package graph.animation;
import graph.*;
import java.awt.Color;

/**
 * A class which animates the linear scaling of a node.
 *
 * @see Node
 * @see AnimationManager
 * @author Michael Shilman (michaels@eecs.berkeley.edu)
 * @version $Id$
 */

public class ScaleAction extends AnimationAction {
	/**
	 * The node that is being animated.
	 */
	Node node;
	
	/**
	 * The initial <i>width</i> of the node when the action
	 * is instantiated.
	 */
	double startW;
	
	/**
	 * The initial <i>height</i> of the node when the action
	 * is instantiated.
	 */
	double startH;
	
	/**
	 * The target <i>width</i> for the node.
	 */
	double finishW;
	
	/**
	 * The target <i>height</i> for the node.
	 */
	double finishH;
	
	/**
	 * Whether or not to scale around the center of the node.
	 */
	boolean center = false;
	
	/**
	 * The start time of the action, for bookkeeping.
	 */
	long startTime;
	
	/**
	 * The finish time of the action, for bookkeeping.
	 */
	long finishTime;
	
	/**
	 * A new action on the specified node to scale
	 * it to the specified size.
	 *
	 * @param n		 The node to animate.
	 * @param w	 	 The final width.
	 * @param w		 The final height.
	 * @param dt	 The duration of the scale.
	 */
	ScaleAction(Node n, double w, double h, int dt) {
		node = n;
		startTime = System.currentTimeMillis();
		finishTime = startTime + dt;
		startW = n.w;
		startH = n.h;
		finishW = w;
		finishH = h;
	}

	/**
	 * Update the animation based on the current time as a linear
	 * interpolation.
	 *
	 * @return <i>true</i> when the action is finished, <i>false</i> otherwise.
	 */
	boolean apply() {
		long currentTime = System.currentTimeMillis();
		if(currentTime >= finishTime) {
			node.w = finishW;//XXX
			node.h = finishH;//XXX
			return true; //we're done
		}
		else {
			//interpolate between the two
			double t = ((double)(currentTime - startTime)) /
						((double)(finishTime - startTime));
			node.w = (startW + (t * (finishW - startW)));
			node.h = (startH + (t * (finishH - startH)));
			return false; //we're not done
		}
	}
}