Classes/MyViewController.m

/*
     File: MyViewController.m 
 Abstract: The main view controller of this app 
  Version: 1.1.1 
  
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*/
 
#import "MyViewController.h"
 
#define kTransitionDuration 0.75
 
@implementation MyViewController
 
@synthesize instructionsView, webView, contentView, flipButton, doneButton, startButton, bus0Switch, bus0VolumeSlider, bus1Switch, bus1VolumeSlider, outputVolumeSlider, mixerController;
 
#pragma mark- UIView
 
- (void)viewDidLoad
{
    // load up the info text
    NSString *infoSouceFile = [[NSBundle mainBundle] pathForResource:@"info" ofType:@"html"];
    NSString *infoText = [NSString stringWithContentsOfFile:infoSouceFile encoding:NSUTF8StringEncoding error:nil];
    [self.webView loadHTMLString:infoText baseURL:nil];
    
    // set up start button
    UIImage *greenImage = [[UIImage imageNamed:@"green_button.png"] stretchableImageWithLeftCapWidth:12.0 topCapHeight:0.0];
    UIImage *redImage = [[UIImage imageNamed:@"red_button.png"] stretchableImageWithLeftCapWidth:12.0 topCapHeight:0.0];
    
    [startButton setBackgroundImage:greenImage forState:UIControlStateNormal];
    [startButton setBackgroundImage:redImage forState:UIControlStateSelected];
    
    // add the subview
    [self.view addSubview:contentView];
    
    // add our custom flip buttons as the nav bars custom right view
    UIButton* infoButton = [UIButton buttonWithType:UIButtonTypeInfoLight];
    [infoButton addTarget:self action:@selector(flipAction:) forControlEvents:UIControlEventTouchUpInside];
    
    flipButton = [[UIBarButtonItem alloc] initWithCustomView:infoButton];
    self.navigationItem.rightBarButtonItem = flipButton;
    
    // create our done button as the nav bar's custom right view for the flipped view (used later)
    doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(flipAction:)];
}
 
- (void)didReceiveMemoryWarning
{
    // invoke super's implementation to do the Right Thing. In practice this is unlikely to be used in this application,
    // and it would be of little benefit, but the principle is the important thing.
    [super didReceiveMemoryWarning];
}
 
- (void)dealloc
{    
    [instructionsView release];
    [webView release];
    [contentView release];
    
    self.flipButton = nil;
    self.doneButton = nil;
 
    [startButton release];
    
    [bus0Switch release];
    [bus0VolumeSlider release];
    [bus1Switch release];
    [bus1VolumeSlider release];
    [outputVolumeSlider release];
        
    [mixerController release];
    
    [super dealloc];
}
 
#pragma mark-
 
// set the mixers values according to the UI state
- (void)setUIDefaults
{
    [mixerController enableInput:0 isOn:bus0Switch.isOn];
    [mixerController enableInput:1 isOn:bus1Switch.isOn];
    [mixerController setInputVolume:0 value:bus0VolumeSlider.value];
    [mixerController setInputVolume:1 value:bus1VolumeSlider.value];
    [mixerController setOutputVolume:outputVolumeSlider.value];
}
 
// do the info button flip
- (void)flipAction:(id)sender
{
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(animationDidStop:animationIDfinished:finished:context:)];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:kTransitionDuration];
    
    [UIView setAnimationTransition:([self.contentView superview] ? UIViewAnimationTransitionFlipFromLeft : UIViewAnimationTransitionFlipFromRight)
                                    forView:self.view
                                    cache:YES];
                                    
    if ([self.instructionsView superview]) {
        [self.instructionsView removeFromSuperview];
        [self.view addSubview:contentView];
    } else {
        [self.contentView removeFromSuperview];
        [self.view addSubview:instructionsView];
    }
    
    [UIView commitAnimations];
    
    // adjust our done/info buttons accordingly
    if ([instructionsView superview]) {
        self.navigationItem.rightBarButtonItem = doneButton;
    } else {
        self.navigationItem.rightBarButtonItem = flipButton;
    }
}
 
// called if we've been interrupted and if we're playing, stop
- (void)stopForInterruption
{
    if (mixerController.isPlaying) {
        [mixerController stopAUGraph];
        self.startButton.selected = NO;
    }
}
 
#pragma mark- Actions
 
// handle input on/off switch action
- (IBAction)enableInput:(UISwitch *)sender
{
    UInt32 inputNum = [sender tag];
    AudioUnitParameterValue isOn = (AudioUnitParameterValue)sender.isOn;
    
    if (0 == inputNum) self.bus0VolumeSlider.enabled = isOn;
    if (1 == inputNum) self.bus1VolumeSlider.enabled = isOn;
                                    
    [mixerController enableInput:inputNum isOn:isOn];
}
 
// handle input volume changes
- (IBAction)setInputVolume:(UISlider *)sender
{
    UInt32 inputNum = [sender tag];
    AudioUnitParameterValue value = sender.value;
    
    [mixerController setInputVolume:inputNum value:value];
}
 
// handle output volume changes
- (IBAction)setOutputVolume:(UISlider *)sender
{
    AudioUnitParameterValue value = sender.value;
    
    [mixerController setOutputVolume:value];
}
 
// handle the button press
- (IBAction)doSomethingAction:(id)sender
{
    if (mixerController.isPlaying) {
        [mixerController stopAUGraph];
        self.startButton.selected = NO;
    } else {
        [mixerController startAUGraph];
        self.startButton.selected = YES;
    } 
}
 
@end