Develop Reference

Doubletap event on input text on mobile [duplicate]

I'm looking for the best solution to adding both "doubletap" and "longtap" events for use with jQuery's live(), bind() and trigger(). I rolled my own quick solution, but it's a little buggy. Does anyone have plugins they would recommend, or implentations of their own they'd like to share?

It has been reported to jQuery as a bug, but as doubletapping isn't the same as doubleclicking, it does not have a high priority. However, mastermind Raul Sanchez coded a jquery solution for doubletap which you can probably use!
Here's the link, works on mobile Safari.
It's easy to use:
$('selector').doubletap(function() {});
-edit-
And there's a longtap plugin here! You can see a demo on your iPad or iPhone here.

rsplak's answer is good. I checked out that link and it does work well.
However, it only implements a doubletap jQuery function
I needed a custom doubletap event that I could bind/delegate to. i.e.
$('.myelement').bind('doubletap', function(event){
//...
});
This is more important if you're writing a backbone.js style app, where there is a lot of event binding going on.
So I took Raul Sanchez's work, and turned it into a "jQuery special event".
Have a look here: https://gist.github.com/1652946 Might be useful to someone.

Just use a multitouch JavaScript library like Hammer.js. Then you can write code like:
canvas
.hammer({prevent_default: true})
.bind('doubletap', function(e) { // Also fires on double click
// Generate a pony
})
.bind('hold', function(e) {
// Generate a unicorn
});
It supports tap, double tap, swipe, hold, transform (i.e., pinch) and drag. The touch events also fire when equivalent mouse actions happen, so you don't need to write two sets of event handlers. Oh, and you need the jQuery plugin if you want to be able to write in the jQueryish way as I did.
I wrote a very similar answer to this question because it's also very popular but not very well answered.

You can also use jQuery Finger which also supports event delegation:
For longtap:
// direct event
$('selector').on('press', function() { /* handle event */ });
// delegated event
$('ancestor').on('press', 'selector', function() { /* handle event */ });
For double tap:
// direct event
$('selector').on('doubletap', function() { /* handle event */ });
// delegated event
$('ancestor').on('doubletap', 'selector', function() { /* handle event */ });

Here's a pretty basic outline of a function you can extend upon for the longtap:
$('#myDiv').mousedown(function() {
var d = new Date;
a = d.getTime();
});
$('#myDiv').mouseup(function() {
var d = new Date;
b = d.getTime();
if (b-a > 500) {
alert('This has been a longtouch!');
}
});
The length of time can be defined by the if block in the mouseup function. This probably could be beefed up upon a good deal. I have a jsFiddle set up for those who want to play with it.
EDIT: I just realized that this depends on mousedown and mouseup being fired with finger touches. If that isn't the case, then substitute whatever the appropriate method is... I'm not that familiar with mobile development.

based on latest jquery docs i've written doubletap event
https://gist.github.com/attenzione/7098476

function itemTapEvent(event) {
if (event.type == 'touchend') {
var lastTouch = $(this).data('lastTouch') || {lastTime: 0},
now = event.timeStamp,
delta = now - lastTouch.lastTime;
if ( delta > 20 && delta < 250 ) {
if (lastTouch.timerEv)
clearTimeout(lastTouch.timerEv);
return;
} else
$(this).data('lastTouch', {lastTime: now});
$(this).data('lastTouch')['timerEv'] = setTimeout(function() {
$(this).trigger('touchend');
}, 250);
}
}
$('selector').bind('touchend', itemTapEvent);

Jquery on mousedown not working on dynamically generated elements

So i'm trying to create a js/css "wave game" like tower defense ones.
When all the pre-generated enemys from first wave are dead, it spawns the second wave and so on.
So far so good.
The problem is that i just can't attack mobs dynamically spawned within second wave.
I used to try .live() in similar cases, but its deprecated, so i'm trying .on(), as instructed
$('.enemy').on('mousedown' , function(event) {
//attack code
}
Its working fine for initial mobs (1st wave) but it still just not working on dynamic mobs (>= 2nd wave)
Help, guys, please?

You need to specify an element that is already there when the DOM is created. In the parameters, you specify the elements you want to add the mousedown method. By simply assigning $('.enemy'), it will attach the method to those that are already present in the DOM.
$('body').on('mousedown', '.enemy', function(event) {
//attack code
}
As Wex mentioned in the comments, instead of writting $('body') you should use the container's name (the container which wraps the .enemy elements. This way, when a .enemy element is added, the event doesn't need to bubble all the way up to the body tag.

