I have javascript/jquery code that will allow the user to drag/drop records to re-sort them. But currently it always sorts the item above whatever item they move it to.
I would like for it to sort above if the mouse is on the top half, and below if the mouse is on the bottom half. And I would like to show a line or border that indicates which side it will be sorted to based on where the mouse currently is.
The only part of this process I'm not sure of is how to tell if the mouse is on the top or bottom half of an element. I suspect I will need to do some math to divide the height by 2 and then see if the relative y coordinate of the mouse in the element is above or below that number.
As I'm writing this, I'm thinking perhaps the title should reflect specifically that I want to know how to get the relative coordinate of the mouse in an element, but I also know when I'm too specific then I end up having to explain the bigger picture anyway as there are often alternative solutions that are better. So there you have the big picture and the specific way I think I need to solve the problem.
You didn’t specify if you’re using the HTML Drag and Drop interface, but assuming you are, you could use the drop event object to get the mouse (or touch) offsetY position and compare that to the height of your target element. If the offsetY is more than half the height of the target, append your record after the target element, and if not append your record after the previousSibling.
function drop(ev) {
ev.preventDefault();
var data = ev.dataTransfer.getData("text");
var target = ev.currentTarget;
var domRect = target.getBoundingClientRect();
console.log("offsetY: " + ev.offsetY + " height: " + domRect.height);
// do the logic and append your record to the right position
}
And if you're not use the HTML Drag and Drop interface, the concept of comparing the event offsetY to your drop target should still be possible.
Similar to this unresolved question (jQuery - parallax - update background position correctly)
I am animating the transform property of an element on page scroll to achieve a parallax-like effect. I want this element to only begin animating up when it is in view. The problem now is that if the element appears further down the page, it has already moved up a lot and loses the effect.
Here is my code currently
function parallax() {
var scrolled = $(window).scrollTop();
$('[data-scroll]').css('transform', 'translateY('+-(scrolled*0.02)+'px)');
}
$(window).scroll(function(e){
parallax();
});
In answer to your question how to separate "parallax'ed" divs, so they shift their position independently from each other upon scrolling, one should rely on their unique coordinates - each one has it's own $(elem).offset().top - a general vertical offset from the top of the page (it's stays the same all the time unless you meddle with the TOP property manually).
so all calculation could be based against this property.
$('.parallax').each(function(){
if ($(this).is_on_screen()) {
var firstTop = $(this).offset().top;
var winScrollTop = $(window).scrollTop();
var shiftDistance = (firstTop - winScrollTop)*0.02;
$(this).css("transform":"translateY("+shiftDistance+"px)");
}
});
plus you check if the element is in the viewport. Thus, you assure it moves the same delta distance in its own time no matter where it's on the page - further down or up.
Another thing is that how to put "borders" of visibility of the element on the screen. If you are moving an element when it's in viewport, i would suggest making a wrapping div within which the movement occurs (like a bg moving within a div wrapper).
<div class="parallax-section slide1">
<span class="moving-block"></span>
</div>
div has a bigger height and we check when this div is on the screen, not the moving element.
demo
Also other modifications can be applied if one needs different speed, offset for each element. I found this plugin a good beginner stuff to learn parallax.
P.S. btw, all initial properties should be cached in variables instead of retrieving them each time in a callback, like firstTop for instance
I have a div that is moveable in all directions with the keyboard arrows.
I'm trying to make it so that when the moveable div 'walks' down the page and reaches a certain point, another div with text in it appears.
How do I make it so that when the character reaches a certain point on the page, a div dialogue shows?
if($('#'+character).position().top > -500) {
if(character == 'character1') {
$('#page2 .dialogue').fadeIn(4000);
}
}
So position() is relative to the containing element while offset() is relative to the document. With that said, you are asking when an element is 500 above the containing div. You may not be able to see it. Try removing the negative sign.
If you provide a jsfiddle then we can confirm and provide better help.
