PermissionsUtil.java

package com.exsoft.musarium.util;

import android.app.Activity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AlertDialog;

import com.exsoft.musarium.R;

/**
 * Helper class to clear Marshmallow permissions handling code a little bit.
 * Still requests results should be handled in appropriate methods:
 * {@link android.support.v4.app.FragmentActivity#onRequestPermissionsResult(int, String[], int[])}
 * {@link android.support.v4.app.Fragment#onRequestPermissionsResult(int, String[], int[])}
 * 
 * Created by Dmitriy Gorodnytskiy on 15-Nov-15.
 */
public abstract class PermissionsUtil {
    public static boolean check(@NonNull Context context, @NonNull String permission) {
        return ActivityCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED;
    }

    public static void request(@NonNull Activity activity, @NonNull String permission, int requestCode) {
        ActivityCompat.requestPermissions(activity, new String[]{ permission }, requestCode);
    }

    public static boolean beg(@NonNull Activity activity, @NonNull String permission) {
        return ActivityCompat.shouldShowRequestPermissionRationale(activity, permission);
    }

    public static void explain(@NonNull Context context, @NonNull String explanation) {
        explain(context, explanation, defaultListener);
    }

    /**
     * Shows default explaining dialog to ask user to grant us permission.
     * External util method, relates on app resources.
     * @param context
     * @param explanation string with explaining text
     * @param okListener handler for positive result
     */
    public static void explain(@NonNull Context context, @NonNull String explanation,
                               @NonNull DialogInterface.OnClickListener okListener) {

        AlertDialog.Builder b = new AlertDialog.Builder(context);
        b.setIcon(R.drawable.ic_alert_circle_white_36dp);
        b.setTitle(R.string.permission_request);
        b.setMessage(explanation);
        b.setPositiveButton(R.string.ok, okListener);
        b.setNegativeButton(R.string.cancel, defaultListener);
        b.create().show();
    }

    private static DialogInterface.OnClickListener defaultListener = new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }
    };
}