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i am developing ball game. i am stuck at i want 3 balls are moving top bottom but every time with random width

I have a ball-game. width of board is 600px. 3 ball at that time coming down and on click it disappearing. but i want to have a one time 3 balls should be coming from different places. top 0 but left amount should be different. i write css
#keyframes ball-move {
0% {
top: 0;
left: 0;
}
For generate random width i make var.
var boardWidth = Math.floor(Math.random() * 600 + 1);
but i am not understanding how can i over right css in JS. i want to have top:0 to enter ball in frame but i want to enter from different width.
i tried with entering in css over ride but.JS is not reading my css.
I have to use only HTML, CSS,j javascript only.

Give each ball a class of ball and select them with javascript to loop through and set custom CSS
document.querySelectAll('.ball').forEach(ball => {
ball.style.left = Math.floor(Math.random() * 600);
}

If you want the ball to fall down from differenct place every time, you may use "on animationiteration". The below will set a new left value to the ball everytime the animation is itreataed.
The line
// Get all ball class element and loop through each
$(".ball").each(function(){
// Set random initial left value for tha ball
let boardWidth = Math.floor(Math.random() * 600);
$(this).css("left", boardWidth + "px");
// Set random left everytime the animation is iterated
$(this).on("animationiteration", function() {
let boardWidth = Math.floor(Math.random() * 600);
$(this).css("left", boardWidth + "px");
})
}
For the function you are using for boardWidth, you may want to consider taking the ball width into account as well, currently your ball may not be shown on the UI when left: 600px.

scrollTop help, Display image only after 600px has been passed once

So imagine that you want to display a red block when the user scrolls down 600px, and when the user scrolls above 600px you want to display a blue box. That's fine; however, you only want to display the blue box, after the red box has been displayed once/or rather, after the user has scrolled passed 600px once. The obvious thing to do would be to display the red block when the "scrollTop" is greater than (>) 600px, and display the blue block when the "scrollTop" is less than (<) 600px; however, doing this displays the blue block as soon as "scrollTop" reaches 1px, since technically, scrollTop < 600px includes every pixel under 600.
So I need to display the blue block, only after the red block has been displayed once/600 px has been passed once.
jQuery:
$(document).scroll(function() {
var y = $(this).scrollTop();
if (y > 600) {
$("#square").css("background-image", "url(images/comp_rel/red_block.gif)");
}
else {
$("#square").css("background-image", "url(images/comp_rel/blue_block.gif)");
}
});
In advance, thanks for any help.

Use this:
var shw = false;
$(document).scroll(function() {
var y = $(this).scrollTop();
if (y > 600) {
shw=true;
$("#square").css("background-image", "url(images/comp_rel/red_block.gif)");
}
else {
if(shw)
$("#square").css("background-image", "url(images/comp_rel/blue_block.gif)");
}
});

Randomize image position with JQuery and HTML

I have this :
<div id="randomp" style="position:absolute;top:3px;left:3px;width:165px;height:29px;background:url(/logo2.png) no-repeat;background-size: 165px;"></div>
I want that the propierty "top" and "left" change every time you enter into the page. I mean that some times it appear on the right top corner, right bottom corner, left top corner and left bottom corner..
Here it is what i have tryied:
http://redzer.com.mx/tabla.html

I would probably start with the div styled as position:fixed and with display:none:
<div id="randomp" style="display:none;position:fixed;width:165px;height:29px;background:url(/logo2.png) no-repeat;background-size: 165px;"></div>
Then use jQuery to determine the position CSS to set and turn on visibility
$(document).ready(function() {
// get jQuery object for the div
var $randomp = $('#randomp');
// determine whether to show top or bottom, left or right
var top = Math.round(Math.random()); // generate 0 or 1 value
if (top === 1) {
$randomp.css('top', '3px');
} else {
$randomp.css('bottom', '3px');
}
var left = Math.round(Math.random());
if (left === 1) {
$randomp.css('left', '3px');
} else {
$randomp.css('right', '3px');
}
// show the div
$randomp.show();
});
Of course, you could also use server-side code to do this, but since you asked specifically about javascript/jquery in your tags, I suggested this solution.

I think i got exactly what you need.
EXAMPLE
With javascript i am generating random numbers for the top and left positioning of your image every time you visit the page.
Right now i set them up to get a random number between 0 and 100 but you can change that to whatever you want.
var random1 = Math.ceil(Math.random() * 100);
var random2 = Math.ceil(Math.random() * 100);
$(document).ready(function () {
$('#randomp').css('top', random1);
$('#randomp').css('left', random2);
});

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;

How to drag a DIV so its width and height are negative values?

I'm a bit stumped here. I am developing a feedback utility that will allow the user to "draw" boxes on a web page to highlight problem areas. Right now I have an overlay DIV that fills the screen and jQuery allows you to draw red outlined DIVs by clicking and dragging.
Here is the JS:
{
var $feedbackOverlay = jQuery('#feedbackOverlay');
var $original = { top: 0, left:0 };
$feedbackOverlay.bind('mousedown', function (e)
{
jQuery('<div id="currentHighlight"></div>')
.css('width', '1px')
.css('height', '1px')
.css('border', 'solid 3px #ff0000')
.css('border-radius', '5px')
.css('position', 'absolute')
.css('left', e.pageX)
.css('top', e.pageY)
.css('z-index', '8000001')
.appendTo('body');
$original = { top: e.pageY, left: e.pageX };
});
$feedbackOverlay.bind('mousemove', function (e)
{
var $currentHighlight = jQuery('#currentHighlight');
if ($currentHighlight.length > 0)
{
var $pos = { top: e.pageY, left: e.pageX };
if($pos.top < $original.top) $currentHighlight.css('top', $pos.top);
if ($pos.left < $original.left) $currentHighlight.css('left', $pos.left);
$currentHighlight.height(Math.abs($pos.top - $original.top));
$currentHighlight.width(Math.abs($pos.left - $original.left));
}
});
$feedbackOverlay.bind('mouseup', function (e)
{
var $currentHighlight = jQuery('#currentHighlight');
$currentHighlight.removeAttr('id');
});
var $feedbackInstructions = jQuery('#feedbackInstructions');
$feedbackInstructions.fadeIn(1000, function ()
{
setTimeout(function ()
{
$feedbackInstructions.fadeOut(1000);
}, 3000);
});
$feedbackOverlay.height(jQuery(document).height());
});
Here is a jsFiddle for the above:
http://jsfiddle.net/Chevex/RSYTq/
The problem is that I can't drag the boxes up or left. The first click puts the top left corner where the mouse clicked. After that subsequent dragging will change the width of the box. Letting go of the mouse completes the box and you may then start drawing another one. If you try to drag the DIV left or up while drawing it's width will remain at 0 but won't go negative.

Here you can find working solution: http://jsfiddle.net/RSYTq/34/

Something like this will get you closer to what you want: http://jsfiddle.net/RSYTq/18/
Doesn't quite handle move up and to the left and then switching to moving down and to the right quite right yet but it gives you the idea.

There's no such thing a a negative width - these are not coorindinates. You need to reposition and recalculate the corner positions relative to the corner that's not being moved.

Sounds like you need to check if the click origin (x,y) is > than the current mouse position, and then swap which one you use for the CSS top-left.

You would need to track the original start point somewhere (variables, data attributes on #currentHighlight, wherever you want), and check for width or height < 0. When so, set the #currentHighlight left/top CSS to be offset by original + (e.pageX - $currentHighlight.position().left) (for example). Then set the #currentHighlight width/height to the same difference (but positive: (e.pageX - $currentHighlight.position().left) * -1).