---
phase: 05-multi-wald-system-wald-pagination-und-navigation-zwischen-w-ldern
plan: 01
subsystem: ui
tags: [pagination, forest, indexeddb, progress, typescript, css]

# Dependency graph
requires:
  - phase: 04-polish-audio
    provides: forest scene rendering, Progress type, IndexedDB storage

provides:
  - Progress.currentForestPage field with migration support
  - SLOTS_PER_PAGE = 12 exported constant
  - renderForestScene with page parameter and element slicing
  - Forest navigation DOM (forest-nav, forest-nav-prev, forest-nav-next, forest-nav-text)
  - CSS styling for forest navigation buttons (44px touch targets, pastel BEM)

affects: [05-02-navigation-event-handlers, any plan reading renderForestScene signature]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Pagination via page * SLOTS_PER_PAGE slice on IndexedDB array"
    - "Navigation UI updated from inside renderForestScene after element rendering"
    - "Progress migration pattern: check === undefined before setting default"

key-files:
  created: []
  modified:
    - src/types.ts
    - src/forest/scene.ts
    - src/app.ts
    - src/storage/db.test.ts
    - src/ui/screens.ts
    - index.html
    - src/styles/main.css

key-decisions:
  - "renderForestScene owns nav UI update: called after element rendering with totalPages from full element array"
  - "SLOTS_PER_PAGE exported as named constant so Plan 02 can import without duplication"
  - "Progress objects in db.test.ts and screens.ts updated to include currentForestPage: 0 to satisfy TypeScript strict interface checks"

patterns-established:
  - "Navigation visibility controlled via navContainer.style.display (none vs flex) from render function"

requirements-completed: [MWLD-01, MWLD-02, MWLD-03, MWLD-04]

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

# Phase 05 Plan 01: Multi-Wald-System — Pagination Data Model and Rendering Summary

**Paginated forest rendering with SLOTS_PER_PAGE=12, currentForestPage in Progress type, and navigation DOM (prev/next buttons + page indicator) hidden by default until multiple pages exist.**

## Performance

- **Duration:** 2 min
- **Started:** 2026-03-29T20:56:13Z
- **Completed:** 2026-03-29T20:58:30Z
- **Tasks:** 2
- **Files modified:** 7

## Accomplishments

- Extended Progress interface with `currentForestPage: number` and migrateProgress entry for backward compatibility
- Modified `renderForestScene` to accept a `page` parameter and slice `elements[start..end]` based on `page * SLOTS_PER_PAGE`
- Added navigation DOM structure (forest-nav container, prev/next buttons with aria-labels in German, page indicator span) hidden by default
- Added CSS for .forest__nav, .forest__nav-btn with 44px minimum touch targets and pastel BEM styling

## Task Commits

Each task was committed atomically:

1. **Task 1: Extend Progress type and add paginated renderForestScene** - `559d57a` (feat)
2. **Task 2: Add navigation DOM elements and CSS styling** - `348a71a` (feat)

**Plan metadata:** _(docs commit follows)_

## Files Created/Modified

- `src/types.ts` - Added `currentForestPage: number` field to Progress interface
- `src/forest/scene.ts` - Added `SLOTS_PER_PAGE = 12` export, changed renderForestScene signature to `(db, page, newElementId?)`, added nav UI update block
- `src/app.ts` - Added `if (progress.currentForestPage === undefined) progress.currentForestPage = 0` in migrateProgress; updated renderForestScene call with page param
- `src/storage/db.test.ts` - Added `currentForestPage: 0` to test Progress literal (Rule 1 auto-fix)
- `src/ui/screens.ts` - Added `currentForestPage: 0` to initial Progress creation (Rule 1 auto-fix)
- `index.html` - Added `<div id="forest-nav">` with prev/next buttons and page text between forest scene and level map
- `src/styles/main.css` - Added forest navigation CSS block after `@keyframes forest-element-appear`

## Decisions Made

- Navigation UI is managed entirely from within `renderForestScene`: after rendering elements, it reads `elements.length` to calculate `totalPages` and updates the nav DOM. This keeps nav state always in sync with rendered content.
- `SLOTS_PER_PAGE` exported as a named constant so Plan 02 can import it without magic numbers.
- Progress objects in `db.test.ts` and `screens.ts` were updated to satisfy TypeScript strict interface checks — these are correctness fixes, not scope creep.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Added currentForestPage to Progress literals in db.test.ts and screens.ts**
- **Found during:** Task 1 (TypeScript compile check)
- **Issue:** Two files had inline `const progress: Progress = {...}` literals that were missing the new required field, causing `tsc --noEmit` to fail with TS2741 errors
- **Fix:** Added `currentForestPage: 0` to both Progress object literals
- **Files modified:** `src/storage/db.test.ts`, `src/ui/screens.ts`
- **Verification:** `npx tsc --noEmit` exits 0 after fix
- **Committed in:** `559d57a` (Task 1 commit)

---

**Total deviations:** 1 auto-fixed (Rule 1 - TypeScript type correctness)
**Impact on plan:** Required fix for TypeScript compilation. No scope creep.

## Issues Encountered

None — plan executed cleanly after TypeScript type fix.

## Next Phase Readiness

- Plan 02 can import `SLOTS_PER_PAGE` from `src/forest/scene.ts` and wire click handlers for `forest-nav-prev` / `forest-nav-next`
- `Progress.currentForestPage` is persisted via existing `saveProgress` flow, no db schema changes needed
- Navigation DOM is in place and hidden; Plan 02 activates it by updating `currentForestPage` and calling `renderForestScene`

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

## Self-Check: PASSED

- FOUND: src/types.ts (contains currentForestPage)
- FOUND: src/forest/scene.ts (contains SLOTS_PER_PAGE, page param)
- FOUND: index.html (contains forest-nav elements)
- FOUND: 05-01-SUMMARY.md
- FOUND commit: 559d57a (Task 1)
- FOUND commit: 348a71a (Task 2)