Let's imagine I have an event handler function attached to an image, for example, an onmouseover handler. I don't want this handler run if an onmouseover event is fired by a particular element.
To be more specific, I have an image which being hovered, a menu is popped out. I want to close that menu if the mouse moves out of that image, unless I move the mouse to the menu, which is adjacent to the image.
So something like this in pseudo code:
img.mouseout = function () {
if (otherelement.onmouseover.fired) {
leave the menu as it is
}
else
{
close the menu
}
So how can I check whether another event was fired?
I would add a timeout and a mouseover handler that clears it in the other handler. While the elements could be exactly next to each other visually, adding a small timer is more safe since there might just be a tiny 1px area where the mouseout event fires, causing an ugly flickering.
This also allows a quick mouseshake without flicker.
Something like:
var timer;
img.onmouseout = other.onmouseout = function() {
timer = setTimeout(closemenu, 100);
}
img.onmouseover = other.onmouseover = function() {
clearTimeout(timer);
}
function closemenu() {
// close it
}
Related
I was trying to make a webapp with html elements that will move form div to antoher div when clicked but also I want to be able fire event when users hold that element for more than a second. So I have this code
$(document).on("click",'.card', function() {
var card=$(this).parent();
if(card.parent().attr('id')==="options"){
card.appendTo("#choice");
}
else{
card.appendTo("#options");
}
});
var timeoutId = 0;
$('.card').on('pointerdown', function() {
timeoutId = setTimeout(showModal, 1000);
}).on('pointerup mouseleave', function() {
clearTimeout(timeoutId);
});
And it is doing almost fine. The problem occures when the element is clicked. It is appended to different div as it should but the mobile pointer is still on it so when I try to fire 'hold' event on another element it is not working for the first time since 'pointerup' event from previous element is firing right after 'pointerdown' event (So you need to try to hold next element twice).
I've dealt with it by adding a simple boolean flag in click event function so it is blocking next first call of 'pointerup' event but this is a very ugly solution.
Do you have any ideas how can i improve this? Maybe there is a way to call 'pointerup' event manually after click?
Removing 'mouseleave' event and adding 'pointerleave' instead fixed the problem.
Not really sure how 'mouseleave' event was fired on mobile device though.
I have an image.
I attached onclick listener and onmouseout listener to it.
onclick listener does parent.removeChild(this) operation.
Image disappears. Nothing happens until I move my mouse. Then fires onmouseout handler.
Is it even possible?
And how, I assume not by propagation because there is nothing attached to onmouseout on parent elements.
Handlers:
function ballMouseoutHandler(e) {
event.stopPropagation();
this.src = ballSrc;
alert('mouse out!');
}
function ballMouseoverHandler() {
this.src = ballInvSrc;
}
function ballClickHandler() {
gameBalls.removeChild(this);
}
Code adding image:
gameBalls = document.getElementById('balls-col');
var tmpBall = createBall();
gameBalls.appendChild(tmpBall);
tmpBall.addEventListener('click', ballClickHandler);
tmpBall.addEventListener('mouseover', ballMouseoverHandler);
tmpBall.addEventListener('mouseout', function(e) {ballMouseoutHandler(e);});
function createBall() {
var ball = new Image();
ball.src = ballSrc;
ball.classList.add('ball');
return ball;
}
It is a part of larger code. So what I have done so far is that I extracted the particular problem to separate smaller files. And it still looks as though the mouse out event was triggered.
OK. After some testing I can say that yes - removing an DOM Object from under the mouse pointer triggers the onmouseout event. Which if you think is quite logic because the move is relative and what counts is that mouse pointer was over the object and now it is out. :)
So what I had to do was to remove Event Listener before removing the Object.
I have a problem with Jquery hover and click on mobile.. Let me explain!
I have square div and, when the mouse is hover it, a new div appear and follow the mouse. You can even click the square div and if so, a new page is opened. The problem now is that, on mobile, I need two click for the new page to be opened, since the first click is read as "hover".
I tried the
$("#mydiv").on('click touchend', function(e)
Actually it works, but with this, if I want to scroll the page on mobile, and I start the swipe on the square div, the new page is opened, which it shouldn't since I didn't click on the square div, just "passed by".
Try using one of those events
https://github.com/benmajor/jQuery-Touch-Events#4-the-events
$('#mydiv').bind('tap', function(e) {
console.log('User tapped #myDiv');
});
As per documentation:
"The event's target is the same element that received the touchstart event corresponding to the touch point, even if the touch point has moved outside that element."
You can see the documentation of touchend also:
https://developer.mozilla.org/en-US/docs/Web/API/TouchEvent
If you start your scroll with the square div then square div touchend event will be fired after the release of that finger even after you move your finger to the other elements.
