<?php
/*
Plugin Name: Parent
Version: 1.0
*/

parent_class::init();

abstract class parent_class
{
	static function init() {
		add_action('plugins_loaded', array(__CLASS__, 'load'));
	}

	static function load() {
		do_action('parent_plugin_loaded');
	}

	static function register_activation($file, $callback) {
		$plugin = plugin_basename($file);
		add_action("parent_class_activate_$plugin", $callback);
	}

	static function do_activation($file) {
		$plugin = plugin_basename($file);
		do_action("parent_class_activate_$plugin");
	}
}

function parent_do_activation($file) {
	parent_class::do_activation($file);
}

class parent_tool
{
	function __construct($file, $bar) {
		$this->bar = $bar;
		parent_class::register_activation($file, array($this, 'activate'));
	}

	function activate() {
		// Do something useful when the child plugin is activated
	}
}