DatabaseHandler

package com.example.mp1;

import java.util.ArrayList;
import java.util.List;
 
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
 
public class DatabaseHandler extends SQLiteOpenHelper {
 
    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "dbTask";
    private static final String TABLE_TASK = "tblTask";
 
    private static final String FIELD_ID = "col_id";
    private static final String FIELD_DESCRIPTION = "col_desc";
 
    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
 
    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_TASK + "("
                + FIELD_ID + " INTEGER PRIMARY KEY," + FIELD_DESCRIPTION + " TEXT" + ")";
        db.execSQL(CREATE_CONTACTS_TABLE);
    }
 
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_TASK);
        onCreate(db);
    }
 
    void addTask(Task task) {
        SQLiteDatabase db = this.getWritableDatabase();
 
        ContentValues values = new ContentValues();
        values.put(FIELD_DESCRIPTION, task.getDesc());
        db.insert(TABLE_TASK, null, values);
        db.close();
    }
 
    public List<Task> getAllTasks() {
        List<Task> contactList = new ArrayList<Task>();
        String selectQuery = "SELECT  * FROM " + TABLE_TASK;
 
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
 
        if (cursor.moveToFirst()) {
            do {
                Task contact = new Task();
                contact.setID(Integer.parseInt(cursor.getString(0)));
                contact.setDesc(cursor.getString(1));
                
                contactList.add(contact);
            } while (cursor.moveToNext());
        }
        return contactList;
    }
    

	public void deleteTask(Task task) {
		SQLiteDatabase db = this.getWritableDatabase();
		db.delete(TABLE_TASK, FIELD_ID + " = ?",
				new String[] { String.valueOf(task.getID()) });
		db.close();
	}
	
	public int updateTask(Task task) {
		SQLiteDatabase db = this.getWritableDatabase();
		
		ContentValues values = new ContentValues();
		values.put(FIELD_DESCRIPTION, task.getDesc());

		// updating row
		return db.update(TABLE_TASK, values, FIELD_ID + " = ?",
				new String[] { String.valueOf(task.getID()) });
	}
 
}

MainActivity

package com.example.mp1;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import android.widget.TwoLineListItem;

public class MainActivity extends Activity {
	EditText txtTask;
	ListView lstTask;
    DatabaseHandler db = new DatabaseHandler(this);
    Task t = new Task();
    SimpleAdapter adapter;
    int position_id;
    String description;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        txtTask = (EditText)findViewById(R.id.txtTask);
        lstTask = (ListView)findViewById(R.id.lstTask);
        lstTask.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
			@Override
			public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int position, long arg3) {
				//pag long press ako sa listview ng isang item, tatawagin ko ang method na mgaPagpipipilian();
				//na nagpapalabas ng alertdialog.
				//kuning ang position_id galing kay text1 sa layout
				position_id = Integer.parseInt(((TwoLineListItem) arg1).getText1().getText().toString());
				//kuning ang description galing kay text2 sa layout
				description = ((TwoLineListItem) arg1).getText2().getText().toString();
				//tawagin ngayon si alertdialog
				mgaPagpipipilian();
				return false;
			}
		});
    }
    public void clickAdd(View v){
    	db.addTask(new Task(txtTask.getText().toString()));
    	txtTask.setText("");
    	populateList();
    }
    
    public void populateList(){
        List<Task> task = db.getAllTasks(); 
        List<Map<String, String>> data = new ArrayList<Map<String, String>>();
        for (Task ta : task) {
        	Map<String, String> datum = new HashMap<String, String>(2);
        	datum.put("id",ta.getID()+"");
        	datum.put("desc",ta.getDesc());
        	data.add(datum);
        }
        //gumamit ako ng SimpleAdapter para gamitin sa listview
		//gumawa din ako ng customized na layout para yun ang gagamitin ni listview "listview_layout" na matatagpuan sa res>layout>listview_layout.xml
		//dalawang TextView ang laman ni listview_layout, text1 at text2. si text1, laman nya yung id, si text2 laman nya yung description. tinago ko si text1 para hindi makita sa listview. ginamitan ko ng android:visibility="gone"
        adapter = new SimpleAdapter(this, data, R.layout.listview_layout, new String[] {"id", "desc"},new int[] {android.R.id.text1, android.R.id.text2});
        lstTask.setAdapter(adapter);
    }
	private void mgaPagpipipilian() {
		//Gawa tayo ng alertdialog galing kay class na AlertDialog.Builder. Pangalanan nating adb.
		AlertDialog.Builder adb = new AlertDialog.Builder(this);
		//gawin nating cancelable ang dialog. ibig sabihin, pag pumindot sa labas si user, matatanggal ang alertdialog
		adb.setCancelable(true);
		//Lagyan ng title ang Dialog Box
		adb.setTitle("Please select option");
		//Nilagyan ng item ang dialog box, ang items ay galing sa res>values>string
		adb.setItems(R.array.array_pagpipilian, new DialogInterface.OnClickListener() {
					@Override
					//laman laman ni item yung index na pinindot mo sa alert dialog
					public void onClick(DialogInterface dialog, int item) {
						//laman laman ni item yung index na pinindot mo sa alert dialog
						switch (item) {
							case 0:
								//pag pinindot si index 0, which is yung unang item, which is Edit, ano mangyayari?
								editItem(description);
								break;
							case 1:
								//pag pinindot si index 1, which is yung pangalawang item, which is Delete, ano mangyayari?
								//Tawagin si method deleteItem()
								deleteItem();
								break;
						}
					}
				});
		adb.show();
	}
	private void deleteItem(){
	//tawagin nating ang databaes method na deleteTask para madelete ang item gamit ang position_id
		db.deleteTask(new Task(position_id));
	//irefresh ang listview
		populateList();
	}
	//Tatawagin naman to pag pinindot si edit. Index 0
	private void editItem(String msg){
		AlertDialog.Builder adb = new AlertDialog.Builder(this);

		adb.setTitle("Edit Task");
		
		// gawa tayo ng edit text na ilalagay sa alert dialog. Magdeclare ng EditText
		final EditText input = new EditText(this);
		//ilagay na ang edittext sa alert dialog.
		adb.setView(input);
		//lagyan natin ng laman ang edittext pagka bukas ng dialog.
		input.setText(msg);
		adb.setPositiveButton("Update", new DialogInterface.OnClickListener() {
		public void onClick(DialogInterface dialog, int whichButton) {
			//laman ni variable value yung bagong value.
			String value = input.getText().toString();
			//tatawagin si database method na updateTask para ipasa sakanya ang iuupdate na ID tapos kung ano yung bagong value
		  	db.updateTask(new Task(position_id, value));
			//irefresh ang listview
			populateList();
		  }
		});
		adb.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
		  public void onClick(DialogInterface dialog, int whichButton) {
		    dialog.cancel();
		  }
		});
		adb.show();
	}
    @Override
    public void onStart(){
    	super.onStart();
    	//Everytime na bubuksan natin si application, tatawagin natin
    	//si populateList() na naglalagay ng laman ng database sa listview.
    	populateList();
    }
}

Task

package com.example.mp1;
/*
 * THE GETTERS AND SETTERS
 */
public class Task {
    int id;
    String desc;
     
    public Task(){
         
    }
    public Task(int id, String desc){
        this.id = id;
        this.desc = desc;
    }
    public Task(String desc){
        this.desc = desc;
    }
    public Task(int id){
        this.id = id;
    }
    public int getID(){
        return this.id;
    }
    public void setID(int id){
        this.id = id;
    }
     
    public String getDesc(){
        return this.desc;
    }
    
    public void setDesc(String desc){
        this.desc = desc;
    }
}