- From: Xianzhu Wang <wangxianzhu@chromium.org>
- Date: Tue, 11 Feb 2014 17:39:52 -0800
- To: Matt Rakow <marakow@microsoft.com>
- Cc: "www-style@w3.org" <www-style@w3.org>
- Message-ID: <CADBxrie8XguA5eW4SweNqvxGz6rmmE+QijfO7fFyFESM2uCdZg@mail.gmail.com>
> > > All this said, I'm not sure if these questions fall into the device > adaptation spec since they pertain more to definition of visual viewport > vs. actual viewport, rather than the definition of initial viewport vs. > actual viewport. I do think they'd be good questions to resolve in some > spec though. > I think this is a good point. Do you mean we should distinguish 'visual viewport' and 'initial viewport'? Thanks, > -Matt > > > >From: wangxianzhu@google.com [mailto:wangxianzhu@google.com] On Behalf > Of Xianzhu Wang > >Sent: Tuesday, February 11, 2014 11:42 AM > >To: www-style@w3.org > >Subject: [css-device-adapt] How should initial viewport contribute to > layout? > > > >Hi, > > > >Actually I have 2 related questions: > >1. Should fixed-position blocks layout according to the 'initial > viewport', 'actual viewport' or something between them? > >2. For a page with unconstrained viewport height, how should the height > of the 'actual viewport' be adjusted when there is temporary height change > of the 'initial viewport', e.g. when the on-screen-keyboard shows? > > > >The answers to the above questions seem to have already been covered by > existing specs, but after we examine the current behavior of different > mobile browsers we found they have tweaked the existing specs to achieve > more user-friendship and/or better performance: > > > >1. All browsers seems not to layout top-level fixed-position blocks > according to the initial-containing-block (i.e. 'actual viewport' in > css-device-adapt), but somehow according to the visible viewport (i.e. > 'initial >viewport' in css-device-adapt). Mobile Safari's behavior is more > complex that seems to use a bigger virtual viewport to contain the > fixed-position elements if the visible viewport is too small. > > > >2. For a page with unconstrained viewport height, the browsers behave > differently about whether to adjust the actual viewport height when > visibility of the top- and/or bottom- controls and the on-screen keyboard > changes. > > > > > https://docs.google.com/a/chromium.org/document/d/1ukfEZGJQq-7VD_Tv9m_cYD4BoR6YZots5_KddtvYZJs/edit#summarizes the current behaviors of the browsers. > > > >I think it'd be better if the spec address the issues that caused the > browsers to tweak the spec, to avoid inconsistency and confusion. > > > >Thanks, > >Xianzhu > > >
Received on Wednesday, 12 February 2014 01:40:20 UTC