Store per-page paragraph indices in section cache to enable precise
XPath-to-page and page-to-XPath mapping without reparsing XHTML.
Forward path (upload): generates XPath directly from paragraph LUT
instead of byte-offset estimation, eliminating drift in chapters
with non-uniform content density.
Reverse path (download): resolves incoming KOReader XPath p[N] to
the exact page via paragraph LUT lookup.
Paragraph counter counts all <p> elements including display:none
to match ChapterXPathIndexer and crengine's standard XPath counting.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
## Summary
* Original implementation had inconsistent positioning logic:
- When XPath parsing succeeded: incorrectly set pageNumber = 0 (always
beginning of chapter)
- When XPath parsing failed: used percentage for positioning (worked
correctly)
- Result: Positions restored to wrong locations depending on XPath
parsing success
- Mentioned in Issue #581
* Solution
- Unified ProgressMapper::toCrossPoint() to use percentage-based
positioning exclusively for both spine identification and intra-chapter
page calculation, eliminating unreliable XPath parsing entirely.
## Additional Context
* ProgressMapper.cpp: Simplified toCrossPoint() to always use percentage
for positioning, removed parseDocFragmentIndex() function
* ProgressMapper.h: Updated comments and removed unused function
declaration
* Tests confirmed appropriate positioning
* __Notabene: the syncing to another device will (most probably) end up
at the current chapter of crosspoints reading position. There is not
much we can do about it, as KOReader needs to have the correct XPath
information - we can only provide an apporximate position (plus
percentage) - the percentage information is not used in KOReaders
current implementation__
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? YES
## Summary
- Adds KOReader progress sync integration, allowing CrossPoint to sync
reading positions with other
KOReader-compatible devices
- Stores credentials securely with XOR obfuscation
- Uses KOReader's partial MD5 document hashing for cross-device book
matching
- Syncs position via percentage with estimated XPath for compatibility
# Features
- Settings: KOReader Username, Password, and Authenticate options
- Sync from chapters menu: "Sync Progress" option appears when
credentials are configured
- Bidirectional sync: Can apply remote progress or upload local progress
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
