Action.java

package vooga.towerdefense.action;

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

/**
 * An Action is the super class of all actions that can be executed by game
 * elements. This includes attacks, upgrades, path creation and anything the
 * developer may wish to implement.
 * 
 * @author Matthew Roy
 * @author XuRui
 * @author Zhen Gou
 * 
 */
public abstract class Action {
	public static final String NULL_POINTER_EXCEPTION = "Attribute(s) does not exist for element.";

	private boolean myEnabledState;
	private boolean targetTracking;
	private List<Action> myFollowUpActions;

	public Action() {
		myFollowUpActions = new ArrayList<Action>();
		myEnabledState = true;
	}

	/**
	 * Executes action after update clears the execute condition.
	 */
	public abstract void executeAction(double elapsedTime);

	/**
	 * Update action status and executes action if it needs to
	 * 
	 * @param elapsedTime
	 */
	public void update(double elapsedTime) {
		if (isEnabled()) {
			executeAction(elapsedTime);
			updateFollowUpActions(elapsedTime);
		}
	}

	/**
	 * Executes action after update clears the execute condition.
	 */
	public void updateFollowUpActions(double elapsedTime) {
		for (Action a : getFollowUpActions()) {
			a.update(elapsedTime);
		}
	}

	/**
	 * Adds a new action to occur after action is done executing
	 * 
	 * @param action
	 */
	public void addFollowUpAction(Action action) {
		myFollowUpActions.add(action);
	}

	/**
	 * Add a list of follow up actions.
	 * 
	 * @param action
	 */
	public void addFollowUpActions(List<Action> action) {
		myFollowUpActions.addAll(action);
	}

	/**
	 * Returns list of followup actions
	 * 
	 * @return
	 */
	public List<Action> getFollowUpActions() {
		return myFollowUpActions;
	}

	/**
	 * Returns list of all targeted follow up actions
	 * 
	 * @return
	 */
	public List<TargetedAction> getTargetedFollowUpActions() {
		List<TargetedAction> actions = new ArrayList<TargetedAction>();
		for (Action a : getFollowUpActions()) {
			if (a.isTargetTracking()) {
				actions.add((TargetedAction) a);
			}
		}
		return actions;
	}

	/**
	 * Checks to see if action is enabled.
	 * 
	 * @return
	 */
	public boolean isEnabled() {
		return myEnabledState;
	}

	/**
	 * Enables and disables action.
	 * 
	 * @param isEnabled
	 */

	public void setEnabled(boolean isEnabled) {
		myEnabledState = isEnabled;
	}

	/**
	 * Checks whether it is a targeted action.
	 * 
	 * @return
	 */
	public boolean isTargetTracking() {
		return targetTracking;
	}

	/**
	 * Set target tracking to be true to become targeted action that holds list
	 * of targets.
	 * 
	 * @param isTargeting
	 */
	public void setTargetTracking(boolean isTargeting) {
		targetTracking = isTargeting;

	}
}