'안드로이드'에 해당되는 글 453건

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">
    <!-- As the main content view, the view below consumes the entire
         space available using match_parent in both dimensions. Note that
         this child does not specify android:layout_gravity attribute. -->
    <FrameLayout
        android:id="@+id/content"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- android:layout_gravity="start" tells DrawerLayout to treat
         this as a sliding drawer on the starting side, which is
         left for left-to-right locales. The navigation view extends
         the full height of the container. A
         solid background is used for contrast with the content view.
         android:fitsSystemWindows="true" tells the system to have
         DrawerLayout span the full height of the screen, including the
         system status bar on Lollipop+ versions of the plaform. -->
    <com.google.android.material.navigation.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="#333"
        android:fitsSystemWindows="true"
        app:menu="@menu/navigation_view_content"
        app:itemIconTint="@color/emerald_translucent"
        app:itemTextColor="@color/emerald_text"
        app:itemBackground="@color/sand_default"
        app:itemTextAppearance="@style/TextMediumStyle" />

</androidx.drawerlayout.widget.DrawerLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">

    <!-- 1. 콘텐츠 영역-->
    <include
        layout="@layout/content_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- 2. 왼쪽 사이드 메뉴-->
    <include layout="@layout/nav_header_main" />   

</androidx.drawerlayout.widget.DrawerLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/navi_view"
    android:layout_width="280dp"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:background="@color/colorWhite"
    android:orientation="vertical"
    android:theme="@style/ThemeOverlay.AppCompat.Dark"
    >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#ededed"
        android:orientation="vertical"
        android:padding="10dp">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/img_info" />

            <ImageView
                android:id="@+id/btn_close"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="right|top"
                android:onClick="NaviItemSelected"
                android:src="@drawable/ic_close" />

        </FrameLayout>
    </LinearLayout>

</LinearLayout> 

public class MainActivity extends AppCompatActivity {
    Context context;
    DrawerLayout drawer_layout;
    ActionBarDrawerToggle toggle;
    //NavigationView navigationView;

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

        drawer_layout = findViewById(R.id.drawer_layout);
        toggle = new ActionBarDrawerToggle(
                this, drawer_layout, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer_layout.addDrawerListener(toggle);
        toggle.syncState();

        // com.google.android.material.navigation.NavigationView 를 구현했을 때 처리 (구현 안해도 됨)
        //navigationView = findViewById(R.id.nav_view);
        //navigationView.setItemIconTintList(null);
        //navigationView.setNavigationItemSelectedListener(this);

        // content_main.xml 에서 지정한 버튼을 클릭하면 drawer 가 오픈되도록 함.
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               drawer_layout.openDrawer(GravityCompat.START);
            }
        });

    }

    // drawer 오픈된 상태에서 실행할 때 동작 이벤트 처리
    public void NaviItemSelected(View view) {
        switch (view.getId()) {
            case R.id.btn_close:
                drawer_layout.closeDrawer(Gravity.LEFT, true);
                break;
            case R.id.btn_logout:
                backPressHandler.appShutdown();
                break;
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.android.material:material:1.1.0'
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        app:tabTextColor="@color/colorDarkGray"
        app:tabSelectedTextColor="@color/colorWhite"
        app:layout_collapseMode="pin"
        app:tabGravity="fill"
        app:tabBackground="@drawable/tab_color_selector"
        app:layout_constraintBottom_toTopOf="@+id/vp_layout"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Monday" />

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Tuesday" />

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Wednesday" />
    </com.google.android.material.tabs.TabLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/vp_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tab_layout">

        <androidx.viewpager.widget.ViewPager
            android:id="@+id/viewPager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="프레그먼트1"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout> 

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="프레그먼트2"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="프레그먼트3"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class Fragment1 extends Fragment {
    private View view;

    private String parameter;

    public static Fragment1 newInstance(String parameter){
        Fragment1 fragment1 = new Fragment1();
        Bundle args = new Bundle(); //Use bundle to pass data
        args.putString("parameter", parameter);
        instance.setArguments(args); //Finally set argument bundle to fragment
        return instance;
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            parameter = getArguments().getString("parameter");
            Log.e("FragParameter", parameter);
        }
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_1,container,false);
        return view;
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
    }
}

public class Fragment2 extends Fragment {
    private View view;

    public static Fragment2 newInstance(){
        Fragment2 fragment2 = new Fragment2();
        return fragment2;
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_2,container,false);
        return view;
    }
} 

public class Fragment3 extends Fragment {
    private View view;

    public static Fragment3 newInstance(){
        Fragment3 fragment3 = new Fragment3();
        return fragment3;
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_3,container,false);
        return view;
    }
} 

import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;

import java.util.ArrayList;
import java.util.List;

class ViewPagerAdapter extends FragmentPagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }

    public void addFrag(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragTitleList.add(title);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mFragTitleList.get(position);
    }
}

