I'm a JavaScript novice. Have patience with me.
I searched this site for relevant questions and found two: How to get width of a dynamically created element with $comiple in Angularj and jQuery + CSS. How do I compute height and width of innerHTML?. Their relevance and their answers are discussed below. If I missed a relevant question and this is a duplicate question, please direct me to it.
I dynamically create a <div class="popup"> (call it "popup"), populate it with innerHTML from a display: none; <div> in the markup, and insert it on the page. The relevant CSS is:
.popup {
top: 0;
left: 0;
width: 200px;
height: 250px;
}
Using event.clientX, I position popup relative to the cursor position at the time the mouseover event fired, as follows:
var widthOffset = 75, heightOffset = 0;
var windowWidth, popupWidth;
// other code ...
windowWidth = $(window).width();
popupWidth = 200; // popup.style.width returns nothing (not null,
// not undefined, just nothing).
// when event.clientX is in the left half of the window, display popup
// offset to the right of clientX;
// when clientX is in the right half, display popup offset to the left.
if( event.clientX > windowWidth/2 ){ widthOffset = -(widthOffset + popupWidth);}
popup.style.top = event.clientY - heightOffset + "px";
popup.style.left = event.clientX + widthOffset + "px";
There is a working reduced case at the Pen Popup Project Reduced Case on CodePen.
The problem is that I want to programmatically obtain popupWidth not set it as a fixed quantity. But, as the comment states,
popupWidth = popup.style.width;
is nothing. (Maybe it's a null string: popupWidth === "". I'm uncertain.)
The answer to the first question referenced above said to insert popup into the DOM before trying to obtain its width. I have done this. (See the Pen.) Still, it doesn't work.
A comment to the second answer to the second question said:
the root issues is that height cannot be set on an element with display:none.
I had display: none but when I changed it to display: block, and set popupWidth = popup.style.width;, popup "stuttered" fiercely on mouseover.
So the question remains: How do I programmatically get popupWidth just as I did with windowWidth?
With help from #Redu and #torazaburo, the answer became clear.
popupWidth = popup.offsetWidth; is the correct statement but both these conditions must be true:
popup must have been inserted into the DOM, and
display: block; must have been set.
If popup is still in memory or display: block; has not been set, then popup.offsetWidth === 0. If both of the conditions are true, then popup.offsetWidth is equal to the width set in the CSS.
Thanks to both commenters for their help.
You can do like
var popupDiv = document.getElementsByClassName("popup")[0],
width = window.getComputedStyle(popupDiv).width;
If you deal with a window or document type of element then getElementsByClassName(element,null), element.offsetWidth or element.clientWidth doesn't work. You have to access the width value like
var w = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
Related
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.
Ok, I thought this would be really simple, but it's turning out not to be. I think I'm just messing something up in my HTML/CSS, but here goes.
I have a basic page like so:
HTML
<!DOCTYPE html>
<html>
<head>
<link href='test2.css' rel="stylesheet" type="text/css" />
<script src="http://code.jquery.com/jquery-1.10.2.js"></script>
<script src="test2.js"></script>
</head>
<body>
<div id="scroll"></div>
</body>
</html>
test2.css
* {
padding: 0;
margin: 0;
}
html, body {
height: 100%;
width: 100%;
}
#scroll {
height: 100%;
width: 100%;
overflow: scroll;
background-color: black;
}
test2.js
$(document).ready(function() {
// my resolution is 1440x900
alert('innerwidth should be 1425');
// all of these return 1440
alert('body innerwidth: ' + $('body').innerWidth());
alert('document width: ' + $(document).width());
alert('window width: ' + $(window).width());
alert('scroll div innerwidth: ' + $('#scroll').innerWidth());
alert('document.documentElement.clientWidth: ' + document.documentElement.clientWidth);
alert('document.documentElement.scrollWidth: ' + document.documentElement.scrollWidth);
});
So I've got one element on the page... a div that takes up the entire screen, or rather it should be taking up the entire screen minus the scrollbars. Now, I've been doing some snooping on how to grab the width and height of a page without the scrollbars, but unfortunately, none of them return the proper value... which makes me believe I'm missing the boat in my HTML or CSS.
