For my webapp I'm working on a popup element, which is used for menus and similar things. I want to redirect all mouse input on the current page to this popup element when it's visible, however I can get it to work.
I have a tile element which, on mouse hover, shows an image (and highlights the tile). When the user clicks on that image the popup is shown (as a context menu). This works already. When the user moves the mouse outside the tile the hover state is gone, the highlight and also the image disappear, which is not what should happen. Instead I want the visual state unaffected as long as the menu is visible.
So I tried to capture the mouse using Element.setPointerCapture. However, this requires a pointer id, which I don't have. I tried to use onPointerDown on the trigger image, but that didn't do anything.
What's the right way to implement this mouse capture, so that no mouse event is scheduled to any other HTML element, but the popup?
This is what I came up with so far:
private handleTriggerClick = (e: React.MouseEvent): void => {
console.log("mouse");
this.props.trigger?.props.onClick?.(e);
if (this.state.open && this.props.closeOnTriggerClick) {
this.close();
} else if (!this.state.open && this.props.openOnTriggerClick) {
this.open();
e.currentTarget.setPointerCapture(this.pointerId);
}
e.stopPropagation();
};
private handleTriggerPointerDown = (e: React.PointerEvent): void => {
console.log("pointer");
this.pointerId = e.pointerId;
};
where trigger is the image used to show the popup.
I also tried using a mouse move handler on the document, but that didn't work either, probably because of event bubbling where first the deeper elements receive the event before it reaches the document, so it's too late then to prevent default handling or stop propagation.
The Element.setPointerCapture API will only work when the pointer is in its "active button" mode (that is between pointerdown and pointerup or pointercancel).
I guess it's not exactly what you want...
Maybe requestPointerLock would be closer to what you are asking, but it may also be a bit too much (a confirm message would pop-up asking your users if they wish to let your app control their mouse etc.)
So a third way, probably easier, is to append an overlay element with a fixed position that would cover the whole page, you could make it appear also only when your menu is hovered, but without seeing your actual situation, I can only give such a broad advice.
I have a webpage that I designed for both use on my phone and a PC. Part of the UI is a table in which multiple cells adjacent cells can be marked easily by dragging a mouse with a button down across them ( using mousedown event from Js). On my smart phone however, the browser tries to scroll the window when I drag across cells. I've looked all morning and can't find the answer I'm looking for. How can I make the touch drag behave like the mouse drag on my webpage.
UPDATE:
I have in each cell of my table onmouseover and onmouseclick events which trigger functions, if the mouse is down, a function increments a variable , and when the mouse is up it decreases it. so when a mouse button is pressed down over a cell an action occurs. Below is how a cell of the table is made. Below it are the functions bob and bob2.
{echo '<td width="8" onttouchmove="bob(id)" ontouchstart="bob2(id)" onmouseover="bob(id)" onmousedown="bob2(id)" id='.$key.'>'.$value.'</td>';}
<script>
document.body.onmousedown = function(){
mouseDown++;
}
function bob(clicked_id)
{
if (mouseDown)
{ THEN DO SOMETHING }
function bob2(clicked_id)
{DO SOMETHING}
</script>
I feel like the jquery swipe event is what I want, but I"m not sure how I would implement it during the table setup.
Mobile phones and tablets do not use a mouse, thus your mouse events are not and will not be firing. You need to use touchstart and touchend instead.
On virtually all current browsers (extensive details from patrickhlauke on github, which I summarised in an SO answer, and also some more info from QuirksMode), touchscreen touches trigger mouseover events (sometimes creating an invisible pseudo-cursor that stays where the user touched until they touch elsewhere).
Sometimes this causes undesirable behaviour in cases where touch/click and mouseover are intended to do different things.
From inside a function responding to a mouseover event, that has been passed the event object, is there any way I can check if this was a "real" mouseover from a moving cursor that moved from outside an element to inside it, or if it was caused by this touchscreen behaviour from a touchscreen touch?
