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721

answers:

7

If I have two layers on a page, split horrizontally, with the second layer overlapping part of the first layer, is it possible to make it "click through"?

I have links in the first layer, which the second layer overlaps, which stops the links from being clickable. Is there a way to make the layer display, but be click through, while still having it's own links clickable?

edit:

Here is an example, with html and a stylesheet.

The test links become unclickable when inline with the header in Layer3, but below that they are fine. Is there a way to rectify this?

<title>Test</title>
<link rel="stylesheet" href="test.css" type="text/css">
<body>
<div id="Layer0">
<div id="Layer1" class="Layer1">
<h3 align="left">Brands</h3>
</div>
<div id="Layer2" class="Layer2"><h1>TEST</h1>
<div id="rightlayer">
<a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p>
</div>
</div>
<div id="Layer3" class="Layer3"><h1>Ed Hardy Auctions</h1>
</div>
</div>
</body>
</html>

And the css

#Layer0 {
    width:100%;
    height:100%;
}
body {
    margin:10px 10px 0px 10px;
    padding:0px;
    color:#999999;
    font-family:"Trebuchet MS",arial,sans-serif;
    font-size:70.5%;
}
#Layer1 {
    position:absolute;
    left:10px;
    width:200px;
    margin-top:17px;
    font-size:1.0em;
    padding-left:12px;
    padding-top:8px;
}
#Layer2 {
    background:#fff;
    margin-left:199px;
    color:#000;
}

#rightlayer {
float:right;
}
.Layer3 {
position:absolute;
top:67%;
padding:20px;
width: 100%;
}
A: 

It is hard to tell without seeing some code.

You could try setting z-index on the bottom layer but that works on elements that have been positioned with absolute, relative or fixed (position:absolute).


edit after seeing code:

Add position:relative; z-index:100; to #rightLayer.

Or you could remove the width:100% from .Layer3.


You may want to refactor your code and go with a two column layout for #rightLayer and .Layer3.

css

#Layer0 {
    width:100%;
    height:100%;
}
body {
    margin:10px 10px 0px 10px;
    padding:0px;
    color:#999999;
    font-family:"Trebuchet MS",arial,sans-serif;
    font-size:70.5%;
}
#Layer1 {
    width:200px;
    margin-top:17px;
    font-size:1.0em;
    padding-left:12px;
    padding-top:8px;
}
#Layer2 {
    background:#fff;
    margin-left:199px;
    color:#000;
}

#rightlayer {
float:right;
}
.Layer3 {
}

html

<div id="Layer0">
    <div id="Layer2" class="Layer2">
     <h1>TEST</h1>
    </div>
    <div id="Layer1" class="Layer1">
     <h3 align="left">Brands</h3>
    </div>
    <div class="content">
     <div id="rightlayer">
      <a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p><a href="test">TEST></a><p>
     </div>
     <div id="Layer3" class="Layer3">
      <h1>Ed Hardy Auctions</h1>
     </div>
    </div>
</div>
Emily
I can't remove the width, as in the actual page the links are more in the middle of the page. I will try as you suggest..thanks
Joshxtothe4
Ahh, changing to position:relative moves layer3 too far down the page. Is there a way to prevent that?
Joshxtothe4
+5  A: 

It is not possible if you want the divs to stay in their current x,y, (and most importantly) z - only the "top" layer is clickable.


Addendum post OP edit:

Think of CSS layout as if you were physically working with bits of paper (this is much easier to visualise if you give all your "layer" divs a different background colour). The rendering engine cuts out a bit of paper in the dimensions you give it (or it works out) for each element it finds. It does this in the order it encounters them putting each bit of paper on the page as it goes - the last item is going to be on top.

Now you've told the rendering engine to put your 3rd div in a position where it overlaps the 2nd. And now you expect to be able to "see" the covered content. Wouldn't work with paper, won't work with HTML. Just because it's transparent doesn't mean it's not taking up space.

So you have to change something.

Looking at your CSS and markup (which honestly could be cleaned up, but I'll assume there's other mark-up you're not showing us which justifies it) there's a couple of easy win ways:

1). Set a z-index of -1 on Layer3 - z-index is how you can change the layering order from the default (as encountered). This just moves the entirety of Layer3 below the rest of the page so what was hidden becomes exposed, but also vice versa depending on content.

2). Change the width from 100% to e.g. 80%, or more likely given your use of pos:abs set left:0px and right:199px; (I'm guessing that padding-left on Layer2 is an intended column width?). The cost of this is that your Layer3 is no longer 100% width

3). Google "CSS column layout" and find a pattern that reflects what you need and adapt that. Every CSS layout which can be done has been done a million times already. Standard techniques exist which solve your problems. CSS is hard if you haven't built up the experience, so leverage the experience of others. Don't reinvent wheels.

annakata
+2  A: 

It would be a mammoth job, but it is possible.
You would need to capture the click event on the top layer/div, and find the cursor x-y position.
Then find all links in the layer/div underneath the top layer, and see if it's position on the screen falls around the current mouse position.
You could then trigger the click of the matched link.
I would use jQuery (if you are not already) for this and then re-post with a jQuery tag if you run into troubles.

danrichardson
Not so mammoth, I think. Would you use jQuery's offset(), width(), and height()?
Nosredna
No, its not a big job at all, and this is the correct and only approach.
Owen
A: 

I'm assuming from the example that the links in the rightlayer are the only links that need to be clicked, and that you don't have links in the other layers. If so, you could solve the problem by changing the z-index order of the divs.

Layer1 and Layer3 have position absolute, so if you add a position style (absolute or relative) to Layer2, you will be able to pull that div to the front, also pulling the rightlayer div to be in a higher layer than Layer3.

I added the following to the CSS:

#Layer2 {    
    position: relative;
    z-index: 1;
}

From what I can see that leaves the current page setup just the way it is, but pulls all the elements (including the rightlayer with the links) to the front, so you'd be able to click all the links in it.

For debugging purposes I suggest adding background colors to all the different layers to get an idea of the z-index order of the different layers. With the background color in place it was quite easy to spot the layer that was falling over the links, but also to verify that the new z-index order makes the links available.

Hope this helps!

ylebre
A: 

I submitted a bug years ago to the Firefox Bugzilla saying that there was this very bug in Firefox.

I was told by a Mozilla engineer that this was not actually a bug and that it is the correct behaviour as per the HTML/CSS specifications. Unfortunately I can't find the original bug to reference as it was about 6 years ago.

The reason I submitted the bug was because I could click through the top div onto the links below when using IE (6 I think) but Firefox would not let me.

As usual, it turned out hat IE had the incorrect implementation and Firefox was working as intended by the spec.

Just because a div is transparent does not mean you should be able to click through it.

I'm not sure how you could get around this with JavaScript or CSS. I would take a step back and have a re-think about what you're trying to achieve and how you're trying to achieve it.

Greg

Greg B
A: 

Can you not simply set the width of the div to auto (the default for absolute positioning - i.e. just delete the width:100% from .Layer3).

That way the div will only be as wide as is necessary, rather than unnecessarily overlapping the links.

Matt
A: 

There would be a lot of security issues involving tricking people to click on things they didn't intend to.

Scott Michaud