I looked at the following:
jquery - how to get screen width without scrollbar?
how to get the browser window size without the scroll bars
So what I need is for a method to return the value of my viewable screen minus the respective scrollbar value... so for my width, my value should be 1425 because the scrollbar is 15 pixels wide. I thought that's what innerWidth's job was, but apparently I'm wrong?
Can anyone provide any insight? (I'm running Firefox 24.)
EDIT
To add some background, I've got a blank page. I will be adding elements one by one to this page, and I need to use the width of the page when calculating the sizes for these elements. Eventually, this page will grow and grow until the scrollbar appears, which is why I'm trying to force the scrollbar there from the start, but apparently, that still doesn't do anything.
EDIT2
Here's something even more interesting... if I do document.getElementById('scroll').clientWidth, I get the proper innerWidth, but if I do $('#scroll').width() or $('#scroll').innerWidth(), they both return the max resolution... sounds like a jQuery bug.
I got this somewhere and would give credit if I knew where, but this has been succesfull for me. I added the result as padding when setting the html overflow to hidden.
Problem is that the scrollbar is a feature of the browser and not the web page self. Measurement should be done dynamically. A measurement with a scrollbar and a measurement without a scrollbar will resolve into calculating the difference in width.
Found the source: http://www.fleegix.org/articles/2006/05/30/getting-the-scrollbar-width-in-pixels
scrollCompensate = function () {
var inner = document.createElement('p');
inner.style.width = "100%";
inner.style.height = "200px";
var outer = document.createElement('div');
outer.style.position = "absolute";
outer.style.top = "0px";
outer.style.left = "0px";
outer.style.visibility = "hidden";
outer.style.width = "200px";
outer.style.height = "150px";
outer.style.overflow = "hidden";
outer.appendChild(inner);
document.body.appendChild(outer);
var w1 = inner.offsetWidth;
outer.style.overflow = 'scroll';
var w2 = inner.offsetWidth;
if (w1 == w2) w2 = outer.clientWidth;
document.body.removeChild(outer);
return (w1 - w2);
}
var htmlpadding = scrollCompensate();
The correct answer is in this post marked as accepted:
CSS media queries and JavaScript window width do not match
This is the correct code:
function viewport() {
var e = window, a = 'inner';
if (!('innerWidth' in window )) {
a = 'client';
e = document.documentElement || document.body;
}
return { width : e[ a+'Width' ] , height : e[ a+'Height' ] };
}
Discovered a very hacky solution... by adding this before my alerts in test2.js, I get the proper width:
var p = $('body').append('<p style="height: 100%; width: 100%;"></p>');
alert(p.width());
$('body').remove('p');
And consequently, all of the alerts now have the proper width. I also don't even need overflow-y in the CSS if I do it this way. Curious why this solves it...
The real answer should be keeping the HTML and CSS as is, then using document.getElementById('scroll').clientWidth. Using clientWidth gets the viewable area minus the scrollbar width.
The correct width of the page is given by $(document).width().
Your problem is that you're using a scroll within the div (overflow: scroll).
Using $(document).width() the returned value is already discounting the visible width of the scroll, but how do you put a scroll within the div value returned is no longer the same.
As the width of the scroll is not standard and varies from system to system and browser to browser, it is difficult to solve.
I suggest you remove the scroll of the div and let the browser manage this by default in the body, then yes you have the correct width.
This question already has answers here:
How can I get the browser's scrollbar sizes?
(25 answers)
Closed 5 years ago.
The following HTML will display a scroll bar on the right inside edge of div.container.
Is it possible to determine the width of that scroll bar?