The event object looks identical. For example, on chrome, a mouseover event caused by a user touching a touchscreen has type: "mouseover" and nothing I can see that would identify it as touch related.
I had the idea of binding an event to touchstart that alters mouseover events then an event to touchend that removes this alteration. Unfortunately, this doesn't work, because the event order appears to be touchstart → touchend → mouseover → click (I can't attach the normalise-mouseover function to click without messing up other functionality).
I'd expected this question to have been asked before but existing questions don't quite cut it:
How to handle mouseover and mouseleave events in Windows 8.1 Touchscreen is about C# / ASP.Net applications on Windows, not web pages in a browser
JQuery .on(“click”) triggers “mouseover” on touch device is similar but is about jQuery and the answer is a bad approach (guessing a hard-coded list of touchscreen user agents, which would break when new device UAs are created, and which falsely assumes all devices are mouse or touchscreen)
Preventing touch from generating mouseOver and mouseMove events in Android browser is the closest I could find, but it is only about Android, is about preventing not identifying mouseover on touch, and has no answer
Browser handling mouseover event for touch devices causes wrong click event to fire is related, but they're trying to elumate the iOS two-tap interaction pattern, and also the only answer makes that mistake of assuming that touches and mouse/clicks are mutually exclusive.
The best I can think of is to have a touch event that sets some globally accessible variable flag like, say, window.touchedRecently = true; on touchstart but not click, then removes this flag after, say, a 500ms setTimeout. This is an ugly hack though.
Note - we cannot assume that touchscreen devices have no mouse-like roving cursor or visa versa, because there are many devices that use a touchscreen and mouse-like pen that moves a cursor while hovering near the screen, or that use a touchscreen and a mouse (e.g. touchscreen laptops). More details in my answer to How do I detect whether a browser supports mouseover events?.
Note #2 - this is not a jQuery question, my events are coming from Raphael.js paths for which jQuery isn't an option and which give a plain vanilla browser event object. If there is a Raphael-specific solution I'd accept that, but it's very unlikely and a raw-javascript solution would be better.
Given the complexity of the issue, I thought it was worth detailing the issues and edge cases involved in any potential solution.
The issues:
1 - Different implementations of touch events across devices and browsers. What works for some will definitely not work for others. You only need to glance at those patrickhlauke resources to get an idea of how differently the process of tapping a touch-screen is currently handled across devices and browsers.
2 - The event handler gives no clue as to its initial trigger. You are also absolutely right in saying that the event object is identical (certainly in the vast majority of cases) between mouse events dispatched by interaction with a mouse, and mouse events dispatched by a touch interaction.
3 - Any solution to this problem which covers all devices could well be short-lived as the current W3C Recommendations do not go into enough detail on how touch/click events should be handled (https://www.w3.org/TR/touch-events/), so browsers will continue to have different implementations. It also appears that the Touch Events standards document has not changed in the past 5 years, so this isn't going to fix itself soon. https://www.w3.org/standards/history/touch-events
4 - Ideally, solutions should not use timeouts as there is no defined time from touch event to mouse event, and given the spec, there most probably won't be any time soon. Unfortunately, timeouts are almost inevitable as I will explain later.
A future solution:
In the future, the solution will probably be to use Pointer Events instead of mouse / touch events as these give us the pointerType (https://developer.mozilla.org/en-US/docs/Web/API/Pointer_events), but unfortunately we're not there yet in terms of an established standard, and so cross-browser compatibility (https://caniuse.com/#search=pointer%20events) is poor.
How do we solve this at the moment
If we accept that:
You can't detect a touchscreen (http://www.stucox.com/blog/you-cant-detect-a-touchscreen/)
Even if we could, there's still the issue of non-touch events on a touch capable screen
Then we can only use data about the mouse event itself to determine its origin. As we've established, the browser doesn't provide this, so we need to add it ourselves. The only way to do this is using the touch events which are triggered around the same time as the mouse event.
Looking at the patrickhlauke resources again, we can make some statements:
mouseover is always followed by the click events mousedown mouseup and click - always in that order. (Sometimes separated by other events). This is backed up by the W3C recommendations: https://www.w3.org/TR/touch-events/.
