833742 - Have -moz-orient:auto on <input type=range> automatically select orientation based on computed size

Status: RESOLVED WONTFIX

(Core :: CSS Parsing and Computation, defect)

Description

[Jonathan Watt [:jwatt]]

When I finish the basic implementation of <input type=range> in bug 344618, it will do as the non-normative section text of the HTML 5 spec suggests and base the orientation of the slider (horizontal or vertical) on the ratio of the element's computed width/height. It would seem to make sense to allow -moz-orient to override this though, but we'll need to allow it to also accept the 'auto' value and make that its initial value in order to do that.

Comment 1

[Mounir Lamouri (:mounir)]

Jonathan, have you looked at <meter> and <progress> implementation? They are both implementing -moz-orient. IIRC, we are not exactly exactly following the spec: if you do not set -moz-orient, I do not think we use the widht/height ratio to guess it. The reason is because we have a pseudo-class to access vertical/horizontal elements but that pseudo-class could be used to change the height/width, putting us in an infinite loop.

Comment 2

[Jonathan Watt [:jwatt]]

The HTML 5 spec doesn't mention using the width/height ratio for <meter> or <progress>, and we just give them the horizontal orientation unless |-moz-orient:vertical| is used to override that. <input type=range> is different given that the spec does mention the width/height ratio thing, and other implementations use the width/height ratio to decide the orientation, and as a result content on the Web now relies on that. So I think we have to do the width/height ratio thing at least.

I'm not aware of the existence of a pseudo-class to access vertical/horizontal elements. What is its name, and where is its documentation? You're not talking about box-orient are you?

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Using -moz-orient sounds like a better idea than using the width/height ratio, I think.

Comment 4

[Jonathan Watt [:jwatt]]

David and I discussed this offline and agreed that, after adding an 'auto' value for -moz-orient and making that its initial value, the following would be sane:

 * if -moz-orient is not auto, use the orientation it specifies
 * else, if width is not auto and height is, make it horizontal
 * else, if height is not auto but width is, make it vertical
 * else, if neither width or height is auto, use the computed width to computed
   height ratio (a ratio >= 1 being horizontal, < 1 being vertical)
 * else (if both width and height are auto) make it horizontal

This would allow content authors to get sane behavior when specifying only one of width/height with the intention of that value being the length of the slider, while allowing the other dimension to fall back to the slider's "natural" size.

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(In reply to Jonathan Watt [:jwatt] from comment #4)
>  * else (if both width and height are auto) make it horizontal

... or, once we implement 'writing-mode', honor make it horizontal in horizontal text and vertical in vertical text.

Comment 6

[Mounir Lamouri (:mounir)]

I was completely wrong in comment 1 and what we implement is actually simply show a vertical progress bar if -moz-orient is set se 'vertical' and use default width/height accordingly if there are not set for the element.

There is indeed no pseudo-class to catch orientation for elements and I'm not sure why. That could be interesting to have that though. I wonder if that would be technically doable.

Comment 7

[Mounir Lamouri (:mounir)]

Ah actually, one more thing. I think it would be better to have <meter>, <progress> and <input type='range'> to behave the same way regarding orientation. Whether we change <meter> and <progress> to use the <input type='range'> behaviour or we make <input type='range'> use the meter behaviour.

I do not really have any strong opinion so I believe we sholud discuss this.

Comment 8

[Jonathan Watt [:jwatt]]

We decided some time ago that the whole auto-orientation thing based on computed size ratios was too magical and that we wouldn't do that. WONTFIX'ing.