I run a small webpage that allows users to click on various links using image maps. I'd like to highlight the section that a user clicks on to give some feedback to the user (they may be clicking on several different parts rapidly).
Is there a way I can invert (or otherwise highlight) a small section of an image JavaScript?
Instead of using image maps, you could try this CSS method:
Use a transparent <div> on top of each "image-map" part (link), and then use the CSS :hover pseudo-class to handle the highlighting.
CSS:
#image {
position: relative;
width: 400px;
height: 100px;
background-image: url(image_map.png);
}
#map-part {
position: absolute;
top: 10px;
left: 10px;
width: 50px;
height: 50px;
background-color: transparent;
}
#map-part:hover {
background-color: yellow; /* Yellow Highlight On Hover */
opacity: 0.2;
filter: alpha(opacity=20);
}
HTML:
<div id="image">
<a id="map-part" href="http://www.example.com/"></a>
</div>
Note that this will only work for rectangular links.
Take a look at jQuery MapHilight.
I'm not sure it does exactly what you need, but you can achieve that with minor tweaking.
How about overlaying a semi-transparent <DIV> block over the clicked area to highlight it?
There are many way,
In a d fashion way, break down your images into many smaller pieces and using table to combine them. After that, by using javascript to replace thr "src" attribute for the highlight effect.
In another CSS way, use CSS to clip the alt. image on top of the original, and control which area should be visible.
It is better to have a single image for all rather then many small images to speed up and user will get it without delay by network.
Related
When clicking on the thumbnail on the image on this site: http://www.grouprecipes.com/138587/banana-oatmeal-chocolate-chip-cookies.html, it expands and loads the original (full-size) version of the image.
I think they are using prototype or something similar. I've been looking around on here and have only mainly found examples that just increase the size of the original image and don't actually load another version of the image (like the linked example does).
Anyone care to help me figure out what techniques I should use for this? Combination of CSS3 and some .animate()?
Here is a simple example using CSS3, a bit of JavaScript.
Explanation:
Initially both the thumbnail and the enlarged version of the picture are placed on the same space using absolute positioning.
The enlarged version is not loaded until the thumbnail is clicked because the enlarged img tag doesn't have any src to begin with. It is assigned dynamically through the JS.
The image move to a different position is achieved using the translateX and translateY options which moves the absolutely positioned enlarged version of the image by the mentioned no. of pixels in both X and Y axes.
JavaScript is used to add a show class to the enlarged picture which triggers the transition effect and also set the src of the img tag to the newer/bigger image.
The enlarged version would return back to its original position when clicked anywhere on the enlarged image.
The JS code is written using class name instead of id just in case you need multiple such thumbnails on the same page. If that is the case, you may want to remove the [0], put it inside a for loop and replace the [0] with the counter variable. Also the enlarged image's source for each such thumbnail image can be maintained through a key-value pair mapping.
The z-index: -1 on the image originally (prior to adding .show through JS) is to make sure that it stays in the background and doesn't hinder the click on the thumbnail.
Points to note:
transform, translateX and translateY are all CSS3 properties/functions and hence have no support in IE8 and less. For older versions of Chrome, Firefox, Opera and Safari, browser prefixes like -webkit-, -moz would be required.
The classList.add and classList.remove functions are HTML5 standard and are not supported in IE9 but they equivalent IE9 code to add or remove class (like className += ..) can be easily done.
var images = {'img1': 'http://placehold.it/400/400'};
document.getElementsByClassName('thumbnail')[0].onclick = function(){
document.getElementById('enlarged').src = images[this.id];
document.getElementById('zoomed').classList.add('show');
}
document.getElementById('enlarged').onclick = function(event){
if(event.target != document.getElementsByClassName('thumbnail')[0])
document.getElementById('zoomed').classList.remove('show');
}
.container{
position: relative;
}
.thumbnail{
height: 200px;
width: 200px;
}
#zoomed .enlarged{
opacity: 0;
z-index: -1;
min-height: 200px;
min-width: 200px;
height: 200px;
width: 200px;
position: absolute;
transition: all 1s;
left: 0px; top: 0px;
}
#zoomed.show .enlarged{
opacity: 1;
z-index: 2;
height: auto;
width: auto;
min-height: 400px;
min-width: 400px;
transform: translateX(200px) translateY(200px);
}
<div class="container">
<img src="http://placehold.it/200/200" alt="" class="thumbnail" id='img1'/>
<div id='zoomed'>
<img src="" alt="" class="enlarged" id='enlarged'/>
</div>
</div>
Additional Resource:
Here is a good article on how to pre-load images (the enlarged versions if needed) using CSS + JS, only JS and AJAX.
I have taken and essentially lightly modified a jQuery image slider to operate how I want, specifically one called: A Beautiful Apple-style Slideshow Gallery With CSS & jQuery.
I am currently attempting to link this slideshow to a separate div below that contains image specific text, I have achieved this in a very simple manor by hyper linking each thumbnail to load the content I want for each image.
Ideally I would like this to happen by using the next and previous controls for the slideshow but have tried multiple solutions without success. My current attempt loads the text for image 1 and image 2 but gets stuck from there onwards.
