Changing marginTop-property via JavaScript leads to wrong result in FireFox - javascript

My problem:
Changing the margin-top property via JavaScript objectName.style.marginTop = value; works well in Chrome and Safari, however in Firefox, the positioning seems to be all wrong. Instead of placing the element over the viewport, subsequently lowering it until it is slightly underneath the desired position and then moving it up a bit, Firefox places it way underneath the final position, moves it up and then down, almost mirroring the desired animation.
If I switch of Javascript and enter the value in CSS, the positioning is alright, so I guess the mistake lies in the .js.
Context:
I am trying to create a simple animated logo via JavaScript. I want it to drop from outside the browser viewport into its position. The logo is the HTML-element <img id="site_logo" src="logo.png" />
Here goes the JavaScript code:
var logoValue = -400;
function onLoad(){
// ...
logoStarter();
}
function logoStarter(){ //sets the logo in its starting position outside the viewport
var site_logo = document.getElementById("site_logo");
site_logo.style.marginTop = logoValue +"px";
logoAnimationDown();
}
function logoAnimationDown(){ // moves the logo down until it is somewhat underneath its final position
if(logoValue <= 20){
console.log(logoValue);
logoValue += 17;
var site_logo = document.getElementById("site_logo");
site_logo.style.marginTop = logoValue +"px";
setTimeout('logoAnimationDown()', 30);
}
else{
setTimeout('logoAnimationUp()', 30);
}
}
function logoAnimationUp(){ // moves the logo up to its final position
if(logoValue > 0){
console.log(logoValue);
logoValue -= 10;
var site_logo = document.getElementById("site_logo");
site_logo.style.marginTop = logoValue + "px";
setTimeout('logoAnimationUp()', 30);
}
}

It seems that FF does the procedure twice. Declare your setTimeouts like this:
setTimeout(logoAnimationDown, 30);
setTimeout(logoAnimationUp, 30);
If you use this kind of a quoted string setTimeout('doFunction()',30) to assign the target function, FF does this: eval('doFunction()'), and executes the function immediately (beacause of "()"), and then again after the delay time.

Related

Matrix intro, can't reload on CodePen. Going slowly on mobile devices(3D). JavaScript, Css

So. Like in my question, i create a Matrix intro, on my deskop(chrome) everything going smoothly. But, when i upload everything in to CodePen my animation stops on final step... Where is a issue?!
For sure there is a trouble with that part of code:
setTimeout(function() {
var elem = document.getElementById("spark");
var size = 0;
var pos=50;
var id = setInterval(frame, 1);
function frame() {
if(size>200){
//if would you like to run animation ones and relocate user to your main website use window.location.href=''; instead of location.reload();
window.location.reload();
}
else{
size+=2;
pos-=1;
elem.style.top = pos+"%";
elem.style.left = pos+"%";
elem.style.width = size + '%';
elem.style.height = size + '%';
}
}
},30000);
full code avaible on codepen
I try to change size, use only location.reload() but nothing. on a spot when function should reload it stops...
2nd issue is that, my function executes so slow... on mobile devices(samsung J5). So there needs to be some problem also but with ones?!
history.go(0); not working eater.

Stopping image from scrolling paraScrolling

edit- I actually had my image originally position:relative. I have fixed that in my code. I would like the image to scroll left until it has disappeared from the window. I would like it to stop moving, or even reset. I can do that part. I used the developer window in chrome to check, and the position:right of the image in question moves on well past 1700px, which I tried to stop with my if block in paraScrollRight
I'm trying to get an image to stop moving, so that I can get another image to move while the user scrolls down the page. For some reason, my if logic doesn't stop scrolling at all.
var yPos, image;
function paraScrollDown(){
yPos = window.pageYOffset;
image = document.getElementById("image");
image.style.top = (yPos * 1.0) + "px";
}
function paraScrollRight(){
yPos = window.pageYOffset;
image = document.getElementById("image");
if(image.style.right <= 1,374 + "px") {
image.style.right = (yPos * 2.7) + "px";
}
}
window.addEventListener("scroll",paraScrollRight);
<img id="image" style="position:relative" src="https://s-media-cache-ak0.pinimg.com/236x/ee/94/32/ee94322ba44eebc686d2e8381a84259c.jpg" />
Try this: https://jsfiddle.net/92rse23e/
I only handled the paraScrollDown method since that's what I understood what you needed to be taken care of. An important thing you needed to add was to make the image position: absolute; in CSS.

javascript (but not jQuery please) fixed position on x-axis but not y?

