Get caret position in HTML input? - javascript

How do I get the index of the text caret in an input?

-> selectionStart
<!doctype html>
<html>
<head>
<meta charset = "utf-8">
<script type = "text/javascript">
window.addEventListener ("load", function () {
var input = document.getElementsByTagName ("input");
input[0].addEventListener ("keydown", function () {
alert ("Caret position: " + this.selectionStart);
// You can also set the caret: this.selectionStart = 2;
});
});
</script>
<title>Test</title>
</head>
<body>
<input type = "text">
</body>
</html>

The following will get you the start and end of the selection as character indices. It works for text inputs and textareas, and is slightly complicated because of IE's strange handling of line breaks.
function getInputSelection(el) {
var start = 0, end = 0, normalizedValue, range,
textInputRange, len, endRange;
if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
start = el.selectionStart;
end = el.selectionEnd;
} else {
range = document.selection.createRange();
if (range && range.parentElement() == el) {
len = el.value.length;
normalizedValue = el.value.replace(/\r\n/g, "\n");
// Create a working TextRange that lives only in the input
textInputRange = el.createTextRange();
textInputRange.moveToBookmark(range.getBookmark());
// Check if the start and end of the selection are at the very end
// of the input, since moveStart/moveEnd doesn't return what we want
// in those cases
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 {
start: start,
end: end
};
}
var textBox = document.getElementById("textBoxId");
textBox.focus();
alert( getInputSelection(textBox).start );

There is now a nice jQuery plugin for this: Caret plugin
Then you can just call $("#myTextBox").caret();

We had used something like this for an old javascript application, but I haven't tested it in a couple years:
function getCaretPos(input) {
// Internet Explorer Caret Position (TextArea)
if (document.selection && document.selection.createRange) {
var range = document.selection.createRange();
var bookmark = range.getBookmark();
var caret_pos = bookmark.charCodeAt(2) - 2;
} else {
// Firefox Caret Position (TextArea)
if (input.setSelectionRange)
var caret_pos = input.selectionStart;
}
return caret_pos;
}

Get coordinates (css: left:x , top:y) of the current caret position in order to position an element (e.g. show tooltip at caret position)
function getCaretCoordinates() {
let x = 0,
y = 0;
const isSupported = typeof window.getSelection !== "undefined";
if (isSupported) {
const selection = window.getSelection();
// Check if there is a selection (i.e. cursor in place)
if (selection.rangeCount !== 0) {
// Clone the range
const range = selection.getRangeAt(0).cloneRange();
// Collapse the range to the start, so there are not multiple chars selected
range.collapse(true);
// getCientRects returns all the positioning information we need
const rect = range.getClientRects()[0];
if (rect) {
x = rect.left; // since the caret is only 1px wide, left == right
y = rect.top; // top edge of the caret
}
}
}
return { x, y };
}
demo: https://codesandbox.io/s/caret-coordinates-index-contenteditable-9tq3o?from-embed
ref: https://javascript.plainenglish.io/how-to-find-the-caret-inside-a-contenteditable-element-955a5ad9bf81

Working example of getting cursor point in text box:
function textbox()
{
var ctl = document.getElementById('Javascript_example');
var startPos = ctl.selectionStart;
var endPos = ctl.selectionEnd;
alert(startPos + ", " + endPos);
}

