Develop Reference

Canceling a custom drag function when mouse slides off div

I have a draggable function in jquery to make it so I can drag and move elements on a div. Sometimes, when dragging the mouse comes off the div and I am not able to put back down the element.
I'm trying to add a keydown event for the escape button or something so that when pressed, the same thing happens on .on("mouseup", function(event) {
I've tried doing .on("mouseup keydown", function(event) { but it doesn't catch any keys that are being pressed.
Does anyone have any ideas on how I can cancel the drag? Either by a keydown or even on a mouseup regardless of if the mouse is on the div or not that is being dragged?
Just to be clear, the problem I am having is sometimes I will be dragging the element, I will mouseup but the mouse wasn't on the element when mouseup was called. Therefore, the element is still dragging and I no longer have my finger on the mouse and I have no way to stop the element from dragging to get it back on the document.
EDIT: Here is a jsfiddle, notice I am trying to get this to work on a scaled container. youtube video showing drag glitch
(function($) {
$.fn.drags = function(opt, callback) {
opt = $.extend({
handle: "",
cursor: "move"
}, opt);
if (opt.handle === "") {
var $el = this;
} else {
var $el = this.find(opt.handle);
}
return $el.css('cursor', opt.cursor).on("mousedown", function(e) {
if (opt.handle === "") {
var $drag = $(this).addClass('draggable');
} else {
var $drag = $(this).addClass('active-handle').parent().addClass('draggable');
}
var z_idx = $drag.css('z-index'),
drg_h = $drag.outerHeight(),
drg_w = $drag.outerWidth(),
pos_y = $drag.offset().top + drg_h - e.pageY,
pos_x = $drag.offset().left + drg_w - e.pageX;
$drag.css('z-index', 1000).parents().on("mousemove", function(e) {
$('.draggable').offset({
top: e.pageY + pos_y - drg_h,
left: e.pageX + pos_x - drg_w
}).on("mouseup", function() {
$(this).removeClass('draggable').css('z-index', z_idx);
});
});
e.preventDefault();
}).on("mouseup", function(event) {
if (opt.handle === "") {
$(this).removeClass('draggable');
} else {
$(this).removeClass('active-handle').parent().removeClass('draggable');
}
if (typeof callback == 'function') {
alert("this is a callback");
}
});
}
})(jQuery);

Here are a few things that might work:
Instead of listening for mouseup on the target element, listen for it on document.body. That way it will fire regardless of if the cursor is over the dragged element.
If you want to cancel the drag when the cursor wanders out of the page, add an event listener for mouseleave on document.body and use it to cancel the drag.
If you make a code-pen (or similar) test case, I will be happy to dig into the code.
Edit__
Handling mouseleave on the document prevents it from getting stuck in a draggable state. It also fixes the multiplied movement that you were seeing.
$(document.body).on('mouseleave', function(){
$el.removeClass('draggable').css('z-index', z_idx);
});
Edit2__
Previous JSFiddle was incorrect.
https://jsfiddle.net/spk4523t/6/

Cancel incoming jQuery click event if mouse is moved after mousedown

I'm trying to prevent a click event from firing if the mouse is moved after the 'mousedown' event. Currently I'm doing everything manually via conditionals and booleans. I still don't have it working how I want, and I feel it's just a poor approach to accomplishing this.
var mousemove = false;
var mousedown = false;
var cancelClick = false;
$('.example').click( function() {
if (!cancelClick) {
if ( $(this).attr('id') === 'example-green') {
$(this).attr('id', 'example-blue');
} else {
$(this).attr('id', 'example-green');
}
}
cancelClick = false;
});
$('.example').mousedown( function() {
mousedown = true;
});
$('.example').mouseup( function() {
if (mousemove) {
cancelClick = true;
}
mousedown = false;
mousemove = false;
});
$('.example').mousemove( function() {
if (mousedown) {
mousemove = true;
}
});
http://jsfiddle.net/aGf6G/4/
Is there is a simpler way to achieve this? Preferably one that prevents the click events from being processed, or removes them from the pending event queue (I'm not sure if they are queued until after you release the mouse). That way the callbacks themselves aren't coupled with the implementation of this.