I've looked everywhere and so far have not found a non-jQuery js to handle this. I would like to avoid using a library for just this one simple task.
I would like to fix three navigation divs ("#header", "#tabs" and "#footer") to viewport left (or alternatively, to the x position of a div "#helper" with "position: fixed; left: 0; top: 0;") -- but not fix y. They can not be vertically fixed.
I've created a working js that forces the divs to reposition based on scrolling, but it's not smooth in the real page (too many dynamic and graphic elements) - I'd like it to either animate smoothly, or mimic fixed-left and not appear to reposition at all.
Anyone who can give pointers or a quick script, or review and modify the script I have made? I've noticed people tend to ask why an obvious solution is not used instead of answering the question... I will be glad to answer, but would prefer help with the actual problem.
Here is a jsFiddle with the problem: http://jsfiddle.net/BMZvt/6/
Thank you for any help!
Smooth animation example:
var box = document.getElementById('box');
var moveTo = function(obj, target) {
// start position
// you should obtain it from obj.style
var cpos = {
x: 0,
y: 0
}
var iv = setInterval(function(){
cpos.x += (target.x - cpos.x) * 0.3; // 0.3 is speed
cpos.y += (target.y - cpos.y) * 0.3; // 0.3 is speed
obj.style.left = Math.floor(cpos.x) + 'px';
obj.style.top = Math.floor(cpos.y) + 'px';
var dist = Math.abs(cpos.y - target.y); // distance (x+y) from destination
dist += Math.abs(cpos.x - target.x); // < 1 = object reached the destination
if(dist < 1) { // here we are checking is box get to the destination
clearInterval(iv);
}
}, 30); // this is also the speed
}
box.onclick = function(){
moveTo(box, {x: 90, y: 75}); // fire this function to move box to specified point
}
Demonstration: http://jsfiddle.net/Qwqf6/5/
Your script is your job, but this is a quick start how to solve animation problem
You can also do some fancy stuff with speed for example use sin(x) to set the speed
Demonstration #2 http://jsfiddle.net/Qwqf6/6/ (very smooth)
Full script here https://gist.github.com/3419179
I don't think there's a straight way to do this...
But here's a way.
First, You need to be able to detect the direction of the scrolling when window.onscroll event happens. You would do this by comparing the current page offsets with the newly acquired page offsets whenever the scroll event happens. (http://stackoverflow.com/questions/1222915/can-one-use-window-onscroll-method-to-include-detection-of-scroll-direction)
Now suppose you know the direction of the scroll, you want to change the styling for the divs depending on the direction of the scroll.
Let FixAtX be the value of the x coordinate that you want to fix your divs at.
Let OriginalY be the y coordinate of the divs.
Also whenever scrolling happens, despite of the direction, you want to remember the pageoffset X and Y. Let's call them OldX and OldY
If scrolling vertically:
Set position value for divs' style to be absolute.
Set top value for divs' style to be OriginalY
Set left value for divs' style to be OldX + FixAtX
If scrolling horizontally:
Set position value for divs' style to be fixed.
set top value for divs' style to be OriginalY - OldY (<- this may be different depending on how the browser computes pageOffset value,)
Set Left value for divs' style to be FixAtX
I think this should work...
Since you are just using browser's rendering for positioning, it should be very smooth!
hope I understood the question correctly.
This is for people who view this post - I wound up going with the solution I initially put together in the jsFiddle that used a simple javascript to mimic fixed x.
The javascript in the first answer was hefty and wound up buggy, and the second answer sounded good but did not work in practice. So, I'm recommending the javascript from the jsFiddle (below) as the best answer to fixed x and fluid y without a javascript library. It's not perfect and has a minimal delay but is the best answer I've found.
function fixLeft() {
function getScrollX() {
var x = 0, y = 0;
if( typeof( window.pageYOffset ) == 'number' ) {
x = window.pageXOffset;
} else if( document.body && ( document.body.scrollLeft) ) {
x = document.body.scrollLeft;
} else if( document.documentElement && ( document.documentElement.scrollLeft) ) {
x = document.documentElement.scrollLeft;
}
return [x];
}
var x = getScrollX();
var x = x[0];
// have to get and add horizontal scroll position px
document.getElementById('header').style.left = x + "px";
document.getElementById('tabs').style.left = x + "px";
document.getElementById('footer').style.left = x + "px";
}
window.onscroll = fixLeft;

