Pressing the tab key which triggers a focus change is also received by the input receiving the focus as a keyup.
a: <input type='text'/><br/>
b: <input type='text' onkeyup='alert("wtf?")'/><br/>
http://jsfiddle.net/59SnP/
As my control also uses tab (not in the example), I would want the focus related keyup event being consumed (but I want to receive other non-focus-change related tab events). I tried to research the rationale behind the current behavior but found nothing. The question: Where is this current behavior specified (event not consumed by focus change), and what would be a cross-browser workaround to force consuming it. Thx.
You can try this. I changed your keyup event in your input :
<input type='text' onkeyup="if(!tabPressed){ alert('This is it !'); }"/>
And I added a little event handler which will raise a flag when the tab button is pressed :
var tabPressed = false;
document.addEventListener('keydown', function (e) {
if(e.keyCode == 9) {
tabPressed = true;
} else {
tabPressed = false;
}
}, false);
Based on Nathan's insight, here is a fully working example:
// First part of Nathan's HACK (set a sentinel when a focus changing tab has happened)
var tabPressed = false;
// remove this listener to break the functionality
$(document).on("keydown", function (e) {
if(e.keyCode == 9) {
tabPressed = true;
} else {
tabPressed = false;
}
});
// The listener on the client input that would kill the keyup tab event upon focus change
$("#magic").on("keyup", function(e) {
if (tabPressed && e.keyCode==9) {
tabPressed = false; // reset the sentinel
e.stopImmediatePropagation()
e.preventDefault()
}
})
And here is the second part, which is a simple skeleton of something meaningful. We disable TAB inside the input, and log it as we do with other keyups:
$("#magic").on("keydown", function(e) {
if (e.keyCode==9) {
e.preventDefault()
e.stopPropagation()
}
})
$("#magic").on("keyup", function(e) {
$(this).val($(this).val() + " " + e.keyCode)
e.stopPropagation()
e.preventDefault()
})
The HTML backing the story is as simple as:
a: <input type='text'/><br/>
b: <input type='text'/><br/>
c: <input type='text' id='magic'/><br/>
If you want to play with it, here it is on jsfiddle
NOTE: This still is not the perfect solution, the sentinel is just reset inside the control, so if a tabpress moving the focus does not activate our input, the sentinel stucks, and the first event will be swallowed.. So here is an example of wrong behaviour:
Click on input A
Press TAB (focus moves to input B, tabPressed becomes true)
Click on input C
Press TAB (it is eaten up as sentinel is true)
Press TAB (now it goes through)
Still it is slightly better to have to press TAB twice as to have something happening automatically, wo user control...
I wanted to make modal dialog accessible . I added two hidden focusable elements
Dialog Start
Some focussable Dialog Elements
Dialog end
function onblurevent(){
document.getElementById("dialog-start").focus();
}
When ever dialog-end element blur event happens i tried to move focus to dialog-start element calling focus() method
but the focus is moving to address bar .dialog start and end anchor tags are hidden by using below style
#dialog-start{
height:1px;
left:-9999px;
overflow:hidden;
position:absolute;
top:0;
width:1px;
}
Iam not sure if anchor styles are the reason or is the only way to make sure focus is inside the dialog is to get list of focusable elments and call focus() method in a keydown event handler on container.
The problem occurs because you don't handle your keydown event. When you pressing Tab on last link browser automatically switches focus to address bar. So you just need to preventDefault() default browser behavior if Tab pressed.
The following code will work:
window.onload = function() {
var firstAnchor = document.getElementById("dialog-start"),
lastAnchor = document.getElementById("dialog-end");
function keydownHandler(e) {
var evt = e || window.event;
var keyCode = evt.which || evt.keyCode;
if(keyCode === 9) { // TAB pressed
if(evt.preventDefault) evt.preventDefault();
else evt.returnValue = false;
firstAnchor.focus();
}
}
if(lastAnchor.addEventListener) lastAnchor.addEventListener('keydown', keydownHandler, false);
else if(lastAnchor.attachEvent) lastAnchor.attachEvent('onkeydown', keydownHandler);
}
(note that you dont need onblurevent function anymore)
$(document).ready(function () {
//set focus on first field in Bootstrap modal when loaded
$("#yourModal").on('shown.bs.modal', function () {
$(this).find('#yourField').focus();
});
});
I need to change the back button functionality of my phonegap project, which I've succeeded in doing without any problem. The only issue now, is that I need to further change the functionality based on if the user has a certain field selected.
