Dnd avatar: how to get wysiwyg-preview on dragOver? - javascript

We've got a request from a customer to support the following scenario:
on a page we have a container: div element which is at the same time dojo.dnd.Source.
inside the container we've got 9 div elements with similar content: 2 buttons and 2 comboboxes
a user should be able to define the sequence of those 9 div elements by simply dragging them around inside the container.
The task is to present a possible layout preview while dragging.
Will appreciate any ideas.

Focusing on your comment and first attempt at this solution, I humbly suggest the following:
If things are being animated and sensitive to mouse pointer changes you should separate the two:
Leave the element with the drag/drop event subscription (the parent) alone. Do not change its appearance ever.
Create an element (the child) inside this element that gets animated, but does not affect its parent.
The parent can be transparent.
Can this be of help?

Related

Event listener does not work when image element blocks it [duplicate]

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.

Creating focus on element that's behind a different element

all. I'm a beginner trying to create my own website.
For an input field, I want the text to appear behind horizontal lines. To achieve this, I created a container div element with many sub divs each two pixels high with a bottom border of one pixel, then placed the container div in front of the input field.
The problem is that when hovering over the input field, the cursor only changes into the "text" style cursor in the small area at the very left edge of the input field not covered by the horizontal lines created by the sub div elements.
What I would like to happen, and I fear I may need Javascript, is to have the cursor, when hovering over the container div's horizontal lines, turn into the "text" cursor and when clicked for the focus to activate within the input field.
I hope my question isn't confusing. Thank you in advance.
Add this CSS to your div with horizontal lines:
pointer-events: none;
This indicates that your div element should not become the target of mouse events, effectively letting them "pass through" it.
For more information, see the MDN article on pointer-events.
Assuming that I'm understanding your question, you do need to use JavaScript. Using jQuery you can do the following:
$('.horizontalLines').click(function() {
$('.inputField').focus();
});
This just makes it so that clicking one div will select the text input box.

How to change content of image elements?

How do I change content of image elements similarly to changing content in p (HTML paragraph) elements? (refer to: http://www.w3schools.com/jquery/html_html.asp)
I would like to have a scatter+sort effect button next to a default carousel view of images that when clicked, will, as you might have already guessed, scatter and sort itself in a stationery template.
Also, having the button change when clicked to flip between "Scatter+Sort" and "Carousel" views.
Here is what I have so far:
Carousel view - https://gyazo.com/18e67f7347de3310d155c0b8624b3716
Stationary view - https://imgur.com/a/coreG
What I intend on doing is following a similar approach to Jennifer Dewalt's a project a day for 180 days, except I am doing 100 projects in an indefinite time period.
Update: I got a button to bring up an image, but the container of images (carousel) is still on the page and does not vanish upon button click. Also, the image is shown as not available on the top left of screen before button click.
Update 2: Something I am looking into: https://www.w3schools.com/css/css3_animations.asp . Animation iteration count of 1. I'm thinking maybe, if it's possible, to rewrite the container class (carousel) in css then pulling the code in an html file, so that way I can manipulate the elements within the container.
document.getElementById("myImg").setAttribute("src", "my-new-image-source.jpg");
http://www.w3schools.com/jsref/met_element_setattribute.asp

JScrollPane Dynamic Height

The demo page referenced can be found here.
I'm trying to determine a way that on the click of a parent category (ex: Stone Tiles, Stone Sinks), that the JScrollPane would re-determine the current height and adjust as needed. Unfortunately, my attempts to do so have not worked yet.
I referenced the example here which provided the following function (to do a refresh)...
api.reinitialise();
I've tried to setup this function to be triggered by the category parents like so...
var pane = $('.menuwrap')
pane.jScrollPane();
var api = pane.data('jsp');
var i = 1;
$("li.expandable.parent").click(function() {
api.reinitialise();
});
Unfortunately, while I was able to verify the click is being rendered, the function (api.reinitialize) doesn't appear to be working. I'm hoping that a fresh pair of eyes could point me in the right direction. :-)
Thanks!
The problem is that api.reinitialise executes immediately after the click, and the li element will not have expanded yet so when jscroll pane goes to to recalculate the height it gets it wrong. You can try adding a delay but the best solution would be to bind api.reinitialise() to an event that's triggered once the your list has finished expanding. I'm not sure how you're expanding the div within the li but if for instance it's using .animate, you could bind the api.reinitialise to the animation complete event.
Also noted that not all the parent li's have the class parent associated it to them. I would expect you would want the pane to reinitialize on the expansion and collapsing of all the main li elements.
Hope that helps !
Cheers :)
What you can do is have your inner divs expanded by default, and then close them with jquery, rather than in the CSS directly.
So instead of doing this:
.mydiv.closed {display:none}
do this in your jquery after the elements are drawn to the page:
$('.mydiv.closed').hide();
This will load the jscrollpane at the necessary height, and then collapse what you want to be initially hidden.

