ISSUE-284: value of lineHeight

value of lineHeight

State:
OPEN
Product:
TTML2
Raised by:
Mike Dolan
Opened on:
2013-10-11
Description:
TTML1SE added a non-normative recommendation for lineHeight: 8.2.12: "Note: It is recommended that presentation processors use a computed line height that is 125% of the size of the largest applicable font size when the value normal is specified. The choice of 125% allows use of a font size of 0.8c in order to obtain a line height of 1c."

However, the WG had previously agreed to 120% which was codified in an editor's draft after closing ISSUE-275. The issue includes the rationale. The Note was a last minute change for the reason stated in the last sentence in the note.

Implementations had been developed to roughly 120% which was re-enforced by the editor's draft text.

This recommendation should be revisited and normative provisions added to TTML2.

Detailed background information can be found here: http://lists.w3.org/Archives/Public/public-tt/2013Aug/0057.html

This is also related to ISSUE-283 and ISSUE-302.
Related Actions Items:
No related actions
Related emails:
  1. Re: ISSUE-302 (line spacing vs line height): Should background of a span be height of text in line or computed lineHeight? [TTML2] (from nigel.megitt@bbc.co.uk on 2014-03-21)
  2. Re: ISSUE-302 (line spacing vs line height): Should background of a span be height of text in line or computed lineHeight? [TTML2] (from glenn@skynav.com on 2014-03-20)
  3. Re: ISSUE-302 (line spacing vs line height): Should background of a span be height of text in line or computed lineHeight? [TTML2] (from glenn@skynav.com on 2014-03-20)
  4. ISSUE-302 (line spacing vs line height): Should background of a span be height of text in line or computed lineHeight? [TTML2] (from sysbot+tracker@w3.org on 2014-03-20)
  5. {minutes} TTWG Meeting 13/3/2014 (from nigel.megitt@bbc.co.uk on 2014-03-13)
  6. Re: Line Height stacking strategy algorithm - approval needed (from pal@sandflow.com on 2014-01-22)
  7. Re: Line Height stacking strategy algorithm - approval needed (from pal@sandflow.com on 2014-01-21)
  8. Re: Line Height stacking strategy algorithm - approval needed (from glenn@skynav.com on 2014-01-20)
  9. Re: Line Height stacking strategy algorithm - approval needed (from nigel.megitt@bbc.co.uk on 2014-01-20)
  10. Re: Line Height stacking strategy algorithm - approval needed (from pal@sandflow.com on 2014-01-17)
  11. Line Height stacking strategy algorithm - approval needed (from nigel.megitt@bbc.co.uk on 2014-01-17)
  12. {minutes} TTML Meeting of 24/10/13 (from glenn@skynav.com on 2013-10-24)
  13. RE: TTML Agenda for 24/10/13 (from mdolan@newtbt.com on 2013-10-23)
  14. TTML Agenda for 24/10/13 (from nigel.megitt@bbc.co.uk on 2013-10-23)
  15. {minutes} TTML Meeting of 17/10/13 (from glenn@skynav.com on 2013-10-17)
  16. TTML Agenda for 17/10/13 (from Sean.Hayes@microsoft.com on 2013-10-17)
  17. Re: ISSUE-284: value of lineHeight [TTML2] (from glenn@skynav.com on 2013-10-11)
  18. RE: ISSUE-284: value of lineHeight [TTML2] (from mdolan@newtbt.com on 2013-10-11)
  19. Re: ISSUE-284: value of lineHeight [TTML2] (from glenn@skynav.com on 2013-10-11)
  20. ISSUE-284: value of lineHeight [TTML2] (from sysbot+tracker@w3.org on 2013-10-11)

Related notes:

Nigel: P1

Philippe Le Hégaret, 24 Oct 2013, 15:50:21

Elaborate resolution of 'normal' in https://dvcs.w3.org/hg/ttml/rev/4b056bc52a0d.

Glenn Adams, 5 Dec 2013, 22:47:21

See also Issue-302 which is related.

Nigel Megitt, 20 Mar 2014, 11:34:49

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David Singer <singer@apple.com>, Nigel Megitt <nigel.megitt@bbc.co.uk>, Chairs, Thierry Michel <tmichel@w3.org>, Philippe Le Hégaret <plh@w3.org>, Staff Contacts
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