package elte.java2_utikalauz5.java2d;

import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;

/**
peldaprogram virtualis kepernyok hasznalatara.

@link.forrásfájl {@docRoot}/../data/java2d/src VirtualisKepernyo.java
@link.letöltés {@docRoot}/../data/java2d VirtualisKepernyo.jar
@since Java 2 Útikalauz programozóknak
*/
class VirtualisKepernyo extends Canvas {
    /** Verziószám */
    private final static long serialVersionUID = 15L;

	BufferedImage kep;
	Image betoltottKep;

	public void kepBetoltes () {
		setBackground (Color.white);
		betoltottKep = getToolkit ().getImage (getClass().getClassLoader().getResource("kep.gif"));
	        try {
        	    MediaTracker tracker = new MediaTracker (this);
	            tracker.addImage (betoltottKep, 0);
        	    tracker.waitForID (0);
	        }

		catch (Exception e) {
		}
	}

	public void paint (Graphics g) {
		Dimension meretek = getSize ();
		Graphics2D g2 = virtualisKepernyotLetrehoz (meretek.width, meretek.height);
		virtualisKepernyoreRajzol (g2, meretek.width, meretek.height);
		g2.dispose ();
		g.drawImage (kep, 0, 0, this);
	}

	public Graphics2D virtualisKepernyotLetrehoz (int w, int h) {
		Graphics2D g2 = null;
		if (kep == null || kep.getWidth () != w || kep.getHeight () != h)
			kep = (BufferedImage) createImage (w, h);

		g2 = kep.createGraphics ();
		g2.setBackground (getBackground ());
		g2.setRenderingHint (RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
		g2.clearRect (0, 0, w, h);
		return g2;
	}

	public void virtualisKepernyoreRajzol (Graphics2D g2, int w, int h) {
		g2.drawImage (betoltottKep, 0, 0, this);
	}

	public static void main (String[] args) {
		Frame f = new Frame ();
		VirtualisKepernyo v = new VirtualisKepernyo ();
		v.kepBetoltes ();

		f.add (v);

		f.addWindowListener (
			new WindowAdapter () {
				public void windowClosing (WindowEvent e) {
					System.exit (0);
				}
			}
		);

		f.setSize (100, 100);
		f.setVisible (true);
	}
}