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|
if not @Tether?
throw new Error "You must include the utils.js file before tether.js"
Tether = @Tether
{getScrollParent, getSize, getOuterSize, getBounds, getOffsetParent, extend, addClass, removeClass, updateClasses, defer, flush, getScrollBarSize} = Tether.Utils
within = (a, b, diff=1) ->
a + diff >= b >= a - diff
transformKey = do ->
el = document.createElement 'div'
for key in ['transform', 'webkitTransform', 'OTransform', 'MozTransform', 'msTransform']
if el.style[key] isnt undefined
return key
tethers = []
position = ->
for tether in tethers
tether.position(false)
flush()
now = ->
performance?.now?() ? +new Date
do ->
lastCall = null
lastDuration = null
pendingTimeout = null
tick = ->
if lastDuration? and lastDuration > 16
# We voluntarily throttle ourselves if we can't manage 60fps
lastDuration = Math.min(lastDuration - 16, 250)
# Just in case this is the last event, remember to position just once more
pendingTimeout = setTimeout tick, 250
return
if lastCall? and (now() - lastCall) < 10
# Some browsers call events a little too frequently, refuse to run more than is reasonable
return
if pendingTimeout?
clearTimeout pendingTimeout
pendingTimeout = null
lastCall = now()
position()
lastDuration = now() - lastCall
for event in ['resize', 'scroll', 'touchmove']
window.addEventListener event, tick
MIRROR_LR =
center: 'center'
left: 'right'
right: 'left'
MIRROR_TB =
middle: 'middle'
top: 'bottom'
bottom: 'top'
OFFSET_MAP =
top: 0
left: 0
middle: '50%'
center: '50%'
bottom: '100%'
right: '100%'
autoToFixedAttachment = (attachment, relativeToAttachment) ->
{left, top} = attachment
if left is 'auto'
left = MIRROR_LR[relativeToAttachment.left]
if top is 'auto'
top = MIRROR_TB[relativeToAttachment.top]
{left, top}
attachmentToOffset = (attachment) ->
return {
left: OFFSET_MAP[attachment.left] ? attachment.left
top: OFFSET_MAP[attachment.top] ? attachment.top
}
addOffset = (offsets...) ->
out = {top: 0, left: 0}
for {top, left} in offsets
if typeof top is 'string'
top = parseFloat(top, 10)
if typeof left is 'string'
left = parseFloat(left, 10)
out.top += top
out.left += left
out
offsetToPx = (offset, size) ->
if typeof offset.left is 'string' and offset.left.indexOf('%') isnt -1
offset.left = parseFloat(offset.left, 10) / 100 * size.width
if typeof offset.top is 'string' and offset.top.indexOf('%') isnt -1
offset.top = parseFloat(offset.top, 10) / 100 * size.height
offset
parseAttachment = parseOffset = (value) ->
[top, left] = value.split(' ')
{top, left}
class _Tether
@modules: []
constructor: (options) ->
tethers.push @
@history = []
@setOptions options, false
for module in Tether.modules
module.initialize?.call(@)
@position()
getClass: (key) ->
if @options.classes?[key]
@options.classes[key]
else if @options.classes?[key] isnt false
if @options.classPrefix
"#{ @options.classPrefix }-#{ key }"
else
key
else
''
setOptions: (@options, position=true) ->
defaults =
offset: '0 0'
targetOffset: '0 0'
targetAttachment: 'auto auto'
classPrefix: 'tether'
@options = extend defaults, @options
{@element, @target, @targetModifier} = @options
if @target is 'viewport'
@target = document.body
@targetModifier = 'visible'
else if @target is 'scroll-handle'
@target = document.body
@targetModifier = 'scroll-handle'
for key in ['element', 'target']
if not @[key]?
throw new Error "Tether Error: Both element and target must be defined"
if @[key].jquery?
