Crazy trouble with addEventListener - javascript

I have a div with id="inn"
and then a code like this:
var zin = document.querySelector("div#inn");
zin.addEventListener("click", function(e){
if (count <= maxzoom) {
startZoomIn();
}
})
The crazy trouble is that, if I click with mouse, all works fine, but if I use (as needed) the over cursor (I'm workin' with Leap Motion), it don't work, it seems isn't recognized...
The very strange thing is that an absolutely equal code, for different element, works perfectly; and that, exactly the same code works fine on a different page...
I'm workin' around this trouble by many hours, and maybe are stultyfied..., but in any way I try to approach to solve, the trouble stay always there...

Just had a quick loop at the Leap Motion JS Reference and it looks like you need to handle gestures (such as click differently)
Additionally, you might find LeapCursor.js helpful.
It should make it easier for you to do something like:
$("#inn").click(function() { alert('Leap cursor click!'); });

Related

Semantic UI dropdown lags entire ui when setting values

I have a large select with about ~1500 items in it. Whenever i call this code
$('#multi-select').dropdown('set exactly', ['my value']);
to set its value, the entire UI locks up and lags. Now I know this is due to the large dropdown (1500 items) but I'd like to know if there is a way to keep that many items without flushing the user experience down the toilet.
I've put together an example below. You can try clicking the button once, or multiple times consecutively to see the browser choke.
http://jsfiddle.net/qhy9do4w/1/
I've looked in the code and profiled the click. Somewhere in its bowels Semantic fires a lot of events and most of the lag time is taken by module.trigger something. Inside the code looks like this:
trigger: {
change: function() {
var
events = document.createEvent('HTMLEvents'),
inputElement = $input[0]
;
if(inputElement) {
module.verbose('Triggering native change event');
events.initEvent('change', true, false);
inputElement.dispatchEvent(events);
}
}
}
I don't see any way to disable the event handling part.
I had a look into the semantic.js code for the dropdown set exactly and it is quite something: https://github.com/Semantic-Org/Semantic-UI/blob/74fea12e1fd548cb870872ba5ed59f5acdcc57ba/dist/components/dropdown.js#L2219:L2295
You could try figure if the code is slow somewere or wether you can do any sort of shortcut.
But, that is hard and you might want to think about an alernative like a search.
Our solution was to simply cache the contents and only put in a selected subset of options into the drop down itself.

JavaScript button fires perfectly in Chrome and IE but won't work in Firefox

I'm sure the title looks like something that's been asked before but I've searched for the answer to this and I can't find it.
I'm really very new to coding, so please excuse any really obvious mistakes I've made.
Context to the code I'm working on: I'm in a Game Design class and I've decided to take up a personal project making an HTML JS game.
I understand that the code is possibly rough / bad / definitely-not-the-best-way-to-do-things, but it will continue to be so until I improve my skills (or am given advice on how to improve it).
What I need help with: For two to three weeks, I could not figure out how to get a button to appear when implemented inside of an if else statement.
Like so:
if(condition)
{
document.write("text");
//desired button here
}
else
{
//Backup code
}
Eventually I figured two ways to do that (for Chrome and Internet Explorer).
First way:
function myFunction()
{
document.close();
document.write("text");
/* There will be buttons in here
too when I get things working. */
}
//In separate script tags
/* myFunction() dwells in the head of the
page while the if statement is in the body
and another function*/
if(condition)
{
document.write("text");
var gameElement=document.createElement("BUTTON");
var text=document.createTextNode("CLICK ME");
gameElement.appendChild(text);
gameElement.onclick = myFunction;
document.body.appendChild(gameElement);
}
else
{
//Backup code
}
The second way:
(The same function, they're both in the same places).
if(condition)
{
document.write("text");
var gameElement;
gameElement = document.createElement('input');
gameElement.id = 'gameButton';
gameElement.type = 'button';
gameElement.value='Continue';
gameElement.onclick = myFunction;
document.body.appendChild(gameElement);
}
This works well for me.
And while it works in IE and Chrome fine, it doesn't work in Firefox.
After how much time and research I've put into just this button, I'd love to know why it won't show up in Firefox. I've read a lot about Firefox and how .onclick won't work or something like JavaScript has to be enabled or disabled. I'm just a bit confused.
I'm also open any real / relevant advice.
I set up this fiddle. I removed your document.write() calls because they're disallowed in JSFiddle, and change your condition to true so the code would work, and it works in FF24.
document.write() might be the cause of your problem. It's bad practice anyway because it can cause a re-parse of a document, or wipe the entire document and start writing it again. You're already using some DOM manipulation to add the button. I suggest you do likewise for anything you're considering using document.write() for.
Instead of suggesting a solution to your problem, I would suggest you take a look at jQuery, which is a very nice JavaScript framework, that makes it possible for you to write cross-browser compatible code, which it seems is your problem here.
Using jQuery, you would be able to write something like:
$("#gameButton").click(function() { myFunction(); }
which would trigger your myFunction() function, when the control with the id 'gameButton' is clicked.
Visit www.jquery.com to learn more

