Re: [Geoserver-users] [Geotools-devel] [SLD] Boxed Labels with TextSymbolizer

[Andrea A. <aa...@op...>]

Jody Garnett ha scritto:
> Andrea Aime wrote:
>> Saul Farber ha scritto:
>>  
>>> Great question!  I'm not sure I have an answer...anyone else have any 
>>> great ideas?
>>>
>>> I guess you could do some math in the <size> of the box.  Have it be 
>>> dependent on the length of the name string.  Anyone know how Hugo 
>>> could formulate that SLD expression?  <size><Mult><Func 
>>> name="length">STREET_NAME</Func><Literal>20</Literal></Mult></size
>>>
>>> Is there a function to get the length of a string attribute?
>>>     
>>
>> strLength(attribute) does compute the number of chars.
>> Yet I'm not sure it's what you want, since the rendered width
>> of "MMMM" and "||||" is different.
>> Unfortunately afaik we do not have a function that does return
>> actual rendered width and height.
>>
>> In fact, to provide a proper answer to this problem, a new
>> element similar to halo should be added to TextSymbolizer,
>> since it has the same function as a halo, that is, make
>> text easier to read... well, it could even be a Halo
>> new attribute.
>> Both would require changing published API in 2.2.x, so I'm
>> not sure we're speaking about a quick change (I doubt it...
>> everything handling styles would need to be changed as
>> an effect, parsers, encoders, implementations of the interface...)
>>   
> We do support optional extensions beyond the SLD specification, for 
> example we did "label shields" where a Mark could be dropped in behind the
> final text position.  This box sounds like a similar idea.

And how does a Halo new attribute sound, shape="radial" (just like now) 
and shape="rectangular" (new rectangle based distance, take the 
rectangle that bounds the text and use radius to increase its size in
each direction)?

Cheers
Andrea