@[key] = @[key][0]
else if typeof @[key] is 'string'
@[key] = document.querySelector @[key]
addClass @element, @getClass 'element'
addClass @target, @getClass 'target'
if not @options.attachment
throw new Error "Tether Error: You must provide an attachment"
@targetAttachment = parseAttachment @options.targetAttachment
@attachment = parseAttachment @options.attachment
@offset = parseOffset @options.offset
@targetOffset = parseOffset @options.targetOffset
if @scrollParent?
@disable()
if @targetModifier is 'scroll-handle'
@scrollParent = @target
else
@scrollParent = getScrollParent @target
unless @options.enabled is false
@enable(position)
getTargetBounds: ->
if @targetModifier?
switch @targetModifier
when 'visible'
if @target is document.body
{top: pageYOffset, left: pageXOffset, height: innerHeight, width: innerWidth}
else
bounds = getBounds @target
out =
height: bounds.height
width: bounds.width
top: bounds.top
left: bounds.left
out.height = Math.min(out.height, bounds.height - (pageYOffset - bounds.top))
out.height = Math.min(out.height, bounds.height - ((bounds.top + bounds.height) - (pageYOffset + innerHeight)))
out.height = Math.min(innerHeight, out.height)
out.height -= 2
out.width = Math.min(out.width, bounds.width - (pageXOffset - bounds.left))
out.width = Math.min(out.width, bounds.width - ((bounds.left + bounds.width) - (pageXOffset + innerWidth)))
out.width = Math.min(innerWidth, out.width)
out.width -= 2
if out.top < pageYOffset
out.top = pageYOffset
if out.left < pageXOffset
out.left = pageXOffset
out
when 'scroll-handle'
target = @target
if target is document.body
target = document.documentElement
bounds =
left: pageXOffset
top: pageYOffset
height: innerHeight
width: innerWidth
else
bounds = getBounds target
style = getComputedStyle target
hasBottomScroll = target.scrollWidth > target.clientWidth or 'scroll' is [style.overflow, style.overflowX] or @target isnt document.body
scrollBottom = 0
if hasBottomScroll
scrollBottom = 15
height = bounds.height - parseFloat(style.borderTopWidth) - parseFloat(style.borderBottomWidth) - scrollBottom
out =
width: 15
height: height * 0.975 * (height / target.scrollHeight)
left: bounds.left + bounds.width - parseFloat(style.borderLeftWidth) - 15
fitAdj = 0
if height < 408 and @target is document.body
fitAdj = -0.00011 * Math.pow(height, 2) - 0.00727 * height + 22.58
if @target isnt document.body
out.height = Math.max out.height, 24
scrollPercentage = @target.scrollTop / (target.scrollHeight - height)
out.top = scrollPercentage * (height - out.height - fitAdj) + bounds.top + parseFloat(style.borderTopWidth)
if @target is document.body
out.height = Math.max out.height, 24
out
else
getBounds @target
clearCache: ->
@_cache = {}
cache: (k, getter) ->
# More than one module will often need the same DOM info, so
# we keep a cache which is cleared on each position call
@_cache ?= {}
if not @_cache[k]?
@_cache[k] = getter.call(@)
@_cache[k]
enable: (position=true) ->
addClass @target, @getClass 'enabled'
addClass @element, @getClass 'enabled'
@enabled = true
if @scrollParent isnt document
@scrollParent.addEventListener 'scroll', @position
if position
@position()
disable: ->
removeClass @target, @getClass 'enabled'
removeClass @element, @getClass 'enabled'
@enabled = false
if @scrollParent?
