Read-only structural inspection of a template package.

inspect/1 reads a .pptx/.potx package and reports what is actually in it: the slide size, the slide masters, and for every slide layout its name, its type, the master it sits on, and every placeholder it defines with the bounding box that placeholder resolves to.

template = Podium.Template.inspect("priv/brand/skeleton.pptx")

for {index, layout} <- Enum.sort(template.layouts) do
  IO.puts("#{index}: #{layout.name}")

  for ph <- layout.placeholders do
    IO.puts("   {#{ph.type}, #{ph.idx}} #{ph.name}")
  end
end

The {type, idx} pair reported for a placeholder is what Podium.set_placeholder/3, Podium.set_picture_placeholder/3, Podium.set_chart_placeholder/6 and Podium.set_table_placeholder/5 take to address that placeholder on a slide built on the layout.

Placeholder attribute defaults

A <p:ph/> element without a type attribute means "obj", and one without an idx attribute means 0. Inspection fills both in, so a placeholder's type is always a string and its idx always an integer.

Box inheritance

A layout placeholder that carries its own <a:xfrm> uses it. One that does not inherits the box of the master placeholder found by type: ctrTitle and title inherit from the master's title; body, subTitle, obj, chart, tbl, pic, clipArt, dgm and media inherit from the master's body; dt, ftr and sldNum inherit from the master placeholder of the same type. This is how PowerPoint resolves it. box is nil when nothing in the chain has a position.