umputun / revdiff / 40219475053

91%

push

github

feat(ui): scroll the diff pane with the horizontal wheel (#411)

* feat(ui): scroll the diff pane with the horizontal wheel

horizontal wheel and trackpad swipes over the diff pane were swallowed. Each
scrollX change invalidates the whole render cache, so rendering per event would
bring back the #179 stall on a fast swipe. The first event with no wheel tick
in flight repaints at once, later events in the burst only set
wheelState.xPending, and the existing wheel tick repaints once per interval.
xPending is kept apart from renderPending so a mid-burst repaint never
discharges a vertical cursor pin.

Related to #334

* fix(ui): drop wheel ticks scheduled before a flush

a key press, resize or blame load during a wheel burst flushes pending work
and clears tickInFlight, but cannot cancel the tick already scheduled. With
horizontal wheel support that leftover tick could clear a newer tick's
ownership or repaint beside it, which could start a second tick chain and
trigger extra full renders during a sideways swipe. Ticks now carry an epoch that
flushWheelPending bumps, and handleWheelDebounce drops a tick from an older
epoch.

Related to #334

44 of 44 new or added lines in 1 file covered. (100.0%)

12192 of 13393 relevant lines covered (91.03%)

3475.88 hits per line