For most devices / browsers, the mouseover event is always preceded by either pointerover, its MS counterpart MSPointerOver, or touchstart
The devices / browsers whose event order begins with mouseover have to be ignored. We can't establish that the mouse event was triggered by a touch event before the touch event itself has been triggered.
Given this, we could set a flag during pointerover, MSPointerOver, and touchstart, and remove it during one of the click events. This would work well, except for a handfull of cases:
event.preventDefault is called on one of the touch events - the flag will never be unset as the click events will not be called, and so any future genuine click events on this element would still be marked as a touch event
if the target element is moved during the event. The W3C Recommendations state
If the contents of the document have changed during processing of the
touch events, then the user agent may dispatch the mouse events to a
different target than the touch events.
Unfortunately this means that we will always need to use timeouts. To my knowledge there is no way of either establishing when a touch event has called event.preventDefault, nor understanding when the touch element has been moved within the DOM and the click event triggered on another element.
I think this is a fascinating scenario, so this answer will be amended shortly to contain a recommended code response. For now, I would recommend the answer provided by #ibowankenobi or the answer provided by #Manuel Otto.
What we do know is:
When the user uses no mouse
the mouseover is directly (within 800ms) fired after either a touchend or a
touchstart (if the user tapped and held).
the position of the mouseover and the touchstart/touchend are identical.
When the user uses a mouse/pen
The mouseover is fired before the touch events, even if not, the position of the mouseover will not match the touch events' position 99% of time.
Keeping these points in mind, I made a snippet, which will add a flag triggeredByTouch = true to the event if the listed conditions are met. Additionally you can add this behaviour to other mouse events or set kill = true in order to discard mouseevents triggered by touch completely.
(function (target){
var keep_ms = 1000 // how long to keep the touchevents
var kill = false // wether to kill any mouse events triggered by touch
var touchpoints = []
function registerTouch(e){
var touch = e.touches[0] || e.changedTouches[0]
var point = {x:touch.pageX,y:touch.pageY}
touchpoints.push(point)
setTimeout(function (){
// remove touchpoint from list after keep_ms
touchpoints.splice(touchpoints.indexOf(point),1)
},keep_ms)
}
function handleMouseEvent(e){
for(var i in touchpoints){
//check if mouseevent's position is (almost) identical to any previously registered touch events' positions
if(Math.abs(touchpoints[i].x-e.pageX)<2 && Math.abs(touchpoints[i].y-e.pageY)<2){
//set flag on event
e.triggeredByTouch = true
//if wanted, kill the event
if(kill){
e.cancel = true
e.returnValue = false
e.cancelBubble = true
e.preventDefault()
e.stopPropagation()
}
return
}
}
}
target.addEventListener('touchstart',registerTouch,true)
target.addEventListener('touchend',registerTouch,true)
// which mouse events to monitor
target.addEventListener('mouseover',handleMouseEvent,true)
//target.addEventListener('click',handleMouseEvent,true) - uncomment or add others if wanted
})(document)
Try it out:
function onMouseOver(e){
console.log('triggered by touch:',e.triggeredByTouch ? 'yes' : 'no')
}
(function (target){
var keep_ms = 1000 // how long to keep the touchevents
var kill = false // wether to kill any mouse events triggered by touch
var touchpoints = []
function registerTouch(e){
var touch = e.touches[0] || e.changedTouches[0]
var point = {x:touch.pageX,y:touch.pageY}
touchpoints.push(point)
setTimeout(function (){
// remove touchpoint from list after keep_ms
touchpoints.splice(touchpoints.indexOf(point),1)
},keep_ms)
}
function handleMouseEvent(e){
for(var i in touchpoints){
//check if mouseevent's position is (almost) identical to any previously registered touch events' positions
if(Math.abs(touchpoints[i].x-e.pageX)<2 && Math.abs(touchpoints[i].y-e.pageY)<2){
//set flag on event
e.triggeredByTouch = true
//if wanted, kill the event
if(kill){
e.cancel = true
e.returnValue = false
e.cancelBubble = true
e.preventDefault()
e.stopPropagation()
}
return
}
}
}
target.addEventListener('touchstart',registerTouch,true)
target.addEventListener('touchend',registerTouch,true)
// which mouse events to monitor
target.addEventListener('mouseover',handleMouseEvent,true)
//target.addEventListener('click',handleMouseEvent,true) - uncomment or add others if wanted
})(document)
a{
font-family: Helvatica, Arial;
font-size: 21pt;
}
Click me
According to https://www.html5rocks.com/en/mobile/touchandmouse/
For a single click the order of events is:
touchstart
touchmove
touchend
mouseover
mousemove
mousedown
mouseup
click
So you might be able to set some arbitrary boolean isFromTouchEvent = true; in onTouchStart() and isFromTouchEvent = false; in onClick() and check for that inside of onMouseOver(). This doesn't work very well since we're not guaranteed to get all those events in the element that we're trying to listen on.
