Overleaf/services/web/frontend/js/features/source-editor/extensions/geometry-change-event.ts

import { EditorView } from '@codemirror/view'

/**
 * An extension that triggers a custom DOM event whenever the editor geometry
 * changes. This is used to synchronize the editor content and review panel
 * height in "Current file" mode.
 */
export const geometryChangeEvent = (reactReviewPanel: boolean) =>
  reactReviewPanel
    ? EditorView.updateListener.of(update => {
        if (update.geometryChanged) {
          window.dispatchEvent(new CustomEvent('editor:geometry-change'))
        }
      })
    : []