rangy-inputs-mod.js

Modified rangyInputs plugin for selection & caret manipulation

Αυτός ο κώδικας δεν πρέπει να εγκατασταθεί άμεσα. Είναι μια βιβλιοθήκη για άλλους κώδικες που περιλαμβάνεται μέσω της οδηγίας meta // @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");
		};
	};
})();