Basically, if the user has clicked in a field with the id of "date-selector1", I need to completely disable the back button.
I was attempting to use document.activeElement, but it only returns the type of the element (input in this case), but I still want the functionality to work when they are in a general input, but not when they are in an input of a specific id.
EDIT
I tried all of the suggestions below, and have ended up with the following code, but still no success.
function pluginDeviceReady() {
document.addEventListener("backbutton", onBackKeyDown, false);
}
function onBackKeyDown() {
var sElement = document.activeElement;
var isBadElement = false;
var eList = ['procedure-date', 'immunization-date', 'lab-test-done', 'condition-onset', 'condition-resolution', 'medication-start-date', 'medication-stop-date', 'reaction-date'];
console.log("[[ACTIVE ELEMENT: --> " + document.activeElement + "]]");
for (var i = 0;i < eList.length - 1;i++) {
if (sElement == $(eList[i])[0]) {
isBadElement = true;
}
}
if (isBadElement) {
console.log('Back button not allowed here');
} else if ($.mobile.activePage.is('#main') || $.mobile.activePage.is('#family') || $.mobile.activePage.is('#login')) {
navigator.app.exitApp();
} else {
navigator.app.backHistory();
}
}
if you're listening for the back button you can add this if statement:
if (document.activeElement == $("#date-selector1")[0]) {
/*disable button here, return false etc...*/
}
or even better (Thanks to Jonathan Sampson)
if (document.activeElement.id === "date-selector1") {
/*disable button here, return false etc...*/
}
You can have a flag set when a user clicks on a field or you can have a click event (or any other type of event) when a user clicks on the field that should disable the back button.
From the documentation it looks like for the specific page that the backbuton is conditional on you can drop back-btn=true removing that back button.
http://jquerymobile.com/test/docs/toolbars/docs-headers.html
If you need complex conditional functionality you can just create your own button in the header or footer, style it using jquery-mobile widgets and implement your own click functionality.
Is there a way to detect if a mouse button is currently down in JavaScript?
I know about the "mousedown" event, but that's not what I need. Some time AFTER the mouse button is pressed, I want to be able to detect if it is still pressed down.
Is this possible?
Regarding Pax' solution: it doesn't work if user clicks more than one button intentionally or accidentally. Don't ask me how I know :-(.
The correct code should be like that:
var mouseDown = 0;
document.body.onmousedown = function() {
++mouseDown;
}
document.body.onmouseup = function() {
--mouseDown;
}
With the test like this:
if(mouseDown){
// crikey! isn't she a beauty?
}
If you want to know what button is pressed, be prepared to make mouseDown an array of counters and count them separately for separate buttons:
// let's pretend that a mouse doesn't have more than 9 buttons
var mouseDown = [0, 0, 0, 0, 0, 0, 0, 0, 0],
mouseDownCount = 0;
document.body.onmousedown = function(evt) {
++mouseDown[evt.button];
++mouseDownCount;
}
document.body.onmouseup = function(evt) {
--mouseDown[evt.button];
--mouseDownCount;
}
Now you can check what buttons were pressed exactly:
if(mouseDownCount){
// alright, let's lift the little bugger up!
for(var i = 0; i < mouseDown.length; ++i){
if(mouseDown[i]){
// we found it right there!
}
}
}
Now be warned that the code above would work only for standard-compliant browsers that pass you a button number starting from 0 and up. IE uses a bit mask of currently pressed buttons:
0 for "nothing is pressed"
1 for left
2 for right
4 for middle
and any combination of above, e.g., 5 for left + middle
So adjust your code accordingly! I leave it as an exercise.
And remember: IE uses a global event object called … "event".
Incidentally IE has a feature useful in your case: when other browsers send "button" only for mouse button events (onclick, onmousedown, and onmouseup), IE sends it with onmousemove too. So you can start listening for onmousemove when you need to know the button state, and check for evt.button as soon as you got it — now you know what mouse buttons were pressed:
// for IE only!
document.body.onmousemove = function(){
if(event.button){
// aha! we caught a feisty little sheila!
}
};
Of course you get nothing if she plays dead and not moving.
