• Lightweight timeline overview for planned satellite contacts, intended for WASM and low-end devices.
• Reusable TimelineView QQuickItem that renders lanes per ground station and a moving "now" marker.
• The bundled Qt/QML application is for testing & development only; not a reference UI.

• Single renderer: one custom C++ QQuickItem draws all lanes, blocks, and markers via the GPU scenegraph.
• Timeline projection is owned by the view; data is provided as timestamps and identifiers.
• Demo application derives data inputs via NATS KV, but the view is transport-agnostic.

• X axis: time window in seconds, with "now" positioned at a configurable ratio (default ~1/3 from left).
• The demo exposes a horizontal scrollbar that shifts the time window via timeOffsetSeconds.
• Y axis: lanes per ground station (gs_id), ordered by first appearance in the input data.
• Labels and a simple time scale are rendered inside the TimelineView item.
• Overlapping contacts within a ground station are stacked into sublanes inside that station's band.
• The view can enforce a minimum pixel density (minPixelsPerHour), shrinking the visible time window on narrow widths while keeping horizontal scrolling available in the demo.
• In portrait aspect ratios, the view auto-rotates 90 degrees anticlockwise.
• Contacts are rendered as filled rectangles per lane; active contacts show a progress fill.

TimelineView consumes a list of maps with at least:

• gs_id (string)
• start_ts (Unix seconds, double)
• end_ts (Unix seconds, double)

Optional fields (forwarded untouched in the raw map):

• sat_id, sat_name, duration_min, max_elev_deg

• Bucket: mplanner (default)
• Key: m.plan.current

Example content (JSON equivalent of CBOR):

{
  "gs_id": "gnd_london",
  "sat_id": 42961,
  "sat_name": "IRIDIUM 132",
  "start_ts": 1768177380.0,
  "end_ts": 1768178220.0,
  "duration_min": 14,
  "max_elev_deg": 17.683277916110466
}

A payload may also be an array of contact maps; the demo watcher accepts either.

• Goal is very lightweight rendering & smooth performance on low-end devices e.g. in WASM.
• Coupling to NATS KV is at application level.
• All rendering stays in one C++ QQuickItem.

This project is distributed under the Mozilla Public License 2.0. See LICENSE.txt for details.