Related

highlighting and editing text in long string

In a HTML/JavaScript/React/Redux web application, I have a long string (around 300kb) of natural language. It is a transcript of a recording being played back.
I need
to highlight the currently uttered word,
to recognize a word that's clicked on,
to extract selected ranges
and to replace parts of the string (when a correction to the transcript is submitted by the user).
Everything is easy when I wrap each word in its own <span>. However, this makes the number of elements unbearable for the browser and the page gets very slow.
I can think of two ways to approach this:
I could wrap each sentence in a <span> and only wrap each word of the currently played-back sentence.
I could leave the text without HTML tags, handle clicks via document.caretPositionFromPoint, but I don't know how to highlight a word.
I would welcome more ideas and thoughts on the balance between difficulty and speed.
"to recognize a word that's clicked on"
New answer
I figure that, the code in my previous answer actually had to split the huge string of text into an huge array on every on click event. After that, a linear search is performed on the array to locate the matching string.
However, this could be improved by precomputing the word array and use binary search instead of linear searching.
Now every highlighting will run in O(log n) instead of O(n)
See: http://jsfiddle.net/amoshydra/vq8y8h19/
// Build character to text map
var text = content.innerText;
var counter = 1;
textMap = text.split(' ').map((word) => {
result = {
word: word,
start: counter,
end: counter + word.length,
}
counter += word.length + 1;
return result;
});
content.addEventListener('click', function (e) {
var selection = window.getSelection();
var result = binarySearch(textMap, selection.focusOffset, compare_word);
var textNode = e.target.childNodes[0];
if (textNode) {
var range = document.createRange();
range.setStart(textNode, textMap[result].start);
range.setEnd(textNode, textMap[result].end);
var r = range.getClientRects()[0];
console.log(r.top, r.left, textMap[result].word);
// Update overlay
var scrollOffset = e.offsetY - e.clientY; // To accomondate scrolling
overlay.innerHTML = textMap[result].word;
overlay.style.top = r.top + scrollOffset + 'px';
overlay.style.left = r.left + 'px';
}
});
// Slightly modified binary search algorithm
function binarySearch(ar, el, compare_fn) {
var m = 0;
var n = ar.length - 1;
while (m <= n) {
var k = (n + m) >> 1;
var cmp = compare_fn(el, ar[k]);
if (cmp > 0) {
m = k + 1;
} else if(cmp < 0) {
n = k - 1;
} else {
return k;
}
}
return m - 1;
}
function compare_word(a, b) {
return a - b.start;
}
Original answer
I took a fork of code from this answer from aaron and implemented this:
Instead of setting a span tag on the paragraph, we could put an overlay on top of the word.
And resize and reposition the overlay when travelling to a word.
Snippet
JavaScript
// Update overlay
overlayDom.innerHTML = word;
overlayDom.style.top = r.top + 'px';
overlayDom.style.left = r.left + 'px';
CSS
Use an overlay with transparent color text, so that we can get the overlay to be of the same width with the word.
#overlay {
background-color: yellow;
opacity: 0.4;
display: block;
position: absolute;
color: transparent;
}
Full forked JavaScript code below
var overlayDom = document.getElementById('overlay');
function findClickedWord(parentElt, x, y) {
if (parentElt.nodeName !== '#text') {
console.log('didn\'t click on text node');
return null;
}
var range = document.createRange();
var words = parentElt.textContent.split(' ');
var start = 0;
var end = 0;
for (var i = 0; i < words.length; i++) {
var word = words[i];
end = start+word.length;
range.setStart(parentElt, start);
range.setEnd(parentElt, end);
// not getBoundingClientRect as word could wrap
var rects = range.getClientRects();
var clickedRect = isClickInRects(rects);
if (clickedRect) {
return [word, start, clickedRect];
}
start = end + 1;
}
function isClickInRects(rects) {
for (var i = 0; i < rects.length; ++i) {
var r = rects[i]
if (r.left<x && r.right>x && r.top<y && r.bottom>y) {
return r;
}
}
return false;
}
return null;
}
function onClick(e) {
var elt = document.getElementById('info');
