Displaying the page number in TOC items

cricobs · 05-01-2017, 09:35 PM

In the ebook viewer, I would like to display the page number in which an entry in the TOC begins. I see the items have some properties that might be useful, like starts_at, start_src_offset, or start_anchor. I'm having trouble in finding out how to calculate the page with those values.

kovidgoyal · 05-01-2017, 10:24 PM

There are no page numbers in ebooks. If you mean the simulated page numbers displayed, you cannot since calculating them requires rendering every html file in advance.

cricobs · 05-02-2017, 08:36 AM

So there is no easy way. Can the item.start_src_offset be used to calculate the page using the page offset from the top and height as reference, or something like that? Haven't looked at the code yet, but any clues on how the the fake page number is being calculated? I hope you don't mind I forked your project

"calibre highway" on github,

. Heavily modifying the viewer, you will hate it :'(

kovidgoyal · 05-02-2017, 10:03 AM

I never mind forks -- that's why calibre is open source -- to encourage others to learn contribute and even fork.

Just so you knwo the existing viewer is in maintenance mode. I have developed an in browser viewer for calibre 3 and the code base of that viewer will eventually replace this one, probably using QtWebEngine instead of QtWebKit.

As for how the fake page number is calculated, see set_page_number and scroll_fraction

cricobs · 05-02-2017, 02:00 PM

Thanks for the heads up! I'm actually planning on a standalone viewer though.

Thanks for your awesome work!

05-01-2017, 09:35 PM	#1
cricobs Junior Member Posts: 3 Karma: 10 Join Date: May 2017 Device: desktop	Displaying the page number in TOC items In the ebook viewer, I would like to display the page number in which an entry in the TOC begins. I see the items have some properties that might be useful, like starts_at, start_src_offset, or start_anchor. I'm having trouble in finding out how to calculate the page with those values. Last edited by cricobs; 05-01-2017 at 09:39 PM. Reason: yes

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05-01-2017, 10:24 PM	#2
kovidgoyal creator of calibre Posts: 43,843 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	There are no page numbers in ebooks. If you mean the simulated page numbers displayed, you cannot since calculating them requires rendering every html file in advance.

05-02-2017, 08:36 AM	#3
cricobs Junior Member Posts: 3 Karma: 10 Join Date: May 2017 Device: desktop	So there is no easy way. Can the item.start_src_offset be used to calculate the page using the page offset from the top and height as reference, or something like that? Haven't looked at the code yet, but any clues on how the the fake page number is being calculated? I hope you don't mind I forked your project "calibre highway" on github, . Heavily modifying the viewer, you will hate it :'(

05-02-2017, 10:03 AM	#4
kovidgoyal creator of calibre Posts: 43,843 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	I never mind forks -- that's why calibre is open source -- to encourage others to learn contribute and even fork. Just so you knwo the existing viewer is in maintenance mode. I have developed an in browser viewer for calibre 3 and the code base of that viewer will eventually replace this one, probably using QtWebEngine instead of QtWebKit. As for how the fake page number is calculated, see set_page_number and scroll_fraction

05-02-2017, 02:00 PM	#5
cricobs Junior Member Posts: 3 Karma: 10 Join Date: May 2017 Device: desktop	Thanks for the heads up! I'm actually planning on a standalone viewer though. Thanks for your awesome work!

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