I have my NSTimer embedded in a class that plays image sequences. Basically it loops and changes a UIImageView. Everything goes well if I let the image sequence finish but... on it's own if I try to stop the timer while it is playing I get a sigabrt. Edit: No longer a sigabrt but now a DeAlloc I can't explain.
The "stop" at the end of a frame sequence is the same stop I am calling mid sequence.
So what might cause an NSTimer to break mid function and DeAlloc. More to the point what might I look at to fix it.
Thanks.
I am using some example code from here: http://www.modejong.com/iOS/PNGAnimatorDemo.zip
Edit: I'll add what I believe to be the pertinent code here.
// Invoke this method to start the animation
- (void) startAnimating
{
self.animationTimer = [NSTimer timerWithTimeInterval: animationFrameDuration target: self selector: @selector(animationTimerCallback:) userInfo: NULL repeats: TRUE];
[[NSRunLoop currentRunLoop] addTimer: animationTimer forMode: NSDefaultRunLoopMode];
animationStep = 0;
if (avAudioPlayer != nil)
[avAudioPlayer play];
// Send notification to object(s) that regestered interest in a start action
[[NSNotificationCenter defaultCenter]
postNotificationName:ImageAnimatorDidStartNotification
object:self];
}
- (void) animationTimerCallback: (NSTimer *)timer {
if (![self isAnimating])
return;
NSTimeInterval currentTime;
NSUInteger frameNow;
if (avAudioPlayer == nil) {
self.animationStep += 1;
// currentTime = animationStep * animationFrameDuration;
frameNow = animationStep;
} else {
currentTime = avAudioPlayer.currentTime;
frameNow = (NSInteger) (currentTime / animationFrameDuration);
}
// Limit the range of frameNow to [0, SIZE-1]
if (frameNow < 0) {
frameNow = 0;
} else if (frameNow >= animationNumFrames) {
frameNow = animationNumFrames - 1;
}
[self animationShowFrame: frameNow];
// animationStep = frameNow + 1;
if (animationStep >= animationNumFrames) {
[self stopAnimating];
// Continue to loop animation until loop counter reaches 0
if (animationRepeatCount > 0) {
self.animationRepeatCount = animationRepeatCount - 1;
[self startAnimating];
}
}
}
- (void) stopAnimating
{
if (![self isAnimating])
return;
[animationTimer invalidate];
self.animationTimer = nil;
animationStep = animationNumFrames - 1;
[self animationShowFrame: animationStep];
if (avAudioPlayer != nil) {
[avAudioPlayer stop];
avAudioPlayer.currentTime = 0.0;
self->lastReportedTime = 0.0;
}
// Send notification to object(s) that regestered interest in a stop action
[[NSNotificationCenter defaultCenter]
postNotificationName:ImageAnimatorDidStopNotification
object:self];
}
Edit2: So I commented out an NSAssert in DeAlloc, commenting that out shed a bit more light. Now getting to self.animationTimer = nil;
and saying *** -ImageAnimator setAnimationTimer:]: Message sent to deallocated instance.
DeAlloc is being called right when I invalidate the timer... so I'm a bit confused here.
I have a solution which is working but not optimal.
I just added another function to set the frame it's on to the last frame and it ends the sequence as I need.
But it doesn't solve the question of why it's doing it's crashing if I try to stop the sequence mid run.