iPhone UISwitch start/stop NSTimer help ! - iphone

Question

I want to start/stop timer(in main class) with switch(from menu class ),based in my code the timer start fire when switch is ON and doesn't stop when i turn switch OFF. Here is my code :
menu.h
#protocol FlipsideViewControllerDelegate;
#interface FlipsideViewController : UIViewController {
id <FlipsideViewControllerDelegate> delegate;
IBOutlet UISwitch *fireSwitch;
}
#property (assign)UISwitch* fireSwitch;
-(IBAction)autoFire;
menu.m
#import "FlipsideViewController.h"
#import "mainViewController.h"
#synthesize fireSwitch;
- (void)viewDidLoad
{
NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
//[super viewDidLoad];
fireSwitch.on = [defs boolForKey:activateautoplay];
}
-(IBAction)autoFire {
NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
[defs setBool:fireSwitch.on forKey:activateautoplay];
[[NSUserDefaults standardUserDefaults] synchronize];
}
Main.h
#import "FlipsideViewController.h"
#define activateautoplay #"isactivateautoplay"
#interface mainViewController : UIViewController <FlipsideViewControllerDelegate> {
NSTimer *Autotimer;
}
-(void)updateImagePosition:(NSTimer*)mytimer;
Main.m
#import "mainViewController.h"
#sunthesize Autotimer;
- (void)awakeFromNib {
NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
if ([defs boolForKey:activateautoplay]) {
self.Autotimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(updateImagePosition:) userInfo:nil repeats:YES];
} else {
[self.Autotimer invalidate];
}
}
-(void)updateImagePosition:(NSTimer*)mytimer {
.....
}

Answer 1

If you don't mind introducing coupling between the two classes, you could always just give FlipsideViewController a reference to mainViewController and have it poke a method directly. Or you could have FlipsideViewController send an appropriate message to its delegate when the value is changed, which could then poke mainViewController.
But the best way from a standpoint of avoiding unnecessary coupling is to have mainViewController listen for NSUserDefaultsDidChangeNotification, which will automatically be sent when setBool:forKey: is called.
Requested edit:
In Main.m, add a method like this:
- (void)startOrStopTimer {
NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
if ([defs boolForKey:activateautoplay]) {
if (!self.Autotimer) self.Autotimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(updateImagePosition:) userInfo:nil repeats:YES];
} else {
[self.Autotimer invalidate];
self.Autotimer = nil;
}
}
Then change your awakeFromNib to something like this:
- (void)awakeFromNib {
[self startOrStopTimer];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(startOrStopTimer) name:NSUserDefaultsDidChangeNotification object:nil];
}
And be sure to add this to dealloc:
[[NSNotificationCenter defaultCenter] removeObserver:self];
No changes are necessary to FlipsideViewController, and no settings bundle is needed.