A spinner running in the background consuming CPU is two bugs...
The non-obvious one is why is the framework consuming any CPU time at all on something not visible? When an element tries to animate, and the whole element is covered/offscreen, the framework should simply pause the animation. When the element becomes visible again, it's simple to calculate how long the element has been invisible, and fast-forward the animation to that frame.
The non-obvious one is why is the framework consuming any CPU time at all on something not visible? When an element tries to animate, and the whole element is covered/offscreen, the framework should simply pause the animation. When the element becomes visible again, it's simple to calculate how long the element has been invisible, and fast-forward the animation to that frame.