Function DiffViewer

packages/session-ui/src/components/file.tsx:921–1183

(props: DiffFileProps<T>)

// ---------------------------------------------------------------------------

function DiffViewer<T>(props: DiffFileProps<T>) {
  let instance: FileDiff<T> | undefined
  let instanceVirtualizer: Virtualizer | undefined
  let instanceWorkerPool: ReturnType<typeof getWorkerPool>
  let instanceVirtualHunkSeparators: FileDiffOptions<T>["hunkSeparators"] | undefined
  let instanceFileDiff: FileDiffMetadata | undefined
  let instanceBefore: FileContents | undefined
  let instanceAfter: FileContents | undefined
  let dragSide: DiffSelectionSide | undefined
  let dragEndSide: DiffSelectionSide | undefined
  let viewer!: Viewer

  const [local, others] = splitProps(props, diffKeys)

  const mobile = createMediaQuery("(max-width: 640px)")

  const lineFromMouseEvent = (event: MouseEvent): MouseHit => mouseHit(event, findDiffLineNumber, diffMouseSide)

  const setSelectedLines = (range: SelectedLineRange | null, preserve?: { root: ShadowRoot; text: Range }) => {
    const active = instance
    if (!active) return

    const fixed = fixDiffSelection(viewer.getRoot(), range)
    if (fixed === undefined) {
      viewer.lastSelection = range
      return
    }

    viewer.lastSelection = fixed
    active.setSelectedLines(fixed)
    restoreShadowTextSelection(preserve?.root, preserve?.text)
  }

  const adapter: ModeAdapter = {
    lineFromMouseEvent,
    setSelectedLines,
    updateSelection: (preserveTextSelection) => {
      const root = viewer.getRoot()
      if (!root) return

      const selected = readShadowLineSelection({
        root,
        lineForNode: findDiffLineNumber,
        sideForNode: diffSelectionSide,
        preserveTextSelection,
      })
      if (!selected) return

      if (selected.text) {
        setSelectedLines(selected.range, { root, text: selected.text })
        return
      }

      setSelectedLines(selected.range)
    },
    buildDragSelection: () => {
      if (viewer.dragStart === undefined || viewer.dragEnd === undefined) return
      const selected: SelectedLineRange = { start: viewer.dragStart, end: viewer.dragEnd }