Function lineNo

external/.scrollLibs.js:1027–1042

(line)

  // Given a line object, find its line number by walking up through
  // its parent links.
  function lineNo(line) {
    if (line.parent == null) {
      return null
    }
    var cur = line.parent,
      no = indexOf(cur.lines, line)
    for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
      for (var i = 0; ; ++i) {
        if (chunk.children[i] == cur) {
          break
        }
        no += chunk.children[i].chunkSize()
      }
    }
    return no + cur.first
  }

  // Find the line at the given vertical position, using the height
  // information in the document tree.