text: import { lineNumberFor } from "../line/utils_line"
  import { compensateForHScroll } from "../measurement/position_measurement"
  import { elt } from "../util/dom"
  
  import { updateGutterSpace } from "./update_display"
  
  // Re-align line numbers and gutter marks to compensate for
  // horizontal scrolling.
  export function alignHorizontally(cm) {
    let display = cm.display, view = display.view
    if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return
    let comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft
    let gutterW = display.gutters.offsetWidth, left = comp + "px"
    for (let i = 0; i < view.length; i++) if (!view[i].hidden) {
      if (cm.options.fixedGutter) {
        if (view[i].gutter)
          view[i].gutter.style.left = left
        if (view[i].gutterBackground)
          view[i].gutterBackground.style.left = left
      }
      let align = view[i].alignable
      if (align) for (let j = 0; j < align.length; j++)
        align[j].style.left = left
    }
    if (cm.options.fixedGutter)
      display.gutters.style.left = (comp + gutterW) + "px"
  }
  
  // Used to ensure that the line number gutter is still the right
  // size for the current document size. Returns true when an update
  // is needed.
  export function maybeUpdateLineNumberWidth(cm) {
    if (!cm.options.lineNumbers) return false
    let doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display
    if (last.length != display.lineNumChars) {
      let test = display.measure.appendChild(elt("div", [elt("div", last)],
                                                 "CodeMirror-linenumber CodeMirror-gutter-elt"))
      let innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW
      display.lineGutter.style.width = ""
      display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1
      display.lineNumWidth = display.lineNumInnerWidth + padding
      display.lineNumChars = display.lineNumInnerWidth ? last.length : -1
      display.lineGutter.style.width = display.lineNumWidth + "px"
      updateGutterSpace(cm)
      return true
    }
    return false
  }
  