@scrollParent.removeEventListener 'scroll', @position
destroy: ->
@disable()
for tether, i in tethers
if tether is @
tethers.splice i, 1
break
updateAttachClasses: (elementAttach=@attachment, targetAttach=@targetAttachment) ->
sides = ['left', 'top', 'bottom', 'right', 'middle', 'center']
if @_addAttachClasses?.length
# updateAttachClasses can be called more than once in a position call, so
# we need to clean up after ourselves such that when the last defer gets
# ran it doesn't add any extra classes from previous calls.
@_addAttachClasses.splice 0, @_addAttachClasses.length
add = @_addAttachClasses ?= []
add.push "#{ @getClass('element-attached') }-#{ elementAttach.top }" if elementAttach.top
add.push "#{ @getClass('element-attached') }-#{ elementAttach.left }" if elementAttach.left
add.push "#{ @getClass('target-attached') }-#{ targetAttach.top }" if targetAttach.top
add.push "#{ @getClass('target-attached') }-#{ targetAttach.left }" if targetAttach.left
all = []
all.push "#{ @getClass('element-attached') }-#{ side }" for side in sides
all.push "#{ @getClass('target-attached') }-#{ side }" for side in sides
defer =>
return unless @_addAttachClasses?
updateClasses @element, @_addAttachClasses, all
updateClasses @target, @_addAttachClasses, all
@_addAttachClasses = undefined
position: (flushChanges=true) =>
# flushChanges commits the changes immediately, leave true unless you are positioning multiple
# tethers (in which case call Tether.Utils.flush yourself when you're done)
return unless @enabled
@clearCache()
# Turn 'auto' attachments into the appropriate corner or edge
targetAttachment = autoToFixedAttachment(@targetAttachment, @attachment)
@updateAttachClasses @attachment, targetAttachment
elementPos = @cache 'element-bounds', => getBounds @element
{width, height} = elementPos
if width is 0 and height is 0 and @lastSize?
# We cache the height and width to make it possible to position elements that are
# getting hidden.
{width, height} = @lastSize
else
@lastSize = {width, height}
targetSize = targetPos = @cache 'target-bounds', => @getTargetBounds()
# Get an actual px offset from the attachment
offset = offsetToPx attachmentToOffset(@attachment), {width, height}
targetOffset = offsetToPx attachmentToOffset(targetAttachment), targetSize
manualOffset = offsetToPx(@offset, {width, height})
manualTargetOffset = offsetToPx(@targetOffset, targetSize)
# Add the manually provided offset
offset = addOffset offset, manualOffset
targetOffset = addOffset targetOffset, manualTargetOffset
# It's now our goal to make (element position + offset) == (target position + target offset)
left = targetPos.left + targetOffset.left - offset.left
top = targetPos.top + targetOffset.top - offset.top
for module in Tether.modules
ret = module.position.call(@, {left, top, targetAttachment, targetPos, @attachment, elementPos, offset, targetOffset, manualOffset, manualTargetOffset, scrollbarSize})
if not ret? or typeof ret isnt 'object'
continue
else if ret is false
return false
else
{top, left} = ret
# We describe the position three different ways to give the optimizer
# a chance to decide the best possible way to position the element
# with the fewest repaints.
next = {
# It's position relative to the page (absolute positioning when
# the element is a child of the body)
page:
top: top
left: left
# It's position relative to the viewport (fixed positioning)
viewport:
top: top - pageYOffset
bottom: pageYOffset - top - height + innerHeight
left: left - pageXOffset
right: pageXOffset - left - width + innerWidth
}
if document.body.scrollWidth > window.innerWidth
scrollbarSize = @cache 'scrollbar-size', getScrollBarSize
next.viewport.bottom -= scrollbarSize.height
if document.body.scrollHeight > window.innerHeight
scrollbarSize = @cache 'scrollbar-size', getScrollBarSize
next.viewport.right -= scrollbarSize.width
if document.body.style.position not in ['', 'static'] or document.body.parentElement.style.position not in ['', 'static']
# Absolute positioning in the body will be relative to the page, not the 'initial containing block'
next.page.bottom = document.body.scrollHeight - top - height
next.page.right = document.body.scrollWidth - left - width
if @options.optimizations?.moveElement isnt false and not @targetModifier?