To solve this problem, you can use these events:
https://github.com/benmajor/jQuery-Touch-Events#4-the-events
If you want to stick with this touchend event then there is a workaround:
Declare a global variable i.e.
var isScroll = false, timer;
Apply touchmove eventhandler on document which will fired for touch devices only, this handler detect whether the document is getting scrolled if yes set the isScroll flag to true that will false after 500ms:
$(document).on("touchmove", function(e) {
isScroll = true;
if(timer) clearTimeout(timer);
timer = setTimeout(function() {
isScroll = false;
}, 800);
})
and insert if condition in your eventHandler:
$("#mydiv").on('click touchend', function(e) {
if(!isScroll) {
//insert your code here;
}
}
I have an input element with 2 events attached: focus and click. They both fire off the same helper function.
When I tab to the input, the focus event fires and my helper is run once. No problems there.
When the element already has focus, and I click on it again, the click event fires and my helper runs once. No problems there either.
But when the element does not have focus, and I click on it, BOTH events fire, and my helper is run TWICE. How can I keep this helper only running once?
I saw a couple similar questions on here, but didn't really follow their answers. I also discovered the .live jQuery handler, which seems like it could work if I had it watch a status class. But seems like there should be a simpler way. The .one handler would work, except I need this to work more than once.
Thanks for any help!
The best answer here would be to come up with a design that isn't trying to trigger the same action on two different events that can both occur on the same user action, but since you haven't really explained the overall problem you're coding, we can't really help you with that approach.
One approach is to keep a single event from triggering the same thing twice is to "debounce" the function call and only call the function from a given element if it hasn't been called very recently (e.g. probably from the same user event). You can do this by recording the time of the last firing for this element and only call the function if the time has been longer than some value.
Here's one way you could do that:
function debounceMyFunction() {
var now = new Date().getTime();
var prevTime = $(this).data("prevActionTime");
$(this).data("prevActionTime", now);
// only call my function if we haven't just called it (within the last second)
if (!prevTime || now - prevTime > 1000) {
callMyFunction();
}
}
$(elem).focus(debounceMyFunction).click(debounceMyFunction);
This worked for me:
http://jsfiddle.net/cjmemay/zN8Ns/1/
$('.button').on('mousedown', function(){
$(this).data("mouseDown", true);
});
$('.button').on('mouseup', function(){
$(this).removeData("mouseDown");
});
$('.button').on('focus', function(){
if (!$(this).data("mouseDown"))
$(this).trigger('click.click');
});
$(".button").on('click.click',evHandler);
Which I stole directly from this:
https://stackoverflow.com/a/9440580/264498
You could use a timeout which get's cleared and set. This would introduce a slight delay but ensures only the last event is triggered.
$(function() {
$('#field').on('click focus', function() {
debounce(function() {
// Your code goes here.
console.log('event');
});
});
});
var debounceTimeout;
function debounce(callback) {
clearTimeout(debounceTimeout);
debounceTimeout = setTimeout(callback, 500);
}
Here's the fiddle http://jsfiddle.net/APEdu/
UPDATE
To address a comment elsewhere about use of a global, you could make the doubleBounceTimeout a collection of timeouts with a key passed in the event handler. Or you could pass the same timeout to any methods handling the same event. This way you could use the same method to handle this for any number of inputs.
Live demo (click).
I'm just simply setting a flag to gate off the click when the element is clicked the first time (focus given). Then, if the element gets focus from tabbing, the flag is also removed so that the first click will work.
var $foo = $('#foo');
var flag = 0;
$foo.click(function() {
if (flag) {
flag = 0;
return false;
}
console.log('clicked');
});
$foo.focus(function() {
flag = 1;
console.log('focused');
});
$(document).keyup(function(e) {
if (e.which === 9) {
var $focused = $('input:focus');
if ($focused.is($foo)) {
flag = 0;
}
}
});
It seems to me that you don't actually need the click handler. It sounds like this event is attached to an element which when clicked gains focus and fires the focus handler. So clicking it is always going to fire your focus handler, so you only need the focus handler.
If this is not the case then unfortunately no, there is no easy way to achieve what you are asking. Adding/removing a class on focus and only firing the click when the class isn't present is about the only way I can think of.
I have it - 2 options
1 - bind the click handler to the element in the focus callback
2 - bind the focus and the click handler to a different class, and use the focus callback to add the click class and use blur to remove the click class
Thanks for the great discussion everybody. Seems like the debouncing solution from #jfriend00, and the mousedown solution from Chris Meyers, are both decent ways to handle it.
I thought some more, and also came up with this solution:
// add focus event
$myInput.focus(function() {
myHelper();
// while focus is active, add click event
setTimeout(function() {
$myInput.click(function() {
myHelper();
});
}, 500); // slight delay seems to be required
});
// when we lose focus, unbind click event
$myInput.blur(function() {
$myInput.off('click');
});
But seems like those others are slightly more elegant. I especially like Chris' because it doesn't involve dealing with the timing.
Thanks again!!
Improving on #Christopher Meyers solution.
Some intro: Before the click event fires, 2 events are preceding it, mousedown & mouseup, if the mousedown is fired, we know that probably the mouseup will fire.
