How to assign the action of adding a task to the button instead of clicking on the Menu item?

Question

Android

Wrote a task list app with a tutorial. Tasks are added when clicking on a menu item (plus icon on the top right)
How can I make a new task not be added on a click on a menu item, but on my custom button?
I did the markup of the button, but how to hang up a method that would implement all this?
Main_menu.xml:

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

    <item
        android:id="@+id/action_add_task"
        android:icon="@drawable/add_item"
        android:title="@string/add_task"
        app:showAsAction="always"
        />
</menu>

item_todo.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:layout_gravity="center_vertical">

    <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="@string/hi"
        android:textSize="20sp" />




    <Button
        android:id="@+id/task_delete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:onClick="deleteTask"
        android:text="@string/done" />

</RelativeLayout>

activity_main:

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

    <ListView
        android:id="@+id/list_todo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

    </ListView>

    <Button

    android:id="@+id/btnAdd"
    android:layout_width="65dp"
    android:layout_height="65dp"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_margin="20dp"
    android:background="@drawable/circle"
    />   
        
</RelativeLayout>

MainActivity class:

package com.kentforth.list5;

import android.content.ContentValues;
import android.content.DialogInterface;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;



import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private TaskHelper mHelper;
    private ListView mTaskListView;
    private ArrayAdapter<String> mAdapter;
    Button btnAdd;

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

        mHelper = new TaskHelper(this);
        mTaskListView = (ListView) findViewById(R.id.list_todo);
        btnAdd = (Button) findViewById(R.id.btnAdd);

        updateUI();
    }


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

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_add_task:
                final EditText taskEditText = new EditText(this);
                AlertDialog dialog = new AlertDialog.Builder(this)
                        .setTitle("New Task")
                        .setMessage("Add a new task")
                        .setView(taskEditText)
                        .setPositiveButton("Add", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                String task = String.valueOf(taskEditText.getText());
                                SQLiteDatabase db = mHelper.getWritableDatabase();
                                ContentValues values = new ContentValues();
                                values.put(Task.TaskEntry.COL_TASK_TITLE, task);
                                db.insertWithOnConflict(Task.TaskEntry.TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
                                db.close();
                                updateUI();

                            }
                        })

                        .setNegativeButton("Cancel", null)
                        .create();
                dialog.show();
                return true;

            default:
                return super.onOptionsItemSelected(item);

        }
    }


    private void updateUI() {

        ArrayList<String> taskList = new ArrayList<>();
        SQLiteDatabase db = mHelper.getReadableDatabase();
        Cursor cursor = db.query(Task.TaskEntry.TABLE,
                new String[] {Task.TaskEntry._ID, Task.TaskEntry.COL_TASK_TITLE}, null, null, null, null, null);
        while (cursor.moveToNext()) {
            int index = cursor.getColumnIndex(Task.TaskEntry.COL_TASK_TITLE);
            taskList.add(cursor.getString(index));
        }

        if (mAdapter == null) {
            mAdapter = new ArrayAdapter<>(this, R.layout.item_todo, R.id.task_title, taskList);
            mTaskListView.setAdapter(mAdapter);
        } else {
            mAdapter.clear();
            mAdapter.addAll(taskList);
            mAdapter.notifyDataSetChanged();

        }

        cursor.close();
        db.close();
    }

    public void deleteTask(View view) {
        View parent = (View) view.getParent();
        TextView taskTextView = (TextView) parent.findViewById(R.id.task_title);
        String task = String.valueOf(taskTextView.getText());
        SQLiteDatabase db = mHelper.getWritableDatabase();
        db.delete(Task.TaskEntry.TABLE, Task.TaskEntry.COL_TASK_TITLE + " = ?", new String[]{task});
        db.close();
        updateUI();
    }


}

Task class:

package com.kentforth.list5;

import android.provider.BaseColumns;

public class Task {

    public static final String DB_NAME = "ToDoDB";
    public static final int DB_VERSION = 1;

    public class TaskEntry implements BaseColumns {
        public static final String TABLE = "tasks";
        public static final String COL_TASK_TITLE = "title";
    }

}

TaskHelper class:

package com.kentforth.list5;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class TaskHelper extends SQLiteOpenHelper{

    public TaskHelper(Context context) {
        super(context, Task.DB_NAME, null, Task.DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
String createTable = "CREATE TABLE " + Task.TaskEntry.TABLE + " ( " +
                                       Task.TaskEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                                       Task.TaskEntry.COL_TASK_TITLE + " TEXT NOT NULL);";
        db.execSQL(createTable);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS" + Task.TaskEntry.TABLE);
        onCreate(db);
    }

}

Answer 1

Just move the "add task" code to a separate method. Call it by clicking on the menu button and by clicking on your Button.