/*
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
import java.awt.*;
import java.awt.image.*;
import java.applet.Applet;

/* 
 * This applet displays an image. When the user enters an angle,
 * the image is rotated to the specified angle.
 */

public class ImageRotator extends Applet {
    TextField degreeField;
    RotatorCanvas rotator;
    double radiansPerDegree = Math.PI / 180;

    public void init() {
	// Load the image.
        Image image = getImage(getCodeBase(), "../images/pizza.gif");

	//Set up the UI.
	GridBagLayout gridBag = new GridBagLayout();
	GridBagConstraints c = new GridBagConstraints();
	setLayout(gridBag);

	Label l = new Label("Number of degrees to rotate the image:");
	gridBag.setConstraints(l, c);
	add(l);

	degreeField = new TextField(5);
	gridBag.setConstraints(degreeField, c);
	add(degreeField);

	Button b = new Button("Redraw image");
	c.gridwidth = GridBagConstraints.REMAINDER;
	gridBag.setConstraints(b, c);
	add(b);

	rotator = new RotatorCanvas(image);
	c.fill = GridBagConstraints.BOTH;
	c.weightx = 1.0;
	c.weighty = 1.0;
	gridBag.setConstraints(rotator, c);
	add(rotator);

	validate();
    }

    public boolean handleEvent(Event e) {
        if (e.id == Event.WINDOW_DESTROY) {
                System.exit(0);
        }   
        return super.handleEvent(e);
    }

    public boolean action(Event evt, Object arg) {
	int degrees;

	try {
	    degrees = Integer.parseInt(degreeField.getText());
	} catch (NumberFormatException e) {
	    degrees = 0;
	}

	//Convert to radians.
	rotator.rotateImage((double)degrees * radiansPerDegree);

	return true;
    }
}

class RotatorCanvas extends Canvas {
    Image sourceImage;
    Image resultImage;

    public RotatorCanvas(Image image) {
	sourceImage = image;
	resultImage = sourceImage;
    }

    public void rotateImage(double angle) {
	ImageFilter filter = new RotateFilter(angle);
	ImageProducer producer = new FilteredImageSource(
					sourceImage.getSource(),
					filter);
	resultImage = createImage(producer);
	repaint();
    }

    public void paint(Graphics g) {
	Dimension d = size();
	int x = (d.width - resultImage.getWidth(this)) / 2;
	int y = (d.height - resultImage.getHeight(this)) / 2;

	g.drawImage(resultImage, x, y, this); 
    }
}