// Get clicked status
var clicked = findClickedWord(e.target.childNodes[0], e.clientX, e.clientY);
// Update status bar
elt.innerHTML = 'Nothing Clicked';
if (clicked) {
var word = clicked[0];
var start = clicked[1];
var r = clicked[2];
elt.innerHTML = 'Clicked: ('+r.top+','+r.left+') word:'+word+' at offset '+start;
// Update overlay
overlayDom.innerHTML = word;
overlayDom.style.top = r.top + 'px';
overlayDom.style.left = r.left + 'px';
}
}
document.addEventListener('click', onClick);
See the forked demo: https://jsfiddle.net/amoshydra/pntzdpff/
This implementation uses the createRange API
I don't think the number of <span> elements is unbearable once they have been positioned. You might just need to minimize reflow by avoiding layout changes.
Small experiment: ~3kb of text highlighted via background-color
// Create ~3kb of text:
let text = document.getElementById("text");
for (let i = 0; i < 100000; ++i) {
let word = document.createElement("span");
word.id = "word_" + i;
word.textContent = "bla ";
text.appendChild(word);
}
document.body.appendChild(text);
// Highlight text:
let i = 0;
let word;
setInterval(function() {
if (word) word.style.backgroundColor = "transparent";
word = document.getElementById("word_" + i);
word.style.backgroundColor = "red";
i++;
}, 100)
<div id="text"></div>
Once the initial layout has finished, this renders smoothly for me in FF/Ubuntu/4+ years old laptop.
Now, if you where to change font-weight instead of background-color, the above would become unbearably slow due to the constant layout changes triggering a reflow.
Here is a simple editor that can easily handle very large string. I tried to use minimum DOM for performance.
It can
recognize a word that's clicked on
highlight the currently clicked word, or drag selection
extract selected ranges
replace parts of the string (when a correction to the transcript is submitted by the user).
See this jsFiddle
var editor = document.getElementById("editor");
var highlighter = document.createElement("span");
highlighter.className = "rename";
var replaceBox = document.createElement("input");
replaceBox.className = "replace";
replaceBox.onclick = function() {
event.stopPropagation();
};
editor.parentElement.appendChild(replaceBox);
editor.onclick = function() {
var sel = window.getSelection();
if (sel.anchorNode.parentElement === highlighter) {
clearSelection();
return;
}
var range = sel.getRangeAt(0);
if (range.collapsed) {
var idx = sel.anchorNode.nodeValue.lastIndexOf(" ", range.startOffset);
range.setStart(sel.anchorNode, idx + 1);
var idx = sel.anchorNode.nodeValue.indexOf(" ", range.endOffset);
if (idx == -1) {
idx = sel.anchorNode.nodeValue.length;
}
range.setEnd(sel.anchorNode, idx);
}
clearSelection();
range.surroundContents(highlighter);
range.detach();
showReplaceBox();
event.stopPropagation();
};
document.onclick = function(){
clearSelection();
};
function clearSelection() {
if (!!highlighter.parentNode) {
replaceBox.style.display = "none";
highlighter.parentNode.insertBefore(document.createTextNode(replaceBox.value), highlighter.nextSibling);
highlighter.parentNode.removeChild(highlighter);
}
editor.normalize(); // comment this line in case of any performance issue after an edit
}
function showReplaceBox() {
if (!!highlighter.parentNode) {
replaceBox.style.display = "block";
replaceBox.style.top = (highlighter.offsetTop + highlighter.offsetHeight) + "px";
replaceBox.style.left = highlighter.offsetLeft + "px";
replaceBox.value = highlighter.textContent;
replaceBox.focus();
replaceBox.selectionStart = 0;
replaceBox.selectionEnd = replaceBox.value.length;
}
}
.rename {
background: yellow;
}
.replace {
position: absolute;
display: none;
}
<div id="editor">
Your very large text goes here...
</div>
I would first find the clicked word via some annoying logic (Try looking here )
Then you can highlight the word simply by wrapping the exact word with a styled span as you suggested above :)
Well, I'm not really sure how you could recognise words. You may need a 3rd party software. To highlight a word, you can use CSS and span as you said.
CSS
span {
background-color: #B6B6B4;
}
To add the 'span' tags, you could use a find and replace thing. Like this one.
Find: all spaces
Replace: <span>

