PermissionsFragment.java

package org.osmdroid.intro;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.design.widget.Snackbar;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import org.osmdroid.R;
import org.osmdroid.config.Configuration;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * created on 1/5/2017.
 *
 * @author Alex O'Ree
 */
public class PermissionsFragment extends Fragment implements View.OnClickListener {

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

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.intro_permissions, container,false);
        if (Build.VERSION.SDK_INT >= 23 && needsPermissions()) {
            v.findViewById(R.id.askPermissions).setOnClickListener(this);
            v.findViewById(R.id.askPermissions).setVisibility(View.VISIBLE);
        } else {
            v.findViewById(R.id.askPermissions).setVisibility(View.GONE);
        }

        return v;
    }


    @Override
    public void onClick(View v) {
        if (Build.VERSION.SDK_INT >= 23) {
            checkPermissions();
        } else {
            Configuration.getInstance().load(getContext(), PreferenceManager.getDefaultSharedPreferences(getContext()));
        }
    }



    // START PERMISSION CHECK
    final private int REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS = 124;

    private boolean needsPermissions() {

            List<String> permissions = new ArrayList<>();
            if (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                permissions.add(Manifest.permission.ACCESS_FINE_LOCATION);
            }
            if (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                permissions.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);

            }
            if (permissions.isEmpty()) {
                return false;
            } // else: We already have permissions, so handle as normal
        return true;

    }
    private void checkPermissions() {
        List<String> permissions = new ArrayList<>();
        String message = "osmdroid permissions:";
        if (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            permissions.add(Manifest.permission.ACCESS_FINE_LOCATION);
            message += "\nLocation to show user location.";
        }
        if (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            permissions.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
            message += "\nStorage access to store map tiles.";
        }
        if (!permissions.isEmpty()) {
            //Toast.makeText(getContext(), message, Toast.LENGTH_LONG).show();
            String[] params = permissions.toArray(new String[permissions.size()]);
            requestPermissions(params, REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS);
        } // else: We already have permissions, so handle as normal
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS: {
                Map<String, Integer> perms = new HashMap<>();
                // Initial
                perms.put(Manifest.permission.ACCESS_FINE_LOCATION, PackageManager.PERMISSION_GRANTED);
                perms.put(Manifest.permission.WRITE_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
                // Fill with results
                for (int i = 0; i < permissions.length; i++)
                    perms.put(permissions[i], grantResults[i]);
                // Check for ACCESS_FINE_LOCATION and WRITE_EXTERNAL_STORAGE
                Boolean location = perms.get(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED;
                Boolean storage = perms.get(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
                if (location && storage) {
                    // All Permissions Granted
                    //Toast.makeText(getContext(), "All permissions granted", Toast.LENGTH_SHORT).show();
                    Snackbar.make(getView(), "All permissions granted", Snackbar.LENGTH_LONG).show();
                } else if (location) {
                    Toast.makeText(getContext(), "Storage permission is required to store map tiles to reduce data usage and for offline usage.", Toast.LENGTH_LONG).show();
                } else if (storage) {
                    Toast.makeText(getContext(), "Location permission is required to show the user's location on map.", Toast.LENGTH_LONG).show();
                } else { // !location && !storage case
                    // Permission Denied
                    Toast.makeText(getContext(), "Storage permission is required to store map tiles to reduce data usage and for offline usage." +
                        "\nLocation permission is required to show the user's location on map.", Toast.LENGTH_SHORT).show();
                }
                Configuration.getInstance().load(getContext(), PreferenceManager.getDefaultSharedPreferences(getContext()));
            }
            break;
            default:
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }
}