tlp-main/apps/android_camera/app/src/main/java/org/apache/tvm/android/androidcamerademo/MainActivity.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.tvm.android.androidcamerademo;

import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

public class MainActivity extends AppCompatActivity implements
        ActivityCompat.OnRequestPermissionsResultCallback {

    private static final int PERMISSIONS_REQUEST_CODE = 1;

    private String[] getRequiredPermissions() {
        try {
            PackageInfo info = getPackageManager()
                    .getPackageInfo(getPackageName(), PackageManager.GET_PERMISSIONS);
            String[] ps = info.requestedPermissions;
            if (ps != null && ps.length > 0) {
                return ps;
            } else {
                return new String[0];
            }
        } catch (Exception e) {
            return new String[0];
        }
    }

    private boolean allPermissionsGranted() {
        for (String permission : getRequiredPermissions()) {
            if (ContextCompat.checkSelfPermission(this, permission)
                    != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (!allPermissionsGranted()) {
            requestPermissions(getRequiredPermissions(), PERMISSIONS_REQUEST_CODE);
            return;
        }
        startFragment();
    }

    private void startFragment() {
        getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.container, Camera2BasicFragment.newInstance())
                .commit();
    }

    @Override
    public void onRequestPermissionsResult(
            int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (allPermissionsGranted()) {
            startFragment();
        } else {
            Toast.makeText(this, "Required permissions are not granted. App may not run", Toast.LENGTH_SHORT).show();
            finish();
        }
    }
}