Animation starts moving out of position after some time

I am trying to create a sort of slideshow animation. I have the codes here: jsFiddle.
These tablets would rotate around.
The problem is that, at random times, the animation will move out of line. The wrong tablets undergo wrong animations. Here are the screenshots:
And this is how it looks like when the animations goes wrong
The main problem is I don't understand why the animation would go wrong random times. In my computer it will run properly for hours, but in other cases (especially on Safari).
You could store the expected final css values for each animated el and then in the animate callback set these values, so for each animated el something like
var el = $(selector);
el.data("finalCSS", { your expected final CSS values })
$("selector").animate({animation properties}, function() {
el.css(el.data("finalCSS")).data("finalCSS", undefined);
})
This doesn't help with figuring out why it's happening (but I can't recreate the issue myself), but provides a failsafe to make sure the layout doesn't break;
I believe this happens when you try to animate before the previous animation has ended. Use jQuery stop() just before you animate. For example:
$('#animatingDiv').stop(false, true).animate({height:300}, 200, callback);
The first param(false) will empty the animation queue on that element and the second param(true) will jumps to the end of current animation before starting a new animation.
You can do this with far less code and far fewer headaches.
1. Store your tablet position attributes in classes
.tablet1{
height:100px;
width:140px;
margin-left:-540px;
top: 200px;
z-index:10;
}
2. Use a general function to handle all your transitions.
JQuery UI will do all the work for you if you use switchClass
switchTabletsRight = function(){
var i, next, max = 5;
for(i = 1; i <= max; i++){
next = (i < max)? i + 1 : 1;
$(".tablet" + i).switchClass("tablet" + i, "tablet" + next);
}
};​
Here's the JSfiddle proof of concept: http://jsfiddle.net/nRHag/4/
You are setting CSS positions to decimal values.
img_w = $("#tablet"+num+" img").width();
img_w = img_w *140 / 600;
img_h = $("#tablet"+num+" img").height();
img_h = img_h *140 /600;
...
var new_width = $(this).width() * 140 / 600;
$(this).css('width', new_width);
var new_height = $(this).height() * 140 / 600;
$(this).css('height', new_height);
Your division could be cause decimal results which have different effects in different browsers. Sub pixel CSS positioning may be creating your unintended errors.

Adjust top position according to height of div with javascript

function jsiBoxAdjustTop()
{
var top
if ( jsiBox.preloadImg.height <= 699){
top = 216;
}
else{
top = 17;
}
jsiBox.boxNode.style.top = (top) + 'px';
}
I'm using that function to adjust a div's top position depending on the image that is in it's height. It's on a light box sort of script so every time I click the next button, a new image which could either be taller or smaller appears. It's working alright and it adjusts its position when the image is taller but my problem is it just jumps to that position. I'm really new to javascript so can anyone help me out to make this as if it's travelling/animating to it's position? I tried using setTimeOut but I think I was doing it wrong. I'd really love to know what I'm doing wrong.
Here's the full script if that helps. Link
you can use jQuery or YUI to do animate, such as
jQuery(jsiBox.boxNode).animate({'top': top}, 3000);
or you can write some simple code with setTimeout just for this case;
following code assume the begin top is 0.
var boxStyle = jsiBox.boxNode.style;
function animateTop(to) {
boxStyle.top = parseInt(boxStyle.top, 10) + 1 + 'px';
if (parseInt(boxStyle.top, 10) != to) {
setTimeout(function() {
animate(to);
}, 50);
}
}
animateTop(top);

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