Re: Inability to change color of individual substrings

[sfeam <sf...@us...>]

On Thursday, 29 September 2016 10:21:13 PM Daniel J Sebald wrote:
> I've noticed that enhanced text mode cannot control the color of a 
> substring.  Just as a brainstorming exercise, has anyone thought of 
> adding such a thing in some way?  In principle it's pretty 
> straightforward: just change terminal color at various points when 
> processing the string.  But I've a feeling implementation may not be so 
> easy.  Approaches might be:
> 
> 1) Add some color code extension to the enhanced text processing.  The 
> code word may not agree with some "standard" described in ps_guide.ps, 
> but I don't see why that should be a problem.  The problem is that all 
> terminal drivers would need to be modified to process that code word.
> 
> 2) Create a tex-processing feature, which is similar to enhanced text 
> (and could use much of the same code), but it would allow using things 
> like "{\color[rgb]{.3 .7 .3}Hello} World".  Of course, this is no simple 
> task, but I'm just thinking long term wish if there is no better approach.
> 
> 3) If there were some way of getting the position at which one 
> label/string ends, then one could concatenate strings.  I've a feeling 
> this isn't possible.  I mean, one has to effective do the plot to get 
> the string-end position, which would be clumsy.
> 
> 4) However, #3 in theory could be implemented as "not lifting pen". 
> Does gnuplot core code have knowledge of this?  That is, can it do one 
> label, not lift the pen, then continue with another label?  If so, the 
> following concept might work:
> 
> set label 1 "{/Times:Bold hello}" textcolor "red" at 1,2
> set label 2 "world^3" textcolor "blue" after label 1
> 
> Or, maybe just allow multiple substring specifications, but only a 
> single "at x,y":
> 
> set label 1 "{/Times:Bold hello}" textcolor "red" "world^3" textcolor 
> "blue" at 1,2
> 
> Would that work easily internally?  Or is there still a problem as far 
> as laying out string alignment?
> 
> Dan

Always been there:

# enhanced text occupy-space-but-don't-print mode
#
set label 1 at 0,0 "I am a &{red} word in blue"
set label 2 at 0,0 "&{I am a} red &{word in blue}"
set label 1 tc "blue"
set label 2 tc "red"

	Ethan