Lib.rs

CLI Tool

The mlt binary provides several commands for working with MLT files:

Commands

• dump - Parse an MLT file and dump raw layer data without decoding
• decode - Parse an MLT file, decode all layers, and dump the result (supports text and GeoJSON output)
• ui - Interactive terminal visualizer for MLT files

Visualizer

The visualizer command provides an interactive terminal-based UI for exploring MLT files:

# Visualize a single MLT file
cargo run -- ui path/to/file.mlt

# Browse and visualize all MLT files in a directory (recursive)
cargo run -- ui path/to/directory

Directory Mode:

• Lists all .mlt files found recursively in the directory
• Use ↑/↓ to navigate the file list
• Press Enter to open and visualize a file
• Press Esc to go back to file list
• Press q to quit

Features:

• Tree View Panel (left): Browse layers and features in a hierarchical tree
• "All Layers" - shows all features from all layers
  • Individual layers - shows all features in that layer
  • Individual features - shows only the selected feature
  • Hovered features are highlighted with underlined green text
• Map Panel (right): Visual representation of the geometries
  • Shows the extent boundary as a thin gray rectangle
  • Color coding by geometry type:
    • Points: Magenta (multipoint: light magenta)
    • LineStrings: Cyan (multi-linestring: light cyan)
    • Polygons: Blue/Red based on winding order (multi-polygon: same)
  • Polygon winding order visualization:
    • Blue: Counter-clockwise rings (typically outer rings)
    • Red: Clockwise rings (typically holes)
  • Selected features: Yellow
  • Hovered features: White
  • Automatically adjusts bounds to fit all visible geometries
• Mouse Interaction:
  • Hover over geometries to highlight them in the tree view
• Keyboard Navigation:
  • ↑/k - Move selection up
  • ↓/j - Move selection down
  • Enter - In layer overview mode, switch to detail mode; In file browser, open selected file
  • Esc - Go back (detail → overview → file list) or quit if at top level
  • q - Quit the visualizer