NSSound not working properly - objective-c

Question

I am using Cocoa on Mac 10.6. I am trying to have a metronome click out the time but when I run the code only the first two sounds are played then it is quiet till the end when a sound plays again. If I replace the [player play] statements with NSBeep() it works fine. Any suggestions?
#import <Cocoa/Cocoa.h>
#interface Metronome : NSObject {
NSInteger timeSig;
NSInteger noteValue;
NSInteger bpm;
NSUInteger beatNumber;
CGFloat duration;
NSSound *tickPlayer;
NSSound *tockPlayer;
}
#property(readwrite) NSInteger timeSig;
#property(readwrite) NSInteger noteValue;
#property(readwrite) NSInteger bpm;
#property(readwrite) float duration;
#property(readwrite) NSUInteger beatNumber;
-(id)init;
-(id)initWithTimeSig:(NSInteger)ts andNoteValue:(NSInteger)nv andBpm:(NSInteger)bp;
-(void)BeginMetronome;
-(void)PlaySound;
#end
#import "Metronome.h"
#define defaultBpm 80
#define defaultTimeSig 4
#define defaultNoteValue 4
#implementation Metronome
#synthesize timeSig, noteValue, duration, bpm, beatNumber;
-(id)init{
return [self initWithTimeSig:defaultTimeSig andNoteValue:defaultNoteValue andBpm:defaultBpm];
}
-(id)initWithTimeSig:(NSInteger)ts andNoteValue:(NSInteger)nv andBpm:(NSInteger)bp {
[super init];
if(self){
self.timeSig = ts;
self.noteValue = nv;
self.bpm = bp;
self.duration = 60.0/bpm;
tickPlayer = [NSSound soundNamed:#"Hat1"];
tockPlayer = [NSSound soundNamed:#"Hat2"];
self.beatNumber = 1;
}
return self;
}
-(void)BeginMetronome{
BOOL continuePlaying = YES;
NSInteger iter=0;
while (continuePlaying){
if(iter > 12){
continuePlaying = FALSE;
}
iter++;
[self PlaySound];
NSDate *curtainTime = [[NSDate alloc] initWithTimeIntervalSinceNow:self.duration];
NSDate *currentTime = [[NSDate alloc] init];
while (continuePlaying && ([currentTime compare:curtainTime] != NSOrderedDescending)) {
// if ([soundPlayerThread isCancelled] == YES) {
// continuePlaying = NO;
//}
//[NSThread sleepForTimeInterval:0.01];
sleep(.01);
//[tickPlayer stop];
//[tockPlayer stop];
[currentTime release];
currentTime = [[NSDate alloc] init];
}
[curtainTime release];
[currentTime release];
}
}
- (void)PlaySound { //***********Problem in this loop
if ([tickPlayer isPlaying])
[tickPlayer stop];
if ([tockPlayer isPlaying])
[tockPlayer stop];
if (beatNumber == 1) {
[tockPlayer play];
}
else if (beatNumber == 2){
[tickPlayer play];
}
else if (beatNumber == self.timeSig) {
beatNumber = 0;
[tickPlayer play];
}
else{
//[tickPlayer stop];
[tickPlayer play];
NSBeep();
}
beatNumber++;
//NSLog(#" %d ", beatNumber);
// NSBeep();
}
#end

Answer 1

I believe your use of sleep() is blocking the playing of NSSound. That's a very sloppy way to do this, instead use a timer like so:
static NSInteger iter;
- (void) beginMetronome {
iter = 0;
NSTimer *timer = [NSTimer timerWithTimeInterval:self.duration target:self selector:#selector(continueMetronome:) userInfo:nil repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
[timer fire];
}
- (void) continueMetronome:(NSTimer *)theTimer {
[self PlaySound];
if (++iter > 12) {
[theTimer invalidate];
}
}
Also, you must retain the sounds that you plan to use in your init method.
tickPlayer = [[NSSound soundNamed:#"Hat1"] retain];
tockPlayer = [[NSSound soundNamed:#"Hat2"] retain];
And Cocoa methods should start with a lowercase letter like I've written them. I'm not too sure how metronomes are supposed to work, so you may have to change the value of 12 to something else.