Method beforeMainKeyHandler

src/codemirror.ts:311–369

(
    doc: CodeMirror.Doc,
    event: KeyboardEvent,
    alsoHandle: { tab: boolean; escape: boolean }
  )

  // If true, consume the event.
  // Otherwise, keep going with other logic.
  beforeMainKeyHandler(
    doc: CodeMirror.Doc,
    event: KeyboardEvent,
    alsoHandle: { tab: boolean; escape: boolean }
  ): { consumeEvent: boolean | undefined; forceTriggerCompletion: boolean } {
    let forceTriggerCompletion = false;
    if (event.ctrlKey) {
      if (event.key === ' ') {
        forceTriggerCompletion = true;
      } else {
        return { consumeEvent: false, forceTriggerCompletion };
      }
    }
    // Classic notebook may autocomplete these.
    if ('"\')}]'.includes(event.key)) {
      forceTriggerCompletion = true;
    }
    if (event.isComposing) {
      this.clearCompletion('composing');
      return { consumeEvent: false, forceTriggerCompletion };
    }
    switch (event.key) {
      case 'Delete':
      case 'ArrowDown':
      case 'ArrowUp':
      case 'ArrowLeft':
      case 'ArrowRight':
      case 'Home':
      case 'End':
      case 'PageDown':
      case 'PageUp':
        this.clearCompletion(`key: ${event.key}`);
        return { consumeEvent: false, forceTriggerCompletion };
    }
    if (!event.metaKey && !event.ctrlKey && !event.altKey && !event.shiftKey) {
      if (alsoHandle.tab && event.key === 'Tab' && this.acceptCompletion()) {
        return { consumeEvent: true, forceTriggerCompletion };
      }
      if (alsoHandle.escape && event.key === 'Escape' && this.clearCompletion('user dismissed')) {
        return { consumeEvent: true, forceTriggerCompletion };
      }
    }
    const cursor = doc.getCursor();
    const characterBeforeCursor =
      cursor.ch === 0 ? '' : doc.getRange({ line: cursor.line, ch: cursor.ch - 1 }, cursor);
    const anyTextMarkerUpdated = this.anyTextMarkerUpdated(
      event.key,
      cursor,
      characterBeforeCursor
    );
    // We don't want caps lock to trigger a clearing of the completion, for example.
    if (!anyTextMarkerUpdated && event.key.length === 1) {
      this.clearCompletion("didn't update text marker and key is a single character");
    }
    if (event.key === 'Enter') {
      this.clearCompletion('enter');
    }
    return { consumeEvent: undefined, forceTriggerCompletion };