I would just store the x/y coordinates of the mouse on mousedown and compare it to the current coordinates in click.
$('.example')
.on('mousedown', function() {
$(this).data("initcoords", { x: event.clientX, y: event.clientY });
})
.on('click', function() {
var initCoords = $(this).data("initcoords") || { x: 0, y: 0 };
if (event.clientX === initCoords.x && event.clientY === initCoords.y) {
if ( $(this).attr('id') === 'example-green') {
$(this).attr('id', 'example-blue');
} else {
$(this).attr('id', 'example-green');
}
$(this).data('initcoords', {x:-1, y:-1});
}
});
http://jsfiddle.net/zp2y2/8/
You could also toggle the click event on and off. It is a little more concise but I wonder about the overhead of setting up event handlers compared to the method above.
$('.example')
.on('mousedown', function() { $(this).one("click", handleClick); })
.on('mousemove mouseout', function() { $(this).off('click'); });
function handleClick(){
var $el = $('.example');
if ( $el.attr('id') === 'example-green') {
$el.attr('id', 'example-blue');
} else {
$el.attr('id', 'example-green');
}
}
http://jsfiddle.net/du7ZX/

EDIT: http://api.jquery.com/event.stopimmediatepropagation/ Here is one that stops all events on one element from executing except the one you want.
If the differnt events are not all on the same element but rather spread among child/parent you could:
Event.stopPropagation() will stop all other events except the one you actually want.
I believe this here is your solution: http://api.jquery.com/event.stoppropagation/
Here is a jsfiddle to actually test with and without stopPropagation:
In this example I show how a div within a div inherits the event from his parent. Notice in the second example if you mouse over the inner div first, you will get two alerts. If you mouseover the inner div in the first example you will only get one alert.
http://jsfiddle.net/Grimbode/vsKM9/3/
/** test with stopprogation **/
$('#test').on('mouseover', function(event){
event.stopPropagation();
alert('mouseover 1');
});
$('#test2').on('mouseover', function(event){
event.stopPropagation();
alert('mouseover 2');
});
/*** test with no stoppropagation ***/
$('#test3').on('mouseover', function(event){
alert('mouseover 3');
});
$('#test4').on('mouseover', function(event){
alert('mouseover 4');
});
You could also use .off() method that removes events on a specific element.

Here's another option, I tested it and it works well:
$('.example')
.on('mousedown', function() {
$(this).data("couldBeClick", true );
})
.on('mousemove', function() {
$(this).data("couldBeClick", false );
})
.on('click', function() {
if($(this).data("couldBeClick")) {
alert('this is really a click !');
}
});

How to preventDefault for event A from event B handler

I have an event handler attached to touchstart and I want to call preventDefault as soon as touchmove occurs. I have this code currently.
link.addEventListener("click", function () {
console.log("clicked");
});
link.addEventListener("touchstart", function (touchStartEvent) {
var mouseMoveHandler = function () {
console.log("moved.");
touchStartEvent.preventDefault(); // This does not work.
link.removeEventListener('touchmove', arguments.callee);
};
link.addEventListener("touchmove", mouseMoveHandler);
});
http://jsfiddle.net/682VP/
I'm calling preventDefault for touchstart within an event handler for touchmove. This does not seem to work because the click event handler is always invoked.
What am I doing wrong here?

When you call preventDefault it works for touchstart event, not for click event.
You can add some property for the link object indicating the moving state and check it inside click handler itself (and stop it either by preventDefault or return false)
var link = document.getElementById("link");
link.addEventListener("click", function () {
if (this.moving) {
this.moving = false;
return false;
}
console.log("clicked");
});
link.addEventListener("touchstart", function (touchStartEvent) {
var mouseMoveHandler = function () {
console.log("moved.");
this.moving = true;
link.removeEventListener('touchmove', arguments.callee);
};
link.addEventListener("touchmove", mouseMoveHandler);
});

Binding multiple events and run a function when all events are fired! JS, Jquery

I want to bind two mouse events to a function (mousedown and moucemove). But I want to run the function only if both events are fired.
This will bind each event to to the function: (It's not what i want)
$("#someid").bind("mousedown mousemove", function (event) { someFunction(); });
I can do this and it works:
$("#someid").bind("mousedown", function (event) {
someFunction();
$("#someid").bind("mousemove", function (event) {
someFunction();
});
});
$("#someid").bind("mouseup", function (event) {
$("#someid").unbind("mousemove");
});
Is there a better, quicker way to do this???

