Node for startbuffer.

Node for startbuffer.

[Andre Caldas]

Hello!

Given some

\startbuffer
  Blah, blah, blah...
\stopbuffer

I'd like to get a "node tree" corresponding to how the buffer would be
processed at a given point. Using luatex, I'd like to identify certain
sub-nodes and change their attributes (to be specific: transparency).

Any hint on how to do it?

Also, are there any good examples on how to use "nodes"?


André Caldas.
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Re: Node for startbuffer.

[Hans Hagen]

On 1/9/2013 2:54 PM, Andre Caldas wrote:
> Hello!
>
> Given some
>
> \startbuffer
>    Blah, blah, blah...
> \stopbuffer
>
> I'd like to get a "node tree" corresponding to how the buffer would be
> processed at a given point. Using luatex, I'd like to identify certain
> sub-nodes and change their attributes (to be specific: transparency).
>
> Any hint on how to do it?

here's an example (I'll add it to the cld manual):

\starttext

\definecolor[mytransparency][a=1,t=.5]

\startluacode
local enabled = false
local count   = 0

function userdata.processmystuff(head)
     if enabled then
         count = count + 1
         for n in node.traverse(head) do
             logs.report("node","run %s: %s",count,n)
             if count % 2 == 0 then
                 nodes.tracers.transparencies.set(n,"mytransparency")
             end
         end
         return head, true
     end
     return head, false
end

function userdata.enablemystuff()
     enabled = true
end

function userdata.disablemystuff()
     enabled = false
end

nodes.tasks.appendaction("processors", "normalizers", 
"userdata.processmystuff")
\stopluacode

\startbuffer
whatever \hbox{you} want
\stopbuffer

\ctxlua{userdata.enablemystuff()}
\par \getbuffer \par
\ctxlua{userdata.disablemystuff()}

\stoptext

> Also, are there any good examples on how to use "nodes"?

all over context ...

Hans

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                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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___________________________________________________________________________________

Re: Node for startbuffer.

[Andre Caldas]

> here's an example (I'll add it to the cld manual):

Wow!!! Thank you for your time, Hans!

I will study your sample... :-)


Cheers,
André Caldas.
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___________________________________________________________________________________

Re: Node for startbuffer.

[Andre Caldas]

Another question...

> function userdata.processmystuff(head)

Shall I use this?
userdata = userdata or {}


> \startbuffer
> whatever \hbox{you} want
> \stopbuffer

How do I identify a specific node? Like...

\startbuffer
  Will this be
  \boxtobechanged{transparent?}
\stopbuffer


André Caldas.
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___________________________________________________________________________________

Re: Node for startbuffer.

[Hans Hagen]

On 1/9/2013 9:57 PM, Andre Caldas wrote:
> Another question...
>
>> function userdata.processmystuff(head)
>
> Shall I use this?
> userdata = userdata or {}
>
>
>> \startbuffer
>> whatever \hbox{you} want
>> \stopbuffer
>
> How do I identify a specific node? Like...
>
> \startbuffer
>    Will this be
>    \boxtobechanged{transparent?}
> \stopbuffer

Here is a start. I've added the markers code to the beta so that we have 
an abstract way to deal with such matters.

\setupbodyfont[dejavu]

\definemarker[mymarker]

\definecolor[mymarker:1][r=.6]
\definecolor[mymarker:2][g=.6]
\definecolor[mymarker:3][r=.6,g=.6]

\startluacode
local setcolor    = nodes.tracers.colors.setlist
local getmarker   = nodes.markers.get
local hlist_code  = nodes.codes.hlist
local traverse_id = node.traverse_id

function userdata.processmystuff(head)
     for n in traverse_id(hlist_code,head) do
         local m = getmarker(n,"mymarker")
         if m then
             setcolor(n.list,"mymarker:" .. m)
         end
     end
     return head, true
end

nodes.tasks.appendaction("processors", "after", "userdata.processmystuff")
nodes.tasks.disableaction("processors", "userdata.processmystuff")
\stopluacode

\starttext

\startluacode
nodes.tasks.enableaction("processors", "userdata.processmystuff")
\stopluacode

Node lists are processed \hbox \boxmarker{mymarker}{1} {nested from 
\hbox{inside}
out} which is not what you might expect. But, \hbox {coloring} does not 
\hbox
{happen} really nested here, more \hbox {in} \hbox 
\boxmarker{mymarker}{2} {the}
\hbox {order} \hbox {of} \hbox \boxmarker{mymarker}{3} {processing}.

