Toast.makeText(getApplicationContext(), "Saving FAILED!", Toast.LENGTH_SHORT)
                    .show();
    }

    protected abstract void saveToGallery();
}