# Merge PR #979: Silent Pre-Indexing + Indexing Display Setting

**Date:** 2026-02-18
**Branch:** `mod/merge-upstream-pr-979`

## Task Description

Merged upstream PR #979 (silent pre-indexing for the next chapter) and implemented both "Possible Improvements" from the PR:
1. A user setting to choose between Popup, Status Bar Text, or Status Bar Icon for indexing feedback.
2. Status bar indicator rendering during silent pre-indexing.

## Changes Made

### PR #979 Cherry-Pick (2 files)
- **`src/activities/reader/EpubReaderActivity.h`** -- Added `silentIndexNextChapterIfNeeded()` method declaration and `silentIndexingActive` flag.
- **`src/activities/reader/EpubReaderActivity.cpp`** -- Moved viewport dimension calculations before the `!section` block. Added `silentIndexNextChapterIfNeeded()` implementation that pre-indexes the next chapter when the penultimate page is displayed.

### New "Indexing Display" Setting (5 files)
- **`src/CrossPointSettings.h`** -- Added `INDEXING_DISPLAY` enum (POPUP, STATUS_TEXT, STATUS_ICON) and `indexingDisplay` field.
- **`src/CrossPointSettings.cpp`** -- Added persistence (write/read) for the new setting at the end of the settings chain.
- **`src/SettingsList.h`** -- Registered the new Enum setting in the Display category.
- **`lib/I18n/I18nKeys.h`** -- Added 4 new string IDs: `STR_INDEXING_DISPLAY`, `STR_INDEXING_POPUP`, `STR_INDEXING_STATUS_TEXT`, `STR_INDEXING_STATUS_ICON`.
- **`lib/I18n/translations/*.yaml`** (8 files) -- Added translations for all 8 languages.

### Status Bar Indicator Implementation
- **`EpubReaderActivity.cpp`** -- Conditional popup logic: only shows popup when setting is POPUP; for STATUS_TEXT/STATUS_ICON, shows centered "Indexing..." text on blank screen during non-silent indexing. For silent pre-indexing, sets `silentIndexingActive` flag before rendering so `renderStatusBar()` draws the indicator (text or 8x8 hourglass icon) in the status bar.
- Defined an 8x8 1-bit hourglass bitmap icon (`kIndexingIcon`) for the icon mode.

## Build Verification

- PlatformIO build: SUCCESS
- RAM: 31.1% (101,820 / 327,680 bytes)
- Flash: 99.6% (6,525,028 / 6,553,600 bytes)

## Follow-Up Items

- Test on device: verify silent indexing triggers on penultimate page, verify all three display modes work correctly.
- The status bar indicator shows optimistically on penultimate pages even if the next chapter is already cached (false positive clears immediately after `loadSectionFile` check).
- Flash usage is at 99.6% -- monitor for future additions.