Add sample applet sources.

examples/jse/SampleApplet.java

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+import java.applet.Applet;
+import java.awt.Graphics;
+
+import org.luaj.vm2.Globals;
+import org.luaj.vm2.LuaValue;
+import org.luaj.vm2.lib.jse.CoerceJavaToLua;
+import org.luaj.vm2.lib.jse.JsePlatform;
+
+/**
+ * Simple Applet that forwards Applet lifecycle events to a lua script.
+ * 
+ * <p>
+ * On Applet.init() a script is loaded and executed, with the Applet instance as
+ * the first argument. Initialization of the Applet UI can be done here.
+ * 
+ * <p>
+ * Other Applet lifecycle events are invoked when they are recieved, and
+ * forwarded to methods in the global environment, if they exist. These are:
+ * <ul>
+ * <li>start() called when {@link Applet#start} is called.
+ * <li>stop() called when {@link Applet#stop} is called.
+ * <li>paint(graphics) called when {@link Applet#paint(Graphics)} is called. If
+ * this is not defined as a function the superclass method will be called.
+ * <li>update(graphics) called when {@link Applet#update(Graphics)} is called.
+ * If this is not defined as a function the superclass method will be called. By
+ * calling <code>applet:paint(graphics)</code> in the implementation the applet
+ * content will not be cleared before painting.
+ * </ul>
+ * 
+ * <p>
+ * Note that these lookups are done at runtime, so the paint method or any other
+ * method can be changed based on application logic, if desired.
+ * 
+ * @see Globals
+ * @see LuaValue
+ * @see Applet
+ */
+public class SampleApplet extends Applet {
+	private static final long serialVersionUID = 1L;
+
+	Globals globals;
+	LuaValue pcall;
+	LuaValue graphics;
+	Graphics coerced;
+
+	// This applet property is searched for the name of script to load.
+	static String script_parameter = "script";
+
+	// This must be located relative to the document base to be loaded.
+	static String default_script = "swingapplet.lua";
+
+	public void init() {
+		// Find the script to load from the applet parameters.
+		String script = getParameter(script_parameter);
+		if (script == null)
+			script = default_script;
+		System.out.println("Loading " + script);
+
+		// Construct globals to use.
+		globals = JsePlatform.debugGlobals();
+		pcall = globals.get("pcall");
+
+		// Load and execute the script, supplying this Applet as the only
+		// argument.
+		globals.loadfile(script).call(CoerceJavaToLua.coerce(this));
+	}
+
+	public void start() {
+		pcall.call(globals.get("start"));
+	}
+
+	public void stop() {
+		pcall.call(globals.get("stop"));
+	}
+
+	public void update(Graphics g) {
+		LuaValue u = globals.get("update");
+		if (!u.isfunction())
+			super.update(g);
+		else
+			pcall.call(
+					u,
+					coerced == g ? graphics : (graphics = CoerceJavaToLua
+							.coerce(coerced = g)));
+	}
+
+	public void paint(Graphics g) {
+		LuaValue p = globals.get("paint");
+		if (!p.isfunction())
+			super.paint(g);
+		else
+			pcall.call(
+					p,
+					coerced == g ? graphics : (graphics = CoerceJavaToLua
+							.coerce(coerced = g)));
+	}
+}

examples/lua/swingapplet.lua

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+-- Sample luaj program that presents an animated Applet designed to work 
+-- with the SampleApplet.java code in the examples/jse directory.
+-- 
+-- The Applet.init() method loads and executes this script with the Applet
+-- as the first argument.
+--
+-- Other Applet lifecycle events are forwarded by the SampleApplet
+-- by looking for these global variables and invoking them:
+--   start()
+--   stop()
+--   paint(graphics)
+--   update(graphics)
+--
+-- This basic applet handles key, and mouse input, has a basic animation loop, 
+-- and renders double-buffered graphics including the logo image in a swing frame.
+--
+local applet = (...)
+print('loading', applet)
+
+-- load the logo
+local logo = applet:getImage(applet:getDocumentBase(), "logo.gif")
+print('logo', logo)
+
+-- implement the applet painting, start, and stop methods.
+local animate,render
+local prev, interval = 0,1/60
+function update(graphics)
+	-- avoids clearing background
+	applet:paint(graphics)
+end
+function paint(graphics)
+	applet:repaint()
+	local curr = os.time()
+	local diff = curr - prev
+	if diff >= interval then
+		prev = curr
+		pcall(animate)
+		pcall(render, graphics)
+	end
+end
+function start()
+	applet:repaint()
+end
+function stop()
+    -- do nothing
+end
+
+-- the animation step moves the line endpoints
+local x1,y1,x2,y2,xi,yi = 160,240,480,240,0,0
+local vx1,vy1,vx2,vy2,vxi,vyi = -5,-6,7,8,3,1
+local advance = function(x,vx,max,rnd)
+	x = x + vx
+	if x < 0 then
+		return 0, math.random(2,10)
+	elseif x > max then
+		return max, math.random(-10,-2)
+	end
+	return x, vx
+end
+animate = function()
+	x1,y1,x2,y2 = x1+1,y1+1,x2-1,y2-1
+	local w,h = applet:getWidth(), applet:getHeight()
+	x1,vx1 = advance(x1,vx1,w)
+	y1,vy1 = advance(y1,vy1,h)
+	x2,vx2 = advance(x2,vx2,w)
+	y2,vy2 = advance(y2,vy2,h)
+	xi,vxi = advance(xi,vxi,w-100)
+	yi,vyi = advance(yi,vyi,h-100)
+end
+
+-- the render step draws the scene
+local bg = luajava.newInstance("java.awt.Color", 0x22112244,true);
+local fg = luajava.newInstance("java.awt.Color", 0xffaa33);
+render = function(graphics)
+	graphics:setColor(bg)
+	graphics:fillRect(0,0,applet:getWidth(), applet:getHeight())
+	graphics:drawImage(logo,xi,yi)
+	graphics:setColor(fg)
+	graphics:drawLine(x1,y1,x2,y2)
+end
+
+-- add mouse listeners for specific mouse events
+applet:addMouseListener(luajava.createProxy("java.awt.event.MouseListener", {
+	mousePressed = function(e)
+		print('mousePressed', e:getX(), e:getY(), e)
+		x1,y1 = e:getX(),e:getY()
+	end,
+	-- mouseClicked = function(e) end, 
+	-- mouseEntered = function(e) end, 
+	-- mouseExited = function(e) end, 
+	-- mouseReleased = function(e) end, 
+}))
+
+applet:addMouseMotionListener(luajava.createProxy("java.awt.event.MouseMotionListener", {
+	mouseDragged = function(e)
+		-- print('mouseDragged', e:getX(), e:getY(), e)
+		x2,y2 = e:getX(),e:getY()
+	end,
+	-- mouseMoved= function(e) end, 
+}))
+
+-- add key listeners
+applet:addKeyListener(luajava.createProxy("java.awt.event.KeyListener", {
+	keyPressed = function(e) 
+		local id, code, char, text = e:getID(), e:getKeyCode(), e:getKeyChar(), e:getKeyText(e:getKeyCode())
+		print('key id, code, char, text, pcall(string.char,char)', id, code, char, text, pcall(string.char,char))
+	end,
+	-- ckeyReleased = function(e) end, 
+	-- keyTyped = function(e) end, 
+}))
+