Re: [css-round-display] Method for setting the viewport into the non-rectangle display

Brad Kemper

On Apr 20, 2016, at 12:10 AM, Jihye Hong <jh.hong@lge.com> wrote:

>> On Apr 13, 2016, at 10:04, Florian Rivoal <florian@rivoal.net> wrote:
>> 
>>  viewport-fit: auto | contain | cover
>>  initial value: auto
>> 
>>  This descriptor only has an effect when the screen/window/viewing area
>>  is not rectangular. When it is rectangular, both values give the same
>> result.
>> 
>>  On non-rectangular screens/windows/viewing areas, it determines what
>>  rectangle is used to set the dimensions of Initial Viewport, and is
>>  used as the Visual Viewport.
> 
> 'viewport-fit' can set the size of the bounding box which is used for
> applying the actual viewport (visual viewport). 
> What would be the appropriate terminology for 'the bounding box'?

I was kind of wondering that too. Is it just a situation of the initial viewport being bigger than the visual viewport, not including content overflow off the bottom? Or is it that the initial viewport is smaller than the physical area  of the display? Do we need a new term for one of these, and define specifics for it?

I think that if your bounding box is smaller than  the physical display area, you should still see whatever overflow is in the gap between the two, including root/body background and absolutely positioned elements (like something with 'right:100%' if it's vertical position was about halfway down the screen at the current scroll). Is this specified anywhere yet?

>>  auto: Same as 'contain', except the UA may also use a slightly larger
>>        rectangle, as long as this would not cause a significant part of
>>        the viewport to be off screen. In any case, the rectangle must not
>>        be larger than the one implied by contain. For example, on
>>        a screen with only slightly rounded corners, the rectangle used
>>        could be the same as with 'cover'
> How can we know that the shape of the display is the rounded rectangle?

Media query?

> When setting the size of the bounding box for the viewport on
> non-rectangular display, we have to consider:
>  - Clipped area which is caused because the area of the viewport bounding
> box is larger than the area of the display.

When does this happen? Do you mean when content overflows or is zoomed? I might be getting confused by interpretation of the terminology. Is bounding box here the same as actual viewport or initial viewport or something else?

Or are you just referring to some of the area being clipped by the display shape?

>  - Gap between the bounding box for the viewport and the border of the
> display.
> 
> There can be the situation that the author doesn't know the exact shape of
> the display (Neither rectangle nor round).
> If the shape of the display cannot be predictable, it have to be guaranteed
> that any part of the web page isn't hidden.
> So, avoiding clipping is more important than having a gap between the
> bounding box of the viewport and the border of the screen. 
> 
> I think 'auto' could be the same as 'contain' when the shape of the display
> is rectangle or round.
> And when the shape of the display is the other shapes such as rounded
> rectangle or star-shape, it works like 'cover'
> 
> Thanks,
> Jihye
> 
> 

Received on Wednesday, 20 April 2016 17:59:44 UTC