[Laszlo-dev] OpenLaszlo Event Model

[P T Withington]

Wow!  What do you think causes this drop in init time?  Less  
allocation of objects?

Do you want to share you changes (as in, send around a review)?

Or, make a more formal API proposal?

On 2008-11-01, at 11:01EDT, André Bargull wrote:

> I've just implemented this "new event-system" locally, and amazon- 
> demo start-time was before my change by about 1350-1450ms [1], with  
> my changes it was dropped to 980-1050ms. And I didn't even updated  
> anything of the LFC to use the new, more effective methods...
>
> [1] FF3 + FP10 (debug-player), demo compiled for swf9 non-debug,  
> time measured with <inittimer>
>
> On 10/29/2008 1:14 AM, André Bargull wrote:
>> I've started to reconcile with that idea and made up a some code  
>> snippets. IMO, there is at least one thing we definitely need to  
>> change: the current for API for LzDelegate#unregisterFrom(..). At  
>> the moment, the method signature is "function unregisterFrom  
>> (event:LzEvent)", this needs to be parallel to  
>> LzDelegate#register(..), so "function unregisterFrom  
>> (target:LzEventTarget, type:String)".
>> (The attached code is neither complete nor fast, I just wanted to  
>> be minimalistic, but also not too abstract.)
>>
>>> We have an (improvement suggestion)[http://jira.openlaszlo.org/jira/browse/LPP-6034 
>>>  ] to change the structure of the event system to be more  
>>> efficient and  more DOM-like.  I recently added a comment:
>>>
>>>
>>>> > What we really want to do is get more in line with http://www.w3.org/TR/DOM-Level-2-Events/
>>>> >
>>>> > This would mean that LzEventable would become EventTarget, and   
>>>> > LzDelegatable [LPP-7037] would become EventListener.
>>>> >
>>>> > The major impact on our system is that LzEvents would no longer  
>>>> be  > objects in themselves, but simply names (event types). This  
>>>> could  > reduce the overhead of events, but would mean a big  
>>>> incompatibility.  > Instead of:
>>>> >
>>>> >   <target>.<event>.sendEvent(<value>);
>>>> >
>>>> > you would have to say:
>>>> >
>>>> >   <target>.dispatchEvent(<event>, <value>);
>>>> >
>>>> > [In DOM2, dispatchEvent takes only an Event as its argument,  
>>>> the  > event is an object that has attributes such as the event  
>>>> name  > (type), state, and depending on the type of the event,  
>>>> additional  > information -- what we usually pass as the single  
>>>> <value>. If we  > want to be more compatible, perhaps we should  
>>>> implement the  > `dispatchEvent` interface and another  
>>>> `dispatchSimpleEvent`  > interface that handles most of our  
>>>> events. Otherwise the overhead we  > save by not having LzEvent  
>>>> objects to attach listeners to will be  > replaced by allocating  
>>>> an Event object every time you want to send  > an event.]
>>>>
>>>
>>> I'd be interested in other ideas and opinions.