Function textHeight

external/.scrollLibs.js:4286–4307

(display)

  var measureText
  // Compute the default text height.
  function textHeight(display) {
    if (display.cachedTextHeight != null) {
      return display.cachedTextHeight
    }
    if (measureText == null) {
      measureText = elt("pre")
      // Measure a bunch of lines, for browsers that compute
      // fractional heights.
      for (var i = 0; i < 49; ++i) {
        measureText.appendChild(document.createTextNode("x"))
        measureText.appendChild(elt("br"))
      }
      measureText.appendChild(document.createTextNode("x"))
    }
    removeChildrenAndAdd(display.measure, measureText)
    var height = measureText.offsetHeight / 50
    if (height > 3) {
      display.cachedTextHeight = height
    }
    removeChildren(display.measure)
    return height || 1
  }

  // Compute the default character width.
  function charWidth(display) {