Expand / shrink div on hover / out with jQuery

问题:

I am looking for a jQuery plugin to expand div elements so as to reveal their overflow (if any) on hover. Illustration:

The plugin should work on relatively positioned div's (which I guess implies that you create a copy of the div, set its positioning to absolute, then figure out where to place it).

Is there such a plugin already available out there?

回答1:

You don't need a plugin. Just add proper css and use jQuery animate:

$div
.on('mouseenter', function(){
    $(this).animate({ margin: -10, width: "+=20", height: "+=20" });
})
.on('mouseleave', function(){
    $(this).animate({ margin: 0, width: "-=20", height: "-=20" });
})​

demo here

回答2:

The images are missing here... but here is how I pulled this off a few years ago. The basic theory is that all of the images/div's whatever are absolute, inside of their own relative area. I then animate the left & top position both -negatively. This makes them protrude above the surrounding boxes and look like they are popping out. (Of course you also need to make sure the z-index of this one is higher than the ones around it).

jsFiddle DEMO

$(".img a img").hover(function() {
    $(this).closest(".img").css("z-index", 1);

    // this is where the popping out effect happens
    $(this).animate({ height: "200", width: "200", left: "-=55", top: "-=55" }, "fast");

}, function() {
    $(this).closest(".img").css("z-index", 0);
    $(this).animate({ height: "90", width: "90", left: "+=55", top: "+=55" }, "fast");
});​

The styles I have for these two things are:

.img { 
   position:relative; 
   z-index:0px;  
}

.img a img { 
   position:absolute;
   border:1px #1b346c solid; 
   background:#f1f1f1; 
   width:90px; 
   height:90px; 
}

回答3:

thanks to @MarkPieszak. For dynamically created elements use

$(document).on({
  mouseenter: function () {
    $(this).animate({ height: "200", width: "200", left: "-=55", top: "-=55" }, "fast");
  },
  mouseleave: function () {
    $(this).animate({ height: "90", width: "90", left: "+=55", top: "+=55" }, "fast");
  }    
}, '.img a img');

.hover() does work only on static elements. more here

回答4:

You can actually do this entirely with css, this is a snipet from a website of mine, im entirly too lazy to edit it, but you get the idea:

<ul class="hover">
  <li style="margin-top:40px;"">
   <a href=""><img src="images/Home/Home.jpg" alt="home" style="width:130px; height:100px;"/>
   <img src="images/Home/Home.jpg" alt="home" class="preview" style="width:180px; height:150px;"/></a>
  </li>
  <li style="margin-left:55px; margin-top:-20px;">
   <a href=""><img src="images/About/About.jpg" alt="About The Author" style="width:200px; height:200px;"/>
   <img src="images/About/About.jpg" alt="About The Author" class="preview" style="width:250px; height:250px;"/></a>
  </li>
</ul>

css:

/* begin hover */

.hover{
cursor: default;
list-style: none;
}

.hover a .preview{
display: none;
}

.hover a:hover .preview{
display: block;
position: absolute;
top: -33px;
left: -45px;
z-index: 1;
}

.hover img{
background: white;
border-color: black;
border-style: solid;
border-width: 4px;
color: inherit;
padding: 2px;
vertical-align: top;
-moz-border-radius: 15px;
border-radius: 15px;
}

.hover li{
background: black;
border-color: black;
border-style: solid;
border-width: 1px;
color: inherit;
display: block;
float: left;
margin: 3px;
padding: 5px;
position: relative;
}

.hover .preview{
border-color:black;
border-width:8px;
border-stle:solid;
}

li{
-moz-border-radius: 15px;
border-radius: 15px;
}

there are some not needed styles in there but again, you get the idea. basically youre just showing one image on top of the original, on hover

回答5:

If it is text, it is a little more complicated...

I use it like this:

$('.floating').mouseenter(function(){
  const $this = $(this);
  const dimension = $this.data('dimension');
  const ratioEnlarged = 2;

  const tempElement = $this.clone();
  tempElement.appendTo('body');
  tempElement.css({
    width: dimension.width,
    height: dimension.height
  });

  if(tempElement.is(':offscreen')){
    // Change this to animate if you want it animated.
    $this.css({
      'margin-left': -dimension.width * ratioEnlarged/2,
      'margin-top': -dimension.height * ratioEnlarged/4,
      'font-size': ratioEnlarged + 'em',
      width: dimension.width * ratioEnlarged,
      height: dimension.height * ratioEnlarged
    });
  } else {
    $this.css({
      'margin-left': -dimension.width * ratioEnlarged/4,
      'margin-top': -dimension.height * ratioEnlarged/4,
      'font-size': ratioEnlarged + 'em',
      width: dimension.width * ratioEnlarged,
      height: dimension.height * ratioEnlarged
    });
  }

  tempElement.remove();
});

$('.floating').mouseleave(function(event) {
  const $this = $(this);
  const dimension = $this.data('dimension');

  if(!$this.hasClass('context-menu-active')){
    $this.css({
      margin: 0,
      'font-size': '1em',
      width: dimension.width,
      height: dimension.height
    });
  }
});