How do I stop all transitions stored in a table?

Solar2D General Questions/Discussion
#1

I have the following code which fades in and out an object using transitions.  After a certain amount of time I’d like to cancel these transitions and remove them from memory.

However after calling the clearTransitions() method below I can see that the tables are cleared (size is 0) however the transitions still run.  Why do they still run?  Any info would be greatly appreciated.

arrowFadeInTransitions = {} arrowFadeOutTransitions = {} arrows = {rect1, rect2, rect3} -- some display object like a rectangle for example beginFadingArrows(arrows) beginFadingArrows = function(arrows)      for i = 1, #arrows do         local arrow = arrows[i]          timer.performWithDelay(400\*i,function() fadeInArrow(arrow) end)      end end fadeInArrow = function(self)     self.onComplete = fadeOutArrow     if #arrowFadeInTransitions \> 7 then -- clear the transitions and stop them running         clearTransitions()     end     arrowFadeInTransitions[#arrowFadeInTransitions + 1] = transition.to(self,{alpha = 1, time=900, onComplete = self}) end fadeOutArrow = function(self)     self.onComplete = fadeInArrow     arrowFadeOutTransitions[#arrowFadeOutTransitions + 1] = transition.to(self,{alpha = 0, time=900, onComplete = self}) end clearTransitions = function()     for i=#arrowFadeInTransitions,1,-1 do      transition.cancel(arrowFadeInTransitions[i])      arrowFadeInTransitions[i]=nil     end     for i=#arrowFadeOutTransitions,1,-1 do      transition.cancel(arrowFadeOutTransitions[i])      arrowFadeOutTransitions[i]=nil     end     print(#arrowFadeInTransitions) -- sizes are 0 but transitions still run     print(#arrowFadeOutTransitions) -- sizes are 0 but transitions still run end
#2

suggest you assign an “.id” property to each “arrow” and monitor (ie print something) whenever a transition starts or finishes.
 
i think (did not attempt to run the code) you’ve got some mixed-up logic in there, specifically the “if #arrowFadeInTransitions > 7 then” bit.  (it’s so mixed up that i’m not even sure what it’s intended to do - so not entirely sure how to suggest fixing it)

i think, given the initial delays, and timings of the transitions, that you are NOT guaranteed that the first 7 transitions are on unique objects.  (especially since you seem to only have 3 - it’s not clear where that “magic” number 7 is coming from)

i think “half” of the transitions you’re cancelling are already dead, but you’ll end up creating another “half-batch” of transitions on the remaining objects before you reach 7 total transitions and clear them again (and again cancelling half that are already dead).

then you fire off a new one, so i don’t see a way this system ever ends (just confirming as you’ve reported) but i can’t guess at the desired result to offer a possible “fix” for it.

#3

Transitions support the concept of tags. If you have a group of transitions that you need to pause or cancel at the same time, simply assign them the same tag, then you can cancel or pause by tag.

While this won’t help with the issues that @davebollinger pointed out, it’s a way of assigning an id, using transition parameters and standard features.

Rob

#4

Thanks for the replies.  The magic number 7 is just a test to see if the transitions stop after a short period of time.  Probably not the best idea to show what I was trying to achieve.  What I probably didn’t make clear is that I want to clear the transitions from memory as this animation is only done during one scene.  I don’t want the transitions continually being added to the table and taking up memory.

#5

Thanks again for the replies Rob and Dave.  I moved the ‘clearTransaction()’ outside the create transition method and all transitions are cancelled and cleared as expected.

#6

suggest you assign an “.id” property to each “arrow” and monitor (ie print something) whenever a transition starts or finishes.
 
i think (did not attempt to run the code) you’ve got some mixed-up logic in there, specifically the “if #arrowFadeInTransitions > 7 then” bit.  (it’s so mixed up that i’m not even sure what it’s intended to do - so not entirely sure how to suggest fixing it)

i think, given the initial delays, and timings of the transitions, that you are NOT guaranteed that the first 7 transitions are on unique objects.  (especially since you seem to only have 3 - it’s not clear where that “magic” number 7 is coming from)

i think “half” of the transitions you’re cancelling are already dead, but you’ll end up creating another “half-batch” of transitions on the remaining objects before you reach 7 total transitions and clear them again (and again cancelling half that are already dead).

then you fire off a new one, so i don’t see a way this system ever ends (just confirming as you’ve reported) but i can’t guess at the desired result to offer a possible “fix” for it.

#7

Transitions support the concept of tags. If you have a group of transitions that you need to pause or cancel at the same time, simply assign them the same tag, then you can cancel or pause by tag.

While this won’t help with the issues that @davebollinger pointed out, it’s a way of assigning an id, using transition parameters and standard features.

Rob

#8

Thanks for the replies.  The magic number 7 is just a test to see if the transitions stop after a short period of time.  Probably not the best idea to show what I was trying to achieve.  What I probably didn’t make clear is that I want to clear the transitions from memory as this animation is only done during one scene.  I don’t want the transitions continually being added to the table and taking up memory.

#9

Thanks again for the replies Rob and Dave.  I moved the ‘clearTransaction()’ outside the create transition method and all transitions are cancelled and cleared as expected.