Re: What is the use case for two levels of background colors?

On Mon, May 12, 2014 at 10:24 AM, Silvia Pfeiffer
<silviapfeiffer1@gmail.com> wrote:
> On Mon, May 12, 2014 at 6:12 PM, Philip Jägenstedt <philipj@opera.com> wrote:
>> Using the cue box as the background box was what I did in
>> http://people.opera.com/philipj/2014/03/vttscroll/background.html
>
> There's a difference: you're putting a background on the individual
> cues while the background on the region is putting a background on the
> group of cues in one go. There is no chance of a gap appearing between
> the cues because of this.

Yes, that is true. (Trying to emulate a grid-based format should have
similar problems.)

>> However, I've realized that this creates a bit of a tension between
>> two goals: in order to "look nice" the background should not be much
>> bigger than the cue text, but to give the cue size to grow when the
>> font size changes, it should be as big as possible.
>>
>> This would likely cause authors to create boxes that are too small,
>> causing unnecessary line wrapping when the font size increases. Note
>> that using a font-relative unit like em doesn't eliminate the problem,
>> as illustrated here:
>> http://jsfiddle.net/zLB3N/
>>
>> If the use case was to provide a common background for a number of
>> lines (possibly from different cues) simply taking the bounding box of
>> those lines and adding some padding would be enough.
>
> That's what the region is for.

Doesn't regions have exactly the problem I describe? Not that I have a
solution, I don't know how this could be made reliably when fonts and
their sizes is under user control...

>> However, if the background needs to be unchanging over time
>
> What do you mean by "unchanging"?

I mean a background which isn't just the bounding box of the cues
current showing, but those that will be shown. The author cannot know
what that box is, and calculating it at runtime would require
rendering all cues once and assuming scripts won't change them...

Philip

Received on Monday, 12 May 2014 12:17:02 UTC