The binding '.on()' works only with the content that created earlier then the script ran.
So one solution could be you bind the event to the parent element.
$('.PARENT_ELEMENT').on('mousedown', '.enemy', function(event){
// your code here
}
That should do it.

I made this google like drop down suggestions search box and I faced a problem similar to yours where there was suggestions disappearing before the re-direct happened. I overcame it by using and modifing vyx.ca answer:
var mousedownHappened = false;
var clicked_link;
$("#search-box").blur(function(e) {
if (mousedownHappened)// cancel the blur event
{
mousedownHappened = false;
window.location.href = clicked_link;
} else {
// no link was clicked just remove the suggestions box if exists
if ($('#search-btn').next().hasClass('suggestions')) {
$(".suggestions").remove();
}
}
});
//attaching the event to the document is better
$(document).on('mousedown', '.suggestions a', function() {
clicked_link= $(this).attr('href');
mousedownHappened = true;
});

Enable and disable jquery knob dynamically

I'm using the excellent jQuery knob plugin. However, I need to dynamically enable/disable the element depending on user input. There is support for having a disabled state on page load which have the effect that no mouse (or touch) events are bound to the canvas element. Does anyone know how to resolve this issue, that is, how to (after page load) bind and unbind these mouse event listeners?
Ideally I would like to do something like this (on a disabled knob)
$('.button').click(function() {
$('.knob').enable();
});
Edit:
I ended up rewriting the source which binds/unbinds the mouse and touch events. The solution is not perfect so I leave the question open if someone perhaps have a better (cleaner) solution.

html
<input class="knobSlider" data-readOnly="true">
<button id="testBtn">clickHere</button>
script
in doc ready,
$(".knobSlider").knob();
$("#testBtn").click(function(){
$(".knobSlider").siblings("canvas").remove();
if($(".knobSlider").attr("data-readOnly")=='true'){
$(".knobSlider").unwrap().removeAttr("data-readOnly readonly").data("kontroled","").data("readonly",false).knob();
}
else{
$(".knobSlider").unwrap().attr("data-readOnly",true).data("kontroled","").data("readonly",true).knob();
}
});
For reference you can use my jsfiddle link > http://jsfiddle.net/EG4QM/ (check this in firefox, because of some external resource load problem in chrome)

If someone doesn't like how the accepted answer destroys and recreates the internal canvas element, then checkout my approach:
https://jsfiddle.net/604kj5g5/1/
Essentially, check the draw() implementation (I also recommend listening on value changes in the draw method instead of the change and release, which work for and click and mousewheel events respectively, which imo is inconvenient).
var $input = $("input");
var knobEnabled = true;
var knobPreviousValue = $input.val();
$input.knob({
draw: function () {
if (knobPreviousValue === $input.val()) {
return;
}
if (!knobEnabled) {
$input.val(knobPreviousValue).trigger("change");
return;
}
knobPreviousValue = $input.val();
console.log($input.val());
},
});

Try this to disable the control.
I'm still trying to find a way to enable it back
$("#btnDisable").click(function(){
$("#knob").off().prev().off();
});

how do I know if the mouse pointer is on the HTML element?

I have a timed event I want to behave differently accordingly to what HTML element the mouse pointer is on.
Is there a way, assuming I have the HTML element, to know if the mouse pointer is currently on top of it.
I am well aware of the onmouseover/onmouseout events and how to use them.
I am using JQuery.
I am obviously looking for some kind of flag, as I need to check a state and not handle an event.
again, I know how to implement this with events.

I'm not aware of any built-in way to ping an element for the status of mouse hovering.
However, you can create one by updating a flag at mouseenter and mouseleave -- which is where Brian Driscoll's suggestion of .hover comes in:
jQuery.fn.tracking = function () {
this.data('hovering', false);
this.hover(function () {
$(this).data('hovering', true);
}, function () {
$(this).data('hovering', false);
});
return this;
};
jQuery.fn.hovering = function () {
return this.data('hovering');
}
You'll need to initialize tracking for each element you care about:
$('#elem1,#elem2').tracking();
But then you can get the status of any of them:
if ($('#elem1').hovering()) {
// ...
} else if ($('#elem2').hovering()) {
// ...
}
Demo: http://jsbin.com/amaxu3/edit

Have you looked into jQuery.hover()? http://api.jquery.com/hover/

You need to give name to html andme and on mouseover you need to check document.getelementsbyName. Then check what your are getting as output. Now you can take decision is it html control or asp.net.
When you use collObjects = object.getElementsByName("htmlcontrol") then compare id of both.
1 morething why you needed to check this in javascript. there may be some other solution for that. Just share with us.