I usually have couple of general schemes which I use for this, one of them uses a manual principle of setTimeout to trigger a property. I will explain this one here, but first try to reason about using touchstart, touchmove and touchend on touch devices and use mouseover on destop.
As you know, calling event.preventDefault (event has to be not passive for this to work with touchstart) in any of the touchevents will cancel the subsequent mousecalls so you do not need to deal with them. But in case this is not what you want, here is what I use sometimes (I refer as "library" to your dom manipulation library, and "elem" as your element):
with setTimeout
library.select(elem) //select the element
.property("_detectTouch",function(){//add a _detectTouch method that will set a property on the element for an arbitrary time
return function(){
this._touchDetected = true;
clearTimeout(this._timeout);
this._timeout = setTimeout(function(self){
self._touchDetected = false;//set this accordingly, I deal with either touch or desktop so I can make this 10000. Otherwise make it ~400ms. (iOS mouse emulation delay is around 300ms)
},10000,this);
}
}).on("click",function(){
/*some action*/
}).on("mouseover",function(){
if (this._touchDetected) {
/*coming from touch device*/
} else {
/*desktop*/
}
}).on("touchstart",function(){
this._detectTouch();//the property method as described at the beginning
toggleClass(document.body,"lock-scroll",true);//disable scroll on body by overflow-y hidden;
}).on("touchmove",function(){
disableScroll();//if the above overflow-y hidden don't work, another function to disable scroll on iOS.
}).on("touchend",function(){
library.event.preventDefault();//now we call this, if you do this on touchstart chrome will complain (unless not passive)
this._detectTouch();
var touchObj = library.event.tagetTouches && library.event.tagetTouches.length
? library.event.tagetTouches[0]
: library.event.changedTouches[0];
if (elem.contains(document.elementFromPoint(touchObj.clientX,touchObj.clientY))) {//check if we are still on the element.
this.click();//click will never be fired since default prevented, so we call it here. Alternatively add the same function ref to this event.
}
toggleClass(document.body,"lock-scroll",false);//enable scroll
enableScroll();//enableScroll
})
Another option without setTimeout is to think mousover is counter to touchstart and mouseout counter to touchend. So former events (the touch events) will set a property, if the mouse events detect that property then they do not fire and reset the property to its initial value and so on. In that case something along these lines will also do:
without setTimeout
....
.on("mouseover",function(dd,ii){
if (this._touchStarted) {//touch device
this._touchStarted = false;//set it back to false, so that next round it can fire incase touch is not detected.
return;
}
/*desktop*/
})
.on("mouseout",function(dd,ii){//same as above
if(this._touchEnded){
this._touchEnded = false;
return;
}
})
.on("touchstart",function(dd,ii){
this._touchStarted = true;
/*some action*/
})
.on("touchend",function(dd,ii){
library.event.preventDefault();//at this point emulations should not fire at all, but incase they do, we have the attached properties
this._touchEnded = true;
/*some action*/
});
I removed a lot of details but I guess this is the main idea.
