Merge pull request #41 from Amrykid/master

Updated events.nim
This commit is contained in:
Araq 2011-07-27 16:15:15 -07:00
commit f622647704
2 changed files with 40 additions and 27 deletions

View file

@ -11,48 +11,62 @@
## ##
## This module implements an event system that is not dependant on external ## This module implements an event system that is not dependant on external
## graphical toolkits. It was originally called ``NimEE`` because ## graphical toolkits. It was originally called ``NimEE`` because
## it was inspired by Ptyhon's PyEE module. ## it was inspired by Python's PyEE module. There are two ways you can use events: one is a python-inspired way; the other is more of a C-style way.
## .. code-block:: Nimrod
## var ee = initEventEmitter()
## var genericargs: TEventArgs
## proc handleevent(e: TEventArgs) =
## echo("Handled!")
##
## # Python way
## ee.on("EventName", handleevent)
## ee.emit("EventName", genericargs)
##
## # C/Java way
## # Declare a type
## type
## TSomeObject = object of TObject
## SomeEvent: TEventHandler
## var myobj: TSomeObject
## myobj.SomeEvent = initEventHandler("SomeEvent")
## myobj.SomeEvent.addHandler(handleevent)
## ee.emit(myobj.SomeEvent, genericargs)
type
TEventArgs* = object of TObject ## Base object for event arguments that are passed to callback functions.
TEventHandler* = tuple[name: string, handlers: seq[proc(e:TEventArgs)]] ## An eventhandler for an event.
type type
TEventArgs* = object of TObject ## Base object for event arguments TEventEmitter* = object {.pure, final.} ## An object that fires events and holds event handlers for an object.
## that are passed to callback functions. s: seq[TEventHandler]
TEventHandler = tuple[name: string, handlers: seq[proc(e:TEventArgs)]]
PEventHandler* = ref TEventHandler ## An eventhandler for an event.
type
TEventEmitter = object {.pure, final.}
s: seq[PEventHandler]
PEventEmitter* = ref TEventEmitter ## An object that fires events and
## holds event handlers for an object.
EInvalidEvent* = object of EInvalidValue EInvalidEvent* = object of EInvalidValue
proc newEventHandler*(name: string): PEventHandler = proc initEventHandler*(name: string): TEventHandler =
## Initializes an EventHandler with the specified name and returns it. ## Initializes an EventHandler with the specified name and returns it.
new(result) #new(result)
result.handlers = @[] result.handlers = @[]
result.name = name result.name = name
proc addHandler*(handler: PEventHandler, func: proc(e: TEventArgs)) = proc addHandler*(handler: var TEventHandler, func: proc(e: TEventArgs)) =
## Adds the callback to the specified event handler. ## Adds the callback to the specified event handler.
handler.handlers.add(func) handler.handlers.add(func)
proc removeHandler*(handler: PEventHandler, func: proc(e: TEventArgs)) = proc removeHandler*(handler: var TEventHandler, func: proc(e: TEventArgs)) =
## Removes the callback from the specified event handler. ## Removes the callback from the specified event handler.
for i in countup(0, len(handler.handlers) -1): for i in countup(0, len(handler.handlers) -1):
if func == handler.handlers[i]: if func == handler.handlers[i]:
handler.handlers.del(i) handler.handlers.del(i)
break break
proc clearHandlers*(handler: PEventHandler) = proc clearHandlers*(handler: var TEventHandler) =
## Clears all of the callbacks from the event handler. ## Clears all of the callbacks from the event handler.
setLen(handler.handlers, 0) setLen(handler.handlers, 0)
proc getEventhandler(emitter: PEventEmitter, event: string): int = proc getEventhandler(emitter: var TEventEmitter, event: string): int =
for k in 0..high(emitter.s): for k in 0..high(emitter.s):
if emitter.s[k].name == event: return k if emitter.s[k].name == event: return k
return -1 return -1
proc on*(emitter: PEventEmitter, event: string, func: proc(e: TEventArgs)) = proc on*(emitter: var TEventEmitter, event: string, func: proc(e: TEventArgs)) =
## Assigns a event handler with the specified callback. If the event ## Assigns a event handler with the specified callback. If the event
## doesn't exist, it will be created. ## doesn't exist, it will be created.
var i = getEventHandler(emitter, event) var i = getEventHandler(emitter, event)
@ -63,12 +77,12 @@ proc on*(emitter: PEventEmitter, event: string, func: proc(e: TEventArgs)) =
else: else:
addHandler(emitter.s[i], func) addHandler(emitter.s[i], func)
proc emit*(emitter: PEventEmitter, eventhandler: PEventHandler, proc emit*(emitter: var TEventEmitter, eventhandler: var TEventHandler,
args: TEventArgs) = args: TEventArgs) =
## Fires an event handler with specified event arguments. ## Fires an event handler with specified event arguments.
for func in items(eventhandler.handlers): func(args) for func in items(eventhandler.handlers): func(args)
proc emit*(emitter: PEventEmitter, event: string, args: TEventArgs) = proc emit*(emitter: var TEventEmitter, event: string, args: TEventArgs) =
## Fires an event handler with specified event arguments. ## Fires an event handler with specified event arguments.
var i = getEventHandler(emitter, event) var i = getEventHandler(emitter, event)
if i >= 0: if i >= 0:
@ -76,8 +90,7 @@ proc emit*(emitter: PEventEmitter, event: string, args: TEventArgs) =
else: else:
raise newException(EInvalidEvent, "invalid event: " & event) raise newException(EInvalidEvent, "invalid event: " & event)
proc newEventEmitter*(): PEventEmitter = proc initEventEmitter*(): TEventEmitter =
## Creates and returns a new EventEmitter. ## Creates and returns a new EventEmitter.
new(result) #new(result)
result.s = @[] result.s = @[]

View file

@ -18,7 +18,7 @@ proc handleprintevent2*(e: TEventArgs) =
var args: TPrintEventArgs = TPrintEventArgs(e) var args: TPrintEventArgs = TPrintEventArgs(e)
write(stdout, "HandlePrintEvent2: Output -> printing for " & args.user) write(stdout, "HandlePrintEvent2: Output -> printing for " & args.user)
var ee = newEventEmitter() var ee = initEventEmitter()
var eventargs: TPrintEventArgs var eventargs: TPrintEventArgs
eventargs.user = "ME\n" eventargs.user = "ME\n"
@ -34,10 +34,10 @@ ee.emit("print", eventargs)
type type
TSomeObject = object of TObject TSomeObject = object of TObject
PrintEvent: PEventHandler PrintEvent: TEventHandler
var obj: TSomeObject var obj: TSomeObject
obj.PrintEvent = newEventHandler("print") obj.PrintEvent = initEventHandler("print")
obj.PrintEvent.addHandler(handleprintevent2) obj.PrintEvent.addHandler(handleprintevent2)
ee.emit(obj.PrintEvent, eventargs) ee.emit(obj.PrintEvent, eventargs)