keys.quickOffset and keys.move stored the drag's new total before the
edit ran. When the edit refused the step (keys.quickOffset with a key
landing past the end of time), the project stayed as it was but the
total kept the refused delta, and with incremental steps (merge without
fromStart) the next step moved by it too.
The drag state is now stored only after the edit applies.
Test: a_refused_step_does_not_count_towards_the_drag (+1 s, a refused
step, -1 s: the keys end where they started; fails before: the last key
ends near the end of time).
keys.move and the nudges snapped each key's destination to the nearest
frame, so moving keys a Quick Offset had staggered onto subframes put
them back on frames: four keys at 0, 1/3, 2/3 and 1 frame, moved one
frame, came out at 1, 1, 2 and 2. Layer bars kept theirs, because
layer.timing snaps the move, not the times.
The move is now rounded to whole frames and every key translated by it.
layer_shift turns a comp-time move into a layer-time move through the
layer's start and stretch (reversed too) without a round trip through
comp time; keys.quickOffset uses it as well.
Test: moving_staggered_keys_keeps_their_subframe_spacing (Quick Offset,
then keys.move and keys.nudgeForward; fails before: 1/3 frame lands on
a frame).
After Effects 25.4's Quick Offset staggers selected layers, or each
layer's selected keyframes, in the order they were selected: the first
stays, the last moves by the drag and the ones between by equal steps,
landing on subframes.
layer.quickOffset {delta, layers?} moves each layer's start, in and out
point by total * i / (n - 1), worked out once in ticks with integer
arithmetic, so 1 frame over 4 layers gives 0, 1/3, 2/3 and 1 frame
exactly. keys.quickOffset {delta} does the same per layer for the
selected keys, the layers in the order their first key was selected;
every selected key of a layer, across its properties, moves by that
layer's comp-time offset through its start and stretch (reversed too),
keeping values, interpolation, easing and labels. Locked layers are
skipped and at least two layers are needed. With merge and fromStart,
delta is the whole drag and each step starts again from before it, so
the drag is one undo step and a key passed over survives. A delta or a
destination out of the range of times is an error, not a clamped move.
Docs: agents.md; architecture.md notes Quick Offset as the exception to
times snapping to frames.
tylerjenningsw