--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.cms/lib/codemirror/src/util/feature_detection.js	Fri Oct 11 22:40:23 2024 +0000
@@ -0,0 +1,84 @@
+import { elt, range, removeChildren, removeChildrenAndAdd } from "./dom.js"
+import { ie, ie_version } from "./browser.js"
+
+// Detect drag-and-drop
+export let dragAndDrop = function() {
+  // There is *some* kind of drag-and-drop support in IE6-8, but I
+  // couldn't get it to work yet.
+  if (ie && ie_version < 9) return false
+  let div = elt('div')
+  return "draggable" in div || "dragDrop" in div
+}()
+
+let zwspSupported
+export function zeroWidthElement(measure) {
+  if (zwspSupported == null) {
+    let test = elt("span", "\u200b")
+    removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]))
+    if (measure.firstChild.offsetHeight != 0)
+      zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8)
+  }
+  let node = zwspSupported ? elt("span", "\u200b") :
+    elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px")
+  node.setAttribute("cm-text", "")
+  return node
+}
+
+// Feature-detect IE's crummy client rect reporting for bidi text
+let badBidiRects
+export function hasBadBidiRects(measure) {
+  if (badBidiRects != null) return badBidiRects
+  let txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"))
+  let r0 = range(txt, 0, 1).getBoundingClientRect()
+  let r1 = range(txt, 1, 2).getBoundingClientRect()
+  removeChildren(measure)
+  if (!r0 || r0.left == r0.right) return false // Safari returns null in some cases (#2780)
+  return badBidiRects = (r1.right - r0.right < 3)
+}
+
+// See if "".split is the broken IE version, if so, provide an
+// alternative way to split lines.
+export let splitLinesAuto = "\n\nb".split(/\n/).length != 3 ? string => {
+  let pos = 0, result = [], l = string.length
+  while (pos <= l) {
+    let nl = string.indexOf("\n", pos)
+    if (nl == -1) nl = string.length
+    let line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl)
+    let rt = line.indexOf("\r")
+    if (rt != -1) {
+      result.push(line.slice(0, rt))
+      pos += rt + 1
+    } else {
+      result.push(line)
+      pos = nl + 1
+    }
+  }
+  return result
+} : string => string.split(/\r\n?|\n/)
+
+export let hasSelection = window.getSelection ? te => {
+  try { return te.selectionStart != te.selectionEnd }
+  catch(e) { return false }
+} : te => {
+  let range
+  try {range = te.ownerDocument.selection.createRange()}
+  catch(e) {}
+  if (!range || range.parentElement() != te) return false
+  return range.compareEndPoints("StartToEnd", range) != 0
+}
+
+export let hasCopyEvent = (() => {
+  let e = elt("div")
+  if ("oncopy" in e) return true
+  e.setAttribute("oncopy", "return;")
+  return typeof e.oncopy == "function"
+})()
+
+let badZoomedRects = null
+export function hasBadZoomedRects(measure) {
+  if (badZoomedRects != null) return badZoomedRects
+  let node = removeChildrenAndAdd(measure, elt("span", "x"))
+  let normal = node.getBoundingClientRect()
+  let fromRange = range(node, 0, 1).getBoundingClientRect()
+  return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1
+}