CSS Writing Modes in January 2015

This report is prepared by fantasai. It summarizes the status of CSS Writing Modes Level 3 in January 2015.

Table of Contents

  1. Background: the W3C Process
  2. Status of CSS Writing Modes
  3. Timeline of Completion
  4. Priorities

Background: the W3C Process

The W3C Recommendation Track Process proceeds through three stages with two short transitions in between:

Working Draft
This is the design phase of the specification. In this phase, the Working Group designs the technology, collecting feedback and republishing the specification as necessary to incorporate the feedback.
Last Call Working Draft
This is the transition from Working Draft to Candidate Recommendation. The Working Group must demonstrate that it has solicited wide review by stakeholders and that it has addressed all their feedback. Note: This stage has been dropped in the most recent Process revision.
Candidate Recommendation
This is the testing phase. In this phase, the Working Group is testing the specification. To do this it creates a test suite and collects implementation feedback. If the tests and the implementation and the specification all match, then the specification is good and can advance. Usually this experience reveals many bugs: in the implementations, in the tests, and in the specification itself.
Proposed Recommendation
This is the transition from Candidate Recommendation to Recomendation. The Working Group must demonstrate that the specification is sufficiently stable, precise, and reliable by showing two independent implementations who can each pass the test suite completed during the Candidate Recommendation phase.
This is the completed phase. In this phase, a good Working Group will maintain errata, but most changes are expected to be minor. a specification enters this phase once the specification, test suite, and implementation reports have been reviewed by W3C (during the Proposed Recommendation phase).

Status of CSS Writing Modes

CSS Writing Modes is in the Candidate Recommendation phase.

Right now, we have:

To complete the Candidate Recommendation phase, we will need:

To reach this goal, we must

Timeline of Completion

Contributions from Japan will be able to help all of these move forward. However, reaching Proposed Recommendation will take time, and will not be possible by the end of March 2015. This is because, even if we complete the test suite by then, the test suite will have revealed many bugs in implementations and probably also errors in the specification. (There have already been two specification errors reported through the efforts of GĂ©rard Talbot to create tests, in addition to bugs reported in implementations.)

A good goal for March 2015, however, can be the completion of a Beta test suite.* By this I mean the test suite will have good coverage of the entire specification, and any remaining gaps are very specific, limited, and precisely identified. We can then use this test suite to identify the implementation bugs, test suite bugs, and specification errors.

* It may be a problem to complete the testing of text-combine-upright due to lack of font experts.

The next phase of CSS Writing Modes development would then be fixing the bugs in implementations, correcting the errors in the specification, updating the test suite (to fill in any identified gaps, to match corrections to the specification, and to fix any errors found in the tests themselves). It is possible, though aggressive, to complete this effort by TPAC 2015; however, success will depend on the complexity of the bugs found. Layout bugs (especially interactions among layout features, for example mixing table layout and vertical text and horizontal text all together) can be very complex.

Nonetheless, in every case, the usability of CSS Writing Modes will improve. Even if not all of the bugs are fixed, and Proposed Recommendation is therefore not attained, by making more and more of CSS Writing Modes implementations compliant, we will make more and more of the layouts it enables possible. And therefore in a very real sense, if not in a bureaucratic one, CSS Writing Modes will have progressed due to these efforts.

Prioritization of Work

To help us prioritize the most helpful and important implementation fixes for Writing Modes, we will need to prioritize testing in those areas and also communicate the importance of such features and the nature of the bugs we find to the implementation development teams affected.

For the Middle East, the most important section is Chapter 2: Inline Direction and Bidirectionality.

For Europe and America, the most important features are writing-mode (both vertical-rl and vertical-lr) and text-orientation: sideways (which switches automatically between sideways-right for vertical-rl and sideways-left for vertical-lr). Vertical writing in these languages is used frequently for captions and table headers.

For Japan and China, bidirectionality is uninteresting, but writing-mode values horizontal-tb and vertical-rl and text-orientation values mixed, upright, and sideways-right are critical and text-combine-upright is also important.

Inner Mongolia is similar to Japan, except that vertical-lr is used.

It is important to understand, however, that these features are complex, and there are many aspects to test. Below is a prioritization breakdown from the Japanese perspective that demonstrates how these features break down.

Note: I have done my best to create an informed prioritization, but one may disagree on the exact priorities. Please inform me of any suggested corrections.

Top Priorites

Top priorities for basic vertical writing in Japan include:

writing-mode: vertical-rl

High Priorities

In addition to top priorities, high priorities for vertical writing in Japan include:

writing-mode: vertical-rl
Other text layout

Medium Priorities

Medium priorities for vertical writing in Japan include:

writing-mode: vertical-rl

Low Priorities

Lowest priorities (of necessary and important things) from a Japanese perspective include:

writing-mode: vertical-rl