Hallo world

CameraFragment.java

package com.example.jlapa.mvdm;


import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.TextureView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;

import com.google.firebase.auth.FirebaseAuth;

import java.io.IOException;
import java.util.List;

import static com.example.jlapa.mvdm.R.*;


/**
* A simple {@link Fragment} subclass.
*/
public class CameraFragment extends Fragment implements SurfaceHolder.Callback{
    Camera camera;

    Camera.PictureCallback jpegCallback;

    SurfaceView mSurfaceView;
    SurfaceHolder mSurfaceHolder;

    final int CAMERA_REQUEST_CODE = 1;

    public static CameraFragment newInstance() {
        CameraFragment fragment = new CameraFragment();
        return fragment;
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(layout.fragment_camera, container, false);

        mSurfaceView = view.findViewById(R.id.surfaceView);
        mSurfaceHolder = mSurfaceView.getHolder();

        if (ActivityCompat.checkSelfPermission(getContext(), android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(getActivity(), new String[]{android.Manifest.permission.CAMERA}, CAMERA_REQUEST_CODE);
        }else{
            mSurfaceHolder.addCallback(this);
            mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);


        }

        Button mLogout = view.findViewById(R.id.logout);
        Button mCapture = view.findViewById(R.id.capture);
        mLogout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Logout();
            }
        });
        mCapture.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                captureImage();
            }
        });

        jpegCallback = new Camera.PictureCallback(){
            @Override
            public void onPictureTaken(byte[] bytes, Camera camera) {
                Intent intent = new Intent(getActivity(), ShowCaptureActivity.class);
                intent.putExtra("capture",bytes);
                startActivity(intent);
                return;
            }
        };



        return view;





    }

    private void captureImage() {
        camera.takePicture(null, null, jpegCallback);
    }


    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
        camera = Camera.open();
        Camera.Parameters parameters;
        parameters = camera.getParameters();

        camera.setDisplayOrientation(90);
        parameters.setPreviewFrameRate(30);
        parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);


        Camera.Size bestSize = null;
        List<Camera.Size> sizeList = camera.getParameters().getSupportedPreviewSizes();
        bestSize = sizeList.get(0);
        for (int i = 1; i < sizeList.size(); i++){
            if ((sizeList.get(i).width * sizeList.get(i).height)>(bestSize.width * bestSize.height)){
                bestSize = sizeList.get(i);
            }
        }
        parameters.setPreviewSize(bestSize.width, bestSize.height);
        camera.setParameters(parameters);



        try {
            camera.setPreviewDisplay(surfaceHolder);
        } catch (IOException e) {
            e.printStackTrace();
        }

        camera.startPreview();



    }
    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

    }
    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode){
            case CAMERA_REQUEST_CODE:{
                if (grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                    mSurfaceHolder.addCallback(this);
                    mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);


                }
                else {
                    Toast.makeText(getContext(), "Please provide the permission", Toast.LENGTH_LONG).show();
                }
                break;
            }
        }
    }
    private void Logout() {
        FirebaseAuth.getInstance().signOut();
        Intent intent = new Intent(getContext(), WelcomeActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(intent);
        return;
    }
}



FragmentCamera.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".CameraFragment">

    <!-- TODO: Update blank fragment layout -->

    <SurfaceView
        android:id="@+id/surfaceView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />



    <Button

        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Logout"
        android:id="@+id/logout"/>

        <Button

            android:layout_gravity="bottom"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="capture"
            android:id="@+id/capture"/>




</FrameLayout>

package com.example.jlapa.mvdm;

import android.content.Intent;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

public class MainActivity extends AppCompatActivity {

    private Toolbar mToolbar;
    private FirebaseAuth mAuth;

    private ViewPager myViewPager;
    private TabLayout myTabLayout;
    private TabsPagerAdapter myTabsPagerAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mAuth = FirebaseAuth.getInstance();

        //Tabs for MainActivity
        myViewPager = (ViewPager) findViewById(R.id.main_tabs_pager);
        myTabsPagerAdapter = new TabsPagerAdapter(getSupportFragmentManager());
        myViewPager.setAdapter(myTabsPagerAdapter);
        myTabLayout = (TabLayout) findViewById(R.id.main_tabs);
        myTabLayout.setupWithViewPager(myViewPager);


        mToolbar = (Toolbar) findViewById(R.id.main_page_toolbar);
        setSupportActionBar(mToolbar);
        getSupportActionBar().setTitle("mvdm");
    }

    @Override
    protected void onStart() {
        super.onStart();
        FirebaseUser currentUser = mAuth.getCurrentUser();
        if(currentUser == null){
            LogOutUser();
        }
    }

    private void LogOutUser() {
        Intent startPageIntent = new Intent(MainActivity.this, StartPageActivity.class);
        startPageIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(startPageIntent);
        finish();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        super.onOptionsItemSelected(item);

        if (item.getItemId() == R.id.main_logout_button){
            mAuth.signOut();
            LogOutUser();
        }

        if(item.getItemId() == R.id.main_account_settings_button){
            Intent settingsIntent = new Intent(MainActivity.this, SettingsActivity.class);
            startActivity(settingsIntent);
        }

        if (item.getItemId() == R.id.main_all_users_button){
            Intent allUsersIntent = new Intent(MainActivity.this, AllUsersActivity.class);
            startActivity(allUsersIntent);
        }

        return true;
    }
}