Display key characters in sample applet

examples/lua/swingapplet.lua

@@ -48,6 +48,7 @@ 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 chars = {}
 local advance = function(x,vx,max,rnd)
 	x = x + vx
 	if x < 0 then
@@ -66,17 +67,40 @@ animate = function()
 	y2,vy2 = advance(y2,vy2,h)
 	xi,vxi = advance(xi,vxi,w-100)
 	yi,vyi = advance(yi,vyi,h-100)
+	while #chars > 0 and chars[1].n <= 1 do
+		table.remove(chars, 1)
+	end
+	for i,c in pairs(chars) do
+		c.n = c.n - 1
+	end
 end
 
 -- the render step draws the scene
 local bg = luajava.newInstance("java.awt.Color", 0x22112244,true);
 local fg = luajava.newInstance("java.awt.Color", 0xffaa33);
+local ct = luajava.newInstance("java.awt.Color", 0x44ffff33,true);
 render = function(graphics)
+	local w,h = applet:getWidth(), applet:getHeight()
 	graphics:setColor(bg)
-	graphics:fillRect(0,0,applet:getWidth(), applet:getHeight())
+	graphics:fillRect(0,0,w,h)
-	graphics:drawImage(logo,xi,yi)
+
+	-- line
 	graphics:setColor(fg)
 	graphics:drawLine(x1,y1,x2,y2)
+	
+	-- text
+	graphics:setColor(ct)
+	graphics:translate(w/2,h/2)
+	for i,c in pairs(chars) do
+		local s = 200 / (256-c.n)
+		graphics:scale(s, s)
+		graphics:drawString(c.text, c.x-4, c.y+6)
+		graphics:scale(1/s, 1/s)
+	end
+	graphics:translate(-w/2,-h/2)
+
+	-- image
+	graphics:drawImage(logo,xi,yi)
 end
 
 -- add mouse listeners for specific mouse events
@@ -102,8 +126,14 @@ applet:addMouseMotionListener(luajava.createProxy("java.awt.event.MouseMotionLis
 -- 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())
+		local id, code, char = e:getID(), e:getKeyCode(), e:getKeyChar()
-		print('key id, code, char, text, pcall(string.char,char)', id, code, char, text, pcall(string.char,char))
+		local text, s, c = e:getKeyText(code), pcall(string.char, char)
+		print('key id, code, char, text, pcall(string.char,char)', id, code, char, text, c)
+		table.insert(chars, {
+			n=255, 
+			x=-6+12*math.random(), 
+			y=-6+12*math.random(), 
+			text=(s and c or '[?]')})
 	end,
 	-- ckeyReleased = function(e) end, 
 	-- keyTyped = function(e) end,