How can I mimic text-overflow: ellipsis in Firefox?

问题

I have some dynamic text contained in a div that is set to whatever a user enters in a textbox field. If the text doesn't fit in the div, right now it just gets cut off at the edge and all the text that extends past the border is not visible. I would like to truncate the text so that it fits inside the box and has an ellipsis (...) appended on the end. For example:

|----div width------|
 Here is some sample text that is too long.
 Here is some sam...

Obviously in the example it's easy because the code tag uses a fixed-width font so it's as simple as counting characters. I have a variable-width font so if they enter "WWWWWWWWWWW" it will fill up in much fewer characters than "................" would.

What's the best way to do this? I found a potential solution for simply finding the actual pixel width of the text here: http://www.codingforums.com/archive/index.php/t-100367.html

But even with a method like that, it's a bit awkward to implement the ellipsis. So if it's 20 characters and I find that it doesn't fit, I would have to truncate to 19, add the ellipsis, and then check if it fits again. Then truncate to 18 (plus the ellipsis) and try again. And again. And again...until it fit. Is there a better way?

EDIT: I have decided based on the answers that my original approach is best, except I have tried to improve on the solution in the link above by not creating a separate td element simply for measuring, which feels like a hack.

Here is my code:

<div id="tab" class="tab">
    <div id="tabTitle" class="tabTitle">
        <div class="line1">user-supplied text will be put here</div>
        <div class="line2">more user-supplied text will be put here</div>
    </div>
</div>

And styles:

.tab {
padding: 10px 5px 0px 10px;
margin-right: 1px;
float: left;
width: 136px;
height: 49px;
background-image: url(../images/example.gif);
background-position: left top;
background-repeat: no-repeat;
}    

.tab .tabTitle {
    height: 30px;
width: 122px;
    overflow: hidden;
    text-overflow: ellipsis;
font-size: 12px;
font-weight: bold;
color: #8B8B8B;
}

.tab .tabTitle .line1, .tab .tabTitle .line2 {
    display:inline;
    width:auto;
}

and the javascript that trims and adds the ellipsis:

function addOverflowEllipsis( containerElement, maxWidth )
{
    var contents = containerElement.innerHTML;
    var pixelWidth = containerElement.offsetWidth;
    if(pixelWidth > maxWidth)
    {
        contents = contents + "…"; // ellipsis character, not "..." but "…"
    }
    while(pixelWidth > maxWidth)
    {
        contents = contents.substring(0,(contents.length - 2)) + "…";
        containerElement.innerHTML = contents;
        pixelWidth = containerElement.offsetWidth;
    }
}

The "line1" and "line2" divs get passed to the function. It works in the case of a single word input like "WWWWWWWWWWWWWWWWW" but does not work a multi-word input "WWWWW WWWWW WWWWW" because it just adds line breaks and measures the text as being the width of "WWWWW".

Is there a way I can fix this without resorting to copying the text into a hidden measuring element? Some way to set the style of the line divs so that they don't wrap text?

回答1:

Some way to set the style of the line divs so that they don't wrap text?

There you have the white-space: nowrap for. Yes, this works in ancient browsers as well.

回答2:

This issue must be working on Firefox too.

HTML

<div class="ellipsis">Here goes too long text and when it is takes more than 200px in "end" of the text appears "..."</div>

CSS

.ellipsis{
width:200px;
text-overflow:ellipsis;
-o-text-overflow:ellipsis;
-moz-binding:url('bindings.xml#ellipsis');//issue for Firefox
}

bindings.xml

<bindings xmlns="http://www.mozilla.org/xbl" xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<binding id="none">
    <content><children/></content>
</binding>
<binding id="ellipsis">
    <content>
        <xul:label crop="end"><children/></xul:label>
    </content>
    <implementation>
        <field name="label">document.getAnonymousNodes(this)[0]</field>
        <field name="style">this.label.style</field>
        <property name="display">
            <getter>this.style.display</getter>
            <setter>if(this.style.display!= val)this.style.display=val</setter>
        </property>
        <property name="value">
            <getter>this.label.value</getter>
            <setter>if(this.label.value!=val)this.label.value=val</setter>
        </property>
        <method name="update">
            <body>
                var strings= this.textContent.split(/\s+/g)
                if(!strings[0])strings.shift()
                if(!strings[strings.length-1])strings.pop()
                this.value=strings.join('')
                this.display=strings.length?'':'none'
            </body>
        </method>
        <constructor>this.update()</constructor>
    </implementation>
    <handlers>
        <handler event="DOMSubtreeModified">this.update()</handler>
    </handlers>
</binding>
</bindings>

回答3:

If you're using jQuery, there's a great plugin I use.

Alternatively, [this example] (404 NOT FOUND!) seems to work cross browser.

Any questions, hit me up in the comments!

404 link: http://www.hedgerwow.com/360/dhtml/text_overflow/demo2.php

回答4:

The new version of CSS (CSS3) should include text-overflow:ellipsis, which does this for you. It currently works in IE versions 6 and up, as well as Safari and Chrome. It's not supported by Firefox, so this isn't really a useful answer yet, but it's worth keeping in mind that the real best way will, eventually, be to let CSS handle this.

CSS3 spec draft: http://www.w3.org/TR/2001/WD-css3-text-20010517/#text-overflow-props

Supported browsers: http://www.quirksmode.org/css/contents.html (scroll down to "text-overflow" near the bottom)

回答5:

Quite simply, no, there's no better way without resorting to hacks.

You could, for example, use a position:absolute span to position your "..." on top of the actual content, with overflow:hidden set on the container, and only hide the extra span if the content fits within the container. That'd let you run the truncation code only once.

Personally, I'd just run the pixel width calculation a few extra times. Setting the text and reading the width is a fast operation, so it shouldn't be noticeable.

回答6:

Use text-overflow:ellipsis. Its not IE-only... Most major browser can do this.
But if you can't here is a jQuery plugin for this.

回答7:

To answer just one of the points you raise:

So if it's 20 characters and I find that it doesn't fit, I would have to truncate to 19, add the ellipsis, and then check if it fits again. Then truncate to 18 (plus the ellipsis) and try again. And again. And again...until it fit. Is there a better way?

A much faster way of finding the correct length is to cut the string in half, test that to see if it fits. If it does: add a quarter of the original length back on, and if it doesn't lop a quarter off, then test that to see if it fits. Repeat recursively with 1/8th, 1/16th, 1/32th, ... of the original length, until this add/subtract value is less than 1.

It's a seeking algorithm: for strings that are longer than just a few words you can typically cut the number of tests you need to perform in the DOM by a factor of 10.

回答8:

Try this:

Link One

Update:

If you use the proprietary {word-wrap: break-word;}, IE will force a line break. Modern browsers could have the default {overflow: visible;}, and they would overflow properly, without expanding the container.

回答9:

No, it's not simple task. I had to do same thing year ago and found that even Internet Explorer (from version 6), Opera and Safari can do it, but no Firefox. So sorry, only hacks can save you