PermissionManager.java

package org.torproject.android.ui.hiddenservices.permissions;


import android.Manifest;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.PowerManager;
import android.provider.Settings;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.view.View;

import org.torproject.android.R;

public class PermissionManager {
    public static int VERY_LONG_LENGTH = 6000;

    public static boolean isLollipopOrHigher() {
        return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
    }

    @SuppressLint("NewApi")
    public static boolean hasExternalWritePermission(Context context) {
        return (context.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED);
    }

    public static void requestExternalWritePermissions(FragmentActivity activity, int action) {
        final int mAction = action;
        final FragmentActivity mActivity = activity;

        if (ActivityCompat.shouldShowRequestPermissionRationale
                (mActivity, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            Snackbar.make(mActivity.findViewById(android.R.id.content),
                    R.string.please_grant_permissions_for_external_storage,
                    Snackbar.LENGTH_INDEFINITE).setAction(R.string.activate,
                    new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            ActivityCompat.requestPermissions(mActivity,
                                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                                    mAction);
                        }
                    }).show();
        } else {
            ActivityCompat.requestPermissions(mActivity,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                    mAction);
        }
    }

    @TargetApi(Build.VERSION_CODES.M)
    public static void requestBatteryPermmssions(FragmentActivity activity, Context context) {
        final Context mContext = context;
        final String packageName = mContext.getPackageName();
        PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);

        if (pm.isIgnoringBatteryOptimizations(packageName))
            return;

        Snackbar.make(activity.findViewById(android.R.id.content),
                R.string.consider_disable_battery_optimizations,
                VERY_LONG_LENGTH).setAction(R.string.disable,
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent();
                        intent.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
                        intent.setData(Uri.parse("package:" + packageName));
                        mContext.startActivity(intent);
                    }
                }).show();
    }

    @TargetApi(Build.VERSION_CODES.M)
    public static void requestDropBatteryPermmssions(FragmentActivity activity, Context context) {
        final Context mContext = context;

        final String packageName = context.getPackageName();
        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);

        if (!pm.isIgnoringBatteryOptimizations(packageName))
            return;

        Snackbar.make(activity.findViewById(android.R.id.content),
                R.string.consider_enable_battery_optimizations,
                VERY_LONG_LENGTH).setAction(R.string.enable,
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent();
                        intent.setAction(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS);
                        mContext.startActivity(intent);
                    }
                }).show();
    }
}