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.viewpager.widget.ViewPager;

import android.os.Bundle;

import com.google.android.material.tabs.TabLayout;

public class MainActivity extends AppCompatActivity {
    private ViewPager viewPager;
    private ViewPagerAdapter adapter;
    private TabLayout tabLayout;

    String code;

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

        code = getIntent().getExtras().getString("code");
        Log.e("MainActivityCode",code);

        Fragment frag1 = new Fragment1().newInstance(code);

        viewPager = findViewById(R.id.viewPager);
        tabLayout = findViewById(R.id.tab_layout);
        adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFrag(frag1, "Web");
        adapter.addFrag(new Fragment2(), "사랑");
        adapter.addFrag(new Fragment3(), "우정");
        viewPager.setAdapter(adapter);
        tabLayout.setupWithViewPager(viewPager);
    }
}

public class FirstFragment extends Fragment {
    // Store instance variables
    private String title;
    private int page;

    // newInstance constructor for creating fragment with arguments
    public static FirstFragment newInstance(int page, String title) {
        FirstFragment fragmentFirst = new FirstFragment();
        Bundle args = new Bundle();
        args.putInt("someInt", page);
        args.putString("someTitle", title);
        fragmentFirst.setArguments(args);
        return fragmentFirst;
    }

    // Store instance variables based on arguments passed
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        page = getArguments().getInt("someInt", 0);
        title = getArguments().getString("someTitle");
    }

    // Inflate the view for the fragment based on layout XML
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_first, container, false);
        TextView tvLabel = (TextView) view.findViewById(R.id.tvLabel);
        tvLabel.setText(page + " -- " + title);
        return view;
    }
} 

buildscript {
    ext.kotlin_version = '1.3.71'
    repositories {
        google()
        jcenter()
       
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.6.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

apply plugin: 'com.android.application'
// 코틀린 혼용 사용을 위해 추가
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.3"

    defaultConfig {
        applicationId "com.link2me.android.javakotlin"
        minSdkVersion 23
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version" // 코틀린 혼용 사용을 위해 추가
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'androidx.annotation:annotation:1.1.0'

    implementation 'com.google.android.material:material:1.0.0'
    implementation 'androidx.recyclerview:recyclerview:1.1.0'
    implementation 'androidx.cardview:cardview:1.0.0'
    implementation 'gun0912.ted:tedpermission:2.0.0'

    implementation 'com.squareup.retrofit2:retrofit:2.7.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.7.0'
    implementation 'com.squareup.okhttp3:logging-interceptor:4.4.0'
}

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

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:paddingLeft="@dimen/activity_horizontal_margin"
            android:paddingTop="@dimen/activity_vertical_margin"
            android:paddingRight="@dimen/activity_horizontal_margin"
            android:paddingBottom="@dimen/activity_vertical_margin">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="300dp"
                android:gravity="center"
                android:text="Login"
                android:textStyle="bold"
                android:textSize="45dp"
                android:fontFamily="cursive"
                android:textColor="@color/colorWhite"
                android:layout_marginTop="0dp"
                android:background="@drawable/logo"/>

            <com.google.android.material.textfield.TextInputLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="20dp"
                android:layout_marginRight="20dp">

                <com.google.android.material.textfield.TextInputEditText
                    android:id="@+id/et_id"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:background="@color/colorWhite"
                    android:autofillHints="@string/prompt_id"
                    android:hint="아이디"
                    android:selectAllOnFocus="true" />

            </com.google.android.material.textfield.TextInputLayout>

            <com.google.android.material.textfield.TextInputLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="10dp"
                android:layout_marginRight="20dp">

                <com.google.android.material.textfield.TextInputEditText
                    android:id="@+id/et_pw"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:autofillHints="@string/prompt_pw"
                    android:hint="비밀번호"
                    android:background="@color/colorWhite"
                    android:imeOptions="actionDone"
                    android:inputType="textPassword"
                    android:selectAllOnFocus="true" />

