BasePermissionRequest.java

private HashMap<String, Integer> generatePermissionHashTab(String[] permissions) {
        HashMap<String, Integer> permissionsHashTab = new HashMap<>();
        for (String p : permissions) {
            permissionsHashTab.put(p, PackageManager.PERMISSION_DENIED);
        }
        return permissionsHashTab;
    }

    protected void checkPermissions(@NonNull String[] permissions, int requestCode, IPermissionCallback callback) {

        HashMap<String, Integer> permResults = generatePermissionHashTab(permissions);
        ArrayList<String> permissionsForRequest = new ArrayList<String>();

        for (String permission : permissions) {

            if (ContextCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {
                permResults.put(permission, PackageManager.PERMISSION_DENIED);
            } else {
                permResults.put(permission, PackageManager.PERMISSION_GRANTED);
            }

            if (ActivityCompat.shouldShowRequestPermissionRationale(this, permission)) {
                showSnack("Permission Needed"); // or do something
            } else {
                permissionsForRequest.add(permission);
            }
        }

        if (permissionsForRequest.size() >= 0) {
            String[] permissionsArray = permissionsForRequest.toArray(new String[permissionsForRequest.size()]);
            permissionCallbacks.put(requestCode, new Pair<>(permResults, callback));

            ActivityCompat.requestPermissions(this, permissionsArray, requestCode);

        } else {
            callback.onPermissionRequestCallBack(permResults);
        }
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        IPermissionCallback callback = permissionCallbacks.get(requestCode).second;
        HashMap<String, Integer> results = permissionCallbacks.get(requestCode).first;

        for (int i = 0; i < permissions.length; i++) {
            String s = permissions[i];
            int v = grantResults[i];
            results.put(s, v);
        }
        callback.onPermissionRequestCallBack(results);
    }