what is needed ...

[Trevor DeVore]

On May 23, 2005, at 4:00 PM, Marielle Lange wrote:
> I am curious to know. I came across the notion of generic programming 
> today. Are the ideas present in the script above something close to 
> generic programming?
> "Generic programming is about generalizing software components so that 
> they can be easily reused in a wide variety of situations. In C++, 
> class and function templates are particularly effective mechanisms for 
> generic programming because they make the generalization possible 
> without sacrificing efficiency".

Not exactly.  In the examples above it looks like you are assigning the 
script of the object you want the behavior to apply to.  This means 
that you will duplicate the script every time you want a certain object 
to have that behavior.  If the script which provides the desired 
behavior were to ever change then you would have to update it in all of 
the objects that use it.  This means your project is larger because 
code is being duplicated and it is more difficult to update.

If we were to generalize the web url example we would do something like 
this in Revolution in order to make a generic component (very rough):

==== libBehavior.rev - stack script (start using) ====
on mouseUp
	if the uLibBehavior["behavior"] of the target <> empty then
		libBehv_process
	end if

	pass mouseUp
end mouseUp


on libBehv_process
	switch the uLibBehavior["behavior"] of the target
		case "gotoURL"
			revGoURL the uLibBehavior["URL"] of the target
			break
	end switch
end libBehv_process

Now once you have libBehavior.rev put in use you can set custom 
properties of a button, image, etc. to control the behavior.  For 
example:

set the uLibBehavior["behavior"] of button "MyButton" to "gotoURL"
set the uLibBehavior["URL"] of button "MyButton" to 
"http://www.runrev.com"

Now when the user clicks on the button the url would be launched using 
revGoURL.  To make life easy for someone just getting started with Rev 
you could create a little plugin that is a palette that would let you 
drag and drop the gotoURL behavior on an object.  When the gotoURL 
behavior was dropped on an object the plugin would just set the custom 
properties of the object as needed and libBehavior.rev would process 
the mouseUp event appropriately.


-- 
Trevor DeVore
Blue Mango Multimedia
trevor at mangomultimedia.com