Therefore we probably wouldn't like that the focus event handler would execute its action. One scenario in which the mouseup wouldn't fire is if the user starts clicking the button then drags the cursor away, for that we use the blur event.
let mousedown = false;
const onMousedown = () => {
mousedown = true;
};
const onMouseup = () => {
mousedown = false;
// perform action
};
const onFocus = () => {
if (mousedown) return;
// perform action
};
const onBlur = () => {
mousedown = false;
// perform action if wanted
};
The following events would be attached:
const events = [
{ type: 'focus', handler: onFocus },
{ type: 'blur', handler: onBlur },
{ type: 'mousedown', handler: onMousedown },
{ type: 'mouseup', handler: onMouseup }
];
I'm trying to create a file drag/drop handler (drag a file into the browser window, to be used for upload).
For some reason when I bind the drag/drop listener to $("body") instead of to a $("div") in the body the events fire several times in a row, sometimes even non-stop (seemingly looping). What could be causing this?
Here's a trimmed down version of the code: http://jsfiddle.net/WxMwK/9/
var over = false;
$("body")
.on("dragover", function(e){
e.preventDefault();
if (! over) {
over = true;
$("ul").append($("<li/>").text("dragover"));
}
})
.on("dragleave", function(e){
e.preventDefault();
if (over) {
over = false;
$("ul").append($("<li/>").text("dragleave"));
}
})
.on("drop", function(e){
e.preventDefault();
if (over) {
over = false;
$("ul").append($("<li/>").text("drop"));
}
});
To test: drag a file into the orange area, you'll see the event firing multiple times in a row.
The anon is (mostly) correct. To put it simply: when the mouse moves over the edge of an element inside your drop target, you get a dropenter for the element under the cursor and a dropleave for the element that was under the cursor previously. This happens for absolutely any descendant.
You can't check the element associated with dragleave, because if you move the mouse from your drop target onto a child element, you'll get a dropenter for the child and then a dropleave for the target! It's kind of ridiculous and I don't see how this is a useful design at all.
Here's a crappy jQuery-based solution I came up with some time ago.
var $drop_target = $(document.body);
var within_enter = false;
$drop_target.bind('dragenter', function(evt) {
// Default behavior is to deny a drop, so this will allow it
evt.preventDefault();
within_enter = true;
setTimeout(function() { within_enter = false; }, 0);
// This is the part that makes the drop area light up
$(this).addClass('js-dropzone');
});
$drop_target.bind('dragover', function(evt) {
// Same as above
evt.preventDefault();
});
$drop_target.bind('dragleave', function(evt) {
if (! within_enter) {
// And this makes it un-light-up :)
$(this).removeClass('js-dropzone');
}
within_enter = false;
});
// Handle the actual drop effect
$drop_target.bind('drop', function(evt) {
// Be sure to reset your state down here
$(this).removeClass('js-dropzone');
within_enter = false;
evt.preventDefault();
do_whatever(evt.originalEvent.dataTransfer.files);
});
The trick relies on two facts:
When you move the mouse from a grandchild into a child, both dragenter and dragleave will be queued up for the target element—in that order.
The dragenter and dragleave are queued together.
So here's what happens.
In the dragenter event, I set some shared variable to indicate that the drag movement hasn't finished resolving yet.
I use setTimeout with a delay of zero to immediately change that variable back.
But! Because the two events are queued at the exact same time, the browser won't run any scheduled functions until both events have finished resolving. So the next thing that happens is dragleave's event handler.
If dragleave sees that it was paired with a dragenter on the same target element, that means the mouse must have moved from some descendant to some other descendant. Otherwise, the mouse is actually leaving the target element.
Then the setTimeout finally resolves zero seconds later, setting back the variable before another event can come along.
I can't think of a simpler approach.
You are adding a listener on the BODY HTMLElement for the dragover, dragleave and drop.
When you continue to drag over the DIV, there is a dragleave that is fired because the mouse is no more dragging over the BODY, but over the DIV.
Secondly, as you are not stopping the bubble event on the DIV (no listener is set), the dragover fired on the DIV is bubling to the BODY.
If I resume:
The mouse enter the body (in dragover)
--> fire drag over (body)
The mouse enter the DIV in the body
--> fire drag leave (of BODY)
--> fire drag over (of DIV) --> event bubling --> fire drag over (of BODY)
There is a similar problem with mouseover and mouseout, which is fixed by using mouseenter and mouseleave.
May be you can try the same code using dragenter event type. If its not working, you can check if the event.target is the BODY. This test could help to skip undesired drag event.
Good luck
var over = false;
$("body")
.on("dragover", function(e){
e.preventDefault();
if (! over) {
over = true;
$("ul").append($("<li/>").text("dragover"));
}
})
.on("dragleave", function(e){
e.preventDefault();
if (over) {
over = false;
$("ul").append($("<li/>").text("dragleave"));
}
})
.on("drop", function(e){
e.preventDefault();
if (over) {
over = false;
}
});
Or you could just use stop(); to stop animation buildup