You might have some luck with document.elementFromPoint, although I believe there are some inconsistencies in older browser implementations (http://www.quirksmode.org/dom/w3c_cssom.html#documentview).
$('#elem').mousemove(function(e){
if (this == document.elementFromPoint(e.clientX, e.clientY)) {
// Do stuff
}
});
Or outside of a handler
if ($('#elem').get(0) == document.elementFromPoint(x, y)) {
// Do stuff
}
Aside from that, the only other option that comes to mind is using event handlers to keep track of which element the mouse is over.

js/jQuery Drag'n'Drop, recalculate the drop targets

I have the following issue, I have a large tree which has subnodes which can be folded and unfolded on demand (the data within nodes gets fetched with AJAX). However, I use jquery.event.drop/drag to create my drag/drop targets.
However, when I fold/unfold the drop targets change position and I need to recalculate. This is how I wanted to do that:
function create_drop_targets() {
$('li a')
.bind('dropstart', function(event) {
})
.bind('drop', function(event) {
})
.bind('dropend', function(event) {
});
}
create_drop_targets() is called upon fold/unfold.
However, this doesn't work. I have located the following within jquery.event.drop:
var drop = $.event.special.drop = {
setup: function(){
drop.$elements = drop.$elements.add( this );
drop.data[ drop.data.length ] = drop.locate( this );
},
locate: function( elem ){ // return { L:left, R:right, T:top, B:bottom, H:height, W:width }
var $el = $(elem), pos = $el.offset(), h = $el.outerHeight(), w = $el.outerWidth();
return { elem: elem, L: pos.left, R: pos.left+w, T: pos.top, B: pos.top+h, W: w, H: h };
}
Now I need to know how I can call the setup() method again so it repopulates $elements with the new positions for the droppables.

Just had the same issue. I wandered around within the source-code of jQuery and found this (in ui.droppable.js):
drag: function(draggable, event) {
//If you have a highly dynamic page, you might try this option. It renders positions every time you move the mouse.
if(draggable.options.refreshPositions) $.ui.ddmanager.prepareOffsets(draggable, event);
...
So, you'd just have to use
$(".cocktails").draggable({
refreshPositions: true,
});
Seems not to be documented very much... but it fixed my problem. Makes everything a bit slower of course, I would advise some usage-dependent tweaking (enable it before the changes occur, and disable it once the user has moved his mouse and the changes have occured).

Maybe it will be better to add live events introduced in jQuery 1.3?
$("li a").live("dropstart", function(){...});

I ran into the same issue when I tried to combine scrolling with draggable rows in liteGrid, but I found a work-around. Your mileage may vary, but what I did was add logic to my drag event handler that would check to see if the grid was being scrolled (which is when I needed to force the droppable positions to be refreshed), and if so, I set refreshPositions to true on the draggable. This doesn't immediately refresh the positions, but it will cause them to refresh the next time the drag handle moves. Since refreshPositions slows things down, I then re-disable it the next time my drag event handler fires. The net result is that refreshPositions is enabled only when the grid is scrolling in liteGrid, and its disabled the rest of the time. Here's some code to illustrate:
//This will be called every time the user moves the draggable helper.
function onDrag(event, ui) {
//We need to re-aquire the drag handle; we don't
//hardcode it to a selector, so this event can be
//used by multiple draggables.
var dragHandle = $(event.target);
//If refreshOptions *was* true, jQueryUI has already refreshed the droppables,
//so we can now switch this option back off.
if (dragHandle.draggable('option', 'refreshPositions')) {
dragHandle.draggable('option', 'refreshPositions', false)
}
//Your other drag handling code
if (/* logic to determine if your droppables need to be refreshed */) {
dragHandle.draggable('option', 'refreshPositions', true);
}
}
$("#mydraggable").draggable({
//Your options here, note that refreshPositions is off.
drag: onDrag
});
I hope that saves you from ramming your head into the keyboard as many times as I did...

I realize the original question is quite old now, but one little trick I came up with to refresh the position of draggable elements without much overhead (AFAICT) is to disable and immediately re-enable them wherever appropriate.
For instance, I noticed that resizing my browser window would not refresh the position of my draggable table rows, so I did this:
$(window).resize(function () {
$(".draggable").draggable("option", "disabled", true);
$(".draggable").draggable("option", "disabled", false);
});
I hope this helps someone out there!