Simply Screens 0.8.4

Highlights & Major Improvements

• Authoritative Multi-Block Screen Lifecycle & Topology Reconciliation:

  • Multi-block screens now maintain an authoritative anchor block entity that synchronizes structure bounds, displayed image, aspect ratio, and linked-screen identity across chunks.
  • Seamlessly handles expanding screens from negative directions, merging adjacent displays, and breaking middle or corner blocks without corrupting metadata or leaving orphan child entities.
  • Leftover blocks outside restructured screens are cleanly detached and promoted to independent anchors with inherited properties.
  • Replicated authoritative state on dedicated multiplayer clients ensures screens render reliably regardless of chunk unload states.
  • Capped structure detection and dimensions to a maximum of 64x64 blocks.

• Atomic Linked Screen Management & Quota Enforcement:

  • Combined Screen ID assignment and image selection into a single atomic transaction packet, preventing partial updates upon permission or claim failure.
  • Linked Screen IDs are now persistent, server-owned resources with claim quotas (MAX_OWNED_SCREEN_IDS_PER_PLAYER = 64) and owner validation.
  • Global cross-dimension image broadcasts now iterate all loaded server levels (server.getAllLevels()).
  • Added support for clearing/unlinking screen IDs directly from the GUI.

• Security & Transfer Hardening:

  • Added strict SSRF protections preventing URL image downloads targeting private, loopback, link-local, multicast, or cloud-metadata network destinations.
  • Added bounded worker queues, per-player upload concurrency limits, transaction timeouts, and deterministic cleanup for chunked transfers.
  • Added full image decode checks (ImageIO.read()) before publication to verify image stream integrity and reject malicious/corrupted payloads.
  • Added server-authoritative packet security validating player permissions, world boundaries, distance, dimension, and loaded chunk status.

• Crash Resilience & Registry Persistence:

  • Registry writes now use a resilient .tmp -> .bak backup with atomic file moves.
  • Automatic backup recovery restores corrupt registry files upon startup or reload.
  • Safe world-switch cleanup and cache invalidation.

• Cross-Platform Compatibility & Fixes:

  • Fixed native file picker on macOS by splitting TinyFileDialogs filter arguments.
  • Fixed stale list item selection callbacks and image list broadcasts.
  • Added automated GitHub Actions PR & release test workflows.