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Layer Service

app.application.services.tracking.layer_service

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Tracking layer (Layer C/D) CRUD operations and track management.

See Also

Layer: Application. Context: Coordinates domain state and infrastructure to complete application use cases.

TrackingLayerService

Bases: QObject

Manages user-editable tracking layer (DataLayer.D) operations.

Responsibilities
  • CRUD operations for DataLayer.D tracked objects.
  • Copy tracks to adjacent frames.
  • Delete tracks by ID (removes across all frames matching ID).
  • Reset tracks (revert to DataLayer.C raw tracking output).
  • Track lifecycle management.
Note

DataLayer.C — Post-processed immutable tracking output (machine-written). DataLayer.D — User-editable tracks seeded from C, allowing corrections. Tracks persist across frames (track ID unites multiple frame detections). User edits don't affect DataLayer.C (can always revert).

Design pattern: New tracking output eagerly seeds Layer D; older sessions retain JIT seeding. User edits to Layer D are persistent (survives re-rendering). Layer C is immutable reference point.

PARAMETER DESCRIPTION
app

Application adapted for session lookup and tracking-layer reads and mutations.

TYPE: Application

__init__(app: Application) -> None

delete_tracks_by_id_and_direction(s_id: SessionId, t_id: str, direction: Direction) -> None

Delete a track's later or earlier occurrences in reviewed Layer D.

PARAMETER DESCRIPTION
s_id

Identifier of the session whose tracks are edited.

TYPE: SessionId

t_id

Track identifier to delete from subsequent or preceding frames.

TYPE: str

direction

Whether to delete forward from or backward before the current frame.

TYPE: Direction

RAISES DESCRIPTION
UnsupportedDirectionException

If direction is neither NEXT nor PREV.
Side Effects

Seeds absent D frames from C using the same filters as tab reads. Resolves display IDs to storage keys before deletion. Current frame, initialized edits, and immutable C remain intact; empty D entries prevent deleted tracks from being re-seeded on subsequent reads.