In CSS, you can set element.style.top but you cannot read it. You need to use element.offsetTop instead, which will give you the position of your div. I'll assume character is a variable which has been defined in advance and is the ID of the div layer.
if(document.getElementById(character).offsetTop > 500) {
if(character == 'character1') {
$('#page2 .dialogue').fadeIn(4000);
}
}
Oughta do the trick. Call it occasionally to keep checking.
Or even better yet, don't bother with any of that. Keep the character's position in a variable, then set their position that way, and when you need to read the coordinates of the character just read the variable. That's how I'd approach it.
I have a div that has background:transparent, along with border. Underneath this div, I have more elements.
Currently, I'm able to click the underlying elements when I click outside of the overlay div. However, I'm unable to click the underlying elements when clicking directly on the overlay div.
I want to be able to click through this div so that I can click on the underlying elements.
Yes, you CAN do this.
Using pointer-events: none along with CSS conditional statements for IE11 (does not work in IE10 or below), you can get a cross browser compatible solution for this problem.
Using AlphaImageLoader, you can even put transparent .PNG/.GIFs in the overlay div and have clicks flow through to elements underneath.
CSS:
pointer-events: none;
background: url('your_transparent.png');
IE11 conditional:
filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='your_transparent.png', sizingMethod='scale');
background: none !important;
Here is a basic example page with all the code.
Yes, you CAN force overlapping layers to pass through (ignore) click events.
PLUS you CAN have specific children excluded from this behavior...
You can do this, using pointer-events
pointer-events influences the reaction to click-, tap-, scroll- und hover events.
In a layer that should ignore / pass-through mentioned events you set
pointer-events: none;
Children of that unresponsive layer that need to react mouse / tap events again need:
pointer-events: auto;
That second part is very helpful if you work with multiple overlapping div layers (probably some parents being transparent), where you need to be able to click on child elements and only that child elements.
Example usage:
.parent {
pointer-events:none;
}
.child {
pointer-events:auto;
}
<div class="parent">
I'm unresponsive
I'm clickable again, wohoo !
</div>
Allowing the user to click through a div to the underlying element depends on the browser. All modern browsers, including Firefox, Chrome, Safari, and Opera, understand pointer-events:none.
For IE, it depends on the background. If the background is transparent, clickthrough works without you needing to do anything. On the other hand, for something like background:white; opacity:0; filter:Alpha(opacity=0);, IE needs manual event forwarding.
See a JSFiddle test and CanIUse pointer events.
I'm adding this answer because I didn’t see it here in full. I was able to do this using elementFromPoint. So basically:
attach a click to the div you want to be clicked through
hide it
determine what element the pointer is on
fire the click on the element there.
var range-selector= $("")
.css("position", "absolute").addClass("range-selector")
.appendTo("")
.click(function(e) {
_range-selector.hide();
$(document.elementFromPoint(e.clientX,e.clientY)).trigger("click");
});
In my case the overlaying div is absolutely positioned—I am not sure if this makes a difference. This works on IE8/9, Safari Chrome and Firefox at least.
Hide overlaying the element
Determine cursor coordinates
Get element on those coordinates
Trigger click on element
Show overlaying element again
$('#elementontop').click(e => {
$('#elementontop').hide();
$(document.elementFromPoint(e.clientX, e.clientY)).trigger("click");
$('#elementontop').show();
});
I needed to do this and decided to take this route:
$('.overlay').click(function(e){
var left = $(window).scrollLeft();
var top = $(window).scrollTop();
//hide the overlay for now so the document can find the underlying elements
$(this).css('display','none');
//use the current scroll position to deduct from the click position
$(document.elementFromPoint(e.pageX-left, e.pageY-top)).click();
//show the overlay again
$(this).css('display','block');
});
I currently work with canvas speech balloons. But because the balloon with the pointer is wrapped in a div, some links under it aren't click able anymore. I cant use extjs in this case.
See basic example for my speech balloon tutorial requires HTML5
So I decided to collect all link coordinates from inside the balloons in an array.
var clickarray=[];
function getcoo(thatdiv){
thatdiv.find(".link").each(function(){
var offset=$(this).offset();
clickarray.unshift([(offset.left),
(offset.top),
(offset.left+$(this).width()),
(offset.top+$(this).height()),
($(this).attr('name')),
1]);
});
}
I call this function on each (new) balloon. It grabs the coordinates of the left/top and right/down corners of a link.class - additionally the name attribute for what to do if someone clicks in that coordinates and I loved to set a 1 which means that it wasn't clicked jet. And unshift this array to the clickarray. You could use push too.
