Additional MVP document reader functionality

[anjackson]

Following initial evaluate, we need to build on the original PDF/ePub implementation #68 and add the following features:

• Citation:
  • Chapter and paragraph citation For ePub documents, show chapter and paragraph numbers when text is selected, for citation purposes. #98
  • Ability to enter chapter and paragraph numbers to resolve a citation.
• Search:
  • Searching for a keyword through an entire ebook and being able to view all of the results (it’s possible to do some limited search using ctrl+f) (seems possible, see https://github.com/futurepress/epub.js/wiki/Tips-and-Tricks-(v0.3)#searching-the-entire-book)
• Print:
  • Being able to preview all pages in print preview (might have to be per-chapter, using whole-chapter view, see Support PDF and ePub 2/3 rendering as HTML #68 (comment))
  • Being able to print a range of pages (might have to be per-chapter , using whole chapter view, as above).

The PDF, viewer does meet this requirements already, although printing can be slow because it currently renders all pages first.

The ePub viewer generally works well but is somewhat confusing because it is so different from the PDF viewer UI. e.g. both can zoom, but the PDF viewer has dedicated buttons whereas the ePub viewer relies on the browser zoom. Ideally, both interfaces would be consistent.

One option is to switch to a UV implementation that supports both formats in a consistent manner. This should be evaluated, with the above requirements (and the core requirements the existing system already meets) kept in mind. I think those core requirements are:

• Outline (if available)
• Thumbnails (if available) with position/page number shown on hover
• Zoom
• Current position/page indicator

[anjackson]

Note that in #99 I experimented with a different ePub reader library called Vivliostyle. This could be considered if adding the above functionality to the existing reader is problematic.

[anjackson]

Note that the citation proposal #98 does not expose (and does not necessarily require) implementation of the EPUB Canonical Fragment Identifiers.

[anjackson]

@tw4l On the Search feature, it is possible to bind it to CTRL-F to use your search rather than the browser page search?

[tw4l]

@tw4l On the Search feature, it is possible to bind it to CTRL-F to use your search rather than the browser page search?

Sure thing! I'll add it on my list for tomorrow's ukwa-pywb work :) I don't think I can make the browser's find box run the app's search function, but I probably can make it so that CTRL-F opens the in-app search tab and focuses on the input.

[tw4l]

@anjackson Merged as part of #108 along with a fix for the Reference bug we had before that required viewing a chapter before "Jump to citation" would work.

Only thing to note is that for now jumping to a citation will only highlight the first character of the paragraph - we can discuss coming back to highlighting the whole paragraph if need be after printing but it was proving to be difficult and I wanted to move on to make sure we hit the next milestone.