ControlActive¶

ControlActive[active, normal] represents an object that is shown as active while it sits inside a control that is being actively manipulated (e.g. while a slider thumb is being dragged), and as normal at all other times. It is used to substitute a cheaper computation during dragging.

Outside of an interactive notebook nothing is ever actively manipulated, so ControlActive always evaluates to its normal (inactive) form — matching wolframscript in script mode.

$ wo 'ControlActive[1, 2]'
2

The chosen argument is evaluated as usual:

$ wo 'ControlActive[1 + 1, 2 + 2]'
4

$ wo 'ControlActive["fast", "slow"]'
slow

A common pattern is picking a coarse plot while dragging and a fine one once the control settles:

$ wo 'ControlActive[10, 100]'
100

Forms other than the two-argument active/normal split have no inactive value to fall back to, so they stay symbolic:

$ wo 'ControlActive[]'
ControlActive[]