Editorauswahl, Fokus und Eingabe

Selection, Focus & Input Handling

Use this skill when implementing cursor management, text/block selection, focus restoration, IME input composition, or keyboard navigation in visual editors.

Predictable Selection & Focus Lifecycle

1. Preserve Selection Across Renders and Edits:
   • Never reset the caret to the start or end of a block on re-render by binding contenteditable directly to reactive state without selection mapping.
   • Use the editor library's position mapping (Selection, ResolvedPos, node key + offset) so insertions, splits, merges, and formatting changes keep the caret in the exact expected logical position.
2. Deterministic Focus After Structural Operations:
   • Split (Enter): Move focus and caret to the start of the newly created block.
   • Merge / Backspace at Block Start: Join with the preceding text block and place the caret at the join boundary, or select an preceding atomic block (NodeSelection).
   • Delete Block: Move focus predictably to the adjacent previous or next block; if the last block is deleted, insert an empty default block and focus it.
   • Inspector / Toolbar Interaction: Modifying block attributes from a floating toolbar or side panel must either preserve the editor selection or restore focus cleanly when the user returns to typing.

IME Composition & International Input Safety

• Never Interrupt Active IME Sessions (isComposing):
  • Users typing CJK characters, dead-key accents, or mobile predictive text rely on compositionstart $\to$ compositionupdate $\to$ compositionend.
  • Never trigger slash menus, Markdown auto-format rules (inputRules), block splits on Enter, or state-resetting re-renders while event.isComposing or view.composing is true; defer structural transforms until compositionend.

Keyboard Shortcuts & Navigation Boundaries

• Respect Platform & Browser Shortcuts:
  • Only call event.preventDefault() when the editor actively handles the shortcut in the current context. Never swallow system shortcuts (tab switching, browser zoom, screen-reader navigation, OS clipboard/window commands).
• Isolating Boundaries:
  • Handle arrow-key and Tab navigation cleanly across nested blocks, tables, code blocks, and embedded widgets so focus never gets trapped or jumps unexpectedly.

Checklist

• Does the caret remain in the exact logical position across re-renders, splits, merges, and toolbar formatting?
• Is focus placed deterministically after block creation, deletion, reordering, and modal/popover closure?
• Are isComposing / IME composition events respected without premature shortcut or input-rule interception?
• Are native browser and OS keyboard shortcuts preserved whenever the editor does not explicitly handle them?