            </com.google.android.material.textfield.TextInputLayout>

            <com.google.android.material.button.MaterialButton
                android:id="@+id/btn_login"
                style="@style/Widget.AppCompat.Button.Borderless.Colored"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="50dp"
                android:layout_marginRight="20dp"
                android:padding="10dp"
                android:text="로그인"
                android:textColor="@color/colorWhite"
                android:textSize="16sp"
                android:textStyle="bold"
                app:backgroundTint="@color/colorMint"
                app:cornerRadius="20dp" />

        </LinearLayout>
    </FrameLayout>

</ScrollView>

public static String getDeviceId(Context context) {

    // 단말기의 ID 정보를 얻기 위해서는 READ_PHONE_STATE 권한이 필요
    String deviceId;

    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
        deviceId = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
    } else {
        final TelephonyManager mTelephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
        if (ActivityCompat.checkSelfPermission(context, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            //권한 없을 경우
            if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.READ_PHONE_STATE)) {
                // 사용자에게 해당 권한이 필요한 이유에 대해 설명
                Toast.makeText(context, "앱 실행을 위해서는 전화 관리 권한을 설정해야 합니다.", Toast.LENGTH_SHORT).show();
            }
            // 최초로 권한을 요청하는 경우
            ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_PHONE_STATE} , 2);
            return null;
        } else {
            Log.v("TAG","Permission is granted");
            if (mTelephony.getDeviceId() != null) {
                deviceId = mTelephony.getDeviceId();
            } else {
                deviceId = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
            }
        }
    }
    return deviceId;
}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case 2: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(getApplicationContext(), "Permission granted", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(getApplicationContext(), "Permission denied", Toast.LENGTH_SHORT).show();
            }
            return;
        }
    }
} 

//TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
String uID = Settings.Secure.getString(getApplicationContext().getContentResolver(), Settings.Secure.ANDROID_ID);

<?php
// 압축을 해제한 phpqrcode 폴더의 qrlib.php 파일을 include한다.
include_once "./phpqrcode/qrlib.php";
$qrContents = "00아파트 122동 703호";
$filePath = sha1($qrContents).".png";

if(!file_exists($filePath)) {
    $ecc = 'H'; // L, M, Q, H, This parameter specifies the error correction capability of QR.
    $pixel_Size = 10; // This specifies the pixel size of QR.
    $frame_Size = 10; // level 1-10
    QRcode::png($qrContents, $filePath, $ecc, $pixel_Size, $frame_Size);
    echo "파일이 정상적으로 생성되었습니다.";
    echo "<hr/>";
} else {
    echo "파일이 이미 생성되어 있습니다.\n파일을 지우고 다시 실행해 보세요.";
    echo "<hr/>";
}

echo "저장된 파일명 : ".$filePath;
echo "<hr/>";
echo "<center><img src='".$filePath."'/></center>"
?>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/btn_fileread"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:layout_gravity="center"
        android:text="File Read"
        android:textAllCaps="false"/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/linear_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#ffffff">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:id="@+id/popupTitle"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="3"
            android:gravity="center"
            android:text="읽은 파일 미리보기"
            android:textSize="18sp"
            android:textStyle="bold"
            android:background="@color/colorPrimary"/>

        <TextView
            android:id="@+id/popupSaveBtn"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="적용"
            android:textSize="18sp"
            android:textStyle="bold"
            android:background="#B5FFD5"/>

        <TextView
            android:id="@+id/popupCancelBtn"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:text="취소"
            android:textSize="18sp"
            android:textStyle="bold"
            android:background="#FFFF00"/>

    </LinearLayout>

    <ScrollView
        android:id="@+id/popupScrollView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#000000">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView
                android:id="@+id/popupText"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:ellipsize="start"
                android:gravity="left"
                android:textColor="#FFFFFF"
                android:textStyle="bold" />
        </LinearLayout>
    </ScrollView>

</LinearLayout>

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private static final String TAG = "MainActivity";
    Context mContext;

    Button popup_alert;
    String select_filePath;
    ScrollView pScrollView;
    View popupView;

    private static final int READ_REQUEST_CODE = 42;

    protected View mPopupView; // 팝업 뷰

    private void initView() {
       // 1. 특정 폴더에 있는 파일 읽어서 미리보기 화면에 보여주기
        popup_alert = findViewById(R.id.btn_fileread);
        popup_alert.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_fileread:
                popupView = view;
                showFileChooser();
                break;
        }
    }

    private void showFileChooser() {
        Intent intent;
        if (android.os.Build.MANUFACTURER.equalsIgnoreCase("samsung")) {
            intent = new Intent("com.sec.android.app.myfiles.PICK_DATA");
            intent.putExtra("CONTENT_TYPE", "*/*");
            intent.addCategory(Intent.CATEGORY_DEFAULT);
        } else {

