Re: Question about relation between File's Owner, First Responder and controller object...

FROM : Ondra Cada
DATE : Mon Apr 11 22:36:58 2005

Mikael,

On 11.4.2005, at 19:19, Mikael Arctaedius wrote:

> OK, so I have an instance of my controller inside the document nib
> file?
> And the File's Owner in MainMenu is an instance of NSApplication and in
> the document nib file File's Owner is an instance of my document class?
> Is that correct?


Could be, if there is some quite special need to do it this way.
Normally though, the NSDocument subclass -- the document NIB's File's
Owner -- is the document controller.

> Well, the implementation of the button actions are inside the
> SystemController why I must connect them to the instance of
> the SystemController. I cannot connect them to the File's
> Owner any more since it is an instance of the document class which
> doesn't implement the button actions. But maybe the implementation
> of button actions should be inside the document class?


Yup, along with all the other document controller code. Or is there a
reason against in your case?

> There are more questions but I think these are the two major
> questions:
> Should the document nib file's File's Owner be an instance of
> my document class or my controller class?


Both :), since your document class is the (document-level) controller.

> If File's Owner is an instance of my document class where
> does the implementation of action methods belong? I have
> learned to put them in the controller class which would force
> me to an instance of the controller class to the nib file.


This can be done too, if need be, but why? Is there a reason you are
doing it this way?

Anyway, if you want to, you *can* split the functionality, if you want
to. For actions triggered by the main menu you'll have though to ensure
re-direction from the NSDocument subclass (which is, from the document
system POV, *the* document controller and which thus lives in the
Responder Chain) to your own SystemController, like this:

@interface MyDocument:NSDocument {
  IBOutlet SystemController *controller; // in NIB, this File's Owner
outlet is bound to the SystemController instance
  ...
}
@end

@implementation MyDocument
...
-(IBAction)thisIsSomeActionOfSystemControllerCalledFromMainMenu:sender {
   [controller
thisIsSomeActionOfSystemControllerCalledFromMainMenu:sender];
}
...
@end

In the MainMenu, you'll connect the menu action to First Responder.
That will ensure the appropriate NSDocument subclass (of the active
window) would get the message, and the redirection then would ensure
the SystemController instance of yours--instantiated from the NIB--gets
the message to do the work.

There are other ways too, but I guess this would be the simplest one
(that is, after removing the SystemController class altogether, moving
its functionality into your NSDocument subclass where it conceptually
belongs to :))
---
Ondra Èada
OCSoftware:    <email_removed>              http://www.ocs.cz
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