References

• Fixes Scroll Jumps and jarring effect with full windowing mode #16326
• Should also fix Scrolling over notebook got unexpected jump backs jupyter-book/jupyterlab-myst#243

Code changes

Adds cellHeightStabilization and assumeHeightStabilityAfter options:

• cellHeightStabilization: Whether to pin height of the cells when scrolling to stabilize viewport (prevent jitter), and for how long since the last scroll event (in milliseconds).
• assumeHeightStabilityAfter: If cell height stabilization is enabled, how many milliseconds should pass since the last height measurement for the stabilization algorithm to be allowed to pin the cell height

To be done:

• minimise public API additions (widgetSizes exposure/_getCellIndex method)
• confirm the default choices:
  • should assumeHeightStabilityAfter be 5 seconds favouring some widgets rendering for up to seconds and less frequent output "unroll" animation, or should it be 1 second favouring more stability when scrolling but less frequent "unroll" animations?
  • what should cellHeightStabilization be? Ideally it is as large as to catch consecutive scroll events (i.e. >= interval between mouse scroll wheel steps, or mouse movements when using scrollbar), and as small as to minimise the time before the outputs are "unrolled" after the scroll stopped.

User-facing changes

Scrolling is no longer jittery.

Backwards-incompatible changes

None