Raphael js problems with mouse events in Safari

Working with Raphael library, I've got a lot of problems with mouse events in Safari (it just doesn't work on mouse events).
I read it's common, and maybe there is a solution for this (from the documentation):
Paper.safari()
There is an inconvenient rendering bug in Safari (WebKit): sometimes
the rendering should be forced. This method should help with dealing
with this bug.
by the way, I can't understand how to make it works..
I do like this:
var Paper = new Raphael(document.getElementById("paperId"), '300px', '300px');
Paper.safari();
can you tell me what I'm doing wrong?
or, otherwise, is there an alternative solution?
I've been searching for hours, with no results... :(
edit:
yes, the problem is about filling a raphael element with an url:
myClass.prototype.PhotoClick = function(){
var that = this;
$('.photo').each(
function(){
$(this).dblclick(function(event) {
that.loadPhoto[index].attr({fill:"url(images/image1.jpg)"});
});
});
}
sorry, I don't post more, because the code is a bit messy.
however, the array item is a raphael object, and the url path is correct.
if I fill the element with a color, everything is fine. just urls give me problems...
hope now it's clearer

one function not running with jQuery infinite carousel build

so i have tried making myself an infinite carousel using html, css & jQuery and everything is working apart from the back button will not loop, i've spent quite a while doing this now and i'm wondering if anyone has any insight? http://jsfiddle.net/e2SKk/ is where you can see the code! i'm only really doing this because i thought it would give me a chance to learn a lot more, but any criticisms of code layout or technique would be helpful!
specifically its this code thats seems not to work
else if(loopPrev==true){
sliderActive=true
$('.item-holder').css({
'left':clonePos
});
$('.item-holder').animate({
'left':holderPos+$('.slider').width()+'px'
},function(){
sliderActive=false;
});
};
that is only a snippet btw and won't make much sense without the rest!
jQuery is cool to write short scripts.
Your slider code in short:
var width = $('.slider').width();
$('.item').css({width:width});
var $holder = $('.item-holder').css({left:-width}).prepend($('.item:last'));
$('.prev').click(function(){
$holder.not(':animated').css({left:-2*width}).prepend($('.item:last')).animate({left:-width});
});
$('.next').click(function(){
$holder.not(':animated').css({left:0}).append($('.item:first')).animate({left:-width});
});
​
That's the complete code.
See this in action on http://jsfiddle.net/creativecouple/YPU2d/
Pretty cool little slider you have going here! You say you are a beginner? I'd say you've picked up on jQuery quite well! Also before I forget, addressing your comment: if you post something on stackoverflow...it WILL be viewed, likely by many people :). It's rare to come here and receive no help (albeit you may not always get an answer).
Fortunately for you, I've found your problem! It's right here:
else if(loopPrev==true){
sliderActive=true
$('.item-holder').css({
'left':clonePos
});
$('.item-holder').animate({
'left':holderPos+$('.slider').width()+'px'
},function(){
sliderActive=false;
});
};
You are checking whether or not to loop, setting the slider to active, setting the next slide to the last slide in the index (and subsequently pushing it to that at the same time), then you animate as you normally would. This results in two movements: first to the back of the index, then to the value of holderPos+$('.slider').width()+'px'...hence your strange behaviour. This should help:
else if(loopPrev==true){
sliderActive=true;
$('.item-holder').animate({
'left':"-1800px"
}, function(){
sliderActive=false;
})
};
The value "-1800px" is just the last slide in your buffer that I precalculated...you should be able to replace it with your clonePos variable without trouble.
*EDIT: You should also change your variable clonePos to look like this:
var clonePos = '-'+($('.item').index()-1)*($('.slider').width());
It will eliminate a bug when you swap between the last slide in the index and the first slide (a "smooth transition" if you will).
**
Part II
**
In order to achieve the illusion of infinite scrollability you will need to embed a callback "push back" function inside the "left pressed" animation call. It's late here so I haven't tested the code I am about to write but I'm fairly confident it will work for you.
else if(loopPrev==true){
sliderActive=true;
$('.item-holder').animate({
'left':clonePos
}, function(){
$(this).css('left':holderPos+$('.slider').width()+'px');
sliderActive=false;
})
};
If you take a look this isn't much different from the original answer I offered. All we have done is take the callback function for animate, and added a call to slip the position to the original index position. Again, untested, but the idea is that .animate() will slide to the clone, once that is done your callback will swap the clone with the original, and then deactivate the slider.
You weren't very far off! Here's a semantic rule of the animate function (to attempt to help your understanding of the way a callback works):
animate( params, [duration], [easing], [callback] )
params is our left call (to the cloned slide in this case)
duration is ignored here
easing is ignored here
callback is our function() call that does our little david copperfield swap
Hope this helps!

