package thinkinginjava.containers;

// A more complex use of PriorityQueue.

import java.util.*;

class ToDoList extends PriorityQueue<ToDoList.ToDoItem> {

static class ToDoItem implements Comparable<ToDoItem> {

private char primary;

private int secondary;

private String item;

public ToDoItem(String td, char pri, int sec) {

primary = pri;

secondary = sec;

item = td;

}

public int compareTo(ToDoItem arg) {

if (primary > arg.primary)

return +1;

if (primary == arg.primary)

if (secondary > arg.secondary)

return +1;

else if (secondary == arg.secondary)

return 0;

return -1;

}

public String toString() {

return Character.toString(primary) + secondary + ": " + item;

}

}

public void add(String td, char pri, int sec) {

super.add(new ToDoItem(td, pri, sec));

}

public static void main(String[] args) {

ToDoList toDoList = new ToDoList();

toDoList.add("Empty trash", 'C', 4);

toDoList.add("Feed dog", 'A', 2);

toDoList.add("Feed bird", 'B', 7);

toDoList.add("Mow lawn", 'C', 3);

toDoList.add("Water lawn", 'A', 1);

toDoList.add("Feed cat", 'B', 1);

while (!toDoList.isEmpty())

System.out.println(toDoList.remove());

}

}