The coming of SVG

prothero at earthlearningsolutions.org prothero at earthlearningsolutions.org
Fri Nov 3 11:46:07 EDT 2017


This is great news!
Bill

William Prothero
http://es.earthednet.org

> On Nov 3, 2017, at 8:18 AM, Mike Kerner via use-livecode <use-livecode at lists.runrev.com> wrote:
> 
> OOOH.  Cooooool.  So pretty soon maybe I can render interfaces in Sketch
> after applying themes from my favorite interface design houses...
> 
> On Fri, Nov 3, 2017 at 9:19 AM, Mark Waddingham via use-livecode <
> use-livecode at lists.runrev.com> wrote:
> 
>> Hi all,
>> 
>> My most recent talk at LCG (in October) was 'Building an SVG Widget' and
>> in order to talk about such a thing, I needed to actually build one - so I
>> did :)
>> 
>> So, we are now firmly on the road to full SVG support in LiveCode!
>> 
>> At the moment the implementation only supports geometric shape tags,
>> paths, and solid color fills. However, it supports the standard fill/stroke
>> attributes and should work with any SVG file - anything which isn't
>> supported just doesn't get rendered (so you have a modicum of graceful
>> degradation in terms of features). In particular, you don't need to
>> preprocess your SVG file to pull out incompatible tags / attributes, or
>> just extract the path (as you do for the SVGIcon widget).
>> 
>> The current implementation successfully renders quite a wide range of
>> simple SVGs (simple in the features they use, rather than how they look!).
>> Indeed, it happily renders the (quite widely known) Tiger and Lion SVGs,
>> and has been tested on quite a few random SVGs I managed to find on
>> Wikipedia. It is certainly more than capable if you want to use simply
>> coloured multi-path SVGs.
>> 
>> LCG attendees got a prototype of a widget to play with - called vectoricon
>> - and integrating this initial version this into the product has now got to
>> the top of my work-list :)
>> 
>> The principal thing which I'd like some feedback on right now is the name
>> of the widget/control - I think we have a good one, but wanted to see what
>> you all thought before committing us to it forever and a day.
>> 
>> Before getting to that though, I should perhaps explain what a potential
>> path for the evolution of this new feature in LiveCode could look like.
>> 
>> SVG as a concept allows arbitrary collections of vector shapes, images and
>> text to be represented in a single high-level way as XML - in particular,
>> you can express geometric shapes, raster images and text all in one unified
>> form.
>> 
>> Previously we had proposed producing a 'shape' object which would be a
>> 'graphic object on steroids' - allowing affine transformation, higher
>> fidelity specification of geometric objects and groups of them; providing
>> an 'svgText' interface similar to htmlText on the field. Essentially, the
>> proposed 'shape' object would have used a subset of SVG to allow easy
>> interchange of what it represents.
>> 
>> That notion of 'shape' object (and thus the current 'graphic' object) can
>> be subsumed into the SVG implementation in an obvious way - if you ask your
>> SVG object to be a rectangle, it creates (notionally) the SVG for a
>> rectangle internally and uses that - which you would see via the svgText.
>> 
>> Similarly, as SVG can represent raster images too, we can fold the current
>> behavior of the 'image' object into it to - in a similar way.
>> 
>> The end result here would be a single object which is a generalization of
>> two existing objects - image and graphic - but without the
>> backwards-compatibility baggage we currently have.
>> 
>> In terms of using this new object in a consistent way to our current
>> model, we propose (subsequently) to generalize the types of objects which
>> can be referenced by imageSource and icon properties - allowing them to use
>> any object which 'knows how to be used as an icon'. Currently, only the
>> image object has this knowledge - but we can extend to other objects by
>> getting them to implement the appropriate internal interface. This would
>> mean that you could just replace the images you use currently for icons and
>> such, with the new control which supports SVG and use SVG instead.
>> 
>> Given the potential future path of this particular feature, we also
>> propose to eventually give it an actual control type - rather than widget
>> (although it will still be a widget). i.e. We think it is has such future
>> potential that being able to do '<noun> "foo"' in script will be very
>> useful (this is almost a requirement if it is to eventually 'replace' the
>> image and graphic objects). [ Note: we have also been considering this for
>> the browser widget too! ].
>> 
>> Thus with all that in mind - we are proposing 'picture' as the name of the
>> new SVG capable control, with the following ideal roadmap:
>> 
>>  a) we would integrate the 'prototype' implemented for SVG as
>> 'com.livecode.widget.picture'
>> 
>>  b) we would add a 'picture' noun to the language as the control type for
>> that widget
>> 
>>  c) we would add icon reference support, allowing it to be used in place
>> of an image
>> 
>>  d) we would add graphic-like shape properties, allowing you to use it in
>> place of a graphic
>> 
>>  e) we would add support to the image tag in svg, and image-like image
>> properties, allowing it to be used in place of an image
>> 
>>  f) we would gradually expand support for the range of SVG it can
>> directly render (gradients and layers are high on the hit list here)
>> 
>> In terms of timescale, we are currently looking at delivering 'just' (a)
>> for 9.0 (although I do have my eye on at least (c) too - we'll have to see
>> how other things we still need to finish for 9 go). The rest all break down
>> into bite-sized chunks which I'd hope we could iterate on it periodically
>> after that.
>> 
>> It goes without saying that we are interested in any and all feedback you
>> might have on this idea; however, right now, our top priority is naming.
>> 
>> As I said above 'picture' is our current top (and perhaps only!) contender
>> - it says what SVG does (it represents pictures of things), can subsume the
>> idea of image and graphic naturally, and is human-friendly. It is also a
>> single word which is a current requirement if it is to be used as a chunk
>> noun (like 'image', and 'graphic' etc.).
>> 
>> I look forward to reading any feedback you might have!
>> 
>> Warmest Regards,
>> 
>> Mark.
>> 
>> --
>> Mark Waddingham ~ mark at livecode.com ~ http://www.livecode.com/
>> LiveCode: Everyone can create apps
>> 
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> 
> 
> 
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