Re: [oslc-core] Issue: Relative Length Units

[Martin P Pain <martinpain@uk.ibm.com>]

In the spirit of responsive layouts, perhaps
it would be better to allow the dialog/preview providers to specify minimum
and maximum widths (in em, ex or px values - that is, in CSS relative length
units) for the range of sizes it can handle. (Or maybe just minimum would
be needed.) Then the page embedding it would choose a size that works for
it. We could provide guidance for the best way to do this, e.g. by calculating,
for width: max(30% of page width, 35em, minimum size specified by provider).
Although exactly how you compare those values when they mix units I'm not
sure.

(They could also specify the existing
height and width properties, which could be interpreted as "preferred"
when given in combination with minimum/maximum).

Lonnie, do you think being more flexible
about the sizes that the dialog supports (when using responsible layouts
within it) would help your situation? If so, how do you think it would
work out best? (I'm not proposing anything yet - just raising the idea
to see if something like that would help you.)



Martin Pain
Software Developer - Green Hat
Rational Test Virtualization Server, Rational Test Control Panel
OASIS Open Services for Lifecycle Collaboration - Automation technical
committee chair

E-mail: martinpain@uk.ibm.com Find me on:  and within IBM on:

IBM United Kingdom Limited
Registered in England and Wales with number 741598
Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU

<oslc-core@lists.oasis-open.org> wrote on 29/05/2014
20:21:53:

> From: Lonnie VanZandt <lvanzandt@sodius.com>
> To: oslc-core@lists.oasis-open.org, 
> Date: 29/05/2014 20:22
> Subject: Re: [oslc-core] Issue: Relative Length
Units
> Sent by: <oslc-core@lists.oasis-open.org>
> 
> I read through this and was getting worried until I read "...[they]
> ignore all this and use px values..." This is exactly what I
did 
> when I came across the em units and couldn't get a pleasing result
> for my preview dialogs.
> 
> A related issue is that I use Angular Bootstrap with Less for our
> CSS management. Bootstrap has a capability for "responsive"
UIs and 
> it will modify the scale and layout of content based on the "media"
> properties provided by the browser platform. Therefore, it is 
> contrary to the vision of the bootstrap religion to try to design
> presentation elements to fit within a particular frame. The idea of
> using "em" rather than "px" was a step in the
right direction but 
> doesn't handle the practical complexity of trying to design scalable
> page presentations.
> 
> Now, thanks to the requirements reminder from Samuel, I see that I
> do need to return to the annotation hints for my dialogs and set the
> units back to ems and find out a better way to deal with the outcome.
;-)

> On 5/29/14, 12:35, Samuel Padgett wrote:
> I have some doubts about our use of relative
length units for 
> delegated UIs in OSLC.
> 
> In OSLC 2.0, widths and heights for dialogs and resource previews
> must always use relative length units [1] [2] [3]. We make the 
> additional statement that em and ex units are relative to the 
> default system font. For instance,
> 
> "Height size MUST be expressed in relative length units as defined
in the 
> W3C Cascading Style Sheets Specification (CSS 2.1) Em and ex units
> are interpreted relative to the default system font (at 100% size)"
> 
> The second sentence to me seems to contradict the first. In CSS, em
> is calculated relative to the font size of the parent element, not
> the system font. As a dialog consumer, how do I adjust for the difference?
> 
> The other issue I see is that I can't accurately size myself as a
> dialog since I have no idea what font size is used on the emedding
> (outer) page. If the outer page uses a larger font than me, my 
> dialog will be bigger than I want. If the outer page uses a smaller
> font, the dialog will be smaller than I want. It's not based on my
> content and font, but the font of the outer page.
> 
> The real OSLC implementations I've seen just ignore all this and use
> px values. I did some searching and couldn't find any history for
> why we require relative units.
> 
> I propose we remove the requirement and simply say use any valid CSS
> length value.
> 
> [1] http://open-services.net/bin/view/Main/OslcCoreUiPreview?
> sortcol=table;up=#Resource_Preview
> [2] http://open-services.net/bin/view/Main/OslcCoreSpecification?
> sortcol=table;up=#Resource_Dialog
> [3] http://open-services.net/bin/view/Main/OslcCoreSpecification?
> sortcol=table;table=up#Dialog_Resizing
> 
> -- 
> Samuel Padgett | IBM Rational | spadgett@us.ibm.com
> Eclipse Lyo: Enabling tool integration with OSLC
> [attachment "signature.asc" deleted
by Martin P Pain/UK/IBM] 
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number
741598. 
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
3AU