added a progressbar as a immutable widget

progressbar is a stripped down version of slider.lua.

core.lua

@@ -22,6 +22,7 @@ function suit.new(theme)
 		Checkbox = require(BASE.."checkbox"),
 		Input = require(BASE.."input"),
 		Slider = require(BASE.."slider"),
+		ProgressBar = require(BASE.."progressbar"),
 
 		layout = require(BASE.."layout").new(),
 	}, suit)

progressbar.lua

@@ -0,0 +1,26 @@
+-- This file is part of SUIT, copyright (c) 2016 Matthias Richter
+
+local BASE = (...):match('(.-)[^%.]+$')
+local min, max = math.min, math.max;
+
+return function(core, info, ...)
+	local opt, x,y,w,h = core.getOptionsAndSize(...)
+
+	opt.id = opt.id or info
+
+	info.min = info.min or min(info.value, 0)
+	info.max = info.max or max(info.value, 1)
+	info.step = info.step or (info.max - info.min) / 10
+	local fraction = (info.value - info.min) / (info.max - info.min)
+
+	opt.state = core:registerHitbox(opt.id, x,y,w,h)
+
+	core:registerDraw(opt.draw or core.theme.ProgressBar, fraction, opt, x,y,w,h)
+
+	return {
+		id = opt.id,
+		hovered = core:isHovered(opt.id),
+		entered = core:isHovered(opt.id) and not core:wasHovered(opt.id),
+		left = not core:isHovered(opt.id) and core:wasHovered(opt.id)
+	}
+end

theme.lua

@@ -105,6 +105,22 @@ function theme.Slider(fraction, opt, x,y,w,h)
 	end
 end
 
+function theme.ProgressBar(fraction, opt, x,y,w,h)
+	local xb, yb, wb, hb -- size of the progress bar
+	local r =  math.min(w,h) / 2.1
+	if opt.vertical then
+		x, w = x + w*.25, w*.5
+		xb, yb, wb, hb = x, y+h*(1-fraction), w, h*fraction
+	else
+		y, h = y + h*.25, h*.5
+		xb, yb, wb, hb = x,y, w*fraction, h
+	end
+
+	local c = opt.color and opt.color.normal or theme.color.normal
+	theme.drawBox(x,y,w,h, c, opt.cornerRadius)
+	theme.drawBox(xb,yb,wb,hb, {bg=c.fg}, opt.cornerRadius)
+end
+
 function theme.Input(input, opt, x,y,w,h)
 	local utf8 = require 'utf8'
 	theme.drawBox(x,y,w,h, (opt.color and opt.color.normal) or theme.color.normal, opt.cornerRadius)