Bind only to the mousemove event. If the left mouse button is pressed while you move, event.which will be 1.
$(document).on('mousemove', function(e) {
if (e.which == 1) {
//do some stuff
}
});

I guess you want the mousemove handler work only when the mouse button is pressed down? If so, I'd suggest using some kind of boolean flag. You toggle its state on mousedown and mouseup events:
var flag = false;
$('#someid')
.on('mousedown', function(e) {
flag = true;
})
.on('mouseup', function(e) {
flag = false;
})
.on('mousemove', function(e) {
if (!flag) {
return false;
}
// else... do your stuff
});

jQuery - don't fire 'click' on 'mousemove'

I created a Fiddle to demonstrate my situation.
I want to not fire the click event when the user is panning--only if it's just a simple click. I've experimented with different placements of .off() and .on() to no avail.
Thanks in advance for your help.

http://jsfiddle.net/Waxen/syTKq/3/
Updated your fiddle to do what you want. I put the re-binding of the event in a timeout so it wouldn't trigger immediately, and adjusted the mousemove to

In on click event, you can detect whether mouse was pressed DOWN or UP. So let's analyse:
DRAG:
mouse down
mosue position changes
mouse up
CLICK:
mouse down
mouse up
You see - the difference is changed mouse position. You can record click coordinate in mouse down and then compare it when muse goes back up. If it is within some treshold, the action was a click.

The only way to tell between a "click" and a "pan" would be the time the mouse has spent held down. You could create a Date in the mousedown, then another in the mouseup, and only fire your click (zoom) event if the difference between the two dates is greater than some threshold (i would guess 1/10 of a second, but you may want to experiment)

I added a "panning" bool for a solution to your problem:
see http://jsfiddle.net/syTKq/4/
Basically, if the user has mousedown and mousemove, then panning is true. once mouseup panning is false. if just mousedown, panning is false, therefore zoom.

This solution solves your problem:
var bClicking = false,
moved = false;;
var previousX, previousY;
var $slider = $('#slider'),
$wrapper = $slider.find('li.wrapper'),
$img = $slider.find('img.foo');
$img.on('click', function()
{
if(!moved)
{
doZoom();
}
});
$wrapper.mousedown(function(e) {
e.preventDefault();
previousX = e.clientX;
previousY = e.clientY;
bClicking = true;
moved = false;
});
$(document).mouseup(function(e) {
bClicking = false;
});
$wrapper.mousemove(function(e) {
if (bClicking)
{
moved = true;
var directionX = (previousX - e.clientX) > 0 ? 1 : -1;
var directionY = (previousY - e.clientY) > 0 ? 1 : -1;
$(this).scrollLeft($(this).scrollLeft() + 10 * directionX);
$(this).scrollTop($(this).scrollTop() + 10 * directionY);
previousX = e.clientX;
previousY = e.clientY;
}
});
function doZoom() {
$img.animate({
height: '+=300',
width: '+=300'
}, 500, function() {
//animation complete
});
}​
Basically, it calls doZoom() only when the mouse has not moved between the mousedown and the mouseup events.

You can use the mousemove/mousedown events to set a flag that can be used in the click event handler to determine if the user was clicking or panning. Something like:
//set a flag for the click event to check
var isClick = false;
//bind to `mousedown` event to set the `isClick` flag to true
$(document).on('mousedown', function (event) {
isClick = true;
//bind to `mousemove` event to set the `isClick` flag to false (since it's not a drag
}).on('mousemove', function () {
isClick = false;
//bind to `click` event, check to see if the `isClick` flag is set to true, if so then this is a click, otherwise this is a drag
}).on('click', function () {
if (isClick) {
console.log('click');
} else {
console.log('drag');
}
});​​
Here is a demo: http://jsfiddle.net/SU7Ef/