Relevant links:
MouseEvent's button (DOM 2)
MSDN's button
Update #1: I don't know why I carried over the document.body-style of code. It will be better to attach event handlers directly to the document.
This is an old question, and the answers here seem to mostly advocate for using mousedown and mouseup to keep track of whether a button is pressed. But as others have pointed out, mouseup will only fire when performed within the browser, which can lead to losing track of the button state.
However, MouseEvent (now) indicates which buttons are currently pushed:
For all modern browsers (including Safari v11.1+ [v11.3+ on iOS]), use MouseEvent.buttons
For Safari < 11.1 (11.3 on iOS), use MouseEvent.which (buttons will be undefined for Safari) Note: which uses different numbers from buttons for Right and Middle clicks.
When registered on document, mousemove will fire immediately as soon as the cursor reenters the browser, so if the user releases outside then the state will be updated as soon as they mouse back inside.
A simple implementation might look like:
var primaryMouseButtonDown = false;
function setPrimaryButtonState(e) {
var flags = e.buttons !== undefined ? e.buttons : e.which;
primaryMouseButtonDown = (flags & 1) === 1;
}
document.addEventListener("mousedown", setPrimaryButtonState);
document.addEventListener("mousemove", setPrimaryButtonState);
document.addEventListener("mouseup", setPrimaryButtonState);
That code tracks the state of the primary mouse button (typically the left), ignoring the state of other mouse buttons.
If more complicated scenarios are required (different buttons/multiple buttons/control keys), check out the MouseEvent docs.
I think the best approach to this is to keep your own record of the mouse button state, as follows:
var mouseDown = 0;
document.body.onmousedown = function() {
mouseDown = 1;
}
document.body.onmouseup = function() {
mouseDown = 0;
}
and then, later in your code:
if (mouseDown == 1) {
// the mouse is down, do what you have to do.
}
the solution isn't good.
one could "mousedown" on the document, then "mouseup" outside the browser, and on this case the browser would still be thinking the mouse is down.
the only good solution is using IE.event object.
I know this is an old post, but I thought the tracking of mouse button using mouse up/down felt a bit clunky, so I found an alternative that may appeal to some.
<style>
div.myDiv:active {
cursor: default;
}
</style>
<script>
function handleMove( div ) {
var style = getComputedStyle( div );
if (style.getPropertyValue('cursor') == 'default')
{
// You're down and moving here!
}
}
</script>
<div class='myDiv' onmousemove='handleMove(this);'>Click and drag me!</div>
The :active selector handles the mouse click much better than mouse up/down, you just need a way of reading that state in the onmousemove event. For that I needed to cheat and relied on the fact that the default cursor is "auto" and I just change it to "default", which is what auto selects by default.
You can use anything in the object that is returned by getComputedStyle that you can use as a flag without upsetting the look of your page e.g. border-color.
I would have liked to set my own user defined style in the :active section, but I couldn't get that to work. It would be better if it's possible.
If you're working within a complex page with existing mouse event handlers, I'd recommend handling the event on capture (instead of bubble). To do this, just set the 3rd parameter of addEventListener to true.
Additionally, you may want to check for event.which to ensure you're handling actual user interaction and not mouse events, e.g. elem.dispatchEvent(new Event('mousedown')).
var isMouseDown = false;
document.addEventListener('mousedown', function(event) {
if ( event.which ) isMouseDown = true;
}, true);
document.addEventListener('mouseup', function(event) {
if ( event.which ) isMouseDown = false;
}, true);
Add the handler to document (or window) instead of document.body is important b/c it ensures that mouseup events outside of the window are still recorded.
The following snippet will attempt to execute the "doStuff" function 2 seconds after the mouseDown event occurs in document.body. If the user lifts up the button, the mouseUp event will occur and cancel the delayed execution.
I'd advise using some method for cross-browser event attachment - setting the mousedown and mouseup properties explicitly was done to simplify the example.
function doStuff() {
// does something when mouse is down in body for longer than 2 seconds
}
var mousedownTimeout;
document.body.onmousedown = function() {
mousedownTimeout = window.setTimeout(doStuff, 2000);
}
document.body.onmouseup = function() {
window.clearTimeout(mousedownTimeout);
}
In case someone else runs into this, you can use .matches with the :active selector:
function mouseDown() {
return document.body.matches(":active");
}
Using the MouseEvent api, to check the pressed button, if any:
// Mouse buttons
document.addEventListener('mousedown', e => console.log(e.buttons))
// Keyboard keys
document.addEventListener('keydown', e => console.log(e.key))
Return:
A number representing one or more buttons. For more than one button
pressed simultaneously, the values are combined (e.g., 3 is primary +
secondary).
