ePub->pdf: How to narrow space between header and book text?

[EbokJunkie]

First, I found that 2.15 almost perfectly converts my ePubs to pdf for reading on my Kindle Paperwhite 2013. I created html template that squeezes author, title, page number, and section into the header: Author and title go to even page, section and page number go to odd page. Template also draws a separation line under the header:

<div style="font-size:x-small">
<span class="even_page"><p style="float:left">_AUTHOR_</p>
<p style="float:right">_TITLE_</p><span><hr width="100%">
</div>
<div style="font-size:x-small">
<span class="odd_page"><p style="float:left">_SECTION_</p>
<p style="float:right">_PAGENUM_</p><span><hr width="100%">
</div>

I'm also happy with Calibre ability to provide hyphens in pdf if source ePub carries properly distributed soft hyphens (see attached PW2 screenshots).

Unfortunately, one issue rains of my parade: Excessively wide space between header and book text.
This space is present even if I don't draw separation line, it always steals at least one line of text from the page top.

My question is: Are there any means to decrease space between header and text?

[meeera]

Stop converting to PDF and let Calibre auto-convert to azw3 instead.

Sorry, I know this doesn't specifically answer your question. But you have a reader that reflows and resizes text in useful and somewhat customisable ways, and a format that converts seamlessly to a format usable by your Kindle - why hobble it by converting to a printed-page-layout format that introduces all sorts of difficulties?

[EbokJunkie]

@meeera

pdf is absolutely perfect format for reading on Kindle Paperwite/Voyage - if conversion is implemented specifically for correct page size, convenient font size and weight, right side margins etc. Kindle Paperwhite/Voyage allow to control text contrast from lightest to darkest, option unavailable for azw3.
Headers/footers make e-reader page look similar to traditional paper book page.
I also noticed that my favorite Helvetica Neue looks prettier in pdf format than in azw3.
Pdf also deserves more attention being an universal format that works on all modern reading devices.
It just needs some TLC from developers and users.

[kovidgoyal]

decrease page margins in the page layout section and set the margins/padding for the html elements in your template to zero

[EbokJunkie]

Originally Posted by kovidgoyal

decrease page margins in the page layout section and set the margins/padding for the html elements in your template to zero

Thanks, I tried as I could

<div style="font-size:x-small;" >
<span class="even_page">
<p style="float:left;margin-top:0px;margin-bottom:0px;
padding-top:0px;padding-bottom:0px;border-width:0px;" >_AUTHOR_</p>
<p style="float:right;margin-top:0px;margin-bottom:0px;
padding-top:0px;padding-bottom:0px;border-width:0px;">_TITLE_</p> 
</div>
<div style="font-size:x-small;" >
<span class="odd_page">
<p style="float:left;margin-top:0px;margin-bottom:0px;
padding-top:0px;padding-bottom:0px;border-width:0px;">_SECTION_</p>
<p style="float:right;margin-top:0px;margin-bottom:0px;
padding-top:0px;padding-bottom:0px;border-width:0px;">_PAGENUM_</p> 
</div>
<hr width="100%">

but result is not very satisfactory (see attached).

The header itself is more compact but the gap between header and text is even more distinctive. I'm out of ideas how to fill it.

[kovidgoyal]

decrease page margins in the page layout section

[EbokJunkie]

All page margins are zeroes.

[kovidgoyal]

Then that is the best you can get.

[EbokJunkie]

Set up an experiment.
Created a batch file and ran conversion from command line.
Noticed that PDF plugin sends message to output: Top margin is too small for header, increasing it.
Experimented with top margin value and found that at margin>=36 pt this message disappears.
Than I commented out header option in batch file leaving top margin at 36 pt and obtained page text shifted down to exactly the same distance as it was when header was activated.

May it be that Calibre overreacts to header presence and forces top margins to the value (36 pt) that exceeds actual height of the header?
That could be the cause of those extra space.

[kovidgoyal]

That is the cause of it and it is not going to change, as there is no easy way to determine the minimum size for the top margin that will fit the header on all the pages of the book.

[EbokJunkie]

Well, found the top margin 36pt limit here:

src/calibre/ebooks/pdf/render/from_html.py

set min_margin to 15, set Windows development environment and got perfect results.
Thank you for implementation this ingenious technique of adding personal hacks

Just one suggestion while we are on the same page:
It'd be nice to have title truncated to fit into the page width. Longer title like Through the Looking-Glass, and What Alice Found There entirely carry over to the next line so that even existing 36 pt limit might be not able to accommodate it.

[kovidgoyal]

Use the overflow:hidden CSS property alongwith white-space: nowrap

[eschwartz]

In order to preserve the change, commit it and then you can update calibre with

git remote update && git rebase origin/master

Much easier than applying the change each time you reset from upstream, unless you don't update weekly I guess.

[EbokJunkie]

@kovidgoyal

How can I add CSS properties to html template?
Whatever I try, I'm getting errors.

[kovidgoyal]

style="overflow:hidden; white-space: nowrap"