<div class="container" style="overflow-y:auto; height:40px;">
<div class="somethingBig"></div>
</div>
This function should give you width of scrollbar
function getScrollbarWidth() {
// Creating invisible container
const outer = document.createElement('div');
outer.style.visibility = 'hidden';
outer.style.overflow = 'scroll'; // forcing scrollbar to appear
outer.style.msOverflowStyle = 'scrollbar'; // needed for WinJS apps
document.body.appendChild(outer);
// Creating inner element and placing it in the container
const inner = document.createElement('div');
outer.appendChild(inner);
// Calculating difference between container's full width and the child width
const scrollbarWidth = (outer.offsetWidth - inner.offsetWidth);
// Removing temporary elements from the DOM
outer.parentNode.removeChild(outer);
return scrollbarWidth;
}
Basic steps here are:
Create hidden div (outer) and get it's offset width
Force scroll bars to appear in div (outer) using CSS overflow property
Create new div (inner) and append to outer, set its width to '100%' and get offset width
Calculate scrollbar width based on gathered offsets
Working example here: http://jsfiddle.net/slavafomin/tsrmgcu9/
Update
If you're using this on a Windows (metro) App, make sure you set the -ms-overflow-style property of the 'outer' div to scrollbar, otherwise the width will not be correctly detected. (code updated)
Update #2
This will not work on Mac OS with the default "Only show scrollbars when scrolling" setting (Yosemite and up).
offsetWidth includes width of scroll bar and clientWidth doesn't. As rule, it equals 14-18px. So:
let scrollBarWidth = element.offsetWidth - element.clientWidth;
That will return 0 if the element doesn't currently have a scroll bar, so here's a simple function which computes the browser's scroll bar width by creating a temporary element that has a scroll bar:
function getScrollBarWidth() {
let el = document.createElement("div");
el.style.cssText = "overflow:scroll; visibility:hidden; position:absolute;";
document.body.appendChild(el);
let width = el.offsetWidth - el.clientWidth;
el.remove();
return width;
}
I think this will be simple and fast -
var scrollWidth= window.innerWidth-$(document).width()
If the child takes the full width of the container excluding scrollbar (the default), then you can subtract the widths:
var child = document.querySelector(".somethingBig");
var scrollbarWidth = child.parentNode.offsetWidth - child.offsetWidth;
If you use jquery.ui, try this code:
$.position.scrollbarWidth()
I've used next function to get scrollbar height/width:
function getBrowserScrollSize(){
var css = {
"border": "none",
"height": "200px",
"margin": "0",
"padding": "0",
"width": "200px"
};
var inner = $("<div>").css($.extend({}, css));
var outer = $("<div>").css($.extend({
"left": "-1000px",
"overflow": "scroll",
"position": "absolute",
"top": "-1000px"
}, css)).append(inner).appendTo("body")
.scrollLeft(1000)
.scrollTop(1000);
var scrollSize = {
"height": (outer.offset().top - inner.offset().top) || 0,
"width": (outer.offset().left - inner.offset().left) || 0
};
outer.remove();
return scrollSize;
}
This jQuery-based solutions works in IE7+ and all other modern browsers (including mobile devices where scrollbar height/width will be 0).
Here's an easy way using jQuery.
var scrollbarWidth = jQuery('div.withScrollBar').get(0).scrollWidth - jQuery('div.withScrollBar').width();
Basically we subtract the scrollable width from the overall width and that should provide the scrollbar's width. Of course, you'd want to cache the jQuery('div.withScrollBar') selection so you're not doing that part twice.
Assuming container is only on page once and you are using jQuery, then:
var containerEl = $('.container')[0];
var scrollbarWidth = containerEl.offsetWidth - containerEl.clientWidth;
Also see this answer for more details.
this worked for me..
function getScrollbarWidth() {
var div = $('<div style="width:50px;height:50px;overflow:hidden;position:absolute;top:-200px;left:-200px;"><div style="height:100px;"></div>');
$('body').append(div);
var w1 = $('div', div).innerWidth();
div.css('overflow-y', 'scroll');
var w2 = $('div', div).innerWidth();
$(div).remove();
return (w1 - w2);
}
I am having this problem where i have a set of 6 UL's having a common class x.Each of them consist of a specific section of the page.Now i have 6 menus that are related to each of the section.What i have to do is highlight the menu when its related section is in users view.
