/
handler_stack.coffee
37 lines (31 loc) · 1.09 KB
/
handler_stack.coffee
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root = exports ? window
class root.HandlerStack
constructor: ->
@stack = []
@counter = 0
genId: -> @counter = ++@counter & 0xffff
# Adds a handler to the stack. Returns a unique ID for that handler that can be used to remove it later.
push: (handler) ->
handler.id = @genId()
@stack.push handler
handler.id
# Called whenever we receive a key event. Each individual handler has the option to stop the event's
# propagation by returning a falsy value.
bubbleEvent: (type, event) ->
for i in [(@stack.length - 1)..0] by -1
handler = @stack[i]
# We need to check for existence of handler because the last function call may have caused the release
# of more than one handler.
if handler && handler[type]
@currentId = handler.id
passThrough = handler[type].call(@, event)
if not passThrough
DomUtils.suppressEvent(event)
return false
true
remove: (id = @currentId) ->
for i in [(@stack.length - 1)..0] by -1
handler = @stack[i]
if handler.id == id
@stack.splice(i, 1)
break