Audio streaming playback: unable to change play/stop button image - ios

Question

I'm developing a radio streaming app with XCode 4.5 for iOS 6 and mainly using storyboards.
I successfully made it to be able to play in background. So wherever I go from my app, whether to other tabs or even after clicking the Home button on the simulator,it keeps playing.
I'm using Matt Gallagher's audio streamer, which I include in my app delegate .m file below
#pragma mark - audio streaming
- (void)playAudio:(indoRadio *)np withButton:(NSString *)currentButton
{
if ([currentButton isEqual:#"playbutton.png"])
{
[self.nowplayingVC.downloadSourceField resignFirstResponder];
[self createStreamer:np.URL];
[self setButtonImageNamed:#"loadingbutton.png"];
[audioStreamer start];
}
else
{
[audioStreamer stop];
}
}
- (void)createStreamer:(NSString *)url
{
if (audioStreamer)
{
return;
}
[self destroyStreamer];
NSString *escapedValue = (__bridge NSString *)CFURLCreateStringByAddingPercentEscapes(nil,(CFStringRef)url,NULL,NULL,kCFStringEncodingUTF8);
NSURL *streamurl = [NSURL URLWithString:escapedValue];
audioStreamer = [[AudioStreamer alloc] initWithURL:streamurl];
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:#selector(playbackStateChanged:)
name:ASStatusChangedNotification
object:audioStreamer];
}
- (void)playbackStateChanged:(NSNotification *)aNotification
{
NSLog(#"playback state changed? %d",[audioStreamer isWaiting]);
if ([audioStreamer isWaiting])
{
[self setButtonImageNamed:#"loadingbutton.png"];
}
else if ([audioStreamer isPlaying])
{
[self setButtonImageNamed:#"stopbutton.png"];
}
else if ([audioStreamer isIdle])
{
[self destroyStreamer];
[self setButtonImageNamed:#"playbutton.png"];
}
}
- (void)destroyStreamer
{
if (audioStreamer)
{
[[NSNotificationCenter defaultCenter]
removeObserver:self
name:ASStatusChangedNotification
object:audioStreamer];
[audioStreamer stop];
audioStreamer = nil;
}
}
- (void)setButtonImageNamed:(NSString *)imageName
{
if (!imageName)
{
imageName = #"playButton";
}
self.nowplayingVC.currentImageName = imageName;
UIImage *image = [UIImage imageNamed:imageName];
[self.nowplayingVC.playBtn.layer removeAllAnimations];
[self.nowplayingVC.playBtn setImage:image forState:0];
if ([imageName isEqual:#"loadingbutton.png"])
{
[self.nowplayingVC spinButton];
}
}
The problem I got is that when I click the play button, it starts the audio streamers but doesn't change into either loading button or stop button. This makes me unable to stop the audio since the button image is not changed. And since I put an NSLog inside the playbackStateChanged: method,I know that the playback state did change. It seems like the setButtonImagedNamed: method is not firing. Any thoughts?

Answer 1

Please have look of my answer:Disabled buttons not changing image in
For a button there is normal, selected, highlighted and disabled state.
So in your case you have to handle the normal and selected state.
In the xib, set image to a button for normal and selected state.
Now in the function of playAudio instead of checking the image name check the button state as below:
- (void)playAudio:(indoRadio *)np withButton:(NSString *)currentButton
{
if (playButton.selected)
{
//Stop the streaming
//set selection NO
[playButton setSelected:NO];
}
else
{
//Start the streaming
//set selection YES
[playButton setSelected:YES];
}
}
playButton is the IBOutlet of play button.
As you have set the images in xib, so the image automatically get changed as per the state of the image

Answer 2

In case you have added the playBtn programmatically, check if the button is declared as weak or its getting released somewhere. If it is weak, make it strong.
In case the button is in the nib file, then the problem is in the IBOutlet. Redo the connection properly.

Answer 3

It turned out that the delegate didn't know which nowplayingVC I was calling. #sarp-kaya's question about Calling a UIViewController method from app delegate has inspired me.
I actually have put this code in my view controller viewDidLoad:
myAppDelegate* appDelegate = [UIApplication sharedApplication].delegate;
but I forgot to add this line:
appDelegate.nowplayingVC = self;
So, all I need to do is adding that one line and it works now. okay, so silly of me for not noticing such a basic thing. But thanks for your helps :D