offsetParent = @cache 'target-offsetparent', => getOffsetParent @target
offsetPosition = @cache 'target-offsetparent-bounds', -> getBounds offsetParent
offsetParentStyle = getComputedStyle offsetParent
elementStyle = getComputedStyle @element
offsetParentSize = offsetPosition
offsetBorder = {}
for side in ['Top', 'Left', 'Bottom', 'Right']
offsetBorder[side.toLowerCase()] = parseFloat offsetParentStyle["border#{ side }Width"]
offsetPosition.right = document.body.scrollWidth - offsetPosition.left - offsetParentSize.width + offsetBorder.right
offsetPosition.bottom = document.body.scrollHeight - offsetPosition.top - offsetParentSize.height + offsetBorder.bottom
if next.page.top >= (offsetPosition.top + offsetBorder.top) and next.page.bottom >= offsetPosition.bottom
if next.page.left >= (offsetPosition.left + offsetBorder.left) and next.page.right >= offsetPosition.right
# We're within the visible part of the target's scroll parent
scrollTop = offsetParent.scrollTop
scrollLeft = offsetParent.scrollLeft
# It's position relative to the target's offset parent (absolute positioning when
# the element is moved to be a child of the target's offset parent).
next.offset =
top: next.page.top - offsetPosition.top + scrollTop - offsetBorder.top
left: next.page.left - offsetPosition.left + scrollLeft - offsetBorder.left
# We could also travel up the DOM and try each containing context, rather than only
# looking at the body, but we're gonna get diminishing returns.
@move next
@history.unshift next
if @history.length > 3
@history.pop()
if flushChanges
flush()
true
move: (position) ->
return if not @element.parentNode?
same = {}
for type of position
same[type] = {}
for key of position[type]
found = false
for point in @history
unless within(point[type]?[key], position[type][key])
found = true
break
if not found
same[type][key] = true
css = {top: '', left: '', right: '', bottom: ''}
transcribe = (same, pos) =>
if @options.optimizations?.gpu isnt false
if same.top
css.top = 0
yPos = pos.top
else
css.bottom = 0
yPos = -pos.bottom
if same.left
css.left = 0
xPos = pos.left
else
css.right = 0
xPos = -pos.right
css[transformKey] = "translateX(#{ Math.round xPos }px) translateY(#{ Math.round yPos }px)"
if transformKey isnt 'msTransform'
# The Z transform will keep this in the GPU (faster, and prevents artifacts),
# but IE9 doesn't support 3d transforms and will choke.
css[transformKey] += " translateZ(0)"
else
if same.top
css.top = "#{ pos.top }px"
else
css.bottom = "#{ pos.bottom }px"
if same.left
css.left = "#{ pos.left }px"
else
css.right = "#{ pos.right }px"
moved = false
if (same.page.top or same.page.bottom) and (same.page.left or same.page.right)
css.position = 'absolute'
transcribe same.page, position.page
else if (same.viewport.top or same.viewport.bottom) and (same.viewport.left or same.viewport.right)
css.position = 'fixed'
transcribe same.viewport, position.viewport
else if same.offset? and same.offset.top and same.offset.left
css.position = 'absolute'
offsetParent = @cache 'target-offsetparent', => getOffsetParent @target
if getOffsetParent(@element) isnt offsetParent
defer =>
@element.parentNode.removeChild @element
offsetParent.appendChild @element
transcribe same.offset, position.offset
moved = true
else
css.position = 'absolute'
transcribe {top: true, left: true}, position.page
if not moved and @element.parentNode.tagName isnt 'BODY'
@element.parentNode.removeChild @element
document.body.appendChild @element
# Any css change will trigger a repaint, so let's avoid one if nothing changed
writeCSS = {}
write = false
for key, val of css
elVal = @element.style[key]
if elVal isnt '' and val isnt '' and key in ['top', 'left', 'bottom', 'right']
elVal = parseFloat elVal
val = parseFloat val
if elVal isnt val
write = true
writeCSS[key] = css[key]
if write
defer =>
extend @element.style, writeCSS
Tether.position = position
@Tether = extend _Tether, Tether
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