To work with that array:
$("body").click(function(event){
event.preventDefault();//if it is a a-tag
var x=event.pageX;
var y=event.pageY;
var job="";
for(var i in clickarray){
if(x>=clickarray[i][0] && x<=clickarray[i][2] && y>=clickarray[i][1] && y<=clickarray[i][3] && clickarray[i][5]==1){
job=clickarray[i][4];
clickarray[i][5]=0;//set to allready clicked
break;
}
}
if(job.length>0){
// --do some thing with the job --
}
});
This function proofs the coordinates of a body click event or whether it was already clicked and returns the name attribute. I think it is not necessary to go deeper, but you see it is not that complicate.
Hope in was enlish...
Another idea to try (situationally) would be to:
Put the content you want in a div;
Put the non-clicking overlay over the entire page with a z-index higher,
make another cropped copy of the original div
overlay and abs position the copy div in the same place as the original content you want to be clickable with an even higher z-index?
Any thoughts?
I think the event.stopPropagation(); should be mentioned here as well. Add this to the Click function of your button.
Prevents the event from bubbling up the DOM tree, preventing any parent handlers from being notified of the event.
Just wrap a tag around all the HTML extract, for example
<a href="/categories/1">
<img alt="test1" class="img-responsive" src="/assets/photo.jpg" />
<div class="caption bg-orange">
<h2>
test1
</h2>
</div>
</a>
in my example my caption class has hover effects, that with pointer-events:none; you just will lose
wrapping the content will keep your hover effects and you can click in all the picture, div included, regards!
An easier way would be to inline the transparent background image using Data URIs as follows:
.click-through {
pointer-events: none;
background: url(data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7);
}
I think that you can consider changing your markup. If I am not wrong, you'd like to put an invisible layer above the document and your invisible markup may be preceding your document image (is this correct?).
Instead, I propose that you put the invisible right after the document image but changing the position to absolute.
Notice that you need a parent element to have position: relative and then you will be able to use this idea. Otherwise your absolute layer will be placed just in the top left corner.
An absolute position element is positioned relative to the first parent
element that has a position other than static.
If no such element is found, the containing block is html
Hope this helps. See here for more information about CSS positioning.
You can place an AP overlay like...
#overlay {
position: absolute;
top: -79px;
left: -60px;
height: 80px;
width: 380px;
z-index: 2;
background: url(fake.gif);
}
<div id="overlay"></div>
just put it over where you dont want ie cliked. Works in all.
This is not a precise answer for the question but may help in finding a workaround for it.
I had an image I was hiding on page load and displaying when waiting on an AJAX call then hiding again however...
I found the only way to display my image when loading the page then make it disappear and be able to click things where the image was located before hiding it was to put the image into a DIV, make the size of the DIV 10x10 pixels or small enough to prevent it causing an issue then hiding the containing div. This allowed the image to overflow the div while visible and when the div was hidden, only the divs area was affected by inability to click objects beneath and not the whole size of the image the DIV contained and was displaying.
I tried all the methods to hide the image including CSS display=none/block, opacity=0, hiding the image with hidden=true. All of them resulted in my image being hidden but the area where it was displayed to act like there was a cover over the stuff underneath so clicks and so on wouldn't act on the underlying objects. Once the image was inside a tiny DIV and I hid the tiny DIV, the entire area occupied by the image was clear and only the tiny area under the DIV I hid was affected but as I made it small enough (10x10 pixels), the issue was fixed (sort of).
I found this to be a dirty workaround for what should be a simple issue but I was not able to find any way to hide the object in its native format without a container. My object was in the form of etc. If anyone has a better way, please let me know.
I couldn't always use pointer-events: none in my scenario, because I wanted both the overlay and the underlying element(s) to be clickable / selectable.
