fxruby-users

[Fxruby-users] implementing connect()

[Claus S. <Doc...@gm...>]

Greetings! I'm at a loss on how to implement event handlers in my
classes. I looked at the API references and saw that connect() is
implemented in Responder2, which led me to believe that I need to
include it in whichever class needs the connect() method. This did not
work, as the objects 'selector', 'target', and 'value' were missing.
I've looked at the class that had those (FXDataTarget) and saw that
they were accessors, so I added those for my class, and it prevents
the compiler from throwing an error at me, but it's a crude solution,
and it doesn't do anything except getting rid of the errors. I'm 99%
sure that what I'm doing is wrong.
I am currently in the dark as to what needs to be done... perhaps I
need to have my class's parent be FXDataTarget, or FXObject? Hints
would be greatly appreciated.
Cheers!
    -CWSpitzer

Re: [Fxruby-users] implementing connect()

[Lyle J. <ly...@kn...>]

On May 12, 2004, at 3:02 PM, Claus Spitzer wrote:

> Greetings! I'm at a loss on how to implement event handlers in my
> classes. I looked at the API references and saw that connect() is
> implemented in Responder2, which led me to believe that I need to
> include it in whichever class needs the connect() method. This did not
> work, as the objects 'selector', 'target', and 'value' were missing.
> I've looked at the class that had those (FXDataTarget) and saw that
> they were accessors, so I added those for my class, and it prevents
> the compiler from throwing an error at me, but it's a crude solution,
> and it doesn't do anything except getting rid of the errors. I'm 99%
> sure that what I'm doing is wrong.

OK, first let's try to pin down what it is that you want to do. You 
want your class to be able to have a message target, i.e. to be able to 
call connect() on that object and provide a block to handle that 
message?

If that's the case, your class needs to provide a "target" accessor 
method that returns a reference to the message target (an FXObject 
instance) for that object. If your class is a subclass of FXWindow or 
FXDataTarget you've already got that. Otherwise, do something like:

	class MyClass < FXObject
		include Responder2
		attr_accessor :target
		def initialize
			@target = nil
		end
	end

You also need to mix-in the Responder2 module to get the connect() 
method, as shown.

Now you should be able to do something like this:

	obj = MyClass.new
	obj.connect(SEL_COMMAND) { puts "hey hey hey" }

And inside your class, when you want to "trigger" that callback, send a 
SEL_COMMAND message to the message target, e.g.

	class MyClass
		def make_it_so
			target.handle(self, MKUINT(0, SEL_COMMAND), nil)
		end
	end

I'm sort of rushing through this, so I may have omitted some details. 
Let me know how it goes and if you have some follow-up questions.

Hope this helps,

Lyle

Re: [Fxruby-users] implementing connect()

[Claus S. <Doc...@gm...>]

First of all, sorry for my earlier vague question, and thanks for the
reply. Now, what I was trying to do:

I'm still working on the program that you previously helped me with
(the canvas stuff). Got the canvas part down, added a few extra
features. Still the same concept basically.
What the whole thing is supposed to be is a lightweight replacement
for FXTable to match my requirements, which are:
 * custom cell colors (hence the canvas)
 * bring up a FXMessageBox when certain areas of the canvas are clicked
 * etc
item #2 is what I'm wanting the connect() for... my previous program,
which was loosely based on the ListView class by Jamey Cribbs borrowed
his method of placing

      connect( SEL_LEFTBUTTONPRESS, method( :onClick ) )
      connect( SEL_LEFTBUTTONRELEASE, method( :onClick ) )

in the ListView (and in my case, CellView) class, and then have the
onClick method handle the different events

      def onClick( sender, sel, event )
         ...
         if event.click_count > 1
            @win.onCmdDoubleClick
            return 1
         end
         ...

Now I'm assuming that the make_it_so method in your example is the
equivalent of my onClick method... right? However, nothing is
happening, and I've got a sneaking suspicion that it's because I've
omitted something crucial. Like using the parent FXWindow instead for
the connect() method. But I thought I'd better ask before banging my
head against the wall repeatedly.
I've attached the source in case you want to take a look at it... take
your time, I've got tons of other work that I can do on it in the
meantime (like adding other needed features and fixing the programming
horrors in there - I've been busy documenting many of them as such so
that should ease the urge to kill me). But eventually, I'd like to
handle these and other types of events.
   -CWSpitzer

PS: the onClick method should crash when executed, as I have commented
out some the methods it relies on... I know, sloppy work, but I'm just
working on things as they bubble to the top of my to do list.

On Wed, 12 May 2004 20:55:55 -0500, Lyle Johnson <ly...@kn...> wrote:
> 
8< ----- snip -----

> OK, first let's try to pin down what it is that you want to do. You
> want your class to be able to have a message target, i.e. to be able to
> call connect() on that object and provide a block to handle that
> message?
> 
> If that's the case, your class needs to provide a "target" accessor
> method that returns a reference to the message target (an FXObject
> instance) for that object. If your class is a subclass of FXWindow or
> FXDataTarget you've already got that. Otherwise, do something like:
> 
>         class MyClass < FXObject
>                 include Responder2
>                 attr_accessor :target
>                 def initialize
>                         @target = nil
>                 end
>         end
> 
> You also need to mix-in the Responder2 module to get the connect()
> method, as shown.
> 
> Now you should be able to do something like this:
> 
>         obj = MyClass.new
>         obj.connect(SEL_COMMAND) { puts "hey hey hey" }
> 
> And inside your class, when you want to "trigger" that callback, send a
> SEL_COMMAND message to the message target, e.g.
> 
>         class MyClass
>                 def make_it_so
>                         target.handle(self, MKUINT(0, SEL_COMMAND), nil)
>                 end
>         end
> 
> I'm sort of rushing through this, so I may have omitted some details.
> Let me know how it goes and if you have some follow-up questions.
> 
> Hope this helps,
> 
> Lyle
> 
>