Notes

//
// IDZViewController.m
// IDZAudoPlayerTutorial
//
// Created by idz on 10/1/12.
// Copyright (c) 2012 iosdeveloperzone.com. All rights reserved.
//

#import "IDZViewController.h"


#define IDZTrace() NSLog(@"%s", __PRETTY_FUNCTION__)

@interface IDZViewController ()

@property (nonatomic, strong) AVAudioPlayer* player;
@property (nonatomic, strong) NSTimer* timer;

- (void)updateDisplay;
- (void)updateSliderLabels;

- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player
successfully:(BOOL)flag;
- (void)audioPlayerDecodeErrorDidOccur:(AVAudioPlayer *)player
error:(NSError *)error;

@end

@implementation IDZViewController
@synthesize currentTimeLabel = mCurrentTimeLabel;
@synthesize deviceCurrentTimeLabel = mDeviceCurrentTimeLabel;
@synthesize durationLabel = mDurationLabel;
@synthesize numberOfChannelsLabel = mNumberOfChannels;
@synthesize playingLabel = mPlayingLabel;
@synthesize elapsedTimeLabel = mElapsedTimeLabel;
@synthesize remainingTimeLabel = mRemainingTimeLabel;
@synthesize currentTimeSlider = mCurrentTimeSlider;
@synthesize playButton = mPlayingButton;
@synthesize pauseButton = mPauseButton;
@synthesize stopButton = mStopButton;
@synthesize player = mPlayer;
@synthesize timer = mTimer;


#pragma mark - View Lifecycle

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
NSURL* url = [[NSBundle mainBundle] URLForResource:@"Sila" withExtension:@".mp3"];
NSAssert(url, @"URL is valid.");
NSError* error = nil;
self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
if(!self.player)
{
NSLog(@"Error creating player: %@", error);
}
self.player.delegate = self;
[self.player prepareToPlay];
// Fill in the labels that do not change
self.durationLabel.text = [NSString stringWithFormat:@"%.02fs",self.player.duration];
self.numberOfChannelsLabel.text = [NSString stringWithFormat:@"%d", self.player.numberOfChannels];
self.currentTimeSlider.minimumValue = 0.0f;
self.currentTimeSlider.maximumValue = self.player.duration;
[self updateDisplay];
}

- (void)viewDidUnload
{
[self setPauseButton:nil];
[self setPlayButton:nil];
[self setStopButton:nil];
[self setCurrentTimeLabel:nil];
[self setDeviceCurrentTimeLabel:nil];
[self setDurationLabel:nil];
[self setNumberOfChannelsLabel:nil];
[self setPlayingLabel:nil];
[self setElapsedTimeLabel:nil];
[self setRemainingTimeLabel:nil];
[self setCurrentTimeSlider:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

#pragma mark - Actions

- (IBAction)play:(id)sender {
IDZTrace();
[self.player play];
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(timerFired:) userInfo:nil repeats:YES];

}

- (IBAction)pause:(id)sender {
IDZTrace();
[self.player pause];
[self stopTimer];
[self updateDisplay];
}

- (IBAction)stop:(id)sender {
IDZTrace();
[self.player stop];
[self stopTimer];
self.player.currentTime = 0;
[self.player prepareToPlay];
[self updateDisplay];
}

- (IBAction)currentTimeSliderValueChanged:(id)sender
{
if(self.timer)
[self stopTimer];
[self updateSliderLabels];
}

- (IBAction)currentTimeSliderTouchUpInside:(id)sender
{
[self.player stop];
self.player.currentTime = self.currentTimeSlider.value;
[self.player prepareToPlay];
[self play:self];
}

#pragma mark - Display Update
- (void)updateDisplay
{
NSTimeInterval currentTime = self.player.currentTime;
NSString* currentTimeString = [NSString stringWithFormat:@"%.02f", currentTime];

self.currentTimeSlider.value = currentTime;
[self updateSliderLabels];

self.currentTimeLabel.text = currentTimeString;
self.playingLabel.text = self.player.playing ? @"YES" : @"NO";
self.deviceCurrentTimeLabel.text = [NSString stringWithFormat:@"%.02f", self.player.deviceCurrentTime];
}

- (void)updateSliderLabels
{
NSTimeInterval currentTime = self.currentTimeSlider.value;
NSString* currentTimeString = [NSString stringWithFormat:@"%.02f", currentTime];

self.elapsedTimeLabel.text = currentTimeString;
self.remainingTimeLabel.text = [NSString stringWithFormat:@"%.02f", self.player.duration - currentTime];
}

#pragma mark - Timer
- (void)timerFired:(NSTimer*)timer
{
[self updateDisplay];
}

- (void)stopTimer
{
[self.timer invalidate];
self.timer = nil;
[self updateDisplay];
}

#pragma mark - AVAudioPlayerDelegate
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
NSLog(@"%s successfully=%@", __PRETTY_FUNCTION__, flag ? @"YES" : @"NO");
[self stopTimer];
[self updateDisplay];
}

- (void)audioPlayerDecodeErrorDidOccur:(AVAudioPlayer *)player error:(NSError *)error
{
NSLog(@"%s error=%@", __PRETTY_FUNCTION__, error);
[self stopTimer];
[self updateDisplay];
}

@end