- From: Jim King <jimk@mathtype.com>
- Date: Thu, 12 Dec 1996 17:23:03 -0800
- To: Hakon Lie <howcome@w3.org>
- Cc: www-style@w3.org, dsr@w3.org
> > The code I am using (within paragraph text) is: > > > > <IMG STYLE="vertical-align: -20%" SRC="equation.gif"> > > > > Does this code look reasonable? > >Yes it does. Your example will lower the image relative to the >baseline of the parent element. It will move a distance equal to 20% >of the 'line-height' property (which most often will be 20% of the >line height of the line the image forms a part of). > >Unfortunately, there are no known implementations of 'vertical-align' >yet. That should change within a few months. Thanks. In reading the section on line-height, I'm not completely clear on what happens with a line that has multiple inline elements (such as three gifs of equations in one line.) Would that % be 20% of the overall line-box plus the leading, or would it be 20% of the line-height ONLY at the point where the image is located (which is different from the line-height 2 characters earlier)? 4.4 seems to imply that the line is sectionalized such that the latter would be the case. If so, does that mean that for any in-line object that I want to align with text I should set: height, width, line-height, leading, and vertical-align? Seems to me that there should be some way to set the vertical alignment in a way that references back to the object I'm aligning. So I should be able to say "20% drop" in a way that says I am dropping by a distance that is 20% of the object itself's height (which I have control over) rather than 20% of the height of the items around the object (whcih I don't usually have control over). The specific situation I'm thinking of is math equations. If I want to put the following into a web page: 1 2--- 2 3y If x=------- then y=-------. 3y 1 2--- 2 then I need a way to drop each math expression by a set distance below the baseline. Each equation has a different distance that is dependent on nothing except for the contents of the expression. That distance can't be based on the overall line-height, because that can change in too many ways. The only thing that doesn't change (and thus is the rock on which I can base my vertical alignment) is the height of the equation itself. Now if 'vertical-align' is based on a line-height that is actually the height of the image + the leading then that's a bit better, but since the 'cascade' aspect of CSS allows a user to have changed the leading value on their own machine, there is the strong posibility that any guess I've made about the leading value will be wrong. What I really want to say is "Here is the baseline point of the image itself. Line it up with your baseline." That is only said if the value is a reference to the object. I havn't found a way to do this with the current spec, but perhaps I've missed something. Is there a better style element to use for this? I'm fairly new to the www-style list, so maybe this has been discussed before - do you know approximately when 'vertical-align' was added so that I can go back through the archived copies to find what concerns were brought up before? Jim King Product Manager jimk@mathtype.com ================================================================== Design Science, Inc. Sales: sales@mathtype.com 4028 Broadway Support: support@mathtype.com Long Beach, CA 90803 USA World Wide Web: voice: 310-433-0685 http://www.mathtype.com fax: 310-433-6969 ==================================================================
Received on Thursday, 12 December 1996 20:24:03 UTC