Modified rangyInputs plugin for selection & caret manipulation
此脚本不应直接安装。它是供其他脚本使用的外部库，要使用该库请加入元指令 // @require https://update.greasyfork.org/scripts/28239/181769/rangy-inputs-modjs.js
/* HEAVILY MODIFIED 3/17/2017 from https://github.com/timdown/rangyinputs
* - The code was unwrapped
* - jQuery elements removed, updated to ES2015
* - Unneeded code removed
* - Added global variable "rangyInput"
*/
/**
* @license Rangy Inputs, a jQuery plug-in for selection and caret manipulation
* within textareas and text inputs.
*
* https://github.com/timdown/rangyinputs
*
* For range and selection features for contenteditable, see Rangy.
* http://code.google.com/p/rangy/
*
* xxxx Depends on jQuery 1.0 or later. xxxxx
*
* Copyright 2014, Tim Down
* Licensed under the MIT license.
* Version: 1.2.0
* Build date: 30 November 2014
*/
/* jshint esnext:true */
(() => {
window.rangyInput = {};
const UNDEF = "undefined";
let getSelection, setSelection;
// Trio of isHost* functions taken from Peter Michaux's article:
// State of the art browser scripting (https://goo.gl/w6HPyE)
function isHostMethod(object, property) {
var t = typeof object[property];
return t === "function" ||
(!!(t == "object" && object[property])) ||
t == "unknown";
}
function isHostProperty(object, property) {
return typeof(object[property]) != UNDEF;
}
function isHostObject(object, property) {
return !!(typeof(object[property]) == "object" && object[property]);
}
function fail(reason) {
if (window.console && window.console.log) {
window.console.log(
`RangyInputs not supported in your browser. Reason: ${reason}`
);
}
}
function adjustOffsets(el, start, end) {
if (start < 0) {
start += el.value.length;
}
if (typeof end == UNDEF) {
end = start;
}
if (end < 0) {
end += el.value.length;
}
return { start: start, end: end };
}
function makeSelection(el, start, end) {
return {
start: start,
end: end,
length: end - start,
text: el.value.slice(start, end)
};
}
function getBody() {
return isHostObject(document, "body") ?
document.body :
document.querySelector("body");
}
window.rangyInput.init = () => {
const testTextArea = document.createElement("textarea");
getBody().appendChild(testTextArea);
if (
isHostProperty(testTextArea, "selectionStart") &&
isHostProperty(testTextArea, "selectionEnd")
) {
getSelection = el => {
return makeSelection(el, el.selectionStart, el.selectionEnd);
};
setSelection = (el, startOffset, endOffset) => {
var offsets = adjustOffsets(el, startOffset, endOffset);
el.selectionStart = offsets.start;
el.selectionEnd = offsets.end;
};
} else if (
isHostMethod(testTextArea, "createTextRange") &&
isHostObject(document, "selection") &&
isHostMethod(document.selection, "createRange")
) {
getSelection = el => {
let normalizedValue, textInputRange, len, endRange,
start = 0,
end = 0;
const range = document.selection.createRange();
if (range && range.parentElement() == el) {
len = el.value.length;
normalizedValue = el.value.replace(/\r\n/g, "\n");
textInputRange = el.createTextRange();
textInputRange.moveToBookmark(range.getBookmark());
endRange = el.createTextRange();
endRange.collapse(false);
if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
start = end = len;
} else {
start = -textInputRange.moveStart("character", -len);
start += normalizedValue.slice(0, start).split("\n").length - 1;
if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
end = len;
} else {
end = -textInputRange.moveEnd("character", -len);
end += normalizedValue.slice(0, end).split("\n").length - 1;
}
}
}
return makeSelection(el, start, end);
};
// Moving across a line break only counts as moving one character in a
// TextRange, whereas a line break in the textarea value is two
// characters. This function corrects for that by converting a text offset
// into a range character offset by subtracting one character for every
// line break in the textarea prior to the offset
const offsetToRangeCharacterMove = function(el, offset) {
return offset - (el.value.slice(0, offset).split("\r\n").length - 1);
};
setSelection = (el, startOffset, endOffset) => {
const offsets = adjustOffsets(el, startOffset, endOffset),
range = el.createTextRange(),
startCharMove = offsetToRangeCharacterMove(el, offsets.start);
range.collapse(true);
if (offsets.start == offsets.end) {
range.move("character", startCharMove);
} else {
range.moveEnd(
"character",
offsetToRangeCharacterMove(el, offsets.end)
);
range.moveStart("character", startCharMove);
}
range.select();
};
} else {
getBody().removeChild(testTextArea);
fail("No means of finding text input caret position");
return;
}
// Clean up
getBody().removeChild(testTextArea);
function getValueAfterPaste(el, text) {
const val = el.value,
sel = getSelection(el),
selStart = sel.start;
return {
value: val.slice(0, selStart) + text + val.slice(sel.end),
index: selStart,
replaced: sel.text
};
}
function pasteTextWithCommand(el, text) {
el.focus();
const sel = getSelection(el);
// Hack to work around incorrect delete command when deleting the last
// word on a line
setSelection(el, sel.start, sel.end);
if (text === "") {
document.execCommand("delete", false, null);
} else {
document.execCommand("insertText", false, text);
}
return {
replaced: sel.text,
index: sel.start
};
}
function pasteTextWithValueChange(el, text) {
el.focus();
const valueAfterPaste = getValueAfterPaste(el, text);
el.value = valueAfterPaste.value;
return valueAfterPaste;
}
let pasteText = (el, text) => {
const valueAfterPaste = getValueAfterPaste(el, text);
try {
const pasteInfo = pasteTextWithCommand(el, text);
if (el.value == valueAfterPaste.value) {
pasteText = pasteTextWithCommand;
return pasteInfo;
}
} catch (ex) {
// Do nothing and fall back to changing the value manually
}
pasteText = pasteTextWithValueChange;
el.value = valueAfterPaste.value;
return valueAfterPaste;
};
function updateSelectionAfterInsert(el, startIndex, text, selBehaviour) {
let endIndex = startIndex + text.length;
selBehaviour = (typeof selBehaviour == "string") ?
selBehaviour.toLowerCase() :
"";
if (
(selBehaviour == "collapsetoend" || selBehaviour == "select") &&
/[\r\n]/.test(text)
) {
// Find the length of the actual text inserted, which could vary
// depending on how the browser deals with line breaks
const normalizedText = text.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
endIndex = startIndex + normalizedText.length;
const firstLineBreakIndex = startIndex + normalizedText.indexOf("\n");
if (
el.value.slice(firstLineBreakIndex, firstLineBreakIndex + 2) == "\r\n"
) {
// Browser uses \r\n, so we need to account for extra \r characters
endIndex += normalizedText.match(/\n/g).length;
}
}
switch (selBehaviour) {
case "collapsetostart":
setSelection(el, startIndex, startIndex);
break;
case "collapsetoend":
setSelection(el, endIndex, endIndex);
break;
case "select":
setSelection(el, startIndex, endIndex);
break;
}
}
window.rangyInput.surroundSelectedText = (el, before, after) => {
if (typeof after == UNDEF) {
after = before;
}
const sel = getSelection(el),
pasteInfo = pasteText(el, before + sel.text + after);
updateSelectionAfterInsert(
el,
pasteInfo.index + before.length,
sel.text,
"select"
);
};
window.rangyInput.indentSelectedText = (el, callback) => {
const sel = getSelection(el),
result = callback(sel.text),
pasteInfo = pasteText(el, result);
updateSelectionAfterInsert(el, pasteInfo.index, result, "select");
};
};
})();