You can use modernizr for that! I just tested this on a local development server and it works.
if (Modernizr.touch) {
console.log('Touch Screen');
} else {
console.log('No Touch Screen');
}
So I would start there?
Pointer Events are widely supported now. So now we can use pointerenter and check event.pointerType:
const element = document.getElementById("hoverableElement")
element.addEventListener("pointerenter", (event) => {
if (event.pointerType === "mouse") {
alert("Hovered")
}
})
<div id="hoverableElement">Trigger on hover, but not on touch</div>
I have a bit of javascript that will allow the user to move stuff around using the mouse, so the user can click and drag things around, which is working all fine, but what I am struggling with is being able to override the users click event.
So what I am trying to do is, if the user moves the item to a certain position I want to stop the click and hold event, this would mean the user would have to the go an reselect the item again and click and drag again.
Can you override the users mouse action from javascript? It seems simple but I am unable to find a way in my javascript to stop the mousehold event
You can try to override onmousedown to store the mouse coordinates and fire the "real click" event on onmouseup if the mouse position did not changed (or if the change is less than say 5 pixels).
document.getElementById('myElement').addEventListener('click', function(e) {
e.preventDefault(); // here is your override
doSomethingElse(); // or not
});
Same thing for IE but use attachEvent instead of addEventListener
Perhaps instead of blocking events, you can put some logic inside your onclick handler to check for this condition?
For example, maybe a couple of properties to maintain state. You could call one itemSelected, which must be true in order for the the item to move. Then if you set itemSelected to false, another click will be necessary to toggle it again.
I have an image that I want to have trigger certain behaviors when the mouse is over, I have a mouseover and mouseout method, but if you happen to have your mouse over the image when the page loads, the mouseover method never fires until you leave the image and come back over it.
Is there a way to detect if the mouse is over an element on the fly without the mouse having to be off of the element and then come over the element to trigger the JS mouseover event? Like is there a document.getElementById("blah").mouseIsOver() type function in Javascript?
I believe this is possible without any action from the user. When your page loads, bind the mouseover event to your image and hide your image (i.e. using CSS display:none). Use setTimeout() to show it again in a few milliseconds (10 should be enough). The even should be fired.
If you don't want to cause the 'flick' effect on your image, you may try using some temporary element instead, attaching event to it, and delegating the event onto your image.
I have no idea if this is cross-browser solution, but it worked from my Firefox 3.0 console ;)
You could use the mousemove event. That would trigger anytime the user moves a mouse; so the only instance of the trigger not firing would be if the user does not move the mouse at all, which should be rare.
The only problem with this is that the event would fire anytime the mouse would move over your image, so you would get a LOT of those events while over the component. What you would probably need to do is implement some sort of flag within your method when the event fires. You turn on the flag when the event first fires, and you turn it off when you leave the component.
This is less than ideal, but I think this will probably satisfy your problem scenario. The following is some quick pseudo code on what that solution might look like, I think it should work.
<img src="blah.png" onmousemove="JavaScript:triggerOn(event)" onmouseout="JavaScript:triggerOff(event)"/>
...
<script type='text/javascript'>
var TriggerActive = false;
function triggerOn(e){
e = e||window.e;
if( !TriggerActive){
TriggerActive = true;
// Do something
} else {
// Trigger already fired, ignore this event.
}
}
function triggerOff(e){
e = e||window.e;
if(TriggerActive)
TriggerActive = false;
}
</script>
You can find some great mouse event information including browser compatibility notes here.
Use document.querySelectpor and onload/onready events.
var a = document.querySelector('#a:hover');
if (a) {
// Mouse cursor is above a
}
else {
// Mouse cursor is outside a
}
There is no way to get the mouse coordinates aside from listening for mouse events, namely mousemove, mouseover etc. However, these events are very sensitive in the sense that moving the cursor by just one pixel is enough to trigger them, so having the cursor hover over your image while perfectly still should be somewhat unusual.