Native browser undo breaks when ta.value is set programmatically (tab,
enter, ctrl+/) — replaced with a custom snapshot-based undo system.
Stack behaviour:
- oninput → debounced capture (600ms) — groups rapid typing into chunks
- Tab / Enter / Ctrl+/ → immediate capture BEFORE edit, then capture AFTER
(each programmatic edit gets its own undo step)
- Content load → vvUndoCaptureInitial() seeds the stack with a clean baseline
- Max 200 history entries (VV_UNDO_MAX); old entries dropped from front
Keyboard: Ctrl/Cmd+Z = undo, Ctrl/Cmd+Y or Ctrl/Cmd+Shift+Z = redo
(both handled in vvEditorKeydown before any other key processing)
Buttons: ↩ Undo / ↪ Redo appear in toolbar beside Cancel/Save when editor
is open; disabled state with 0.28 opacity when no steps available; Undo
button shows step count "↩ Undo 5" so you can see how deep the history is
Cleanup: vvEditorReset() calls vvUndoReset() so stack is cleared on every
editor open/close — fresh baseline each time
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