            String[] mimeTypes =
                    {"application/msword", "application/vnd.openxmlformats-officedocument.wordprocessingml.document", // .doc & .docx
                            "application/vnd.ms-powerpoint", "application/vnd.openxmlformats-officedocument.presentationml.presentation", // .ppt & .pptx
                            "application/vnd.ms-excel", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", // .xls & .xlsx
                            "text/plain",
                            "application/pdf",
                            "application/zip", "application/vnd.android.package-archive"};

            intent = new Intent(Intent.ACTION_GET_CONTENT); // or ACTION_OPEN_DOCUMENT
            intent.setType("*/*");
            intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes);
            intent.addCategory(Intent.CATEGORY_OPENABLE);
            intent.putExtra(Intent.EXTRA_LOCAL_ONLY, true);
        }

        try {
            startActivityForResult(Intent.createChooser(intent, "Select a File"), READ_REQUEST_CODE);
        } catch (android.content.ActivityNotFoundException ex) {
            Toast.makeText(this, "Please install a File Manager.",Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
            case READ_REQUEST_CODE:
                if (resultCode == RESULT_OK) {
                    // Get the Uri of the selected file
                    Uri uri = data.getData();
                    select_filePath = getRealPathFromURI(uri); // 이 함수를 다른 걸로 대체하는게 공부
                    Log.e(TAG, "file_path = " + select_filePath);
                    if(select_filePath != null){
                        mPopupWindowShow(readFile(select_filePath));
                    }
                }
                break;
        }
        super.onActivityResult(requestCode, resultCode, data);
    }

    private String getRealPathFromURI(Uri uri) {
        String filePath = "";
        filePath = uri.getPath();
        //경로에 /storage가 들어가면 real file path로 판단
        if (filePath.startsWith("/storage"))
            return filePath;

        String wholeID = DocumentsContract.getDocumentId(uri);

        //wholeID는 파일명이 abc.zip이라면 /document/B5D7-1CE9:abc.zip와 같다.
        // Split at colon, use second item in the array
        String id = wholeID.split(":")[1];

        Log.e(TAG, "id = " + id);

        String[] column = { MediaStore.Files.FileColumns.DATA };

        //파일의 이름을 통해 where 조건식을 만든다.
        String sel = MediaStore.Files.FileColumns.DATA + " LIKE '%" + id + "%'";

        //External storage에 있는 파일의 DB를 접근하는 방법이다.
        Cursor cursor = getContentResolver().query(MediaStore.Files.getContentUri("external"),
                column, sel, null, null);

        int columnIndex = cursor.getColumnIndex(column[0]);

        if (cursor.moveToFirst()) {
            filePath = cursor.getString(columnIndex);
        }
        cursor.close();
        return filePath;
    }

    private String readFile(String filepath) {
        File fileEvents = new File(filepath);
        StringBuilder text = new StringBuilder();
        try {
            BufferedReader br = new BufferedReader(new FileReader(fileEvents));
            String line;
            while ((line = br.readLine()) != null) {
                text.append(line);
                text.append('\n');
            }
            br.close();
        } catch (IOException e) { }
        String result = text.toString();
        return result;
    }

    public void mPopupWindowShow(String url) {
        Display display = ((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
        Point point = new Point();
        display.getSize(point);
        int height = (int) (point.y * 0.8);
        int width = (int) (point.x * 0.9); // Display 사이즈의 90%

        // inflate the layout of the popup window
        LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
        LinearLayout layout = (LinearLayout) inflater.inflate(R.layout.popup_window,null);
        mPopupView = layout.findViewById(R.id.linear_layout);

        TextView popupTitle = layout.findViewById(R.id.popupTitle);
        popupTitle.setText("내용 미리보기");
        TextView popupSave = layout.findViewById(R.id.popupSaveBtn);

        TextView popupCancel = layout.findViewById(R.id.popupCancelBtn);

        pScrollView = layout.findViewById(R.id.popupScrollView);
        TextView popupContent = layout.findViewById(R.id.popupText);
        popupContent.setText(url);

        pScrollView.setVerticalScrollBarEnabled(true); // 수직방향 스크롤바 사용 가능하도록 설정
        popupContent.setMovementMethod(new ScrollingMovementMethod());
        popupContent.setTextSize(12);

