548378 - -moz-transform should be a shorthand

Status: RESOLVED DUPLICATE of bug 598609

(Core :: CSS Parsing and Computation, defect)

Description

[patrickjdempsey]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

When -moz-transform is used on the same element with different selectors, it resets properties of overlapping selectors to the default settings, and only uses the last in order.

Reproducible: Always

Steps to Reproduce:
1. Set a -moz-transform property for one selector, say [iconsize="small"].
2. Set a -moz-transform property for an overlapping selector, say :-moz-locale-dir(rtl).
3. Set a -moz-transform property for another overlapping selector, say toolbar[orient="vertical"].
Actual Results:  
Whichever property was assigned last is used and the overlapping properties are reset to the default.  In the case of the example, only the instructions for a vertical toolbar are used, even if Firefox is in a RTL locale and is in small icons mode.  The only way to work around this is to create separate instructions for each and every individual case.

Expected Results:  
-moz-transform properties should carry over from overlapping instructions.  In the above example, those three statements are all that should be needed to handle a wide range of circumstances.

The "background" property is an example of the expected behavior.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Yes, this is how CSS works.  You have a list of rules, you take the most specific one that sets the property, you use the value it sets as the specified value.  background works exactly the same way as -moz-transform in this regard.

Unless you mean that -moz-transform resets properties _other_ than -moz-transform?  In that case, I'd like to see a testcase showing that.

Comment 2

[patrickjdempsey]

No, I mean that -moz-transform has several different properties like rotate, scale, skew, translate etc. that are all reset every time -moz-transform is called.  Background allows you to change say the background color without resetting the background image, position or repeat values.  Maybe what is needed is separate properties:

-moz-transform-rotate
-moz-transform-scale
-moz-transform-translate
-moz-transform-skew

This probably still wouldn't help for mirroring images for RTL, but it would be a start.

Comment 3

[Boris Zbarsky [:bzbarsky]]

> I mean that -moz-transform has several different properties like rotate,
> scale, skew, translate etc

But it doesn't.  It just has a single value that has those parts, but they're not settable independently.

> Background allows you to change say the background color without
> resetting the background image,

Right, because it's a shorthand.

> Maybe what is needed is separate properties:

If you want it to work the way I think you do, yes.  You may want to post to [e-mail] about this, since that's something that would need to change in the http://www.w3.org/TR/css3-2d-transforms/ draft specification.  The "transform" property would need to have the final transformation matrix decomposed into the 4 parts you list.  That said, such decompositions are non-unique, so a method of choosing the preferred decomposition would need to be chosen, and the exact order in which the four are combined into the overall transform would need to be defined.

> This probably still wouldn't help for mirroring images for RTL

What exactly is needed for that?

Comment 4

[patrickjdempsey]

That just seems terribly short-sighted for something that could possibly completely re-invent the way that many parts of the web and browsers are handled.

Comment 5

[Boris Zbarsky [:bzbarsky]]

What seems short-sighted?

Comment 6

[Aryeh Gregor (:ayg) (no longer with Mozilla)]

Looks like the same as bug 598609?