Open up the MainActivity file, to make some quick updates that will enable you to show the dialog.

In the onCreateOptionsMenu, make the following changes:

override fun onCreateOptionsMenu(menu: Menu): Boolean {
    ...
    val reminderItem = menu.findItem(R.id.reminder_item)

    if (showMenuItems) {
        ...
        reminderItem.isVisible = true
    }

    return true
}

You have just added a reminder menu item to be displayed when the user clicks on a task. Now, go to onOptionsItemSelected to start the time picker when this menu item is selected. Use the following code to achieve that:

} else if (R.id.delete_item == item?.itemId) {
    ...
} else if (R.id.reminder_item == item?.itemId) {
    TimePickerFragment.newInstance("Time picker argument")
            .show(fragmentManager, "MainActivity")
}

Next, update the menu items in the to_do_list_menu.xml with the following code:

<item
    android:id="@+id/reminder_item"
    android:title="@string/reminder"
    android:icon="@android:drawable/ic_menu_agenda"
    android:visible="false"
    app:showAsAction="ifRoom"/>

Now, add the "reminder" string resource in your strings.xml file using the code shown here:

<resources>
    ...
    <string name="reminder">Reminder</string>
</resources>

Okay, that was great. Now, remember the AlarmReceiver class above? What does it do? Move on to find out.