views:

3752

answers:

6

Lets say I have a text box that I want to fill a whole line. I would give it a style like this:

input.wide {display:block; width: 100%}

This causes problems because the width is based on the content of the text box. Text boxes have margin, borders, & padding by default, which makes a 100% width text box larger than its container.

Is there any way to make a text box fill the width of its container without expanding beyond it?

Here is some example HTML to show what I mean:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>Untitled Page</title>
    <style type="text/css">
        #outer{border: 1px solid #000; width: 320px; margin: 0px;padding:0px}
        #inner{margin: 20px; padding: 20px; background: #999;border: 1px solid #000;}
        input.wide {display:block; margin: 0px}
        input.normal {display:block; float: right}
    </style>
</head>
<body>
    <div id="outer">
        <div id="inner">
            <input type="text" class="wide" />
            <input type="text" class="normal" />
            <div style="clear:both;"></div>
        </div>
    </div>
</body>
</html>

If this is run, you can see by looking at the "normal" text box that the "wide" text box is sticking out beyond the container. The "normal" text box floats to the actual edge of the container. I'm trying to make the "wide" text box fill its container, without expanding beyond edge like the "normal" text box is.

A: 

Quick poking around didn't result in anything productive.

I'm assuming you cannot set absolute width, right? With that in mind, if all else fails, you can use Javascript to grab inner element's offsetWidth and set wide's width to that minus any borders, paddings and margins.

MK_Dev
A: 

Actually, it's because CSS defines 100% relative to the entire width of the container, including its margins, borders, and padding; that means that the space avail. to its contents is some amount smaller than 100%, unless the container has no margins, borders, or padding.

This is counter-intuitive and widely regarded by many to be a mistake that we are now stuck with. It effectively means that % dimensions are no good for anything other than a top level container, and even then, only if it has no margins, borders or padding.

Note that the text field's margins, borders, and padding are included in the CSS size specified for it - it's the container's which throw things off.

I have tolerably worked around it by using 98%, but that is a less than perfect solution, since the input fields tend to fall further short as the container gets larger.


EDIT: I came across this similar question - I've never tried the answer given, and I don't know for sure if it applies to your problem, but it seems like it will.

Software Monkey
+11  A: 

Is there any way to make a text box fill the width of its container without expanding beyond it?

Yes: by using the CSS3 property ‘box-sizing: border-box’, you can redefine what ‘width’ means to include the external padding and border.

Unfortunately because it's CSS3, support isn't very mature, and as the spec process isn't finished yet, it has different temporary names in browsers in the meantime. So:

input.wide {
    width: 100%;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
}

The old-school alternative is simply to put a quantity of ‘padding-right’ on the enclosing <div> or <td> element equal to about how much extra left-and-right padding/border in ‘px’ you think browsers will give the input. (Typically 6px for IE<8.)

bobince
This would work great, except can't use this because I'm targeting mobile devices which probably won't support this for years. :-\
Dan Herbert
I think mobile devices will have full HTML5 support before computers.
Kindred
@Kindred: definitely not if you include IEMobile and Blackberry in that.
bobince
+8  A: 

What you could do is to remove the default "exta's" on the input:

input.wide {display:block; width:100%;padding:0;border-width:0}

This will keep the input inside it's container. Now If you do want the borders, wrap the input in a div, with the borders set on the div (that way you can remove the display:block from the input too). Something like:

<div style="border:1px solid gray;">
 <input type="text" class="wide" />
</div>

Edit: An other option is to, instead of removing the style from the input to compensate for it in the wrapped div:

input.wide {width:100%;}

<div style="padding-right:4px;padding-left:1px;margin-right:2px">
  <input type="text" class="wide" />
</div>

This will give you somewhat different results in different browsers, but they will not overlap the container. The values in the div depend on how large the border is on the input and how much space you want between the input and the border.

Hilbrand
This is a very creative solution. The only issue I have with it is that I can't define an outline on the text box when it gains focus unless I use JavaScript to change the border of the wrapper div.
Dan Herbert
+1  A: 

Just came across this problem myself, and the only solution I could find that worked in all my test browsers (IE6, IE7, Firefox) was the following:

  1. Wrap the input field in two separate DIVs
  2. Set the outer DIV to width 100%, this prevents our container from overflowing the document
  3. Put padding in the inner DIV of the exact amount to compensate for the horizontal overflow of the input.
  4. Set custom padding on the input so it overflows by the same amount as I allowed for in the inner DIV

The code:

<div style="width: 100%">
    <div style="padding-right: 6px;">
        <input type="text" style="width: 100%; padding: 2px; margin: 0;
                                  border : solid 1px #999" />
    </div>
</div>

Here, the total horizontal overflow for the input element is 6px - 2x(padding + border) - so we set a padding-right for the inner DIV of 6px.

Tobias Cohen
A: 

Just remove doctype declaration!

johan yong
I really hope you were being sarcastic. If you want to use a different box model, bobince's solution is the best option.
Dan Herbert