IconGrid: Keep icons reactive during pulse animation
reactive property of icon actors was being restored multiple times
over the course of the pulse animation, all at slightly different times
as each icon finished animating at different times.
The problem is that toggling
reactive on an
StWidget incurs a style
change of the
insensitive pseudo class, and style changes would quickly
queue relayouts incurring full stage reallocation. This occurred many times
during a pulse animation, limiting its smoothness and performance.
The solution is to not toggle the
reactive property in the pulse
animation at all, which avoids incurring multiple full stage relayouts.
As a bonus, this means the icon under the cursor pulses with the correct selection highlight, appearing more seamless and responsive.