\startluacode
nodes.tasks.disableaction("processors", "userdata.processmystuff")
\stopluacode

\stoptext

It's somewhat experimental. Up to you to update the wiki. I've added the 
example to the cld manual.

Hans

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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___________________________________________________________________________________

Re: Node for startbuffer.

[Andre Caldas]

>> How do I identify a specific node? Like...
>> [...]
>
> Here is a start. I've added the markers code to the beta so that we
> have an abstract way to deal with such matters.
> [...]
> \hbox \boxmarker{mymarker}{2}

Can't the mark be a string?


André Caldas.
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___________________________________________________________________________________

Re: Node for startbuffer.

[Hans Hagen]

On 1/10/2013 1:18 PM, Andre Caldas wrote:
>>> How do I identify a specific node? Like...
>>> [...]
>>
>> Here is a start. I've added the markers code to the beta so that we
>> have an abstract way to deal with such matters.
>> [...]
>> \hbox \boxmarker{mymarker}{2}
>
> Can't the mark be a string?

currently not (not hard to implement, but no time now).

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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archive  : http://foundry.supelec.fr/projects/contextrev/
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___________________________________________________________________________________

Re: Node for startbuffer.

[Andre Caldas]

> I've added the markers code to the beta so that we have an
> abstract way to deal with such matters.
> [...]
> Node lists are processed \hbox \boxmarker{mymarker}{1} {nested from
> [...]

Does it have to be an "hbox"?


>
> It's somewhat experimental. Up to you to update the wiki.

I've never updated the wiki... I am a bit scared... but I will... :-)


> I've added the example to the cld manual.

How can I see it?


André Caldas.
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___________________________________________________________________________________

Re: Node for startbuffer.

[Hans Hagen]

On 1/12/2013 3:49 PM, Andre Caldas wrote:
>> I've added the markers code to the beta so that we have an
>> abstract way to deal with such matters.
>> [...]
>> Node lists are processed \hbox \boxmarker{mymarker}{1} {nested from
>> [...]
>
> Does it have to be an "hbox"?

no, but only a few node types make sense .. it all depends on what you 
want to do

>> It's somewhat experimental. Up to you to update the wiki.
>
> I've never updated the wiki... I am a bit scared... but I will... :-)

I bet Sietse will keep an eye on your edits.

>> I've added the example to the cld manual.
>
> How can I see it?

google for cld-mkiv.pdf or browse the pragma website

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: Node for startbuffer.

[Andre Caldas]

> It's somewhat experimental. Up to you to update the wiki.

Anyone can suggest a category for it?
http://wiki.contextgarden.net/Category:Commands

Nodes?


André Caldas.
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Re: Node for startbuffer.

[Sietse Brouwer]

Hi André,

> Anyone can suggest a category for it?
> http://wiki.contextgarden.net/Category:Commands
>
> Nodes?

Yep. Creating [[Category:Command/Nodes]] seems like a good idea. To
create the command page, navigate to the intended title (e.g.
Command/boxmarker), click ‘Create’ in the top right, and
copy-and-modify the command page template that you can find here:
http://wiki.contextgarden.net/Help:Command_reference#Command_page_template

Possibly add it to the category [[Category:Command/LuaTeX]], too.

If you find yourself having questions about the wiki, or just wanting
help, even for trivial stuff, just poke me on my talk page:
http://wiki.contextgarden.net/User_talk:Esteis
Or send me a private e-mail, of course, that's also fine.

Hans wrote:
> I've added the example to the cld manual.
...
> google for cld-mkiv.pdf or browse the pragma website

For the benefit of future people:
http://www.pragma-ade.com/general/manuals/cld-mkiv.pdf
It's on page 33, in section 4.4, "Node lists".

Cheers,
Sietse

On Tue, Jan 29, 2013 at 9:57 PM, Andre Caldas <andre.em.caldas@gmail.com> wrote:
>> It's somewhat experimental. Up to you to update the wiki.
>
> Anyone can suggest a category for it?
> http://wiki.contextgarden.net/Category:Commands
>
> Nodes?
>
>
> André Caldas.
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
>
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
> archive  : http://foundry.supelec.fr/projects/contextrev/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________