SPTween affecting sprite position even after removal

abvi

Either I'm missing something basic, or there's a bug in SPTween.

I have a "balloon" class derived from SPSprite that has a tween attached to it:

// In init function of class myBalloon (subclass of SPSprite)
mTween2 = [SPTween tweenWithTarget:self time:10 transition:SP_TRANSITION_LINEAR];
[mTween2 animateProperty:@"y" targetValue:-50];
mTween2.repeatCount = 1; // repeat indefinitely
mTween2.reverse = NO;

The tween makes the balloon float upward.

When an event occurs, I want to reset the balloon to the bottom of the screen and then float up again. So I remove the old tween, set self.y, and attach a new tween:

// remove all tweens, including the one that makes the balloon float up
[Sparrow.juggler removeObjectsWithTarget:self];

// reset pos
self.y = 770; // place at bottom of screen

// attach the tween again
mTween2 = [SPTween tweenWithTarget:self time:10 transition:SP_TRANSITION_LINEAR];
[mTween2 animateProperty:@"y" targetValue:-50];
mTween2.repeatCount = 1; // repeat indefinitely
mTween2.reverse = NO;

I expect the result to be that the balloon is "reset" to the bottom of the screen, and then floats up from there.

What actually happens is that the balloon continues floating up from the same place on the screen as it previously. I'm resetting self.x to a random value as well, so what actually happens is that the balloon seems to "jump" horizontally and then continue its upward motion.

I've traced the balloon's y position through a callback for the SP_EVENT_TYPE_ENTER_FRAME event, and I can see that it seems to continue from its previous (tweened) y position even after it's reset to 770.

I've dug into this as much as possible, and I don't see any bug in my code. Is there something I'm doing wrong, or is the previous SPTween somehow not getting detached from the object and preventing its y value from being reset?

Shilo

I don't see a problem with the code you provided. You didn't provide the code for adding the tween to the juggler though. If the tween is added to a custom juggler (not Sparrow.juggler), than you will need to remove the tween from the same custom juggler. If you are adding the tween to Sparrow.juggler, I don't see what would be causing the problem.

What version of Sparrow are you using? The MRC (newest bleeding-edge) version could possibly still have bugs.

My suggestions are the following:

Replace this line:

[Sparrow.juggler removeObjectsWithTarget:self];

... With this line:

[Sparrow.juggler removeObject:mTween2]

Create a barebones project with the code you provided and see the problem is replicated.
Try an alternative version of Sparrow to see if the problem is replicated.
Remove all the code below:

[Sparrow.juggler removeObjectsWithTarget:self];

... and test to make sure the object stops.

Than add this line below the above line:

self.y = 770;

... and test to make sure the object stops and is repositioned.

If your project is fairly big, you could be over-looking code that might create unexpected behaviors, such as overriding core methods or extensions, or other code that manipulates the tween, juggler, or balloon object.

The below sample code works fine for me. I am using Sparrow 2.0 (ARC version):

@implementation Game
{
    SPQuad *mQuad;
    SPTween *mTween2;
}

- (id)init
{
    if ((self = [super init]))
    {
        mQuad = [SPQuad quadWithWidth:100 height:100];
        mQuad.color = 0xff0000;
        mQuad.x = (Sparrow.stage.width-100)/2;
        mQuad.y = 770;
        [self addChild:mQuad];

        mTween2 = [SPTween tweenWithTarget:mQuad time:10 transition:SP_TRANSITION_LINEAR];
        [mTween2 animateProperty:@"y" targetValue:-50];
        mTween2.repeatCount = 1; // repeat indefinitely
        mTween2.reverse = NO;
        [Sparrow.juggler addObject:mTween2];

        [self addEventListener:@selector(onTouch:) atObject:self forType:SP_EVENT_TYPE_TOUCH];
    }
    return self;
}

- (void)onTouch:(SPTouchEvent *)event
{
    if (((SPTouch *)[event touches].anyObject).phase != SPTouchPhaseEnded) return;

    NSLog(@"reset");

    // remove all tweens, including the one that makes the balloon float up
    [Sparrow.juggler removeObjectsWithTarget:mQuad];

    // reset pos
    mQuad.y = 770; // place at bottom of screen

    // attach the tween again
    mTween2 = [SPTween tweenWithTarget:mQuad time:10 transition:SP_TRANSITION_LINEAR];
    [mTween2 animateProperty:@"y" targetValue:-50];
    mTween2.repeatCount = 1; // repeat indefinitely
    mTween2.reverse = NO;
    [Sparrow.juggler addObject:mTween2];
}

- (void)render:(SPRenderSupport *)support
{
    [super render:support];
    NSLog(@"mQuad.y = %i", (int)mQuad.y);
}

@end