rollover images - javascript

Hi I am trying out simple rollover images for a site I am currently working on. When I test the effect in firefox, the mouseover effect moves other elements on the webpage. any suggestions on how to fix this?
<head>
<script type="text/javascript">
if (document.images) {
img1 = new Image();
img1.src = "training2.png";
} </script></head>
<body>
<script type="text/javascript">
function rollover(name, filename)
{
var fullpath = '' + filename;
document.images[name].src = fullpath; }
</script>
<div id="trainingbutton"><a href="#" onmouseover="rollover('button1','training2.png');" onmouseout="rollover('button1','training.png')">
<img src="training.png" name="button1" border="0" alt="training" /></a></div></body>

As the previous person answered; sprites are the way to go. It takes care of having to preload the "hover" image; and it's pure CSS.
Example (an image link rollover):
HTML:
Join Newsletter
Put both your non-hover and hover state images on a single canvas. If each "image" is 20px tall, the two stacked would be 40px. So to make the bottom image show, you simply shift the background up 20px (hence -20px on the hover state below)
CSS:
.mysprite {
display: block;
width: 100px;
height: 20px;
background: url('mysprite.png') no-repeat;
background-position: 0 0; /* technically not neccesary, but illustrates the example */
text-indent: -9999px; /* eliminates the link text so only the background image shows */
font: 0px; /* eliminates IE displaying the text despite text-indent */
}
.mysprite:hover {
background-position: 0 -20px;
}
Essentially, your creating a "mask" from which you shift the background image underneath to reveal what you want it to.

I would not use javascript for roll over images, simply create a sprite containing both the normal state and the hover state, and then by using the hover attribute of css you can shift the background position.
Something like this:
<a class="rollover">Link</a>
And then the style:
a.rollover
{
background-image:url('/images/background.png');
background-position:top left;
}
a.rollover:hover
{
background-position:bottom left;
}
This method also does not suffer from having to download the image when you rollover as it is downloaded as part of the initial request

Related

need help removing an IMG and replacing it with text in its position with javascript

Im working on a project and a part of it is making an image disapear on hover, and replace that with text in the same location! I have to do it through javascript.
im very new to front end web development so any help would be great!
.main-img1{
height: 400px;
width: 600px;
margin-top: 80px;
background-size: 600px 400px;
box-shadow: 10px 10px 5px rgb(24, 22, 22);
position: relative;
text-align: center;
font-size: 25px;
color: black;
border-radius: 50px;
}
.img1-text{
display: none;
position: absolute;
bottom: 8px;
left: 150px;
<section class="main-body">
<div>
<img class="main-img1" src="img/automotive.jpg">
<h1 class="img1-text" id="img1text"> Here are some samples of my automotive photography! I specialize in "Rolling Shots" which are caputring a vehicle in motion, while the background and foreground show the motion.</h1>
</div>
You can replace any element using the "magical" outerHTML like this...
First, I gave your image an ID to make javascript operations easier...
<img id="I" class="main-img1" src="img/automotive.jpg">
Now replace the image with a paragraph of text...
I.outerHTML='<p>Well what do you know!</p>';
For easy one-line HTML...
<img onmouseover="this.outerHTML='<p>Well what do you know!</p>';" class="main-img1" src="img/automotive.jpg">
First off, this is a very odd thing to do in Javascript. Usually hover states, appearing and disappearing, etc. are handled by CSS.
to do it in js you have to add a mouseover event listener to the image to execute a function to grab the element you want to disappear, add a css class to apply "display: none" to it, grab the element you want to appear and remove a class that adds "display: none" from it.
assuming you have a 'display-none' class on your text element that applies 'display: none' to it, you can do this:
const image = document.querySelector('.main-image1')
const text = document.querySelector('.img1-text')
image.addEventListener('mouseover', () => {
image.classList.add('display-none')
text.classList.remove('display-none')
}
if you were to do this with css its as simple as
.image {
z-index: 2;
}
.image:hover {
display: none;
}
.text {
z-index: 1;
}
that way the text is set behind the image and when you hover over the image it disappears. This also has the benefit of when you take your cursor off the image for the image to reappear where js will need to be told explicitly to do that.