Insert text at current cursor position on dropdown list changed inside iframe

I am using a text editor provided by Microsoft ajax-toolkit.
It renders iframe on browser. I have added a dropdown in that editor and I want that when user changes the drop-down index the value should be added in the editor current cursor position.
I got a code on SO which gives me the current selected text inside editor is as follows
function getIframeSelectionText(iframe) {
var win = iframe.contentWindow;
var doc = iframe.contentDocument || win.document;
if (win.getSelection) {
return win.getSelection().toString();
} else if (doc.selection && doc.selection.createRange) {
return doc.selection.createRange().text;
}
}
But I want to add some text at the current position. The html is rendering as below
<td class="ajax__htmleditor_editor_editpanel"><div id="Editor1_ctl02" style="height:100%;width:100%;">
<iframe id="Editor1_ctl02_ctl00" name="Editor1_ctl02_ctl00" marginheight="0" marginwidth="0" frameborder="0" style="height:100%;width:100%;display:none;border-width:0px;">
</iframe><textarea id="Editor1_ctl02_ctl01" class="ajax__htmleditor_htmlpanel_default" style="height:100%;width:100%;display:none;"></textarea><iframe id="Editor1_ctl02_ctl02" name="Editor1_ctl02_ctl02" marginheight="0" marginwidth="0" frameborder="0" style="height:100%;width:100%;display:none;border-width:0px;">
</iframe>
</div></td>
I am trying as follow
$("#imgDropdown").change(function () {
//var iframeBody = $(window.Editor1_ctl02_ctl00.document.getElementsByTagName("body")[0]);
var iframe = document.getElementById("Editor1_ctl02_ctl00");
$("#Editor1_ctl02_ctl00").find("body").insertAtCaret("value");
//alert(getIframeSelectionText(iframe));
});
the function for inserting text is not working with iframe is as follow
$.fn.extend({
insertAtCaret: function (myValue) {
if (document.selection) {
this.focus();
sel = document.selection.createRange();
sel.text = myValue;
this.focus();
}
else if (this.selectionStart || this.selectionStart == '0') {
var startPos = this.selectionStart;
var endPos = this.selectionEnd;
var scrollTop = this.scrollTop;
this.value = this.value.substring(0, startPos) + myValue + this.value.substring(endPos, this.value.length);
this.focus();
this.selectionStart = startPos + myValue.length;
this.selectionEnd = startPos + myValue.length;
this.scrollTop = scrollTop;
} else {
this.value += myValue;
this.focus();
}
}
})
Easy, you just have to use.
$("#Editor1_ctl02_ctl00").contents().find('textarea').insertAtCaret('value');
Updated
Sorry, I thought the insertAtCaret function is working for you, you just needed to work inside iFrame. You can use this version of insertAtCaret:
jQuery.fn.extend({
insertAtCaret: function (html) {
var winObject = function (el){
var doc = el.ownerDocument;
return doc.defaultView || doc.parentWindow
};
return this.each(function (i) {
var sel, range, w = this;
w = winObject(w);
if (w.getSelection) {
// IE9 and non-IE
sel = w.getSelection();
if (sel.getRangeAt && sel.rangeCount) {
range = sel.getRangeAt(0);
range.deleteContents();
// Range.createContextualFragment() would be useful here but is
// only relatively recently standardized and is not supported in
// some browsers (IE9, for one)
var el = w.document.createElement("div");
el.innerHTML = html;
var frag = w.document.createDocumentFragment(), node, lastNode;
while ((node = el.firstChild)) {
lastNode = frag.appendChild(node);
}
range.insertNode(frag);
// Preserve the selection
if (lastNode) {
range = range.cloneRange();
range.setStartAfter(lastNode);
range.collapse(true);
sel.removeAllRanges();
sel.addRange(range);
}
}
} else if (w.document.selection && w.document.selection.type != "Control") {
// IE < 9
w.document.selection.createRange().pasteHTML(html);
}
}
)
}
});
and call it like:
$("#Editor1_ctl02_ctl00").contents().find('body').insertAtCaret($val);
Function adapted from here
Happy coding!
There seem to be a few issues here.
The Microsoft ajax-toolkit editor creates an iframe where the designMode property is turned on, and that's why it's editable, it has no value, and textNodes are added straight to the body, which makes it a little more difficult.
When you're selecting something from a dropdown, the focus is on the dropdown, and there is no caret position, as the focus is shifted away from the iFrame.
I'm assuming that the dropdown is in the top menubar for the editor or anywhere else that is outside the iFrame.
Also, the Microsoft ajax-toolkit editor has a recommended update, the HTMLEditorExtender.
The code you have to capture the caret position seems to be for a regular input / textarea, and you'd have to adapt that code to work with any Node inside an iframe that is in designMode, with it's own window and document etc.
Given the above considerations, this is what I came up with to do this
var frameID = 'Editor1_ctl02_ctl00',
selectID = 'imgDropdown',
iframe = document.getElementById(frameID),
iWin = iframe.contentWindow ? iframe.contentWindow : window.frames[frameID];
$(iWin).on('blur', function() {
$(iframe).data('range', getRange(iWin));
});
$('#' + selectID).on('change', function() {
var range = $(iframe).data('range');
addText(iWin, range, this.value);
});
function getRange(win) {
var sel, range, html;
if (win.getSelection) {
sel = win.getSelection();
if (sel.getRangeAt && sel.rangeCount) {
range = sel.getRangeAt(0);
range.deleteContents();
}
} else if (win.document.selection && win.document.selection.createRange) {
range = win.document.selection.createRange();
}
return range;
}
function addText(win, range, text) {
if (win.getSelection) {
range.insertNode(win.document.createTextNode(text));
} else if (win.document.selection && win.document.selection.createRange) {
range.text = text;
}
}
FIDDLE

