Develop Reference

How to find css unit for this number

I have a input type text
<input type="text">
Basically I am using javascript ClientRect to get caret details. ClientRect looks like this
[object ClientRect]
{
[functions]: ,
__proto__: { },
bottom: 540.7999877929687,
constructor: { },
height: 24,
left: 1034.5399169921875,
right: 1034.5399169921875,
top: 516.7999877929687,
width: 0
}
This is generated on everytext input.
left: 1034.5399169921875,
left: 1065.5399169921875,
left: 1078.5399169921875,
I want to convert this number to CSS units like px/%/rem/vh. So that I can put dynamic css. How to do it?

Try accessing the left position of your input and subtract the left position of your caret. This should give you an approximate width of the text in the input, if that's what you are looking for. You'll need to add an id or create a selector for your text input.
var inputElementRect = document.getElementById('YOURINPUTID').getBoundingClientRect()
var width = inputElementRect.left - caretRect.left

Those values are px by default .. so just add suffix as px to that value and use it.
<input type="text">
to get that value
let text = document.querySelector('input');
let values = text.getBoundingClientRect();
let top_value = values.top + 'px';
let bottom_value = values.bottom + 'px';
let width_value = values.width + 'px';
let height_value = values.height + 'px';
console.log('top: '+ top_value);
console.log('bottom: '+ bottom_value);
console.log('width: '+ width_value);
console.log('height: '+ height_value);
here properties other than width and height are relative to the view port ( top, bottom, left, right ) ,
so if scroll this values will changes ..
to get the perfect values even if scroll add this values with window.scrollX , window.scrollY or can use window.pageXOffset , window.pageYOffset

So if I understand the question correctly, you have position values for the cursor inside of the input and you want to convert it into different types of CSS units, presumably so you can do something to the input or related things
The first thing to understand is that ClientRect positions are relative to the viewport. So as vhutchinson pointed out, if you want the width of text you need to compare to the input's "left" value as defined by getBoundingClientRects. That's a good start, but if you're not just influencing left but also care about top, you need to account for scrolling. If your window/page is the only scrolling container, you should be able to do this simply by adding window.scrollY to top, and window.scrollX to left to understand your offset relative to the window.
All of these units are pixels by default... if you want to convert to rem it's pretty straightforward, 1 rem = the font-size of your root element, so to convert to rem you can do something like
var remBase = parseInt(window.getComputedStyle(document.body).getPropertyValue('font-size'), 10);
var remValue = (myComputedPixelValue / remBase) + "rem";
Doing VW is similar using the answer in Get the browser viewport dimensions with JavaScript for cross-browser window dimensions, you'd end up with something that looks like
var viewportWidth = Math.max(document.documentElement.clientWidth, window.innerWidth || 0);
var vwValue = (myComputedPixelValue / viewportWidth) + "vw";
Percentages are trickier, because you'd need to compute it based on the parent of the element you're applying the css value to, but the general idea follows the same principle.

Set div width based on scroll position

The code:
http://codepen.io/anon/pen/EjrpMM
So, i'm working on an interesting problem. I am working with a 2000px HTML document, that has a modal placed ontop of it.
The width of the div lightbox is 80%, and it's sitting positioned fixed.
The goal is, when scrolling down the page, to control the width of the div based on the scroll position. At the bottom of the page, it's only a third in size.
I've had trouble figuring out the proper equation or formula for this, and was seeking help.
Currently, I've been trying to look at the window.pageYOffset, to add 2.5% to the div while increasing, and minus 2.5% when scrolling back up, to bring it back to it's 80% width.
However, something isn't working right. I was seeing if the community had any ideas to help solve the problem.
I'm not using any frameworks for this.
Here's my javascript:
var lightBox = document.getElementById('lightBox'),
count = 80,
num = window.pageYOffset;
document.addEventListener('scroll', function(e) {
var offset = window.pageYOffset;
num >= offset ? count += 2.5 : count -= 2.5;
num = offset;
lightBox.style.width = count + '%';
});
View the code here, in this codepen
http://codepen.io/anon/pen/EjrpMM
Thank you!

You just have to change
+= 2.5 and -=2.5 to += 0.7 and -= 0.7
When I checked your code I did this and it worked.

Scroll event fired once on scroll independently on how much you've scrolled. E.g. if you've scrolled 1px scrollbar, or scrolled 100px using mousewheel scroll event will be fired once.
So if you need stable results you will need to calculate your div width depending on scroll position (window.pageYOffset).
Check this codepen fork. I've assumed that in the end of page div width should be 50%.
Core part is:
var lightBox = document.getElementById('lightBox');
var upperBound = 80;
var lowerBound = 50;
var tickValue = (upperBound - lowerBound) / window.innerHeight;
document.addEventListener('scroll', function(e) {
var offset = window.pageYOffset;
var count = upperBound - offset * tickValue;
lightBox.style.width = count + '%';
});
Important note: for crossbrowser way to get innerHeight you can check this answer

This is a simple equation. Let f : scroll |-> f(scroll) be the function that gives you the width of your div. You want f(0) = 0.8, f(2000)= 1/3.
Let's say you want the progression to be linear so f(scroll) = a*scroll + b, you can easily deduce that b = 0.8 and a = (1/3 - 0.8)/2000 = -0.000233. Now for any scroll value, you can find the width of your div.
Now you can change the values when you want, f(scroll) = (minWidth-maxWidth)/pageLength * scroll + maxWidth.

need 100% div without setting a fixed height on container div

Here is a link to a JSFiddle http://jsfiddle.net/9NYcn/11/ i put together with what i would like to do, but i need to do this with pure css.
function expand(){
var sect = document.getElementById("sect");
var body = document.getElementById("main");
var panes = document.getElementById("panes");
var newHeight = 40 + "px";
var newHeight2 = 120 + "px";
var topVal = 120 + "px";
sect.style.display = "block";
sect.style.height = newHeight;
body.style.height = newHeight2;
panes.style.top = topVal;
}
In the above function i had to set the "top" property of panes in order to get this to work. i need to get it so that the panes section will work like it currently does without using javascript to change the "top" property of "panes". When the user clicks the "expand" button the div with the class "body" will expand and not stick behind or overlap the "panes" div.
I know im doing a terrible job explaining i apologize for that.

