---
phase: 05-multi-wald-system-wald-pagination-und-navigation-zwischen-w-ldern
plan: 02
subsystem: ui
tags: [forest, pagination, navigation, indexeddb, animation]

# Dependency graph
requires:
  - phase: 05-01
    provides: renderForestScene with page param, SLOTS_PER_PAGE constant, currentForestPage in Progress

provides:
  - Arrow navigation between forest pages (prev/next buttons wired in initForestScreen)
  - currentForestPage persisted to IndexedDB on every navigation
  - Fade-out/fade-in opacity transition on page change
  - Post-lesson "Zurück zum Wald" navigates to page containing new element
  - slotIndex in reward.ts uses SLOTS_PER_PAGE constant (no more hardcoded 12)

affects:
  - forest navigation flow
  - reward screen back-to-forest flow

# Tech tracking
tech-stack:
  added: []
  patterns:
    - navigateToPage closure captures currentPage in initForestScreen for correct button wiring
    - saveProgress called with fresh getProgress read to avoid stale data on navigation

key-files:
  created: []
  modified:
    - src/forest/scene.ts
    - src/forest/reward.ts
    - src/app.ts

key-decisions:
  - "navigateToPage in initForestScreen reads fresh progress before saving to avoid overwriting concurrent changes"
  - "Zurück zum Wald computes newPage from elements.length before initForestScreen to control which page is shown"
  - "Fade animation uses grid.style.opacity toggle with requestAnimationFrame for natural transition"

patterns-established:
  - "Pattern: Page persistence reads fresh progress (getProgress) rather than mutating stale reference"

requirements-completed: [MWLD-05, MWLD-06, MWLD-07]

# Metrics
duration: 2min
completed: 2026-03-29
---

# Phase 05 Plan 02: Multi-Wald Navigation Summary

**Arrow navigation between forest pages with IndexedDB persistence, fade animation, and correct post-lesson page targeting**

## Performance

- **Duration:** 2 min
- **Started:** 2026-03-29T21:01:24Z
- **Completed:** 2026-03-29T21:03:30Z
- **Tasks:** 2 (+ 1 auto-approved checkpoint)
- **Files modified:** 3

## Accomplishments

- Wired prev/next navigation buttons in `initForestScreen` with closure over `currentPage`
- Persists `currentForestPage` to IndexedDB on every page navigation via `saveProgress`
- Added 0.3s opacity fade-out/fade-in transition to `renderForestScene` for smooth page changes
- "Zurück zum Wald" after lesson now computes last page from element count and updates progress before `initForestScreen`
- Replaced hardcoded `% 12` in `reward.ts` slot calculation with `% SLOTS_PER_PAGE` import

## Task Commits

Each task was committed atomically:

1. **Task 1: Wire navigation handlers and page persistence in initForestScreen** - `13b8df5` (feat)
2. **Task 2: Fix reward flow and all renderForestScene call sites for pagination** - `8f88843` (feat)
3. **Task 3: Verify multi-forest navigation** - auto-approved checkpoint (--auto mode)

## Files Created/Modified

- `src/forest/scene.ts` - Added `saveProgress` import, navigation button handlers with `navigateToPage` closure, fade animation
- `src/forest/reward.ts` - Imported `SLOTS_PER_PAGE` from `./scene`, replaced `% 12` with `% SLOTS_PER_PAGE`
- `src/app.ts` - Imported `SLOTS_PER_PAGE` and `getForestElements`; updated Zurück-zum-Wald callback to navigate to element's page

## Decisions Made

- `navigateToPage` reads fresh progress before saving to avoid overwriting data changed by other parts of the app during navigation
- The "Zurück zum Wald" callback computes `newPage` from `elements.length` after the new element is already saved, so it always resolves to the correct last page
- `initForestScreen` is called after setting `currentForestPage` in progress so the nav renders correctly from the start

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None.

## Next Phase Readiness

- Multi-Wald navigation complete. Phase 05 is fully done.
- Forest pagination is interactive, persistent, and animated.
- No blockers.

## Self-Check: PASSED

- src/forest/scene.ts: FOUND
- src/forest/reward.ts: FOUND
- src/app.ts: FOUND
- 05-02-SUMMARY.md: FOUND
- Commit 13b8df5: FOUND
- Commit 8f88843: FOUND

---
*Phase: 05-multi-wald-system-wald-pagination-und-navigation-zwischen-w-ldern*
*Completed: 2026-03-29*