Set textarea's caret position using x and y position

I want to implement inline edition, so if user clicks on a div with some text, the textarea will appear at the same position as clicked div's position and will get the text from the div. This is fine for me, but what I want to do next is to set textarea's caret position according to x and y position from div click event. Any ideas?
HTML:
<div id="content" style="display: block; z-index: 10">Some text</div>
<textarea id="editor" style="position: absolute; display: none; z-index: 11"></textarea>
JS:
$('#content').click(function(e) {
var content = $(this);
var editor = $('#editor');
var position = content.offset();
editor.css('left', position.left);
editor.css('top', position.top);
editor.val(content.text());
editor.show();
var mousePosition = { x: e.offsetX, y: e.offsetY };
// here I want to set the #editor caret position at the same place,
// where user clicks the #content (mousePosition variable)
});
Looks like you could do something like this:
createTextArea = function (e) {
var range = window.getSelection().getRangeAt(0),
start = range.startOffset,
target = e.target,
setPoint;
while (target.tagName.toLowerCase() !== 'div') {
target = target.parentElement;
if (!target) return;
}
range.setStart(target, 0);
setPoint = range.toString().length;
// place and show #editor
editor.focus();
editor.setSelectionRange(setPoint, setPoint);
return;
};
An example at jsFiddle. Notice that this works only in modern browsers. Older IE's don't have Input API, and the Selection/Range model is totally different.
I've found a solution:
JS:
function getCaretPosition(editableDiv) {
var caretPos = 0, containerEl = null, sel, range;
if (window.getSelection) {
sel = window.getSelection();
if (sel.rangeCount) {
range = sel.getRangeAt(0);
if (range.commonAncestorContainer.parentNode == editableDiv) {
caretPos = range.endOffset;
}
}
} else if (document.selection && document.selection.createRange) {
range = document.selection.createRange();
if (range.parentElement() == editableDiv) {
var tempEl = document.createElement("span");
editableDiv.insertBefore(tempEl, editableDiv.firstChild);
var tempRange = range.duplicate();
tempRange.moveToElementText(tempEl);
tempRange.setEndPoint("EndToEnd", range);
caretPos = tempRange.text.length;
}
}
return caretPos;
}
$.fn.selectRange = function (start, end) {
if (!end) end = start;
return this.each(function () {
if (this.setSelectionRange) {
this.focus();
this.setSelectionRange(start, end);
} else if (this.createTextRange) {
var range = this.createTextRange();
range.collapse(true);
range.moveEnd('character', end);
range.moveStart('character', start);
range.select();
}
});
};
Usage:
$('#content').click(function (e) {
var content = $(this);
var editor = $('#editor');
var caret = getCaretPosition(this);
var position = content.offset();
editor.css('left', position.left);
editor.css('top', position.top);
editor.val(content.text());
editor.show();
var mousePosition = { x: e.offsetX, y: e.offsetY };
// here I want to set the #editor caret position at the same place,
// where user clicks the #content (mousePosition variable)
editor.selectRange(caret, caret);
});