Remove the absolute positioning of .panes: http://jsfiddle.net/rHTM8/
It will make it naturally flow after the middle div.

how do i get the x and y position directly under the left bottom side of the input rectangle?

I'm thinking of implementing a custom auto-complete feature so basically my idea now is that i will make an abs positioned div and give it the position here:
(image) http://i.stack.imgur.com/3c5BH.gif
So my question is with a variable referencing the textbox, how do i get the x and y position directly under the left bottom side of the input rectangle?
My script must work in latest versions of IE / FF / Safari / Opera / Chrome
I know i can use a library to do it, but no i'm interested in learning how do they do it (or maybe better ways)?

This question is a lot more complicated than it seems and involves getting the position of the element relative to the document. The code to do so can be pulled from the jquery source (http://code.jquery.com/jquery-1.6.1.js -- search for "jQuery.fn.offset")
in jQuery:
var node = $('#textbox'),
pos = box.offset(); // the complicated piece I'm using jQuery for
node.top += node.height(); // node.offsetHeight without jQuery
node.left += node.width(); // node.offsetWidth without jQuery
The answer can be extremely simplified if you don't care about FF2 or Safari3:
var box = document.getElementById('yourTextBox').getBoundingClientRect(),
left = box.left,
bottom = box.bottom;

x = x offset
y = y offset - ( textbox height +
padding-top + padding-bottom )

Good comments! For my scenario, there is always an offset parent (which is why I use position - http://api.jquery.com/position/). In hopes that it might help someone else wanting a quick fix, here's the code:
// I have a parent item (item) and a div (detail)
// that pops up at the bottom left corner of the parent:
var jItem = $(item);
var pos = jItem.position();
var marginTop = parseInt(jItem.css('margin-top'));
if (isNaN(marginTop)) {
marginTop = 0;
}
$(detail).css("top", pos.top + jItem.outerHeight() + marginTop)
.css("left", pos.left);
$(detail).show();

Just give the box a defined width and height. Then, get its top and left property and add it with the width and height. Simple. I am gonna give you Pseodocode.
<STYLE>
object{width: 100px; height: 20px;}
</STYLE>
<SCRIPT>
x = object.left;
y = object.top;
x = x + object.width;
y = y + object.height;
</SCRIPT>

Get position of map area(html)?

Is this possible? I'm trying to find the x and y coordinates of the element in relation to the browser.
var position = $(this).position();
x = position.left;
y = position.right;
Doesn't work.
Is there any way to do this?
http://adamsaewitz.com/housing/
highlight the blue room 070

The problem lies in the fact that you are accessing the top/left of an area element.
The area element is not positioned where its coords say. This is handled behind the scenes by the dom/browser.
So you need to find the image that the area relates to and grab its offset.
var imgId = $(this).closest('map').attr('name');
var imgPos = $('#' + imgId).offset();
Then, you grab the coords attribute of the area and split it to get left/top/width and use those to pinpoint the location inside the image.
var coords = $(this).attr('coords').split(',');
var box = {
left: parseInt(coords[0],10),
top: parseInt(coords[1],10),
width: parseInt(coords[2],10)-parseInt(coords[0],10),
height: parseInt(coords[3],10)-parseInt(coords[1],10)
};
Take into consideration the width/height of the info box that appears (and since you animate it, take that into consideration as well) and you get to
x = imgPos.left + box.left + box.width/2 - 65; // 65 is the info width/2
y = imgPos.top + box.top -20 -160 -1; // 20 is the animation, 160 is the info height, 1 is a safe distance from the top
demo: http://www.jsfiddle.net/XBjwN/

Edit for updated question: Since you're using <area> it's a different story, and fetching from the coords attribute is much easier, like this:
var position = $(this).attr('coords').split(',');
x = +position[0] - 50;
y = +position[1] - 170;
The offsets are just to account for the hard-coded width/height of the tooltip itself. In addition to the above, you want to use top and left rather than margin-top and margin-left. Also to account for the #content <div>'s position in the page, give it a relative position for the tooltip to sit in, like this:
#content { position: relative; }
Then...instead of .after(), use .append() so it gets added inside that parent.
You can test the result here.
For original question:
The object .position() returns has top and left properties...but you want .offset() here anyway (it's relative to the document, where .position() is relative to the offset parent), so it should look like this:
var position = $(this).offset(),
x = position.left,
y = position.top; //not right!
Or this:
var position = $(this).offset();
var x = position.left;
var y = position.top;
...but without a single var comma-separated statement, or a var on each line, you're also creating (or trying to) global variables, which will blow up in IE.

$(document).ready(function () {
$('map').imageMapResize();
$('area').hover(function () {
$('.imgpopover').css({ "display": "block", "top": $(this).attr("coords").split(',')[1]+"px", "left": $(this).attr("coords").split(',')[0]+"px" })
$('.imgpopover label').text($(this).attr("title"))
}, )
});