/* Thinlet GUI toolkit - www.thinlet.com
* Copyright (C) 2002-2003 Robert Bajzat (robert.bajzat@thinlet.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
package com.bluedragon.browser.thinlet;
import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Label;
/**
* <code>AppletLauncher</code> is a double buffered applet
* to launch any <i>thinlet</i> component
*/
public class AppletLauncher extends Applet implements Runnable {
private static final long serialVersionUID = 1L;
private transient Thinlet content;
private transient Image doublebuffer;
/**
* Applet instance is created by the browser or applet viewer
*/
public AppletLauncher() {
super(); // for javadoc
}
/**
* Called by the browser to inform this applet that it has been loaded into
* the system, it displays the <i>Loading...</i> label and starts the loader thread
*/
public void init() {
setBackground(Color.white); setForeground(Color.darkGray);
setLayout(new BorderLayout());
add(new Label("Loading...", Label.CENTER), BorderLayout.CENTER);
new Thread(this).start();
}
/**
* Create a new <i>thinlet</i> instance of the class given as
* <code>class</code> applet parameter, and show it or the
* message of the thrown exception. First try a contructor with
* an applet parameter (thus you get this applet instance e.g. for
* the parameters of the applet HTML tag), then the empty constructor
*/
public void run() {
try {
Class thinletclass = Class.forName(getParameter("class"));
try {
content = (Thinlet) thinletclass.getConstructor(new Class[] {
Applet.class }).newInstance(new Object[] { this });
} catch (NoSuchMethodException nsme) {
content = (Thinlet) thinletclass.newInstance();
}
removeAll();
add(content, BorderLayout.CENTER);
} catch (Throwable exc) {
removeAll();
add(new Label(exc.getClass().getName() + " " +
exc.getMessage(), Label.CENTER), BorderLayout.CENTER);
}
doLayout(); repaint();
}
/**
* Clear the double buffer image, the overriden method lays out its
* components (centers the <i>thinlet</i> component)
*/
public void doLayout() {
super.doLayout();
if (doublebuffer != null) {
doublebuffer.flush();
doublebuffer = null;
}
}
/**
* Called by the browser to inform this applet that it should stop its execution,
* it clears the double buffer image
*/
public void stop() {
if (doublebuffer != null) {
doublebuffer.flush();
doublebuffer = null;
}
}
/**
* Call the paint method to redraw this component without painting a
* background rectangle
*/
public void update(Graphics g) {
paint(g);
}
/**
* Create a double buffer if needed,
* the <i>thinlet</i> component paints the content
*/
public void paint(Graphics g) {
if (doublebuffer == null) {
Dimension d = getSize();
doublebuffer = createImage(d.width, d.height);
}
Graphics dg = doublebuffer.getGraphics();
dg.setClip(g.getClipBounds());
super.paint(dg);
dg.dispose();
g.drawImage(doublebuffer, 0, 0, this);
}
/**
* Called by the browser to inform this applet that it is being reclaimed,
* it calls the <i>thinlet</i> component's <code>destroy</code> method
* (its return value is irrelevant)
*/
public void destroy() {
content.destroy();
}
}