The DOM structure looked like this:
<div id="outerElement">
<div id="canvas-wrapper">
<canvas id="overlay"></canvas>
</div>
<!-- Omitted: element(s) behind canvas that should still be selectable -->
</div>
(The outerElement, canvas-wrapper and canvas elements have the same size.)
To make the elements behind the canvas act normally (e.g. selectable, editable), I used the following code:
canvasWrapper.style.pointerEvents = 'none';
outerElement.addEventListener('mousedown', event => {
const clickedOnElementInCanvas = yourCheck // TODO: check if the event *would* click a canvas element.
if (!clickedOnElementInCanvas) {
// if necessary, add logic to deselect your canvas elements ...
wrapper.style.pointerEvents = 'none';
return true;
}
// Check if we emitted the event ourselves (avoid endless loop)
if (event.isTrusted) {
// Manually forward element to the canvas
const mouseEvent = new MouseEvent(event.type, event);
canvas.dispatchEvent(mouseEvent);
mouseEvent.stopPropagation();
}
return true;
});
Some canvas objects also came with input fields, so I had to allow keyboard events, too.
To do this, I had to update the pointerEvents property based on whether a canvas input field was currently focused or not:
onCanvasModified(canvas, () => {
const inputFieldInCanvasActive = // TODO: Check if an input field of the canvas is active.
wrapper.style.pointerEvents = inputFieldInCanvasActive ? 'auto' : 'none';
});
it doesn't work that way. the work around is to manually check the coordinates of the mouse click against the area occupied by each element.
area occupied by an element can found found by 1. getting the location of the element with respect to the top left of the page, and 2. the width and the height. a library like jQuery makes this pretty simple, although it can be done in plain js. adding an event handler for mousemove on the document object will provide continuous updates of the mouse position from the top and left of the page. deciding if the mouse is over any given object consists of checking if the mouse position is between the left, right, top and bottom edges of an element.
Nope, you can't click ‘through’ an element. You can get the co-ordinates of the click and try to work out what element was underneath the clicked element, but this is really tedious for browsers that don't have document.elementFromPoint. Then you still have to emulate the default action of clicking, which isn't necessarily trivial depending on what elements you have under there.
Since you've got a fully-transparent window area, you'll probably be better off implementing it as separate border elements around the outside, leaving the centre area free of obstruction so you can really just click straight through.
Ok, the subject is not super specific to the overall need I am looking to address. So I have this function that is called on a given element, which is a hidden submenu next to a triggering element. The way the page renders, and to keep the styling optimized I can't just style the position in via css. So I need javascript/jquerys help.
With that I have come up with a function that I can reuse as needed, and works fine all around. However my key problem is, that I have a couple cases where the submenu will overlap the edge of the <section> element it resides in. Which that elements overflow is set to hidden, that and its also about 30 pixels from the bottom of the page anyway. All in all the submenu element gets hidden a bit by either falling completely out of the pages view half way through the element, or it gets hidden by the section tags overflow state.
With that. In a case where this happens I am wanting to instead of have the element align to the bottom of the trigger element, have it align to the top instead so that way the menu in that case is above the trigger element and not below.
Problem is Im not sure how to compensate for that.
Here is the function I came up with to do what I need, now I just need some help in a sense catching when the menu element falls off the page so to speak, so I can adjust for it when it does.
function openSubOrgMenu(triggerID, elem)
{
orgSubOpenID = triggerID;
orgSubShowing = true;
elemOffset = elem.offset(); //trigger element
elemWidth = elem.width();
elemHeight = elem.height();
elemWrap = elem.siblings('.org_group_wrapper');//menu element
elemWrapWidth = elemWrap.width();
elemWrapHeight = elemWrap.height();
moveTop = elemHeight + elemOffset.top + 4;
moveLeft = elemOffset.left - (elemWrapWidth-elemWidth-15);
elemWrap.show().offset({top:moveTop, left:moveLeft});
}
Well here is a JS Fiddle, not necessarily showing a working logic of what I want, but demonstrating the desired effect when its an element that at the bottom of the page/section:
http://jsfiddle.net/4zwEr/