`<PlaceObject vreference="middle">`?

[pr-apes]

@pgundlach,

in some cases (also with rotation), the object needs a middle vertical reference to get properly placed.

I know I have to translate all code from ConTeXt to Publisher. So I’m closing the issue now.

Once I will need it (because I would make use of it), I’ll reopen it.

Many thanks for your help.

[pr-apes]

@pgundlach,

here you have a patch for <PlaceObject vreference="middle">:

diff -ru ../old-spp/sw/lua/publisher/commands.lua sw/lua/publisher/commands.lua
--- ../old-spp/sw/lua/publisher/commands.lua    2022-08-25 14:39:43.000000000 +0200
+++ sw/lua/publisher/commands.lua   2022-08-26 14:18:31.893119200 +0200
@@ -2716,6 +2737,8 @@
         options.ht_max = areaheight
         if vreference == "bottom" then
             options.current_height = areaheight
+        elseif vreference == "middle" then
+            options.current_height = areaheight
         else
             options.current_height = math.min(current_grid:remaining_height_sp(row,area,tonumber(column)),areaheight)
         end
@@ -2813,6 +2836,8 @@
             local top = row + current_grid.extra_margin
             if vreference == "bottom" then
                 top = top - object.height
+            elseif vreference == "middle" then
+                top = top - object.height / 2
             end
             publisher.output_absolute_position({
                 nodelist = object,
@@ -2840,6 +2865,8 @@
             if row then
                 if vreference == "bottom" then
                     current_row = row - height_in_gridcells + 1
+                elseif vreference == "middle" then
+                    current_row = row - math.round (height_in_gridcells / 2,0) + 1
                 else
                     current_row = row
                 end

I have just replicated what was available for hreference.

BTW, I'm afraid that I couldn't solve the value with the condition publisher.current_group == nil (I have just copied it).

I don't know which are the conditions there (all grid typesetting is too complex for me). This is still pending.

Just in case it helps.

[pgundlach]

Not sure about the semantics when in grid positioning. See this example:

<Layout xmlns="urn:speedata.de:2009/publisher/en"
    xmlns:sd="urn:speedata:2009/publisher/functions/en">
    <Trace grid="yes"/>
    <Record element="data">
        <PlaceObject row="5" vreference="middle">
          <Image file="_samplea.pdf" width="4"></Image>
        </PlaceObject>
    </Record>
</Layout>

I am not sure if this is the expected behaviour or if the start should be at row 4.5

[pr-apes]

@pgundlach,

if grid typesetting forces the placement of every element starting in a new row or column (sorry for my poor wording, but grid is not my thing), then starting at a decimal row/column value is not an option (only integer values are allowed, if I'm getting this right).

Another question would be how the decimal values should be rounded (only .5-.9 should increase the row/column in one unit).

Just in case it might help.

[pr-apes]

@pgundlach,

just in case it might help:

<Layout xmlns="urn:speedata.de:2009/publisher/en"
    xmlns:sd="urn:speedata:2009/publisher/functions/en">
    <Trace grid="yes"/>
    <Record element="data">
        <PlaceObject column="5" hreference="center">
          <Image file="_samplea.pdf" width="5"></Image>
        </PlaceObject>
    </Record>
</Layout>

I think grid positioning should behave following the same patterns in horizontal and in vertical centering.

Rounding values is also not considered for horizontal centering.

Just in case it might help.

[pgundlach]

I am not sure if I am happy with it. left/right and top/bottom are easy but this leads to decisions that are not intuitively "correct".

Perhaps it was a mistake to allow hreference="center". This is only good if the width of the object is a) an integer value and b) an odd number.

See this:

<Layout xmlns="urn:speedata.de:2009/publisher/en" xmlns:sd="urn:speedata:2009/publisher/functions/en">
  <Trace grid="yes" />
  <Pageformat height="8cm" width="8cm" />
  <Record element="data">
    <PlaceObject column="2" hreference="center">
      <Image file="_samplea.pdf" width="1" />
    </PlaceObject>
    <PlaceObject column="2" hreference="center">
      <Image file="_samplea.pdf" width="2" />
    </PlaceObject>
    <PlaceObject column="2" hreference="center">
      <Image file="_samplea.pdf" width="2.5" />
    </PlaceObject>
  </Record>
</Layout>

[pr-apes]

I am not sure if I am happy with it. left/right and top/bottom are easy but this leads to decisions that are not intuitively "correct".

Perhaps it was a mistake to allow hreference="center". This is only good if the width of the object is a) an integer value and b) an odd number.

I have just read in https://doc.speedata.de/publisher/en/commandreference/placeobject/ about hreference:

center

The column determines the center of the object. Works only with absolute positioning.

So, no need to extend vreference="middle" to grid. Only for absolute positioning makes total sense (and it would be consistent with hreference="center".

[pgundlach]

I should read the documentation.... Thank you for the link

[pgundlach]

Will be included in the next version

[pr-apes]

Great to read that!