From dd892ee7ff0f2c9a4c35d120abc215bc221740d6 Mon Sep 17 00:00:00 2001
From: James Roseborough <james.roseborough@luaj.org>
Date: Tue, 6 Jan 2009 23:36:56 +0000
Subject: [PATCH] Add sample applet that runs scripts colocated with the
 document root.

---
 src/sample/org/luaj/sample/SampleApplet.java | 152 +++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 src/sample/org/luaj/sample/SampleApplet.java

diff --git a/src/sample/org/luaj/sample/SampleApplet.java b/src/sample/org/luaj/sample/SampleApplet.java
new file mode 100644
index 00000000..09e5bc74
--- /dev/null
+++ b/src/sample/org/luaj/sample/SampleApplet.java
@@ -0,0 +1,152 @@
+/*******************************************************************************
+* Copyright (c) 2009 LuaJ. All rights reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+* 
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+******************************************************************************/
+package org.luaj.sample;
+
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.net.URLConnection;
+
+import javax.swing.JApplet;
+
+import org.luaj.lib.j2se.CoerceJavaToLua;
+import org.luaj.lib.j2se.J2seIoLib;
+import org.luaj.platform.J2sePlatform;
+import org.luaj.vm.LValue;
+import org.luaj.vm.LuaState;
+import org.luaj.vm.Platform;
+
+/**
+ * Sample JApplet that runs a lua script in the init phase, and calls
+ * global functions for applet lifecycle events.
+ * 
+ * The script(s) should be located relative to the document root in order 
+ * for the lua scripts to be loaded.
+ * 
+ * The functions init(), start(), stop() and destroy() and the script itself 
+ * are called with the applet as the first argument, so that the 
+ * lua script can perform whatever operations it needs to using the applet 
+ * as the main context.  
+ * 
+ * The applet looks runs the script identified by the applet parameter 'script' 
+ * or 'main.lua' if there is no value for 'script' provided.
+ */
+public class SampleApplet extends JApplet {
+	private static final long serialVersionUID = 1L;
+
+	// the script will be loaded as a resource 
+	private static final String DEFAULT_SCRIPT = "main.lua";
+
+	private LuaState vm;
+	private String base;
+	
+	private final LValue lthis = CoerceJavaToLua.coerce(this);
+
+	public synchronized void init() {
+		System.out.println("init() called");
+		super.init();
+		if ( vm == null ) {
+	
+			// get the script as an app property
+			String script = this.getParameter("script");
+			if ( script == null )
+				script = DEFAULT_SCRIPT;
+			base  = tobase( getDocumentBase().toExternalForm() );
+			System.out.println("script: "+script);
+			System.out.println("base: "+base);
+	
+			// set up the j2me platform.  files will be loaded as resources
+			Platform.setInstance( new J2sePlatform() {
+				public InputStream openFile(String fileName) {
+					// System.out.println("openFile('"+fileName+"')");
+					URLConnection c = null;
+					try {
+						URL u = new URL(base + fileName);
+						c = u.openConnection();
+						return c.getInputStream();
+					} catch ( Exception e ) {
+						e.printStackTrace( System.out );
+						if ( c instanceof HttpURLConnection )
+							((HttpURLConnection)c).disconnect();
+						return null;
+					}
+				}			
+			});
+			vm = Platform.newLuaState();
+			
+			// extend the basic vm to include the compiler and io packages
+			org.luaj.compiler.LuaC.install();
+			J2seIoLib.install(vm._G);
+			
+			// run the script
+			try {
+				vm.getglobal( "loadfile" );
+				vm.pushstring( script );
+				vm.call( 1, 1 );
+				vm.pushlvalue( lthis );
+				vm.call( 1, 0 );
+			} catch ( Throwable t ) {
+				t.printStackTrace( System.err );
+			}
+		} 	
+		callFunction( "init" );
+	}
+	
+	private String tobase(String path) {
+		int i = path.lastIndexOf('/');
+		return i>=0? path.substring(0,i+1): path;
+	}
+
+	private boolean callFunction( String name ) {
+		try {
+			vm.getglobal( name );
+			if ( ! vm.isfunction(-1) ) {
+				vm.pop(1);
+				return false;
+			}
+			else {
+				vm.pushlvalue( lthis );
+				vm.call( 1, 0 );
+				return true;
+			}
+		} catch ( Throwable t ) {
+			System.out.println(name+"():");
+			t.printStackTrace( System.err );
+			return true;
+		}
+	}
+	
+	public synchronized void start() {
+		super.start();
+		callFunction( "start" );
+	}
+
+	public synchronized void stop() {
+		callFunction( "stop" );
+		super.stop();
+	}
+
+	public synchronized void destroy() {
+		callFunction( "destroy" );
+		super.destroy();
+	}
+}