Improve the swing sample lua application.

README.html

@@ -19,7 +19,7 @@ Getting Started with LuaJ
 James Roseborough, Ian Farmer, Version 2.0.3
 <p>
 <small>
-Copyright &copy; 2009-2010 Luaj.org.
+Copyright &copy; 2009-2012 Luaj.org.
 Freely available under the terms of the
 <a href="http://sourceforge.net/dbimage.php?id=196142">Luaj license</a>.
 </small>
@@ -191,6 +191,12 @@ You should see the following output:
 	hello, world
 </pre>
 
+To see how luaj can be used to acccess most Java API's including swing, try:
+
+<pre>
+	java -cp lib/luaj-jse-2.0.3.jar lua examples/lua/swingapp.lua
+</pre>
+
 <h2>Compile lua source to lua bytecode</h2>
 
 <p>
@@ -501,7 +507,7 @@ The <em>JsePlatform.standardGlobals()</em> includes the <em>luajava</em> library
 It is patterned after the original <a href="http://www.keplerproject.org/luajava/">luajava project</a>.
 
 <p>
-The following lua script will open a swiing frame on Java SE:
+The following lua script will open a swing frame on Java SE:
 <pre>
 	jframe = luajava.bindClass( "javax.swing.JFrame" )
 	frame = luajava.newInstance( "javax.swing.JFrame", "Texts" );
@@ -511,7 +517,8 @@ The following lua script will open a swiing frame on Java SE:
 </pre>
 
 <p>
-See a longer sample in <em>examples/lua/swingapp.lua</em> for details, or try running it using: 
+See a longer sample in <em>examples/lua/swingapp.lua</em> for details, including a simple animation loop, rendering graphics, mouse and key handling, and image loading. 
+Or try running it using: 
 <pre>
 	java -cp lib/luaj-jse-2.0.3.jar lua examples/lua/swingapp.lua
 </pre>

examples/lua/swingapp.lua

@@ -1,29 +1,132 @@
+-- Sample luaj program that presents an animated Swing window.
+-- 
+-- This basic application handles key, and mouse input, has a basic animation loop, 
+-- and renders double-buffered graphics including the logo image in a swing frame.
+--
 
-frame = luajava.newInstance( "javax.swing.JFrame", "Texts" );
+-- bind to classes we need
-pane = luajava.newInstance( "javax.swing.JPanel" );
+local borderLayout = luajava.bindClass("java.awt.BorderLayout")
-borderFactory = luajava.bindClass( "javax.swing.BorderFactory" )
+local jframe = luajava.bindClass("javax.swing.JFrame")
-border = borderFactory:createEmptyBorder( 30, 30, 10, 30 )
+local bufferedImage = luajava.bindClass("java.awt.image.BufferedImage")
-pane:setBorder( border )
+local swingUtilities = luajava.bindClass("javax.swing.SwingUtilities")
-label = luajava.newInstance( "javax.swing.JLabel", "This is a Label" );
+local thread = luajava.bindClass("java.lang.Thread")
 
+-- set up frame, get content pane
+local frame = luajava.newInstance("javax.swing.JFrame", "Sample Luaj Application");
+local content = frame:getContentPane()
 
-layout = luajava.newInstance( "java.awt.GridLayout", 2, 2 );
+-- add a buffered image as content
-pane:setLayout( layout )
+local image = luajava.newInstance("java.awt.image.BufferedImage", 640, 480, bufferedImage.TYPE_INT_RGB)
-pane:add( label )
+local icon = luajava.newInstance("javax.swing.ImageIcon", image)
-pane:setBounds( 20, 30, 10, 30 )
+local label = luajava.newInstance("javax.swing.JLabel", icon)
 
-borderLayout = luajava.bindClass( "java.awt.BorderLayout" )
+-- add the main pane to the main content
-frame:getContentPane():add(pane, borderLayout.CENTER )
+content:add(label, borderLayout.CENTER)
-jframe = luajava.bindClass( "javax.swing.JFrame" )
 frame:setDefaultCloseOperation(jframe.EXIT_ON_CLOSE)
 frame:pack()
-frame:setVisible(true)
 
-local listener = luajava.createProxy("java.awt.event.MouseListener",
+-- simple animation framework
-					{
+local tick,animate,render
-						mouseClicked = function(me)
+local tnext = 0
-							print("clicked!", me)
+tick = luajava.createProxy("java.lang.Runnable", {
+	run = function()
+		swingUtilities:invokeLater(tick)
+		if os.time()< tnext then return thread:sleep(1) end
+		tnext = math.max(os.time(),tnext+1000/60)
+		pcall(animate)
+		pcall(render)
+		label:repaint(0,0,0,640,480)
 	end
-					})
+})
 
-frame:addMouseListener(listener)
+-- 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
+	x1,vx1 = advance(x1,vx1,640)
+	y1,vy1 = advance(y1,vy1,480)
+	x2,vx2 = advance(x2,vx2,640)
+	y2,vy2 = advance(y2,vy2,480)
+	xi,vxi = advance(xi,vxi,540)
+	yi,vyi = advance(yi,vyi,380)
+end
+
+-- try loading the logo image from a couple locations
+local imageio = luajava.bindClass("javax.imageio.ImageIO")
+local file = luajava.bindClass("java.io.File")
+local loadimage = function(path)
+	local s,i = pcall(imageio.read, imageio, luajava.new(file, path))
+	return s and i
+end
+local logo = loadimage("logo.gif") or loadimage("examples/lua/logo.gif")
+
+-- the render step draws the scene
+local g = image:getGraphics()
+local bg = luajava.newInstance("java.awt.Color", 0x22112244, true);
+local fg = luajava.newInstance("java.awt.Color", 0xffaa33);
+render = function()
+	g:setColor(bg)
+	g:fillRect(0,0,640,480)
+	if logo then g:drawImage(logo,xi,yi) end
+	g:setColor(fg)
+	g:drawLine(x1,y1,x2,y2)
+end
+
+-- add mouse listeners for specific mouse events
+label: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, 
+}))
+label: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
+frame: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,
+	-- keyReleased = function(e) end, 
+	-- keyTyped = function(e) end, 
+}))
+
+-- use the window listener to kick off animation
+frame:addWindowListener(luajava.createProxy("java.awt.event.WindowListener", {
+	windowOpened = function(e) 
+		swingUtilities:invokeLater(tick)
+	end,
+	-- windowActivated = function(e) end, 
+	-- windowClosed = function(e) end, 
+	-- windowClosing = function(e) end, 
+	-- windowDeactivated = function(e) end, 
+	-- windowDeiconified = function(e) end, 
+	-- windowIconified = function(e) end, 
+}))
+
+-- utility function to load an image from a file, for reference
+local loadimage = function(filename)
+end
+
+-- Set window visible last to start app.
+frame:setVisible(true)