How do I use CSS to alter the colour of my logo when I scroll onto a different background colour

I currently have a white SVG logo that I am using as my website is mostly dark backgrounds. However, I do have a section that is white so I am looking to change the colour of the logo to black while scrolling through the white section.
Here is a copy of the logo code and white section:
<!-- Logo -->
<div class="logo" style="display: block;">
</div>
<!-- About -->
<div class="scrollview about">
<div class="col-sm-3">
</div>
</div>
Here is my current styles:
.logo {
position: fixed;
top: 0;
left: 0;
margin: 20px;
padding: 2.8em 2.8em;
z-index: 9;
}
.logo a {
width: 95px;
height: 16px;
display: block !important;
background-image: url('../img/logo-light.png') transparent 0 0 no-repeat;
background-image: none,url('../img/logo-light.svg');
}
.about {
padding: 12.25em 10.25em;
margin: 0;
overflow: hidden;
background: #fff;
width: 100%;
height: auto;
z-index: 3;
}
I'm not sure if it can be done using only CSS, but if someone can even point me towards a plugin or script it would be much appreciated.
Thanks
You can't use CSS like that to change the style of an SVG that's in a separate file. CSS rules do not cross document boundaries.
To style the SVG, you would need to need to inline it in your HTML page.
Assuming you made that change, then you could add a scroll event handler to the page and watch the position of the logo. If you detect it is at the right point on the page (ie. it is over the white section), then you could add a class to it (or the <a> or the <div>). The class would change the colour of the logo using fill: black, or whatever.
Have you considered an easier solution? Such as giving the logo a dark outline, so that it stands out when over the white background?
The fill property in CSS is for filling in the color of a SVGs.
svg {
fill: currentColor;
}
But you can't change the color of your logo for specific section of your site.
i check your demo link and I found out that they are use jquery to add and remove css class from there logo.
So you need add jquery 2.3.+
get the value of the bottom of the #main element by adding the offset of that element plus its height, set it as a variable
var mainbottom = $('#main').offset().top + $('#main').height();
Now on scroll add function
$(window).on('scroll',function()
and in it just add
stop = Math.round($(window).scrollTop());
if (stop > mainbottom) {
$('.logo').addClass('logo-dark');
} else {
$('.logo').removeClass('logo-dark');
}
Here's demo on codepen I made for you hope this will help you.

How to put an img element behind a transparent img element?

