Faditor mini ARCHITECTURE

Faditor Mini — Architecture Overview

Quick Reference: File Locations

Core Activity & Entry Point

• FaditorEditorActivity.java — Main editor activity (full-screen)
  📍 app/src/main/java/com/fadcam/ui/faditor/FaditorEditorActivity.java
• FaditorMiniFragment.java — Tab entry point (video picker)
  📍 app/src/main/java/com/fadcam/ui/FaditorMiniFragment.java

Data Models

• Clip.java — Single video segment
  📍 app/src/main/java/com/fadcam/ui/faditor/model/Clip.java
• Timeline.java — Ordered list of clips
  📍 app/src/main/java/com/fadcam/ui/faditor/model/Timeline.java
• FaditorProject.java — Project wrapper
  📍 app/src/main/java/com/fadcam/ui/faditor/model/FaditorProject.java
• ExportSettings.java — Export configuration
  📍 app/src/main/java/com/fadcam/ui/faditor/model/ExportSettings.java

Player & Playback

• FaditorPlayerManager.java — ExoPlayer lifecycle & controls
  📍 app/src/main/java/com/fadcam/ui/faditor/player/FaditorPlayerManager.java
• TimelineView.java — Custom timeline widget with trim handles
  📍 app/src/main/java/com/fadcam/ui/faditor/timeline/TimelineView.java

Export & Processing

• ExportManager.java — Media3 Transformer orchestration
  📍 app/src/main/java/com/fadcam/ui/faditor/export/ExportManager.java

Project Persistence

• ProjectStorage.java — JSON persistence (Gson + auto-save)
  📍 app/src/main/java/com/fadcam/ui/faditor/project/ProjectStorage.java
• UndoManager.java — Undo/redo state management
  📍 app/src/main/java/com/fadcam/ui/faditor/undo/UndoManager.java

Utilities

• crop/ — Crop transformation logic
  📍 app/src/main/java/com/fadcam/ui/faditor/crop/
• util/ — Helpers (time formatting, etc.)
  📍 app/src/main/java/com/fadcam/ui/faditor/util/

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Architecture Summary

User Flow:
FaditorMiniFragment (tab)
  ↓ [video picker]
FaditorEditorActivity (full-screen)
  ├─ FaditorPlayerManager (ExoPlayer playback)
  ├─ TimelineView (custom timeline UI)
  ├─ ProjectStorage (JSON persistence)
  └─ ExportManager (Media3 Transformer)
  ↓ [export done]
FaditorMiniFragment (back to tab with exported file)

Key Design Decisions

Component	Technology	Why
Playback	Media3 ExoPlayer	Battle-tested, hardware acceleration, effects-capable
Export	Media3 Transformer	Frame-accurate lossless trim, unified pipeline
Trim Mode	EditList (near-lossless)	Precise frame-level accuracy without re-encoding entire file
Persistence	JSON (Gson) + auto-save	Simple, scalable, 3-second debounce
Navigation	Separate Activity	Clean lifecycle, SurfaceView z-order isolation

Data Model (Scalable)

FaditorProject
├── id: UUID
├── name: String
├── timeline: Timeline
│   └── clips: List<Clip>
│       ├── sourceUri: Uri
│       ├── inPointMs: long
│       ├── outPointMs: long
│       ├── speedMultiplier: float
│       └── effects: List<Effect>
└── exportSettings: ExportSettings
    ├── resolution, quality, format

Supports: Single trim → multi-clip → effects → audio mixing (future phases)

Auto-Save Mechanism

• Debounce Delay: 3 seconds (configurable via AUTO_SAVE_DELAY_MS)
• Trigger: Every edit (trim, rotate, flip, crop, speed, audio)
• Files Saved Together:
  • files/faditor/projects/{projectId}/project.json
  • files/faditor/projects/{projectId}/undo_history.json
• Implementation: Handler-based debounce in FaditorEditorActivity

  Handler.postDelayed(autoSaveRunnable, AUTO_SAVE_DELAY_MS)
  // Resets timer on each edit (debounce)

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Referenced Document

• Full details: See the main repo file FADITOR_MINI_PLAN.md for complete tech stack and phase roadmap.