TO DO APP TUTOTIAL

1. DB HELPER 

package com.todo.raj.todo;

import android.content.ContentValues;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

import java.util.ArrayList;

public class DbHelper extends SQLiteOpenHelper {

    private static final String DB_NAME="VirajToDo";

    private static final int DB_VER = 1;

    public static final String DB_TABLE="Task";

    public static final String DB_COLUMN = "TaskName";

    public DbHelper(Context context) {

        super(context, DB_NAME, null, DB_VER);

    }

    @Override

    public void onCreate(SQLiteDatabase db) {

        String query = String.format("CREATE TABLE %s (ID INTEGER PRIMARY KEY AUTOINCREMENT,%s TEXT NOT NULL);",DB_TABLE,DB_COLUMN);

        db.execSQL(query);

    }

    @Override

    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        String query = String.format("DELETE TABLE IF EXISTS %s",DB_TABLE);

        db.execSQL(query);

        onCreate(db);

    }

    public void insertNewTask(String task){

        SQLiteDatabase db= this.getWritableDatabase();

        ContentValues values = new ContentValues();

        values.put(DB_COLUMN,task);

        db.insertWithOnConflict(DB_TABLE,null,values,SQLiteDatabase.CONFLICT_REPLACE);

        db.close();

    }

    public void deleteTask(String task){

        SQLiteDatabase db = this.getWritableDatabase();

        db.delete(DB_TABLE,DB_COLUMN + " = ?",new String[]{task});

        db.close();

    }

    public ArrayList<String> getTaskList(){

        ArrayList<String> taskList = new ArrayList<>();

        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(DB_TABLE,new String[]{DB_COLUMN},null,null,null,null,null);

        while(cursor.moveToNext()){

            int index = cursor.getColumnIndex(DB_COLUMN);

            taskList.add(cursor.getString(index));

        }

        cursor.close();

        db.close();

        return taskList;

    }

}

1. 2MAIN ACTIVITY 

package com.todo.raj.todo;

import android.content.DialogInterface;

import android.graphics.PorterDuff;

import android.graphics.drawable.Drawable;

import android.os.Bundle;

import android.support.design.widget.FloatingActionButton;

import android.support.design.widget.Snackbar;

import android.support.v7.app.AlertDialog;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.Toolbar;

import android.util.Log;

import android.view.View;

import android.view.Menu;

import android.view.MenuItem;

import android.widget.ArrayAdapter;

import android.widget.EditText;

import android.widget.ListView;

import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    DbHelper dbHelper;

    ArrayAdapter<String> mAdapter;

    ListView lstTask;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        dbHelper = new DbHelper(this);

        lstTask = (ListView)findViewById(R.id.lstTask);

        loadTaskList();

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);

        setSupportActionBar(toolbar);

/*

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        fab.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View view) {

//                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)

//                        .setAction("Action", null).show();

            }

        });*/

    }

    private void loadTaskList() {

        ArrayList<String> taskList = dbHelper.getTaskList();

        if(mAdapter==null){

            mAdapter = new ArrayAdapter<String>(this,R.layout.row,R.id.task_title,taskList);

            lstTask.setAdapter(mAdapter);

        }

        else{

            mAdapter.clear();

            mAdapter.addAll(taskList);

            mAdapter.notifyDataSetChanged();

        }

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.menu_main, menu);

        //Change menu icon color

        Drawable icon = menu.getItem(0).getIcon();

        icon.mutate();

        icon.setColorFilter(getResources().getColor(android.R.color.white), PorterDuff.Mode.SRC_IN);

        return true;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        switch (item.getItemId()){

            case R.id.action_add_task:

                final EditText taskEditText = new EditText(this);

                AlertDialog dialog = new AlertDialog.Builder(this)

                        .setTitle("Add New Task")

                        .setMessage("What do you want to do next?")

                        .setView(taskEditText)

                        .setPositiveButton("Add", new DialogInterface.OnClickListener() {

                            @Override

                            public void onClick(DialogInterface dialog, int which) {

                                String task = String.valueOf(taskEditText.getText());

                                dbHelper.insertNewTask(task);

                                loadTaskList();

                            }

                        })

                        .setNegativeButton("Cancel",null)

                        .create();

                dialog.show();

                return true;

        }

        return super.onOptionsItemSelected(item);

    }

    public void deleteTask(View view){

        View parent = (View)view.getParent();

        TextView taskTextView = (TextView)parent.findViewById(R.id.task_title);

        Log.e("String", (String) taskTextView.getText());

        String task = String.valueOf(taskTextView.getText());

        dbHelper.deleteTask(task);

        loadTaskList();

    }

}

1. 3MAIN ACTIVITY XML 

<?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:layout_width="match_parent"

    android:layout_height="match_parent"

    app:layout_behavior="@string/appbar_scrolling_view_behavior"

    tools:context=".MainActivity"

    tools:showIn="@layout/activity_main">

    <ListView

        android:id="@+id/lstTask"

    android:layout_width="match_parent"

    android:layout_height="match_parent"></ListView>

</LinearLayout>

1. 4ROW.XML

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout

    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"

    android:layout_height="match_parent">

    <RelativeLayout

        android:layout_width="match_parent"

        android:layout_height="match_parent">

        <TextView

            android:id="@+id/task_title"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_alignParentLeft="true"

            android:layout_alignParentStart="true"

            android:text="Example"

            android:textSize="20sp" />

        <Button

            android:id="@+id/btnDelete"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_alignParentEnd="true"

            android:layout_alignParentRight="true"

            android:onClick="deleteTask"

            android:text="DELETE" />

    </RelativeLayout>

</android.support.constraint.ConstraintLayout>

1. 5MENU_MAIN.XML

<menu 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"

    tools:context="com.todo.raj.todo.MainActivity">

   <!-- <item

        android:id="@+id/action_settings"

        android:orderInCategory="100"

        android:title="@string/action_settings"

        app:showAsAction="never" />

-->

    <item

        android:id="@+id/action_add_task"

        android:icon="@android:drawable/ic_menu_add"

        android:title="Add New Task"

        app:showAsAction="always"

        />

</menu>

1. 6GRADEL

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

    implementation 'com.android.support:appcompat-v7:27.0.0'

    implementation 'com.android.support.constraint:constraint-layout:1.1.2'

    implementation 'com.android.support:design:27.0.0'