JavaScript: Scroll to selection after using textarea.setSelectionRange in Chrome

A JavaScript function selects a certain word in a textarea using .setSelectionRange().
In Firefox, the textarea automatically scrolls down to show the selected text. In Chrome (v14), it does not. Is there a way to get Chrome to scroll the textarea down to the newly selected text?
jQuery solutions are welcome.
Here is a simple and efficient solution in pure JavaScript:
// Get the textarea
var textArea = document.getElementById('myTextArea');
// Define your selection
var selectionStart = 50;
var selectionEnd = 60;
textArea.setSelectionRange(selectionStart, selectionEnd);
// Mow let’s do some math.
// We need the number of characters in a row
var charsPerRow = textArea.cols;
// We need to know at which row our selection starts
var selectionRow = (selectionStart - (selectionStart % charsPerRow)) / charsPerRow;
// We need to scroll to this row but scrolls are in pixels,
// so we need to know a row's height, in pixels
var lineHeight = textArea.clientHeight / textArea.rows;
// Scroll!!
textArea.scrollTop = lineHeight * selectionRow;
Put this in a function, extend the prototype of JavaScript's Element object with it, and you're good.
A lot of answers, but the accepted one doesn't consider line breaks, Matthew Flaschen didn't add the solution code, and naXa answer has a mistake. The simplest solution code is:
textArea.focus();
const fullText = textArea.value;
textArea.value = fullText.substring(0, selectionEnd);
textArea.scrollTop = textArea.scrollHeight;
textArea.value = fullText;
textArea.setSelectionRange(selectionStart, selectionEnd);
You can see how we solved the problem in ProveIt (see highlightLengthAtIndex). Basically, the trick is to truncate the textarea, scroll to the end, then restore the second part of the text. We also used the textSelection plugin for consistent cross-browser behavior.
Valeriy Katkov's elegant solution works great but has two problems:
It does not work for long strings
Selected contents are scrolled to the bottom of the textarea, making it hard to see the context which surrounds the selection
Here's my improved version that works for long strings (tested with at least 50,000 words) and scroll selection to the center of the textarea:
function setSelectionRange(textarea, selectionStart, selectionEnd) {
// First scroll selection region to view
const fullText = textarea.value;
textarea.value = fullText.substring(0, selectionEnd);
// For some unknown reason, you must store the scollHeight to a variable
// before setting the textarea value. Otherwise it won't work for long strings
const scrollHeight = textarea.scrollHeight
textarea.value = fullText;
let scrollTop = scrollHeight;
const textareaHeight = textarea.clientHeight;
if (scrollTop > textareaHeight){
// scroll selection to center of textarea
scrollTop -= textareaHeight / 2;
} else{
scrollTop = 0;
}
textarea.scrollTop = scrollTop;
// Continue to set selection range
textarea.setSelectionRange(selectionStart, selectionEnd);
}
It works in Chrome 72, Firefox 65, Opera 58, and Edge 42.
For an example of using this function, see my GitHub project SmartTextarea.
This is a code inspired by the Matthew Flaschen's answer.
/**
* Scroll textarea to position.
*
* #param {HTMLInputElement} textarea
* #param {Number} position
*/
function scrollTo(textarea, position) {
if (!textarea) { return; }
if (position < 0) { return; }
var body = textarea.value;
if (body) {
textarea.value = body.substring(0, position);
textarea.scrollTop = position;
textarea.value = body;
}
}
Basically, the trick is to truncate the textarea, scroll to the end, then restore the second part of the text.
Use it as follows
var textarea, start, end;
/* ... */
scrollTo(textarea, end);
textarea.focus();
textarea.setSelectionRange(start, end);
Based on the idea from naXa and Valeriy Katkov, I refined the function with fewer bugs. It should work out of the box (It's written with TypeScript. For JavaScript, just remove the type declaration):
function scrollTo(textarea: HTMLTextAreaElement, offset: number) {
const txt = textarea.value;
if (offset >= txt.length || offset < 0)
return;
// Important, so that scrollHeight will be adjusted
textarea.scrollTop = 0;
textarea.value = txt.substring(0, offset);
const height = textarea.scrollHeight;
textarea.value = txt;
// Margin between selection and top of viewport
textarea.scrollTop = height - 40;
}
Usage:
let textarea, start, end;
/* ... */
scrollTo(textarea, start);
textarea.focus();
textarea.setSelectionRange(start, end);
Complete code for Chrome:
<script type="text/javascript">
var SAR = {};
SAR.find = function () {
debugger;
var parola_cercata = $("#text_box_1").val(); // The searched word
// Make text lowercase if search is
// supposed to be case insensitive
var txt = $('#remarks').val().toLowerCase();
parola_cercata = parola_cercata.toLowerCase();
// Take the position of the word in the text
var posi = jQuery('#remarks').getCursorPosEnd();
var termPos = txt.indexOf(parola_cercata, posi);
if (termPos !== -1) {
debugger;
var target = document.getElementById("remarks");
var parola_cercata2 = $("#text_box_1").val();
// Select the textarea and the word
if (target.setSelectionRange) {
if ('selectionStart' in target) {
target.selectionStart = termPos;
target.selectionEnd = termPos;
this.selectionStart = this.selectionEnd = target.value.indexOf(parola_cercata2);
target.blur();
target.focus();
target.setSelectionRange(termPos, termPos + parola_cercata.length);
}
} else {
var r = target.createTextRange();
r.collapse(true);
r.moveEnd('character', termPos + parola_cercata);
r.moveStart('character', termPos);
r.select();
}
} else {
// Not found from cursor pos, so start from beginning
termPos = txt.indexOf(parola_cercata);
if (termPos !== -1) {
var target = document.getElementById("remarks");
var parola_cercata2 = $("#text_box_1").val();
// Select the textarea and the word
if (target.setSelectionRange) {
if ('selectionStart' in target) {
target.selectionStart = termPos;
target.selectionEnd = termPos;
this.selectionStart = this.selectionEnd = target.value.indexOf(parola_cercata2);
target.blur();
target.focus();
target.setSelectionRange(termPos, termPos + parola_cercata.length);
}
} else {
var r = target.createTextRange();
r.collapse(true);
r.moveEnd('character', termPos + parola_cercata);
r.moveStart('character', termPos);
r.select();
}
} else {
alert("not found");
}
}
};
$.fn.getCursorPosEnd = function () {
var pos = 0;
var input = this.get(0);
// IE support
if (document.selection) {
input.focus();
var sel = document.selection.createRange();
pos = sel.text.length;
}
// Firefox support
else if (input.selectionStart || input.selectionStart === '0')
pos = input.selectionEnd;
return pos;
};
</script>
I published an answer here:
http://blog.blupixelit.eu/scroll-textarea-to-selected-word-using-javascript-jquery/
It works perfectly with just one needed rule: Set a line-height in the CSS content of the textarea!
It calculate the position of the word to scroll to just by doing some simple mathematical calculation and it worked perfectly in all my experiments!

