HUDElement.java

package vooga.fighter.view;

import java.awt.geom.Point2D;
import java.lang.reflect.Field;
import java.util.Observer;

import util.Paintable;

/**
 * Acts as a display for model data. Throws NullPointerExceptions on Update.
 * (Update method signature would not be properly overridden if it was given
 * throw statements.) ALWAYS APPEND SUBCLASSES WITH "HUD", e.g. HUDHistogram.
 * 
 * @author Wayne You
 * 
 */
public abstract class HUDElement implements Observer, Paintable {
    public static final int  DEFAULT_TEXT_HEIGHT = 20;
    
    protected String         myName;
    protected String         myFieldName;
    protected Point2D.Double myLocation          = new Point2D.Double();
    
    public void setName(String name) {
        myName = name;
    }
    
    public void setObservedValue(String fieldName) {
        myFieldName = fieldName;
    }
    
    /**
     * Reflects on the observed object to retrieve the information.
     * 
     * @param o
     *            The observed object.
     * @return The observed member variable.
     * @throws SecurityException
     *             Thrown when attempting to change access level of a private
     *             member
     * @throws NoSuchFieldException
     *             Thrown when the saved field name is wrong
     * @throws IllegalArgumentException
     *             Thrown if the object given ceases to be the right
     *             class/extant
     * @throws IllegalAccessException
     *             Thrown when attempting to access a private member without
     *             access granted
     */
    protected Object getObservedValue(Object o) throws SecurityException,
            NoSuchFieldException, IllegalArgumentException,
            IllegalAccessException {
        Field member = o.getClass().getDeclaredField(myFieldName);
        member.setAccessible(true);
        return member.get(o);
    }
    
    public void setLocation(double x, double y) {
        myLocation.x = x;
        myLocation.y = y;
    }
    
    public void setLocation(Point2D location) {
        myLocation.x = location.getX();
        myLocation.y = location.getY();
    }
}