HTML "overlay" which allows clicks to fall through to elements behind it [duplicate]

This question already has answers here:
HTML/CSS: Make a div "invisible" to clicks?
(5 answers)
Closed 7 years ago.
I'm trying to overlay a element on top of a webpage (to draw arbitrary graphics), and I've come to the point where I can stack it inside of a element on top of everything, but this prevents the user from clicking on any links/buttons/etc.
Is there a way to have its content float on top of everything (it's semi-transparent, so you can still see what is behind) and have the user interact with the layer below it?
I've found a lot of information on the DOM event model, but none of it addresses the problem where the buttons and other "native" controls never seem to get the clicks in the first place.
A silly hack I did was to set the height of the element to zero but overflow:visible; combining this with pointer-events:none; seems to cover all the bases.
.overlay {
height:0px;
overflow:visible;
pointer-events:none;
background:none !important;
}
Add pointer-events: none; to the overlay.
Original answer: My suggestion would be that you could capture the click event with the overlay, hide the overlay, then refire the click event, then display the overlay again. I'm not sure if you'd get a flicker effect though.
[Update] Exactly this problem and exactly my solution just appeared in this post: "Forwarding Mouse Events Through Layers". I know its probably a little late for the OP, but for the sake of somebody having this problem in the future, I though I would include it.
For the record an alternative approach might be to make the clickable layer the overlay: you make it semi-transparent and then place the "overlay" image behind it (somewhat counterintuitively, the "overlay" image could then be opaque). Depending on what you're trying to do, you might well be able to get the exact same visual effect (of an image and a clickable layer semi-transparently superimposed on top of each other), while avoiding clickability problems (because the "overlay" is in fact in the background).
In case anyone else is running in to the same problem, the only solution I could find that satisfied me was to have the canvas cover everything and then to raise the Z-index of all clickable elements. You can't draw on them, but at least they are clickable...
My team ran into this issue and resolved it very nicely.
add a class "passthrough" or something to each element you want clickable and which is under the overlay.
for each ".passthrough" element append a div and position it exactly on top of its parent. add class "element-overlay" to this new div.
The ".element-overlay" css should have a high z-index (above the page's overlay), and the elements should be transparent.
This should resolve your problem as the events on the ".element-overlay" should bubble up to ".passthrough". If you still have problems (we did not see any so far) you can play around with the binding.
This is an enhancement to #jvenema's solution.
The nice thing about this is that
you don't pass through ALL events to ALL elements. Just the ones you want. (resolved #jvenema's argument)
All events will work properly. (hover for example).
If you have any problems please let me know so I can elaborate.
You can use an overlay with opacity set in order to the buttons/anchors in the back stay visible, but once you have that overlay over an element, you can't click it.
Generally, this isn't a great idea. Taking your scenario, if you had evil intentions, you could hide everything underneath your "overlay". Then, when a user clicks on a link they think should take them to bankofamerica.com, instead it triggers the hidden link which takes them to myevilsite.com.
That said, event bubbling works, and if it's within an application, it's not a big deal. The following code is an example. Clicking the blue area pops up an alert, even though the alert is set on the red area. Note that the orange area does NOT work, because the event will propagate through the PARENT elements, so your overlay needs to be inside whatever element you're observing the clicks on. In your scenario, you may be out of luck.
<html>
<head>
</head>
<body>
<div id="outer" style="position:absolute;height:50px;width:60px;z-index:1;background-color:red;top:5px;left:5px;" onclick="alert('outer')">
<div id="nested" style="position:absolute;height:50px;width:60px;z-index:2;background-color:blue;top:15px;left:15px;">
</div>
</div>
<div id="separate" style="position:absolute;height:50px;width:60px;z-index:3;background-color:orange;top:25px;left:25px;">
</div>
</body>
</html>
How about this for IE?:
onmousedown: Hide all elements which could overlay the event. Because display:none visibility:hidden not realy works, push the overlaying div out of the screen for a fixed number of pixels. After a delay push back the overlaying div with the same number of pixels.
onmouseup: Meanwhile this is the event you like to fire.
//script
var allclickthrough=[];
function hidedivover(){
if(allclickthrough.length==0){
allclickthrough=getElementsByClassName(document.body,"clickthrough");// if so .parentNode
}
for(var i=0;i<allclickthrough.length;i++){
allclickthrough[i].style.left=parseInt(allclickthrough[i].style.left)+2000+"px";
}
setTimeout(function(){showdivover()},1000);
}
function showdivover(){
for(var i=0;i<allclickthrough.length;i++){
allclickthrough[i].style.left=parseInt(allclickthrough[i].style.left)-2000+"px";
}
}
//html
<span onmouseup="Dreck_he_got_me()">Click me if you can.</span>
<div onmousedown="hidedivover()" style="position:absolute" class="clickthrough">You'll don't get through!</div>
I was having this issue when viewing my website on a phone. While I was trying to close the overlay, I was pretty much clicking on anything under the overlay. A solution that I found working for myself is to just add a tag around the entire overlay

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