Pepes Permission klass

gistfile1.txt

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.content.ContextCompat;
import android.util.Log;

// Pepes permission class

public class Permissions extends Fragment {

    public static final String[] PERMISSIONS = {
            Manifest.permission.WRITE_EXTERNAL_STORAGE,
            Manifest.permission.READ_EXTERNAL_STORAGE
    };

        private static final String TAG = "PermissionsFragment";

        private Callback mCallback;
        private String[] mPermissions;
        private int      mRequestPermissions;

        public static Permissions start(FragmentManager manager, final int requestPermissions, String... permissions) {
            Permissions headlessFrag = (Permissions) manager
                    .findFragmentByTag(TAG);

                headlessFrag = new Permissions();

                Bundle bundle = new Bundle();
                bundle.putStringArray("permissions", permissions);
                bundle.putInt("RequestPermissions", requestPermissions);
                headlessFrag.setArguments(bundle);

                manager.beginTransaction()
                        .add(headlessFrag, TAG)
                        .commit();



            return headlessFrag;
        }

        @Override
        public void onAttach(final Context context) {

            super.onAttach(context);
            if (context instanceof Callback) {
                mCallback = (Callback) context;
                Log.d(TAG, "onAttach: " + mCallback);
            } else if (getParentFragment() instanceof Callback) {
                mCallback = (Callback)getParentFragment();
            }
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setRetainInstance(true);

            mPermissions = getArguments().getStringArray("permissions");
            mRequestPermissions = getArguments().getInt("RequestPermissions");
            checkPermissions(mPermissions);
        }


        @Override
        public void onDetach() {
            super.onDetach();
            mCallback = null;
        }

        public void checkPermissions(final String[] permissions) {
            mPermissions = permissions;

            if (!hasPermissions(permissions)) {
                if (shouldShowRequestPermissionRationale(permissions)) {
                    mCallback.showExplanationDialog();
                } else {
                    requestPermissions();
                }
            } else {
                mCallback.onPermissionGranted();
            }
        }

        public void requestPermissions() {
            requestPermissions(mPermissions, mRequestPermissions);
        }

        public boolean hasPermissions(String... permissions) {
            for (String permission : permissions) {
                if (ContextCompat.checkSelfPermission(getContext(), permission) != PackageManager.PERMISSION_GRANTED) {
                    return false;
                }
            }

            return true;
        }

        public boolean shouldShowRequestPermissionRationale(String... permissions) {
            for (String permission : permissions) {
                if (shouldShowRequestPermissionRationale(permission)) {
                    return true;
                }
            }

            return false;
        }

        @Override
        public void onRequestPermissionsResult(final int requestCode, @NonNull final String[] permissions, @NonNull final int[] grantResults) {
            if (mRequestPermissions == requestCode) {
                if (checkPermissionsResult(grantResults)) {
                    mCallback.onPermissionGranted();
                } else {
                    mCallback.onPermissionDenied();
                }
            }
        }

        private boolean checkPermissionsResult(int[] grantResults) {
            for (int result : grantResults) {
                if (result != PackageManager.PERMISSION_GRANTED) {
                    return false;
                }
            }

            return true;
        }

        public interface Callback {
            void onPermissionGranted();

            void showExplanationDialog();

            void onPermissionDenied();

        }
    }