breadcrumbs/example/cs/breadcrumbs.coffee

Plugin for creating awesome breadcrumbs

async = require 'async'

bs_item_s = '.bs-item'
bs_static = '.bs-static'

memoize_width = (item) -> $(item).data width: $(item).outerWidth()
read_width = (item) -> $(item).data().width

animation = 
	hide: (item, cb) -> 
		animate_cb = ->
			$(item).hide()
			cb()
		memoize_width item
		$(item).animate({width: "0px", opacity: 0}, animate_cb)

	show: (item, cb) -> 
		$(item).show()
		$(item).animate({width: read_width(item), opacity: 1}, -> cb())


get_outer_width = (items) ->
	width_count_reduce_func = (a, b) -> a += ($ b).outerWidth()
	items.reduce width_count_reduce_func, 0


init = (breadcumbs_wrapper) ->
	collapsable_items = ($ "#{bs_item_s}:not(#{bs_static})").toArray()
	static_items = ($ bs_static).toArray()

	expander = $(collapsable_items[0]).clone()
	expander.text '...'
	expander.css {cursor: "pointer"}

	process 
		result_width: get_outer_width collapsable_items.concat static_items
		allowed_width: $(breadcumbs_wrapper).width()
		collapsable_items: collapsable_items
		static_items: static_items
		expander: expander


toggle_items = (collapsable_items, effect, action="show", cb) ->
	item_action = if effect?
		if action is "show"
			effect.show
		else
			effect.hide
	else
		if action is "show"
			(item, cb) -> 
				$(item).show()
				cb()
		else
			(item, cb) ->
				$(item).hide()
				cb()

	async.map collapsable_items, item_action, (err, items) ->
		items.map (i) -> ($ i).hide()
		cb?()


show_expander = (expander, item_after) -> expander.insertAfter item_after


get_show_hide_items = (from_head=true, items, static_items, allowed_width) ->
	items.reverse()
	reduce_by_allowed_width = (a, b) ->
		[current_width, _items_to_hide, _items_to_show] = a

		new_width = ($ b).outerWidth() + current_width

		a = if new_width <= allowed_width
			[new_width, _items_to_hide, _items_to_show.concat b]
		else
			[new_width, (_items_to_hide.concat b), _items_to_show]

	[width, items_to_hide, items_to_show] = items.reduce reduce_by_allowed_width, [get_outer_width(static_items), [], []]

	[items_to_hide, items_to_show]


process = ({result_width
		 	allowed_width
		 	static_items
		 	expander
		 	collapsable_items}) ->

	if result_width > allowed_width

		[from_head_hide_items, from_head_show_items] = get_show_hide_items(
			true, collapsable_items, static_items, allowed_width)

		[from_tail_hide_items, from_tail_show_items] = get_show_hide_items(
			false, collapsable_items, static_items, allowed_width)

		toggle_items(from_head_hide_items, animation, "hide", () -> show_expander expander, from_head_hide_items[0])

		from_head = true

		$(expander).click (ev) ->
			if from_head is true
				hide_from_head_visible = (cb) ->
					toggle_items from_tail_hide_items, animation, "hide", () -> cb()

				show_from_tail_visible = (cb) ->
					toggle_items from_tail_show_items, animation, "show", () -> 
						show_expander expander, from_tail_show_items[-1..]
						cb()

				async.parallel([hide_from_head_visible, show_from_tail_visible]
								() -> from_head = false)
			else
				hide_from_tail_head_visible = (cb) ->
					toggle_items from_head_hide_items, animation, "hide", () -> cb()


				show_from_tail_tail_visible = (cb) ->
					toggle_items from_tail_hide_items, animation, "show", () -> 
						show_expander expander, from_head_hide_items[0]
						cb()

				async.parallel(
					[
						hide_from_tail_head_visible
						show_from_tail_tail_visible
					]
					() -> from_head = true)


module.exports = init