0 : No button or un-initialized
1 : Primary button (usually the left button)
2 : Secondary button (usually the right button)
4 : Auxilary button (usually the mouse wheel button or middle button)
8 : 4th button (typically the "Browser Back" button)
16 : 5th button (typically the "Browser Forward" button)
You can combine #Pax and my answers to also get the duration that the mouse has been down for:
var mousedownTimeout,
mousedown = 0;
document.body.onmousedown = function() {
mousedown = 0;
window.clearInterval(mousedownTimeout);
mousedownTimeout = window.setInterval(function() { mousedown += 200 }, 200);
}
document.body.onmouseup = function() {
mousedown = 0;
window.clearInterval(mousedownTimeout);
}
Then later:
if (mousedown >= 2000) {
// do something if the mousebutton has been down for at least 2 seconds
}
You need to handle the MouseDown and MouseUp and set some flag or something to track it "later down the road"... :(
Short and sweet
I'm not sure why none of the previous answers worked for me, but I came up with this solution during a eureka moment. It not only works, but it is also most elegant:
Add to body tag:
onmouseup="down=0;" onmousedown="down=1;"
Then test and execute myfunction() if down equals 1:
onmousemove="if (down==1) myfunction();"
Using jQuery, the following solution handles even the "drag off the page then release case".
$(document).mousedown(function(e) {
mouseDown = true;
}).mouseup(function(e) {
mouseDown = false;
}).mouseleave(function(e) {
mouseDown = false;
});
I don't know how it handles multiple mouse buttons.
If there were a way to start the click outside the window, then bring the mouse into the window, then this would probably not work properly there either.
As said #Jack, when mouseup happens outside of browser window, we are not aware of it...
This code (almost) worked for me:
window.addEventListener('mouseup', mouseUpHandler, false);
window.addEventListener('mousedown', mouseDownHandler, false);
Unfortunately, I won't get the mouseup event in one of those cases:
user simultaneously presses a keyboard key and a mouse button, releases mouse button outside of browser window then releases key.
user presses two mouse buttons simultaneously, releases one mouse button then the other one, both outside of browser window.
var mousedown = 0;
$(function(){
document.onmousedown = function(e){
mousedown = mousedown | getWindowStyleButton(e);
e = e || window.event;
console.log("Button: " + e.button + " Which: " + e.which + " MouseDown: " + mousedown);
}
document.onmouseup = function(e){
mousedown = mousedown ^ getWindowStyleButton(e);
e = e || window.event;
console.log("Button: " + e.button + " Which: " + e.which + " MouseDown: " + mousedown);
}
document.oncontextmenu = function(e){
// to suppress oncontextmenu because it blocks
// a mouseup when two buttons are pressed and
// the right-mouse button is released before
// the other button.
return false;
}
});
function getWindowStyleButton(e){
var button = 0;
if (e) {
if (e.button === 0) button = 1;
else if (e.button === 1) button = 4;
else if (e.button === 2) button = 2;
}else if (window.event){
button = window.event.button;
}
return button;
}
this cross-browser version works fine for me.
Below jQuery example, when mouse is over $('.element'), color is changing depending on which mouse button is pressed.
var clicableArea = {
init: function () {
var self = this;
('.element').mouseover(function (e) {
self.handlemouseClick(e, $(this));
}).mousedown(function (e) {
self.handlemouseClick(e, $(this));
});
},
handlemouseClick: function (e, element) {
if (e.buttons === 1) {//left button
element.css('background', '#f00');
}
if (e.buttons === 2) { //right buttom
element.css('background', 'none');
}
}
};
$(document).ready(function () {
clicableArea.init();
});
Well, you can't check if it's down after the event, but you can check if it's Up... If it's up.. it means that no longer is down :P lol
So the user presses the button down (onMouseDown event) ... and after that, you check if is up (onMouseUp). While it's not up, you can do what you need.