For this i thought that may be jQuery position(); or offset(); could have helped but they give the top and left of the element.I also tried using jQuery viewport plugin but apparently view port is big it can show more than one UL at a time hence i cant apply element specific logic here.I am not familliar to this but does anything changes of an element on scrolling?If yes then how to access it?
Please share your views.
Regards
Himanshu Sharma.
Is very easy to do it using jQuery and a dummy fixed HTML block that helps you find the current position of the viewport.
$(window).on("scroll load",function(){
var once = true;
$(".title").each(function(ele, index){
if($(this).offset().top > $("#viewport_helper").offset().top && once){
var index = $(this).index(".title");
$(".current").removeClass('current')
$("#menu li").eq(index).addClass('current')
once = false;
}
});
})
Check out a working example: http://jsfiddle.net/6c8Az/1/
You could also do something similar with the jQuery plugin, together with the :first selector:
$(window).on("scroll load",function(){
$(".title:in-viewport:first").each(function(){
var index = $(this).index(".title");
$(".current").removeClass('current')
$("#menu li").eq(index).addClass('current')
});
})
You can get the viewport's width and height via $(document).width() and $(document).height()
You can get how many pixels user scrolls via $(document).scrollTop() and $(document).scrollLeft
Combining 1 and 2, you can calculate where the viewport rectangle is
You can get the rectangle of an element using $(element).offset(), $(element).width() and $(element).height()
So the only thing left to you is to determine whether the viewport's rectangle contains (or interacts) the elements's rectangle
So the whole code may look like:
/**
* Check wether outer contains inner
* You can change this logic to matches what you need
*/
function rectContains(outer, inner) {
return outer.top <= inner.top &&
outer.bottom >= inner.bottom &&
outer.left <= inner.left &&
outer.right >= inner.right;
}
/**
* Use this function to find the menu related to <ul> element
*/
function findRelatedMenu(element) {
return $('#menu-' + element.attr('id'));
}
function whenScroll() {
var doc = $(document);
var elem = $(element);
var viewportRect = {
top: doc.scrollTop(),
left: doc.scrollLeft(),
width: doc.width(),
height: doc.height()
};
viewportRect.bottom = viewportRect.top + viewportRect.height;
viewportRect.right = viewportRect.left + viewportRect.width;
var elements = $('ul.your-class');
for (var i = 0; i < elements.length; i++) {
var elem = $(elements[i]);
var elementRect = {
top: elem.offset().top,
left: elem.offset().left,
width: elem.width(),
height: elem.height()
};
elementRect.bottom = elementRect.top + elementRect.height;
elementRect.right = elementRect.left + elementRect.width;
if (rectContains(viewportRect, elementRect)) {
findRelatedMenu(elem).addClass('highlight');
}
}
}
$(window).on('scroll', whenScroll);
Let's see if i understood well. You have a page long enough to scroll, and there is an element that when it appears in the viewport, you wanna do something with it. So the only event that's is triggered for sure on the time the element gets in the viewport is the 'scroll'. So if the element is on the page and the scroll is on the viewport, what you need to do is bind an action to the scroll event to check if the element is in the view each time the event is trigger. Pretty much like this:
$(window).scroll(function() {
check_element_position();
});
Now, in order for you to know if the element is in the viewport, you need 3 things. The offset top of that element, the size of the viewport and the scroll top of the window. Should pretty much look like this:
function check_element_position() {
var win = $(window);
var window_height = win.height();
var element = $(your_element);
var elem_offset_top = element.offset().top;
var elem_height = element.height();
var win_scroll = win.scrollTop();
var pseudo_offset = (elem_offset_top - win_scroll);
if (pseudo_offset < window_height && pseudo_offset >= 0) {
// element in view
}
else {
// elem not in view
}
}
Here, (elem_offset_top - win_scroll) represent the element position if there was no scroll. Like this, you just have to check if the element offset top is higher then the window viewport to see if it's in view or not.
Finally, you could be more precise on you calculations by adding the element height (variable already in there) because the code i just did will fire the event even if the element is visible by only 1 pixels.
Note: I just did that in five minutes so you might have to fix some of this, but this gives you a pretty darn good idea of what's going on ;)
Feel free to comment and ask questions
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>