Print to pdf doesn't center in page or print code blocks

[braje]

I am using the latest version of reveal.js (from 8/16 master) and am having a couple of problems with the print to pdf plugin.

The first is that code snippets (inside of a

 block) aren't being included in the pdf.  I am using the highlight plugin (though I am using my own downloaded version so I could include source languages not included with reveal).

The second (much more minor) is that the content of each slide is not centered vertically like it is in the html presentation.

[braje]

Ignore the first issue. It is a problem with my own css...

[hakimel]

I tried but was never able to achieve vertically centered slides in PDF output. Unfortunately no change since then so this limitation will remain.

[tomByrer]

I would try with a 'print' or 'PDF' specific CSS rule to make a box around the slide, a box inside the full page, then center.

[millermedeiros]

I got the vertical centering to work by wrapping all slide contents with 2 divs and using flexbox:

function toArray(o) {
  return Array.prototype.slice.call(o);
}

toArray( document.querySelectorAll( '.reveal .slides section' ) ).forEach(function(slide){
  var outerWrapper = document.createElement('div');
  outerWrapper.style.cssText = 'display:flex; align-items:center; height:100%';

  var wrapper = document.createElement('div');
  wrapper.style.width = '100%';
  outerWrapper.appendChild(wrapper);

  toArray( slide.children ).forEach(wrapper.appendChild, wrapper);

  slide.style.height = '100%';
  slide.appendChild(outerWrapper);
});

running this snippet on the dev tools just before exporting the PDF solved the issue for me (chrome 32.0.1652.0 canary).

I'm not submitting a pull request because I don't know what you guys would like to do, if the whole centering logic should be changed to use flexbox in all cases or if it should be just a simple monkey-patch in case isPrintingPDF.

I had the "idea" thanks to solved by flexbox

PS: there is also another issue asking for same feature (#458)

[hakimel]

Thanks @millermedeiros. Hadn't considered flexbox for this.

Judging by http://caniuse.com/flexbox it seems compatible enough to merit a migration from the current JS-based centering for both normal viewing and PDF printing. Will file a new issue to give that a try.

[Ciges]

Great! I have just added to my reveal.js presentation and works perfectly

Thanks @millermedeiros!

[Ciges]

When using markdown syntax this code does not work and I have not been able to solve it.

I used JQuery and the sections are identified but the content is not inserted :-(

@millermedeiros Could you help me?