The html, css and JavaScript for my attempt can be found at http://jsfiddle.net/v9vf9/ (The result does not appear correctly as all my files are for the moment stored locally)
I am sure that what I am trying to achieve is not very complicated but seems to be beyond my ability, I appreciate any advice, help or solutions to succeed with this!! And look forwards to improving my knowledge.
Thank you in advance, Carl
So, as suggested in the comments
http://jsfiddle.net/lollero/Sw4y8/
It's a bit easier to put the text inside the animated slides so that they are animated with the images automatically and most importantly give #slides element a bigger height where the text can fit in.
HTML:
<div class="slide">
<img src="http://placekitten.com/g/500/230" alt="" />
<div class="text">Text</div>
</div>
</div>
<div id="thumbnails">Thumbnails</div>
CSS:
#slides {
height: 550px; /* or what ever amount is big enough to fit the text there too */
float: left;
position: relative;
z-index: 5;
}
#thumbnails {
float: left;
clear: both;
position: relative;
z-index: 10;
top: -110px;
}
.text { margin-top: 50px; /* for example if you want to give thumbnails room to sit above the text */ }
Is there a Javascript tutorial or code to make a subtle image hover or move in the background, like the effect on http://www.saratusar.com/?
If you wrap the img or div in an anchor tag, you can apply an effect using pure CSS. (This appears to be the technique used by the site you're referencing.)
HTML:
<a id="thing" href="javascript:void(0);"><div></div></a>
CSS:
#thing div { background: url(image.jpg); width: 100px; height: 100px; min-height: 100px; }
#thing:hover div { background: url(image2.jpg); }
If you're talking about these buttons on top, check out CSS (Cascading Style Sheet). More effects using JS and CSS you can get by using JavaScript JQuery Library.
Good luck!
I'm trying to get various locations to appear on a image with mouseovers. So basically I have an image and when you hover over a link nearby a hoverbox appears at the location specified in CSS on the image. However I'm trying to get it to happen with multiple links without creating code for each CSS box.
I have something like 50 links and and when I hover over one I want to be able to pull from a db or text file to grab the location where it should create a hover on the image. My original thought was using PHP to help pull in the information from a file, put it into an array and then having the CSS update on the fly. This seems doable if the user just clicks the link as then I can tell CSS what place in the array to look for the location. I am unsure how I could get this to work with mouseovers if at all possible.
The CSS code is very basic at the moment as shown below.
#box {
position: absolute;
top: 100px;
left: 200px;
background-color: #ffffff;}
Let me know if anything doesn't make sense or if I'm just forgetting something.
Thank you!
Ok, so what you're trying to do is called a CSS sprite. Here's what you want (my example is orthogonal to your code, but teaches the principle):
.link {
width: 50px;
heigh: 50px;
float: left;
text-indent: -9000px;
background-color: transparent;
background-image: url(path/to/sprite.png);
background-repeat: no-repeat;
}
.link#one {
background-position: 0px 0px; /* This one is top left on the image. */
}
.link#two {
background-position: 0px 50px; /* This one is 50px from top and 0px from left on the image. */
}
You can see where to go from here (and you don't need to use .link#one. I just used it for example purposes. You could just use #one, or even a class .one.
Practice with this and you'll get how it works soon enough. Here's some sample HTML:
<a id="one" class="link">One</a>
<a id="two" class="link">Two</a>
Just through all that together, and make your image a 100px tall by 50px wide .png file with 50px x 50px for each link.
I'm relatively new to Web development and wouldn't even know where to start in coding a JavaScript that fades a grayscale thumbnail image into a color thumbnail image on mouseover, and vice versa on mouseoff (<--or whatever this is called).
I've looked all over and can't find a script that does this. Is this possible? Could I use jQuery to do this? Other thoughts?
I think all you could do is load two thumbnails into a container at once, with the black and white laying over top of the colour. Then, you could use jquery to fade the opacity of the to thumbnail to 0.0. Here is a working example (it just uses a click to change it once, but I'll leave the mouseover / mouseout to you - you may want to speed up the animation):
some html:
<div class="container">
<img src="blackandwhite.jpg" class="bw" />
<img src="colour.jpg" class="colour" />
</div>
some css:
.container { position: relative; }
.container img { position: absolute; }
.bw { z-index: 101; }
.colour { z-index: 100; }
some jquery:
$(function() {
$(".bw").click(function() {
$(this).animate({ opacity: 0.0 }, 800);
});
});
The best way to do this would be to actually have two versions of the image. One that's grayscale and one that's color. To keep it strictly within javascript and html, I don't believe there's any other way than with the two image method. Flash, Silverlight, and maybe even HTML 5, can do it easily.
Do you really want to fade, or just to swap?
Typically the swap is done via CSS
<a class="btn"></a>
and the CSS
a.btn {
background: url(../images/button-image.png) no-repeat 0 0;
width: 110px;
height: 16px;
margin: 10px 0 0;
}
a.btn:hover {
background-position: 0 -16px;
}
In this case there's a little performance improvement going on where button-image contains both images vertically stacked, and the css is sliding the background image around, but it's the same idea. It's a performance enhancement because the browser only needs to download 1 image, not 2.