Question

6. What is lint ? Give two examples where lint will give erros 7. (A) Explain the differences between Option menu and Context menu. (B) Create an App with a single activity. The activity houses a list view. The list view should show names of any five diseases. On long clicking on any list iten(disease name) should show a menu, "Delete" On clicking delete should delete the particular disease from the list view ning tasks.

7)

Answer 1

Option menu:The options menu is the primary collection of menu items for an activity. It's where you should place actions that have a global impact on the app, such as "Search," "Compose email," and "Settings."​

A context menu: is a floating menu that appears when the user performs a long-click on an element. It provides actions that affect the selected content or context frame​.
for the given question we need to use a context menu to perform delete on long press of item

Activity main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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">

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</android.support.constraint.ConstraintLayout>

MainActivity.java

package com.example.android.listexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

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

public class MainActivity extends AppCompatActivity {
   ListView list_view;
   List<String> list = new ArrayList<String>();
   ArrayAdapter<String> adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        list_view= (ListView) findViewById(R.id.list_view);
        list.add("cold");
        list.add("fever");
        list.add("cough");
        list.add("cancer");
        list.add("headache");
        adapter = new ArrayAdapter<String>(this,android.R.layout.simple_expandable_list_item_1,list);
        list_view.setAdapter(adapter);
        registerForContextMenu(list_view);


    }@Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo){
        super.onCreateContextMenu(menu,v,menuInfo);

        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main_context_menu,menu);

    }
    public boolean onContextItemSelected(MenuItem item){
        AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
        switch (item.getItemId()) {
            case R.id.delete_id:
                adapter.remove(adapter.getItem(info.position));
            default:
                return super.onContextItemSelected(item);

        }
    }
}

min_context_menu.xml

menu xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <item android:id="@+id/delete_id"
        android:title="Delete Item"

    />


</menu>