This is Observer.m in view mode; [Download] [Up]
/*--------------------------------------------------------------------------
*
* You may freely copy, distribute, and reuse the code in this example.
* SHL Systemhouse disclaims any warranty of any kind, expressed or
* implied, as to its fitness for any particular use.
*
*
* Observer
*
* Inherits From: NSObject
*
* Conforms To: None
*
* Declared In: Observer.h
*
*
*------------------------------------------------------------------------*/
#import "Observer.h"
#import "Poster.h"
#import <appkit/appkit.h>
#import <foundation/NSNotification.h>
#import <foundation/NSUtilities.h>
@implementation Observer
- registerObserver: sender
{
// Registers this object for the notification named "FlagRaised".
// Registering from object nil means that it will be
// notified for all FlagRaised notifications regardless of what
// instance sends it. "flagRaised:" is the method that will
// be called when the notification occurs.
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:@selector(flagRaised:)
notificationName:@"RaiseFlag"
object:nil];
[registerButton setEnabled:NO];
[removeButton setEnabled:YES];
return self;
}
- removeObserver: sender
{
// Removes this observer from the notification center's observer list.
[[NSNotificationCenter defaultCenter]
removeObserver:self
notificationName:@"RaiseFlag"
object:nil];
[registerButton setEnabled:YES];
[removeButton setEnabled:NO];
return self;
}
- (void) flagRaised: (NSNotification*) aNotification
{
// Each notification has an associated sender. Note that sender
// may contain any arbitrary data that you wish. If observer is
// aware of this data and how to get to it (in this example
// the observer knows it can get the current flag from the
// sender) application relevant info can be passed between them.
switch (NXRunAlertPanel (NULL,
"Event '%s' was observed !",
"Acknowledge", "Ignore", NULL,
[[aNotification notificationName] cString]))
{
case NX_ALERTALTERNATE:
break;
case NX_ALERTDEFAULT:
default:
{
id superview = [[flagButton superview] superview];
int y = 0;
NXRect rect;
[flagButton getFrame:&rect];
[flagButton setIcon:[[[aNotification notificationObject]
currentFlag] icon]];
while (y <= 50)
{
[flagButton moveTo:NX_X(&rect) :NX_Y(&rect) + y];
y += 3;
[superview display];
}
while (y >= 0)
{
[flagButton moveTo:NX_X(&rect) :NX_Y(&rect) + y];
y -= 3;
[superview display];
}
break;
}
}
}
@end
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.