/*
 *  =======================================================================
 *  DemoTexturePaint.java : This applet demonstrates how texture patterns
 *  are created from "*.jpg" files. The applet window displays a sequence
 *  of textures as thumbnails. Clicking on a thumbnail will fill the canvas
 *  at the center of the window with the corresponding texture.
 * 
 *  Note. Pantham's implementation of this program is as a standalone
 *  Java program. The applet version is a bit more complicated because the
 *  texture patterns need to be downloaded over the net. 
 * 
 *  Adapted from : Pantham S., Pure JFC Swing, 1999.
 *  Modified by : Mark Austin                                   March, 2001
 *  =======================================================================
 */

import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.*;
import java.util.*;
import java.net.URL;

public class DemoTexturePaint extends JApplet {
    DemoTexturePaintCanvas canvas;
    URL codeBase;  // URL for applet codebase

    public void init() {

        // 1. Get the content pane and assign layout

        Container container = getContentPane();

        // 2. Add the canvas with rectangles

        canvas = new DemoTexturePaintCanvas();
        container.add(canvas);

        // 3. Create a panel to display various textures (canvases)

        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(1,10));
        panel.setBorder(new TitledBorder(
            "Select a Texture by Clicking the Mouse..."));

        // 4. Get codebase for applet ....

        codeBase = getCodeBase();

        // 5. Create canvas objects displaying thumb nails of textures,
        //    and add them to the panel.

        for (int i=0 ; i < 10; i++) {
           panel.add( new DemoTextureSelectableCanvas(
                              codeBase, "textures/texture"+(i+1)+".jpg",
                              canvas ) );
        }

        // 6. Add the panel to the content pane ....

        container.add(BorderLayout.SOUTH, panel);
    }
}

// 7. Canvas to display the selected texture

class DemoTexturePaintCanvas extends Canvas {
    Image displayImage;

    // Constructor

    DemoTexturePaintCanvas() {
        // Add the mouse listener to receive a rectangle selection
        setBackground(Color.white);  // For canvas background color
    }

    public void setImage(Image image) {
        displayImage = image; 
    }
        
    public void paint(Graphics g) {

        // Create the graphics context object

        Graphics2D g2D = (Graphics2D) g;

        // Create a texture paint object and display it in a rectangle
        // by filling it.

        if (displayImage != null) {
            BufferedImage bi = new BufferedImage(
                               displayImage.getWidth(this),
                               displayImage.getHeight(this),
                               BufferedImage.TYPE_INT_RGB);
            bi.createGraphics().drawImage(displayImage, 0, 0, this);

            Rectangle2D rectangle = new Rectangle2D.Float(0, 0,
                                       displayImage.getWidth(this),
                                       displayImage.getHeight(this));

            TexturePaint tp = new TexturePaint(bi, rectangle);
            g2D.setPaint(tp);
            g2D.fill(new Rectangle2D.Float(0, 0, getWidth(), getHeight()));
        }
    }
}

// 8. Class to define thumb nail objects of textures. The
//    user can select a texture by clicking the mouse on the
//    corresponding thumb nail.

class DemoTextureSelectableCanvas extends Canvas {
    Image image;
    DemoTexturePaintCanvas canvas;
    URL textureURL;  // URL for texture image ...

    DemoTextureSelectableCanvas( URL codeBase, String imageFile,
                                 DemoTexturePaintCanvas canvas ) {

        // Construct URL for texture ....

        try {
           textureURL = new URL( codeBase, imageFile );
        } catch ( java.net.MalformedURLException e ) {
           System.out.println("Badly specified URL!!");
        }

        // Download and save image icon ....

        this.image  = new ImageIcon( textureURL ).getImage();
        this.canvas = canvas;

        addMouseListener(new MouseEventHandler());

        setSize( 35, 35);
        setBackground(Color.white);
    }
                                           
    public void paint(Graphics g) {
        g.drawImage( image, 0, 0, this);
    }

    // 9. Class to handle mouse events that are generated
    //    when the mouse is clicked on the canvas.

    class MouseEventHandler extends MouseAdapter {
        public void mouseClicked(MouseEvent evt) {
            canvas.setImage( image);
            canvas.repaint();
        }
    }
}