How to insert text at the current caret position in a textarea

On a function call from an image, I am trying to insert the alt tag value from the image into the textarea at the position where the caret currently is.
This is the code that I currently have which inserts the alt tag value to the end of the text area.
$("#emoticons").children().children().click(function () {
var ch = $(this).attr("alt");
$("#txtPost").append(ch);
});
The 2 things I have been having a problem with is determining the position of the caret, and creating a new string with the value of the textarea before the carets positon + the code I'm inserting + the value of the textarea after the carets position.
i've currently got this extension in place:
$.fn.insertAtCaret = function(text) {
return this.each(function() {
if (document.selection && this.tagName == 'TEXTAREA') {
//IE textarea support
this.focus();
sel = document.selection.createRange();
sel.text = text;
this.focus();
} else if (this.selectionStart || this.selectionStart == '0') {
//MOZILLA/NETSCAPE support
startPos = this.selectionStart;
endPos = this.selectionEnd;
scrollTop = this.scrollTop;
this.value = this.value.substring(0, startPos) + text + this.value.substring(endPos, this.value.length);
this.focus();
this.selectionStart = startPos + text.length;
this.selectionEnd = startPos + text.length;
this.scrollTop = scrollTop;
} else {
// IE input[type=text] and other browsers
this.value += text;
this.focus();
this.value = this.value; // forces cursor to end
}
});
};
and you can use it like so:
$("#txtPost").insertAtCaret(ch);

Categories

Resources