I have two img elements and I want the first image.png to go behind the transparent image.png. I have tried a lot of different things (z-index, transparent background color, rgba background color, positioning absolute and relative, nesting one in a div, making them both divs). Right now i've been trying to use a transparent .png image. The image .png is actually behind it, but it still shows through it. Please help.
html:
<body>
<main class="site-wrapper">
<div class="carnival"></div>
<div id="images">
<img id="divbox" src="images/divbox.png">
<img id="clown1" src="images/clown1.png">
</div>
</main>
</body>
js: (i did the styles in js b/c I was interested in learning how to do it that way):
//styles
//divbox:
document.getElementById('divbox').style.display = "inline-block";
document.getElementById('divbox').style.transform = "skew(-2deg)";
document.getElementById('divbox').style.marginTop = "21%";
document.getElementById('divbox').style.marginLeft = "47.6%";
document.getElementById('divbox').style.height = "200px";
document.getElementById('divbox').style.width = "200px";
document.getElementById('divbox').style.border = "1px solid orange";
document.getElementById('divbox').style.position = "absolute";
document.getElementById('divbox').style.zIndex = "2";
//clown1:
document.getElementById('clown1').style.display = "inline-block";
document.getElementById('clown1').style.transform = "rotate(90deg)";
document.getElementById('clown1').style.marginTop = "21%";
document.getElementById('clown1').style.marginLeft = "53%";
document.getElementById('clown1').style.border = "1px solid green";
document.getElementById('clown1').style.position = "relative";
document.getElementById('clown1').style.zIndex = "1";
Thanks for any help, please let me know if I can answer questions.
UPDATE:
Sorry for not being clearer. I have now achieved getting the image behind the other image, but since the image ontop is transparent, the image behind is showing. How do I stop this?
Here is an example of what is happening:
http://oi61.tinypic.com/2mw9egx.jpg
Notice the orange border is ontop so it is definitely ontop.
UPDATE 2:
This should make it really clear what I want. Again sorry for the confusion:
http://oi59.tinypic.com/eamb0n.jpg
I would do something like the following jsFiddle: http://jsfiddle.net/7gdx48fu/. Might need to reload a couple times to see a good example of the overlay working.
Create a wrapper DIV for your two images. Set that wrapper DIV's to position: relative so we can use absolute positioning on one of the images it contains. By doing this we prevent the absolute positioned image from potentially aligning itself elsewhere in the page, like the upper left corner of the browser window.
Then, set the position of our overlay image, the transparent PNG, to position: absolute along with top: 0 and left: 0 to align it with the first images upper left corner.
You can do this without using z-index if you watch the order you include your images. Place the image you want behind the transparent PNG in the markup first followed by the transparent PNG.
<div class="img-container">
<img src="http://lorempixel.com/200/200/city/">
<img class="overlay" src="http://lorempixel.com/200/200/city">
</div>
.img-container {
position: relative;
}
.overlay {
position: absolute;
top: 0;
left: 0;
opacity: 0.25; /* using this to replicate the transparent PNG */
}
EDIT
The OP's requirements have changed to include how to prevent an image behind a transparent image from showing through the transparent image.
Here is an updated jsFiddle: http://jsfiddle.net/7gdx48fu/2/.
This approach I wrapped the transparent PNG in a wrapper DIV and set it's background color. I used white in my example but you may use any color.
<div class="img-container">
<img src="http://lorempixel.com/200/200/city/">
<div class="overlay">
<img src="http://lorempixel.com/200/200/city">
</div>
</div>
.img-container {
position: relative;
}
.overlay {
position: absolute;
top: 0;
left: 0;
background-color: white;
top: 15px; /* shifting overlay for illustrative purposes - not use case code */
left: 15px; /* shifting overlay for illustrative purposes - not use case code */
}
.overlay img {
opacity: 0.25; /* using this to replicate the transparent PNG */
}
Not perfect but I'm unsure of how else to proceed.
EDIT 2
It seems the OP wants to do a form of masking. You can do this with overflow: hidden.
I have updated the jsFiddle: http://jsfiddle.net/7gdx48fu/4/
In this updated answer I have kept the wrapper DIV and set it with a fixed width and height. Then applied overflow: hidden. What we are doing here is creating an invisible window that will only show content when it is within the dimensions of the window.
To have the image appear as if it is coming out of the base layer image simply adjust the position of the image inside the wrapper DIV. For the jsFiddle simply play with the value of top in .mask img.
This will need a little tweaking for the proper placement and size of the .mask DIV to fit your needs but hopefully points you in the right direction.
<div class="img-container">
<img src="http://lorempixel.com/200/200/city/">
<div class="mask">
<img src="http://lorempixel.com/200/50/city">
</div>
</div>
.img-container {
position: relative;
}
.mask {
position: absolute;
top: 25px;
left: 25px;
height: 100px;
width: 100px;
overflow: hidden;
border: 1px solid red; /* for illustrative purposes */
}
.mask img {
position: relative;
top: 25px;
}
Have you tried the css opacity property ?
#clown1{ opacity:0.3;}
make both images' position absolute instead of relative
for the above to work, some common ancestor (i.e. #images) must have a non-default position too (e.g. relative)
forget zIndex - all else being equal, the latter element will be "topmost"
put all the above in a CSS style sheet instead of in JS code!
Forgetting the other transformations and margins, etc, the core CSS that you need is:
#images {
position: relative;
}
#divbox, #clown1 {
position: absolute;
}
Put them both in a parent container. Make the parent have position: relative and put both images having position:absolute. That way they will stack.(Something like that that I didn't check The order of img's could be wrong - play around a bit.
CSS:
.parent > img.transparent {
position: absolute;
}
.parent > img {
position: absolute; opacity: 0.5
}
HTML:
<div class="parent" style="position:relative">
<img src="other.png" class="transparent"/>
<img src="transparent.gif"/>
</div>
Some more explanation: When you make a parent/ancestor element's position relative it means that its contents that are absolute will be relative to the parent and not to the whole window

overlaying an image with a button on html page

so I have an image which i would like to overlay with an html button attribute like so:
here is a blank image
i would like to overlay a button like so on the image
and then if the button is clicked have it then look like this
from what i can gather this could be done using CSS using {index-z} somehow, or possible with html5 canvas tag. and then to handle the actually button click with java script.
However i am not completely sure how to accomplish this (the handling of button click with javascript i do know). Could someone link to a tutorial on how to do this or give an explanation it would be greatly appreciated.
Note: the image itself is also an href / link if this changes how this should be done, additionally te image itself will be in a sort of gallery with around 50 similar images or so
You can use positioning to place the "star" button on top of the other image. Your image and button will need to be in a container with the position set to relative. Then you can set your "star" to be absolutely positioned, and that position will be relative to the container:
.image-container {
display: inline-block;
position: relative;
}
.star-button {
position: absolute;
right: 10px;
top: 10px;
}
<div class="image-container">
<img src="main image here">
<img class="star-button" src="star image here">
</div>
Then you can handle the click of the image (or button, or a, or what have you) in your javascript.
JSFiddle
Maybe this example will help you my friend:
Source: ye5
HTML :
<div id="header1" width="259px">
<img src='http://2aek.com/inventory/MyBlogspot/ye5-templete/ye5Header3b.jpg' style='margin-left:259px; margin-top:-128px;'/>
CSS :
#header1 a {
background-image: url(http://2aek.com/inventory/MyBlogspot/ye5-templete/ye5Header3a1.jpg);
height:128px;
width:259px;
display: block;
}
#header1 a:link {
background-image: url(http://2aek.com/inventory/MyBlogspot/ye5-templete/ye5Header3a1.jpg);
height:128px;
width:259px;
display: block;
}
#header1 a:hover {
background-image: url(http://2aek.com/inventory/MyBlogspot/ye5-templete/ye5Header3a2.jpg);
height:128px;
width:259px;
display: block;
}
#header1 a:active {
background-image: url(http://2aek.com/inventory/MyBlogspot/ye5 templete/ye5Header3a3.jpg);
height:128px;
width:259px;
display: block;
}

