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comparison .cms/lib/codemirror/src/util/feature_detection.js @ 0:78edf6b517a0 draft

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24.10
author Coffee CMS <info@coffee-cms.ru>
date Fri, 11 Oct 2024 22:40:23 +0000
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-1:000000000000 0:78edf6b517a0
1 import { elt, range, removeChildren, removeChildrenAndAdd } from "./dom.js"
2 import { ie, ie_version } from "./browser.js"
3
4 // Detect drag-and-drop
5 export let dragAndDrop = function() {
6 // There is *some* kind of drag-and-drop support in IE6-8, but I
7 // couldn't get it to work yet.
8 if (ie && ie_version < 9) return false
9 let div = elt('div')
10 return "draggable" in div || "dragDrop" in div
11 }()
12
13 let zwspSupported
14 export function zeroWidthElement(measure) {
15 if (zwspSupported == null) {
16 let test = elt("span", "\u200b")
17 removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]))
18 if (measure.firstChild.offsetHeight != 0)
19 zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8)
20 }
21 let node = zwspSupported ? elt("span", "\u200b") :
22 elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px")
23 node.setAttribute("cm-text", "")
24 return node
25 }
26
27 // Feature-detect IE's crummy client rect reporting for bidi text
28 let badBidiRects
29 export function hasBadBidiRects(measure) {
30 if (badBidiRects != null) return badBidiRects
31 let txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"))
32 let r0 = range(txt, 0, 1).getBoundingClientRect()
33 let r1 = range(txt, 1, 2).getBoundingClientRect()
34 removeChildren(measure)
35 if (!r0 || r0.left == r0.right) return false // Safari returns null in some cases (#2780)
36 return badBidiRects = (r1.right - r0.right < 3)
37 }
38
39 // See if "".split is the broken IE version, if so, provide an
40 // alternative way to split lines.
41 export let splitLinesAuto = "\n\nb".split(/\n/).length != 3 ? string => {
42 let pos = 0, result = [], l = string.length
43 while (pos <= l) {
44 let nl = string.indexOf("\n", pos)
45 if (nl == -1) nl = string.length
46 let line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl)
47 let rt = line.indexOf("\r")
48 if (rt != -1) {
49 result.push(line.slice(0, rt))
50 pos += rt + 1
51 } else {
52 result.push(line)
53 pos = nl + 1
54 }
55 }
56 return result
57 } : string => string.split(/\r\n?|\n/)
58
59 export let hasSelection = window.getSelection ? te => {
60 try { return te.selectionStart != te.selectionEnd }
61 catch(e) { return false }
62 } : te => {
63 let range
64 try {range = te.ownerDocument.selection.createRange()}
65 catch(e) {}
66 if (!range || range.parentElement() != te) return false
67 return range.compareEndPoints("StartToEnd", range) != 0
68 }
69
70 export let hasCopyEvent = (() => {
71 let e = elt("div")
72 if ("oncopy" in e) return true
73 e.setAttribute("oncopy", "return;")
74 return typeof e.oncopy == "function"
75 })()
76
77 let badZoomedRects = null
78 export function hasBadZoomedRects(measure) {
79 if (badZoomedRects != null) return badZoomedRects
80 let node = removeChildrenAndAdd(measure, elt("span", "x"))
81 let normal = node.getBoundingClientRect()
82 let fromRange = range(node, 0, 1).getBoundingClientRect()
83 return badZoomedRects = Math.abs(normal.left - fromRange.left) > 1
84 }