Mootools problem when zoomed in

I am using Mootools extensively for a site which I am developing. But recently I noticed a problem that the animations slow down alot when I zoom (using the browsers Zoom In) in into the site. What could be a possible reason for this problem ? Or is this problem inherit in Mootools itself. This happens in Chrome 6.0.472 as well as Firefox 3.6.8.
Thanks,
Nitin
many things are wrong here with regards to speed optimisations.
lets take a look at this mouseover code that seems to slow down:
this.childNodes.item(1).style.left="0px";
this.getElements('div').setStyles({'opacity':'1'});
this.getElements('div').set('morph', {duration:'normal',transition: 'sine:out'});
this.getElements('span').set('morph', {duration:'normal',transition: 'sine:out'});
this.getElements('div').morph({'left':'-28px'});
this.getElements('span').morph({'left':'-30px','color':'#FFF'});
obviously this will work as it does but it's so very wrong i don't know where to begin.
the idea is to abstract and setup the repetitive tasks so they are done as a one off.
consider line by line the code above:
this.childNodes.item(1).style.left="0px";
this is wrong for a mootools app anyway, it would need to be this.getFirst().setStyle("left", 0);
the this.getFirst() is a lookup, it should be cached - although that's not a slow one.
then comes the bad part.
you select all child divs 3 times and all spans twice, where NO SELECTION should be applicable. VERY EXPENSIVE
you reset the Fx.morph options every mouseover event where there are no changes (although you seem to have a different duration for mouseenter and mouseleave - this is expensive)
consider this code:
[document.id("menu1"), document.id("menu2")].each(function(el) {
// use element storage to save lookups during events
el.store("first", el.getFirst());
el.store("divs", el.getElements("div"));
el.store("spans", el.getElements("span"));
// store the fx.morph options once and for all, no need to do so
// on every event unless you are changing something
el.retrieve("divs").set("morph", {
duration: 'normal',
transition: 'sine:out',
link: 'cancel'
});
el.retrieve("spans").set("morph", {
duration: 'normal',
transition: 'sine:out',
link: 'cancel'
});
// add the events
el.addEvents({
mouseenter: function(e) {
// retrieve the saved selectors from storage and do effects
this.retrieve("first").setStyle("left", 0);
this.retrieve("divs").morph({
"left": -28
});
this.retrieve("spans").morph({
'left': '-30px',
'color': '#FFF'
});
}
});
});
it will save a lot of processing on the events.
similarly, there are plenty of places where you are not really using the mootools api.
document.getElementById(curr).style.cursor="pointer";
$(this).removeEvents -> no need for $, this is not jquery.
document.getElementById("lightbox").style.visibility="hidden";
m=setTimeout('gallery()',5000); --> use the mootools var timer = (function() { ... }).delay(5000);, don't use strings with setTimeout/interval as it forces eval and reflows but pure anon functions
etc etc.
you really can make a day out of refactoring all this and making it 'nice' but it's going to be worth it.
also, learn about chaining
$("ribbon").set('morph', {duration:'long',transition: 'bounce:out'});
$("ribbon").morph({'top':'-10px'});
$("ribbon").addEvents({
this is calling up a selector 3 times. instead you can:
store it. var ribbon = $("ribbon"); ribbon.set...
chain it. $("ribbon").set("morph", {duration: 500}).morph({top:-10}).addEvents() - mootools element methods tend to return the original element so you can take the response of the last function and apply more to it.
1 is better for readibility, 2 is faster to do.
also. you have way too many global variables which makes your scope chain lookups more expensive, this will affect many call ups and places. try to namespace properly, if you need to access real global vars from functions and closures, use window.varname etc etc.
Another possible improvement here would be the use of event delegation (event bubbling will cause events to fire up the dom tree to the parents, mootools has an api to deal with it so you can add singular events to parent elements and not have to attach nnn events to all children) - look it up.
P.S. please don't take this in the wrong way - it's not meant to rubbish your work and it's just some constructive (i hope) advice that can help you bring it to the next level. good luck :)
I haven't seen any specific code in MooTools or any other library that checks if browser is zooming during animation, so I think that animation slows down, since browser using more CPU for computing zooming process.

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