grow/shrink image gallery with jquery WITHOUT affecting the layout

I got an image gallery organized as an <ul>. all images are in <li> elements and when I move my mouse over one of those pictures, it should grow to give the user a visual feedback. thing is, when I just change the size of the image using animate(), the other pictures will be pushed to the side as the resized image uses more space.
therefore I went with cloning the image element, float it right over the original image and then calling animate. this comes with the problem that onMouseOut() is called as soon as the cloned images pops up. so I need a nested hover() function and this is where things got complicated.
I got two errors and I can't find out whats causing them. the first one is, that animate() won't let the cloned image grow beyond the right border of its original, the second is, that I get weird grow/shrink behavior, when moving my mouse quickly over the gallery.
html:
<ul id="gallery1" class="gallery_container">
<li class="frame">
<img src="pic1.jpg" class="picture" /></li><li class="frame">
<img src="pic2.jpg" class="picture" /></li><li class="frame">
<img src="pic3.jpg" class="picture" /></li>
</ul>
css:
.picture
{
height: 200px;
border: 0px;
margin: 0px;
padding: 0px;
}
.frame
{
display: inline-block;
position: relative;
margin: 0px;
margin-right:8px;
padding: 0px;
}
.frame a
{
padding: 0px;
margin: 0px;
}
.gallery_container
{
height: 200px;
width: 150%;
position: relative;
top: 4px;
padding: 0px;
margin: 0px;
}
and finally the code that is giving me those headaches:
$(document).ready(function()
{
var zooming = false;
var zoom = 4;
var speed_zoom = 100;
$('.gallery_container li a').hover(function(element)
{
// disable zooming to prevent unwanted behavior
if(zooming) return;
zooming = true;
$(this).after( $(this).clone(false) );
$(this).next().attr('id', 'focus_frame');
},
function(element) // when the new element pops up, onmouseout is triggered, since the focus_frame is in front of the image
{
$(this).next().hover(function(element)
{
// we need to re-position the element in the dom-tree, since it needs to grow out of a container with overflow: hidden
$('#focus_frame img').animate({'left' : zoom * -1, 'top' : zoom * -1, 'height' : 200+(zoom*2), 'width' : $('#focus_frame img').outerWidth() + (zoom*2)}, speed_zoom);
},
function(element)
{
$(this).remove();
zooming = false;
});
});
});
var $doc=$(document.body)
$doc.on({
"mouseenter" : function (e) {
$doc.find("> .gallery_clone").remove();
var $i=$(this).parent();
$i.pos = $i.offset();
$i.clone()
.addClass("gallery_clone "+$i.parent().parent().attr("class"))
.css({
top:(Math.round($i.pos.top)-3)+"px"
,left:(Math.round($i.pos.left)-3)+"px"
,width:$i.width()
}).appendTo($doc);
}
},
" ul > li > img"
).on ({
"mouseleave" : function (e) {
$(this).remove();
},"> .gallery_clone");
in css .gallery_clone is position:absolute
then i animate .gallery_clone:hover through css but you can do it in the jquery as well i guess, adding a mouseenter event on .gallery_clone
edit : i've literally copy/pasted from my script so you'll have to adapt this code to your html
nb: give css anim a go, it's worth it even if older ie will not animate; (i also made lightbox effect almost pure css for that same gallery - will publish later, not ready for plugin release just now sorry)
nb2: that part "+$i.parent().parent().attr("class") is because in the cms they can chose gallery background color so adding that class forward the background color & other gallery style to the clone (ie you should not need it)

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