        // create the popup window
        boolean focusable = true; // lets taps outside the popup also dismiss it
        final PopupWindow popupWindow = new PopupWindow(mPopupView, width, height, focusable);

        popupWindow.showAtLocation(popupView, Gravity.BOTTOM, 0, 0); // Parent View 로부터의 위치

        popupSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(mContext, "적용을 시작합니다.", Toast.LENGTH_SHORT).show();
            }
        });

        popupCancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (popupWindow != null && popupWindow.isShowing()){
                    popupWindow.dismiss();
                }
            }
        });
    }

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.link2me.android.MyPhone">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

    <application
        android:allowBackup="false"
        android:icon="@drawable/icon"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:usesCleartextTraffic="true"  <!-- http:// 통신일 경우에도 통신 가능하도록 -->

        android:theme="@style/AppTheme.NoActionBar">
        <activity android:name="com.link2me.android.MyPhone.Intro">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="${applicationId}.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths"
                tools:replace="android:resource" />
        </provider>
    </application>
</manifest>

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    // implementation 'com.android.support:appcompat-v7:28.0.0'
    //implementation 'com.android.support.constraint:constraint-layout:1.1.3'

    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'gun0912.ted:tedpermission:2.0.0'
    implementation 'com.android.volley:volley:1.1.1'
}

fun main(){
    // Person은 그 자체로 하나의 객체이기 때문에, 바로 .을 찍어 프로퍼티나 메서드에 접근할 수 있다.
    Person.name = "홍길동"
    Person.age = 30
    println("이름 : ${Person.name}, 나이 : ${Person.age}")
}

// object 는 subclass 의 명시적인 선언 없이 객체 생성
object Person {
    var name: String = ""
    var age: Int = 0
} 

// 예제 2.1

fun main(args: Array<String>) {
    Singleton.printVarName()

    println("\nSingleton variableName Change")
    Singleton.variableName = "강감찬"
    var a = A()
}

object Singleton{
    init {
        println("Singleton class invoked.")
    }
    var variableName = "홍길동"
    fun printVarName(){
        println("변수명 : $variableName ")
    }
}

class A {
    init {
        println("Class init method. Singleton variableName property : ${Singleton.variableName}")
        Singleton.printVarName()
    }
}

// 예제 2.2
fun main(args: Array<String>) {
    var a = A()
    a.printVarName()

    println()
    Singleton.printVarName()
}

open class A {
    open fun printVarName() {
        println("I am in class printVarName")
    }

    init {
        println("I am in init of A")
    }
}

object Singleton : A() {
    init {
        println("Singleton class invoked.")
    }

    var variableName = "홍길동"
    override fun printVarName() {
        println(variableName)
    }
}

fun main(args: Array<String>){
    var car1 = CarSales("아우디")
    var car2 = CarSales("그랜저")

    car1.sales()
    car1.sales()
    car1.sales()
    car1.sales()

    car2.sales()
    car2.sales()

    println("${car1.name} : ${car1.count}")
    println("${car2.name} : ${car2.count}")
    println("총계 : ${CarSales.total}")
 
}

// object 는 subclass 의 명시적인 선언 없이 객체 생성

class CarSales(val name: String){
    // 코틀린에는 정적(static) 변수 혹은 메소드가 없고,
    // 대신 패키지 내에 함수를 선언하여 사용할 수 있다.
    companion object {
        var total = 0
    }

    var count = 0
    fun sales(){
        total++
        count++
    }
}

fun main(args: Array<String>){
    var first = MyHtml.generateHtmlObject("first")
    first.setColumnHeaders("1열","2열","3열")
    //println("first.generateTable() => ${first.generateTable()}")

    val second = MyHtml.generateHtmlObject("second", 5,5)
    second.setColumnHeaders("월","화","수","목","금")

    val third = MyHtml.generateHtmlObject("third",2,7)
    third.setColumnHeaders("적색","녹색","노랑","파랑","보라","검정","주황")

    println("생성된 table 개수 : ${MyRecord.showTableCount()}")
    for( (k,v) in MyRecord.showTable()) {
        println("\n <!-- $k table (${v.row} x ${v.col}) -->")
        println(v.generateTable())
        println()
    }
}

object MyRecord {
    private var _count = 0
    private val _tables = hashMapOf<String,MyHtml>()

    fun gen(table: MyHtml){
        _tables.put(table.name, table)
        _count++
    }
    fun showTableCount() = _count
    fun showTable(): Map<String,MyHtml> = _tables
}

