maxSlideThreshold property
maxSlideThreshold would be used to determine the max ratio of the panel that can slide, it should be in 0, 1
for example, if child's size is Size(200, 100) along Axis.horizontal, the max sliding distance would be 200 * maxSlideThreshold along Axis.horizontal, and the max sliding distance would be converted to a tight BoxConstraints for layouting SlideActionPanels
Implementation
final double maxSlideThreshold;