Pausing a NSTimer/Stopwatch [duplicate] - ios

Question

This question already has an answer here:
Adding pause functionality for NSTimer
(1 answer)
Closed 9 years ago.
In the project I am working on I need to have a stopwatch that will pause and continue. So far All of the basic functions work, but I have not been able to find a way to pause the timer and re-start it. FYI, I have already checked the other postings and they didn't work. Code:
.h:
#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
#interface Timer : UIViewController <AVAudioRecorderDelegate, AVAudioPlayerDelegate>
{
AVAudioRecorder *recorder;
AVAudioPlayer *player;
}
#property (weak, nonatomic) IBOutlet UIButton *recordPauseButton;
#property (weak, nonatomic) IBOutlet UIButton *stopButton;
#property (weak, nonatomic) IBOutlet UILabel *stopwatchLabel;
-(IBAction)recordPauseTapped:(id)sender;
-(IBAction)stopTapped:(id)sender;
#end
.m:
#import "Timer.h"
#interface SongIdeasRecording ()
#property (strong, nonatomic) NSTimer *stopWatchTimer; // Store the timer that fires after a certain time
#property (strong, nonatomic) NSDate *startDate; // Stores the date of the click on the start button
#end
#implementation Timer
#synthesize stopButton, playButton, recordPauseButton, stopwatchLabel;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)updateTimer
{
// Timer is 1/10 of a second so thats what we add to stopwatch
NSTimeInterval timeInterval = 0.1;
// Create a date formatter
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"HH:mm:ss.SSS"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]];
// Take the time currently displayed on the stopwatch and add the time interval to it
NSDate *oldDate = [dateFormatter dateFromString:self.stopwatchLabel.text];
NSDate *newDate = [oldDate dateByAddingTimeInterval:timeInterval];
//Get a string representation of the new date
NSString *timeString = [dateFormatter stringFromDate:newDate];
self.stopwatchLabel.text = timeString;
}
- (IBAction)recordPauseTapped:(id)sender {
self.startDate = [NSDate date];
// Create the stop watch timer that fires every 100 ms
self.stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0
target:self
selector:#selector(updateTimer)
userInfo:nil
repeats:YES];
// Stop the audio player before recording
if (player.playing) {
[player stop];
}
if (!recorder.recording) {
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setActive:YES error:nil];
// Start recording
[recorder record];
[recordPauseButton setTitle:#"Pause" forState:UIControlStateNormal];
} else {
// Pause recording
[self.stopWatchTimer invalidate];
self.stopWatchTimer = nil;
[self updateTimer];
[recorder pause];
[recordPauseButton setTitle:#"Record" forState:UIControlStateNormal];
}
[stopButton setEnabled:YES];
[playButton setEnabled:NO];
}
- (IBAction)stopTapped:(id)sender {
[recorder stop];
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setActive:NO error:nil];
[self.stopWatchTimer invalidate];
self.stopWatchTimer = nil;
[self updateTimer];
}
- (void) audioRecorderDidFinishRecording:(AVAudioRecorder *)avrecorder successfully: (BOOL)flag{
[recordPauseButton setTitle:#"Record" forState:UIControlStateNormal];
[stopButton setEnabled:NO];
[playButton setEnabled:YES];
}
- (IBAction)playTapped:(id)sender {
if (!recorder.recording){
player = [[AVAudioPlayer alloc] initWithContentsOfURL:recorder.url error:nil];
[player setDelegate:self];
[player play];
self.startDate = [NSDate date];
stopwatchLabel.text = #"00:00:00.000";
self.stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0
target:self
selector:#selector(updateTimer)
userInfo:nil
repeats:YES];
}
}
- (void) audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
[self.stopWatchTimer invalidate];
self.stopWatchTimer = nil;
[self updateTimer];
}
#end

Answer 1

In your case, you are calculating the value of the stopwatch label with the NSDate that the record button was originally pressed. There is no way to pause the timer in this way, as for every time you recalculate the value of the stopwatch label, it will reflect the original date of which the record button was pressed. I would recommend changing this method to something like this:
- (void)updateTimer
{
// Timer is 1/10 of a second so thats what we add to stopwatch
NSTimeInterval timeInterval = 0.1;
// Create a date formatter
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"HH:mm:ss.SSS"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]];
// Take the time currently displayed on the stopwatch and add the time interval to it
NSDate *oldDate = [dateFormatter dateFromString:self.stopwatchLabel.text];
NSDate *newDate = [oldDate dateByAddingTimeInterval:timeInterval];
//Get a string representation of the new date and BOOM POW.
NSString *timeString = [dateFormatter stringFromDate:newDate];
self.stopwatchLabel.text = timeString;
}
Have not tested this but I hope it works. I wouldn't be surprised if there were some syntax issues too. Also, make sure the string that is in self.stopwatchLabel.text follows the format to start (Ex. 00:00:00.000).

Answer 2

Try commenting your code inside - (void) audioPlayerDidFinishPlaying:(AVAudioPlayer *)player.
My guess is that in - (IBAction)recordPauseTapped:(id)sender you're calling [player stop], which triggers - (void) audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag which invalidates your new timer.

Answer 3

- (IBAction)recordPauseTapped:(id)sender {
if ([stopwatchLabel.text isEqual: #"00:00:00.000"]) {
self.startDate = [NSDate date];
// Create the stop watch timer that fires every 100 ms
self.stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0
target:self
selector:#selector(updateTimer)
userInfo:nil
repeats:YES];
// Stop the audio player before recording
if (player.playing) {
[player stop];
}
if (!recorder.recording) {
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setActive:YES error:nil];
// Start recording
[recorder record];
[recordPauseButton setTitle:#"Pause" forState:UIControlStateNormal];
}
}else {
// Pause recording
[self.stopWatchTimer invalidate];
self.stopWatchTimer = nil;
[self updateTimer];
[recorder pause];
[recordPauseButton setTitle:#"Record" forState:UIControlStateNormal];
}
[stopButton setEnabled:YES];
[playButton setEnabled:NO];
}