Allow absolutely positioned element to be wider than parent absolutely positioned element

问题

Background

I have a small one-level CSS flyout menu (well, technically it's an expanding element). It is absolutely positioned at the bottom left of a parent absolutely-positioned element that is fairly narrow. See the second h1 element below:

<div id="controls">
   <h1>Controls 1</h1>
   <h1 id="size" class="poplinks button">
      Size
      <a href="#" class="button selected" title="small"><img src=""></a>
      <a href="#" class="button" title="medium"><img src=""></a>
      <a href="#" class="button" title="large"><img src=""></a>
   </h1>
</div>

This is very simply turned into an expanding menu/flyout like so:

.poplinks:hover {
   width:auto;
}
.poplinks a {
   display:none;
}
.poplinks:hover a {
   display:inline-block;
}

Problem

This results in the following button-like element:

The h1 has style width:48px;, and there is also a style rule to apply width:auto; to the h1 element upon hover, so it should be able to widen. However, upon hovering, the submenu is being forced to stay no wider than the parent element's width, when I'd like it to extend to the right (out of the parent's containing box).

What I want to see (obtained by moving the element outside the parent, but I would like it to remain inside for inheriting styling and so when I move the menu bar from the left to the top, it follows automatically):

Is this possible? Do you have any recommendations?

See this in action for yourself in a JS Fiddle.

Browsers

Note: I plan for this to work in Firefox, Chrome, and IE 8. I am doing the main styling in Firefox & Chrome and when basically done, will add conditional CSS to get IE to work right and look as close as I can.

Rationale

The reason I am positioning the parent menu absolutely is that I'm building an application-like page for displaying images. The page will be hosted within a parent Windows application and doesn't need a lot of identifying information: just to display the desired images. I chose to make the menu absolutely positioned rather than using inline-block or floats or some other method to get my menu columns into place (there are two). However, it doesn't have to be this way. If you have a suggestion for an alternate layout or strategy, I am all ears.

回答1:

First, your #controls need overflow:visible. Then, #size should be given an explicit left instead of right. And finally, .poplinks needs white-space: nowrap to prevent the wrap.

http://jsfiddle.net/VaWeK/11/

回答2:

Two ways: you can either hardcode an absolutely defined width, or you can do a relative width that is greater than 100%. Width of 100% will be 100% of the containing div (as long as that div has a defined width). If this div has an absolute width, meaning it is defined with pixels instead of percentages or ems, then you can simply make the hover css wider than the parent div. For example, if your parent div is 100px wide, the hover on the child should be 200px wide or 200% or something like that.

来源：https://stackoverflow.com/questions/17606079/allow-absolutely-positioned-element-to-be-wider-than-parent-absolutely-positione

标签

css

css-position

absolute