Mega update: Auto layout, code cleanup, api change.

Basically half a rewrite.

mouse.lua

@@ -0,0 +1,86 @@
+--[[
+Copyright (c) 2012 Matthias Richter
+
+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.
+
+Except as contained in this notice, the name(s) of the above copyright holders
+shall not be used in advertising or otherwise to promote the sale, use or
+other dealings in this Software without prior written authorization.
+
+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.
+]]--
+
+local _M -- holds the module. needed to make widgetHit overridable
+
+local x,y = 0,0
+local down = false
+local hot, active = nil, nil
+
+local function widgetHit(mouse, pos, size)
+	return mouse[1] >= pos[1] and mouse[1] <= pos[1] + size[1] and
+	       mouse[2] >= pos[2] and mouse[2] <= pos[2] + size[2]
+end
+
+local function setHot(id)    hot = id end
+local function setActive(id) active = id end
+local function isHot(id)     return id == hot end
+local function isActive(id)  return id == active end
+
+local function updateWidget(id, pos, size, hit)
+	hit = hit or _M.widgetHit
+
+	if hit({x,y}, pos, size) then
+		setHot(id)
+		if not active and down then
+			setActive(id)
+		end
+	end
+end
+
+local function releasedOn(id)
+	return not down and isHot(id) and isActive(id)
+end
+
+local function beginFrame()
+	hot = nil
+	x,y = love.mouse.getPosition()
+	down = love.mouse.isDown('l')
+end
+
+local function endFrame()
+	if not down then -- released
+		setActive(nil)
+	elseif not active then -- clicked outside
+		setActive(NO_WIDGET)
+	end
+end
+
+_M = {
+	widgetHit    = widgetHit,
+	setHot       = setHot,
+	setActive    = setActive,
+	isHot        = isHot,
+	isActive     = isActive,
+	updateWidget = updateWidget,
+	releasedOn   = releasedOn,
+
+	beginFrame   = beginFrame,
+	endFrame     = endFrame,
+}
+
+-- metatable provides getters to x, y and down
+return setmetatable(_M, {__index = function(_,k) return ({x = x, y = y, down = down})[k] end})