class MyHtml {
    val name: String
    val row: Int
    val col: Int
    private val HEAD = "<table border='1' cell-spacing='10' cell-padding='10'"
    private val TAIL = "</table>"
    private lateinit var comment: String
    private val tableColumns = ArrayList<String>()

    private constructor(_name: String, row: Int, col: Int ){
        this.name = _name
        this.row = row
        this.col = col
    }

    fun setColumnHeaders(vararg colNames: String){
        this.tableColumns.addAll(colNames)
    }

    companion object _GenTable {
        fun generateHtmlObject(_name: String, row: Int = 2, col: Int = 3): MyHtml {
            val mh = MyHtml(_name, row, col)
            mh.comment = "<!-- auto-generator table by MyHtml v1.0 -->"
            // 테이블 객체 기록
            MyRecord.gen(mh)
            return mh
        }
    }

    private inner class Tr {
        val rowHtml = """
            |<tr>
            | ${"<td>-</td>".repeat(col)}
            |</tr>${"\n"}
        """.trimMargin()
    }

    private inner class Th(val wpx: Int = 40) {
        val headers = tableColumns.map {
            "<th width='$wpx'> $it </th>"
        }
        val rowHtml = """
            |<tr>
            | ${headers.joinToString("")}
            |</tr>
        """.trimMargin()
    }

    // 테이블 생성 실행
    fun generateTable() =
        """
                |$comment
                |$HEAD
                |${Th().rowHtml}
                |${Tr().rowHtml.repeat(row)}
                |$TAIL
            """.trimMargin()
}

package com.myapp.funcargs

fun main(){
    val a = sum(4,5) // 일반 인자
    println("a result : $a")
    val b = mul(sum(1,2), 3) // 인자에 함수 사용
    println("b result : $b")

    println("ResultFun : ${resultFun()}")
}

fun sum(a: Int, b: Int) = a + b
fun mul(a: Int, b: Int) = a * b
fun resultFun(): Int {
    return mul(3,5) // 함수의 반환 값으로 함수 사용
}

package com.myapp.funcargs

fun main(){
    val a = sum(4,5) // 일반 인자
    println("a result : $a")
    val b = mul(sum(1,2), 3) // 인자에 함수 사용
    println("b result : $b")

    println("ResultFun : ${resultFun()}")

    val c:(String)->Unit ={str -> println("$str 람다함수")}
    b(c)
}

val sum ={a: Int, b: Int -> a + b}
// val sum: (Int, Int) -> Int ={a, b -> a + b}
// val mul ={a: Int, b: Int -> a * b}
val mul: (Int, Int) -> Int ={a, b -> a * b}
fun resultFun(): Int {
    return mul(3,5) // 함수의 반환 값으로 함수 사용
}
fun b (function: (String)->Unit){
    function("b가 호출한")
}

class Car {
    fun getPrice() : Int {
        return 8000
    }
}

fun Car.getBrandName() : String {
    return "BMW"
}

fun Car.getBrandName2() : Car {
    println("KIA")
    return this
}

fun main(args: Array<String>) {
    val car = Car()
    println(car.getBrandName())
    println(car.getBrandName2().getPrice())
} 

fun String.getLonggerLength(x: Int) : Int {
    return if(this.length > x) this.length else x
}

fun main(args: Array<String>) {
    println("Hello".getLonggerLength(3))
} 

fun main(args: Array<String>) {
    println("Hello".getLonggerStringLength("Have a nice day!"))
}

fun String.getLonggerStringLength(x: String) : Int {
    return if(this.length > x.length) this.length else x.length
}

class Car {
    fun getPrice(): Int {
        return 10000
    }
}

fun Car.getPrice(): Int {
    return 20000
}

fun Car.getPrice(price: Int): Int {
    return 30000
}

fun main(args: Array<String>) {
    val car = Car()
    println(car.getPrice())
    println(car.getPrice(0))
} 

fun List<Int>.getHigherThan(num: Int): List<Int> {
    val result = arrayListOf<Int>()
    for (item in this) {
        if (item > num) {
            result.add(item)
        }
    }
    return result
}

fun main() {
    val numbers: List<Int> = listOf(1, 2, 3, 4, 5, 6, 7)
    val filtered = numbers.getHigherThan(3).toString()
    System.out.println(filtered)
} 

private, protected, public 과 Java와 코틀린에서 같은 의미로 사용된다.
하지만 internal은
자바에서는 default(같은 패키지내에서만 접근가능)
코틀린에서는 같은 모듈안에서만 사용 가능하다. 

