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137 lines
3.5 KiB
JavaScript
137 lines
3.5 KiB
JavaScript
// http://stackoverflow.com/questions/263743/how-to-get-caret-position-in-textarea
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var clone, getCaret;
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getCaret = function(el) {
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var r, rc, re;
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if (el.selectionStart) {
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return el.selectionStart;
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} else if (document.selection) {
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el.focus();
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r = document.selection.createRange();
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if (!r) return 0;
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re = el.createTextRange();
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rc = re.duplicate();
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re.moveToBookmark(r.getBookmark());
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rc.setEndPoint("EndToStart", re);
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return rc.text.length;
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}
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return 0;
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};
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clone = null;
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$.fn.caret = function(){
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return getCaret(this[0]);
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};
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/**
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This is a jQuery plugin to retrieve the caret position in a textarea
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@module $.fn.caretPosition
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**/
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$.fn.caretPosition = function(options) {
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var after, before, getStyles, guard, html, important, insertSpaceAfterBefore, letter, makeCursor, p, pPos, pos, span, styles, textarea, val;
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if (clone) {
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clone.remove();
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}
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span = $("#pos span");
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textarea = $(this);
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getStyles = function(el) {
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if (el.currentStyle) {
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return el.currentStyle;
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} else {
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return document.defaultView.getComputedStyle(el, "");
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}
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};
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styles = getStyles(textarea[0]);
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clone = $("<div><p></p></div>").appendTo("body");
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p = clone.find("p");
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clone.width(textarea.width());
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clone.height(textarea.height());
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important = function(prop) {
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return styles.getPropertyValue(prop);
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};
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clone.css({
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border: "1px solid black",
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padding: important("padding"),
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resize: important("resize"),
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"max-height": textarea.height() + "px",
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"overflow-y": "auto",
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"word-wrap": "break-word",
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position: "absolute",
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left: "-7000px"
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});
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p.css({
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margin: 0,
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padding: 0,
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"word-wrap": "break-word",
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"letter-spacing": important("letter-spacing"),
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"font-family": important("font-family"),
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"font-size": important("font-size"),
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"line-height": important("line-height")
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});
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pos = options && (options.pos || options.pos === 0) ? options.pos : getCaret(textarea[0]);
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val = textarea.val().replace("\r", "");
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if (options && options.key) {
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val = val.substring(0, pos) + options.key + val.substring(pos);
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}
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before = pos - 1;
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after = pos;
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insertSpaceAfterBefore = false;
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// if before and after are \n insert a space
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if (val[before] === "\n" && val[after] === "\n") {
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insertSpaceAfterBefore = true;
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}
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guard = function(v) {
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var buf;
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buf = v.replace(/</g, "<");
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buf = buf.replace(/>/g, ">");
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buf = buf.replace(/[ ]/g, "​ ​");
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return buf.replace(/\n/g, "<br />");
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};
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makeCursor = function(pos, klass, color) {
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var l;
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l = val.substring(pos, pos + 1);
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if (l === "\n") return "<br>";
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return "<span class='" + klass + "' style='background-color:" + color + "; margin:0; padding: 0'>" + guard(l) + "</span>";
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};
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html = "";
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if (before >= 0) {
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html += guard(val.substring(0, pos - 1)) + makeCursor(before, "before", "#d0ffff");
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if (insertSpaceAfterBefore) {
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html += makeCursor(0, "post-before", "#d0ffff");
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}
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}
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if (after >= 0) {
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html += makeCursor(after, "after", "#ffd0ff");
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if (after - 1 < val.length) {
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html += guard(val.substring(after + 1));
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}
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}
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p.html(html);
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clone.scrollTop(textarea.scrollTop());
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letter = p.find("span:first");
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pos = letter.offset();
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if (letter.hasClass("before")) {
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pos.left = pos.left + letter.width();
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}
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pPos = p.offset();
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return {
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left: pos.left - pPos.left,
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top: (pos.top - pPos.top) - clone.scrollTop()
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};
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};
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