Events?

Ruby IronRuby
#1

Hi all,
Is there a built-in event system for IronRuby? I know I can handle
events
with button.click { }, but what if I want to dispatch my own, custom
events
(from a class I created myself?).

I wrote my own event system, but I would prefer to use a built-in
dispatch
method if it exists.

Thanks!
~sean

#2

I’m not sure I understand the scenario. Would you like to declare an
event on Ruby object that you want to hook from C# code? Like
rubyEngine.Operations.GetMember(obj, “my_event”) += delegate { …}?

Tomas

From: [email protected]
[mailto:[email protected]] On Behalf Of Sean C.
Hess
Sent: Thursday, August 14, 2008 12:04 PM
To: [email protected]
Subject: [Ironruby-core] Events?

Hi all,

Is there a built-in event system for IronRuby? I know I can handle
events with button.click { }, but what if I want to dispatch my own,
custom events (from a class I created myself?).

I wrote my own event system, but I would prefer to use a built-in
dispatch method if it exists.

Thanks!
~sean

#3

Let’s say I create a class called MovieControls, that wraps some
existing
xaml. The xaml has several buttons, including a toggle play/pause
button,
and a previous and next button.
MovieControls would listen to the click of the play/pause button, and
would
dispatch a “play” event when they clicked it to play it, and “pause” for
the
opposite.

I want to be able to listen to MovieControls to know when to tell my
video
to “play” and “pause”.

So, it would be something like this… In MovieControls
play_pause_button.click { if (isPlayState) dispatch(“play”) else
dispatch(“pause”) end }

Then, in my app
myMovieControls.play { doPlay }
myMovieControls.pause { doPause }

Does that make more sense now? If this seems totally out of the blue,
how
are people currently handling abstracting away this kind of
functionality?

Thanks
~sean

On Thu, Aug 14, 2008 at 2:22 PM, Tomas M. <

#4

Cool… that’s pretty much what I did. Thanks
On Thu, Aug 14, 2008 at 4:08 PM, Tomas M. <

#5

It seems that both parts of the code are Ruby. So you should use Ruby
language features. It’s possible to emulate CLR events by a list of
blocks.

event = []

adding a handler:

handler = lambda { … }
event << handler

removing a handler:

event.delete handler

firing an event:

event.each { |handler| handler[args] }

Tomas

From: [email protected]
[mailto:[email protected]] On Behalf Of Sean C.
Hess
Sent: Thursday, August 14, 2008 1:29 PM
To: [email protected]
Subject: Re: [Ironruby-core] Events?

Let’s say I create a class called MovieControls, that wraps some
existing xaml. The xaml has several buttons, including a toggle
play/pause button, and a previous and next button.

MovieControls would listen to the click of the play/pause button, and
would dispatch a “play” event when they clicked it to play it, and
“pause” for the opposite.

I want to be able to listen to MovieControls to know when to tell my
video to “play” and “pause”.

So, it would be something like this… In MovieControls
play_pause_button.click { if (isPlayState) dispatch(“play”) else
dispatch(“pause”) end }

Then, in my app
myMovieControls.play { doPlay }
myMovieControls.pause { doPause }

Does that make more sense now? If this seems totally out of the blue,
how are people currently handling abstracting away this kind of
functionality?

Thanks
~sean

On Thu, Aug 14, 2008 at 2:22 PM, Tomas M.
<[email protected]mailto:[email protected]>
wrote:

I’m not sure I understand the scenario. Would you like to declare an
event on Ruby object that you want to hook from C# code? Like
rubyEngine.Operations.GetMember(obj, “my_event”) += delegate { …}?

Tomas

From:
[email protected]mailto:[email protected]
[mailto:[email protected]mailto:[email protected]]
On Behalf Of Sean C. Hess
Sent: Thursday, August 14, 2008 12:04 PM
To: [email protected]mailto:[email protected]
Subject: [Ironruby-core] Events?

Hi all,

Is there a built-in event system for IronRuby? I know I can handle
events with button.click { }, but what if I want to dispatch my own,
custom events (from a class I created myself?).

I wrote my own event system, but I would prefer to use a built-in
dispatch method if it exists.

Thanks!

~sean

#6

I actually use a customized version of Observable that includes the
sender
of the event.
It’s that approach but a little bit more formalized. It’s in the
IronNails
framework
http://github.com/casualjim/ironnails/tree/master/IronNails/vendor/iron_nails/lib/observable.rb
That should look a lot like how events are implemented in C#.

2008/8/15 Sean C. Hess [email protected]

#7

Here is another way to do it:

  • In the XAML add commands to the appropriate buttons. You can use
    MediaCommands - Play, Pause, Stop, etc.
  • Have something like a ViewModel that holds the logic for what
    should
    happen when each command get executed.
  • Somehow add/attach/inject the view model to the view and create
    CommandBinding foreach of the supported commands. Add this command
    bindings
    to some visual element from the XAML, maybe the root.

Regards,
Stefan

2008/8/15 Sean C. Hess [email protected]

#8

Awesome, thanks for the example Ivan. It’s good to see it done
“correctly”
:stuck_out_tongue_winking_eye: Actually, mine includes the sender of the event and an event object
to,
I just wasn’t paying attention to them in the handler example, but yours
is
definitely more formal. Thanks again