fun main(args: Array<String>) {
    var a = Person()
    a.click()
    a.run()
}

interface Clickable {
    // 일반함수 : open 함수로 간주한다.
    fun click() {
        println("버튼을 눌렀어요.")
    }
}

interface Runner {
    // 추상함수 : abstract 함수로 간주한다.
    fun run()
}

class Person : Runner, Clickable {
    override fun run(){
        println("성큼 성큼 달린다.")
    }
} 

fun main(args: Array<String>) {
    var a = Person()
    a.click()
    a.run()
}

interface Clickable {
    // 일반함수 : open 함수로 간주한다.
    fun click() {
        println("클릭 버튼을 눌렀어요.")
    }
}

interface Runner {
    // 추상함수 : abstract 함수로 간주한다.
    fun run()
    fun click() {
        println("Runner 버튼을 눌렀어요.")
    }
}

class Person : Runner, Clickable {
    override fun run(){
        println("성큼 성큼 달린다.")
    }

    override fun click() {
        super<Clickable>.click()
        super<Runner>.click()
    }
} 

fun main() {
    var b = Dog("불독", 5)

    b.introduce()
    b.bark()
    b.sniff()

    var c = Cat("나갈래", 4)
    c.introduce()
    c.meow()
    c.sniff()
}

abstract class Animal(var name:String, var age:Int, var type:String){
    abstract fun introduce()
    fun sniff(){
        println("냄새를 맡느라고 끙끙거린다.")
    }
}

class Dog(name:String, age:Int) : Animal (name,age,"개"){
    override fun introduce(){
        println("타입 : Dog, ${name}, ${age}살 입니다.")
    }

    fun bark(){
        println("멍멍멍")
    }
}

class Cat(name: String, age: Int) : Animal(name, age, "고양이"){
    override fun introduce(){
        println("타입 : Cat, ${name}, ${age}살 입니다.")
    }

    fun meow() {
        println("야옹야옹")
    }
}

abstract class Person(name: String) {
    init {
        println("My name is $name.")
    }
    // 일반 메서드
    fun displaySSN(ssn: Int) {
        println("My SSN is $ssn.")
    }
    // 추상 메서드
    abstract fun displayJob(description: String)
}

class Teacher(name: String): Person(name) {
    // 추상 메서드 구현
    override fun displayJob(description: String) {
        println(description)
    }
}

fun main(args: Array<String>) {
    val jack = Teacher("Jack Smith")
    jack.displayJob("I'm a mathematics teacher.")
    jack.displaySSN(23123)
}

fun main() {
    var a = Person("박보영", 1990)  // 코틀린은 new 키워드 없이 인스턴스를 생성한다.
    var b = Person("전영경",1997)
    var c = Person("차은우")
    var d = Person("홍길동")

    //println("안녕하세요, ${a.birthYear}년생 ${a.name} 입니다.")
}

class Person (var name:String, val birthYear:Int) {

    // var name:String, val birthYear:Int

    // 프로퍼티 선언 및 초기화는 기본 생성자에서 간결한 구분으로 사용 가능

    // 초기화
    init {

        // init 안에서는 자바처럼 [this.클래스변수= 매개변수]를 얼마든지 할 수 있다.

        println("안녕하세요, ${this.birthYear}년생 ${this.name}입니다.")
    }

    // 보조 생성자 : constructor 키워드로 선언하고 클래스 body에 구현한다.

    // 클래스 별로 여러 개를 가질 수 있다.
    constructor(name: String) : this(name,1997)
} 

fun main() {
    var a = Animal("불독", 3,"개")
    var b = Dog("불독", 5)

    a.introduce()
    b.introduce()
    b.bark()

    var c = Cat("나갈래", 4)
    c.introduce()
    c.meow()
}

open class Animal(var name:String, var age:Int, var type:String){
        open fun introduce(){ // open 이므로 override 가능하다.
        println("저는 ${type} : ${name}, ${age} 살 입니다.")
    }
}

class Dog(name:String, age:Int) : Animal (name,age,"개"){
    // 상위 클래스 함수에 open 키워드를 명시하고, 서브 클래스 함수에 override 를 붙인다.
    override fun introduce(){
        println("타입 : 개, ${name}, ${age} 살 입니다.")
    }

    fun bark(){
        println("멍멍멍")
    }
}

class Cat(name: String, age: Int) : Animal(name, age, "고양이"){
    fun meow() {
        println("야옹야옹")
    }
} 

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.2"

    defaultConfig {
        applicationId "com.link2me.android.googleauth"
        minSdkVersion 21
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.firebase:firebase-analytics:17.2.0'
    implementation 'com.google.firebase:firebase-auth:19.1.0'  // Firebase 인증에 대한 항목을 추가
    implementation 'com.google.android.gms:play-services-auth:17.0.0'
}

apply plugin: 'com.google.gms.google-services'

<RelativeLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center" >

    <!-- 구글 로그인 버튼 -->
    <com.google.android.gms.common.SignInButton
        android:id="@+id/sign_in_button"
        android:layout_width="254dp"
        android:layout_height="50sp">
    </com.google.android.gms.common.SignInButton>

    <ImageView
        android:id="@+id/sign_out_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/sign_in_button"
        android:background="@drawable/google_signout"/>

    <TextView
        android:id="@+id/mStatusTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/sign_in_button"
        android:layout_marginTop="99dp"
        android:text="TextView" />

</RelativeLayout >

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;

public class GoogleSignInActivity extends AppCompatActivity implements View.OnClickListener {
    private static final String TAG = "GoogleActivity";
    private static final int RC_SIGN_IN = 9001;
    private FirebaseAuth mAuth;
    private GoogleSignInClient mGoogleSignInClient;

    private TextView mStatusTextView;

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

        // Button listeners
        findViewById(R.id.sign_in_button).setOnClickListener(this);
        findViewById(R.id.sign_out_button).setOnClickListener(this);
        mStatusTextView = findViewById(R.id.mStatusTextView);

        // Configure Google Sign In
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();

        mGoogleSignInClient = GoogleSignIn.getClient(this, gso);

        // Initialize Firebase Auth
        mAuth = FirebaseAuth.getInstance();
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.sign_in_button:
                signIn(); // 구글 로그인 버튼 클릭시
                break;
            case R.id.sign_out_button:
                signOut();
                break;
        }
    }

    @Override
    public void onStart() {
        super.onStart();
        // Check if user is signed in (non-null) and update UI accordingly.
        FirebaseUser currentUser = mAuth.getCurrentUser();
        updateUI(currentUser);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
            try {
                // Google Sign In was successful, authenticate with Firebase
                GoogleSignInAccount account = task.getResult(ApiException.class);
                firebaseAuthWithGoogle(account);
            } catch (ApiException e) {
                Log.w(TAG, "Google sign in failed", e);
                updateUI(null);
            }
        }
    }

    private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
        Log.d(TAG, "firebaseAuthWithGoogle:" + acct.getId());

        AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            // Sign in success, update UI with the signed-in user's information
                            Log.e(TAG, "signInWithCredential:success");
                            FirebaseUser user = mAuth.getCurrentUser();
                            updateUI(user);
                            Log.e(TAG,"user getEmail : "+user.getEmail());
                            Log.e(TAG,"user getDisplayName : "+user.getDisplayName());
                            Log.e(TAG,"user getUid : "+user.getUid());
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w(TAG, "signInWithCredential:failure", task.getException());
                            Toast.makeText(GoogleSignInActivity.this, "Authentication Failed.", Toast.LENGTH_SHORT).show();
                            updateUI(null);
                        }

                        // [START_EXCLUDE]
                        //hideProgressDialog();
                        // [END_EXCLUDE]
                    }
                });
    }

    private void signIn() {
        Intent signInIntent = mGoogleSignInClient.getSignInIntent();
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    private void signOut() {
        mAuth.signOut(); // Firebase sign out

        // Google sign out
        mGoogleSignInClient.signOut().addOnCompleteListener(this,
                new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        updateUI(null);
                    }
                });
    }

    private void revokeAccess() {
        // Firebase sign out
        mAuth.signOut();

        // Google revoke access
        mGoogleSignInClient.revokeAccess().addOnCompleteListener(this,
                new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        updateUI(null);
                    }
                });
    }

    private void updateUI(FirebaseUser user) {
        //hideProgressDialog();
        if (user != null) {
            mStatusTextView.setText(user.getEmail() + " : " + user.getDisplayName());

            findViewById(R.id.sign_in_button).setVisibility(View.GONE);
            findViewById(R.id.sign_out_button).setVisibility(View.VISIBLE);
        } else {
            mStatusTextView.setText("LogOut");

            findViewById(R.id.sign_in_button).setVisibility(View.VISIBLE);
            findViewById(R.id.sign_out_button).setVisibility(View.GONE);
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //FirebaseAuth.getInstance().signOut();
    }
}