oak-editor/docs/plans/issues-9-20-dependency-plan.md

Issues 9–20 (#34–#45): Dependency Analysis & Two-Person Split

Scope: the twelve "Structure migrations" sub-issues of #26 (Eliminating EventBridge), GitHub issues #34–#45. Each is independently shippable; this document captures the real ordering constraints so two people can work in parallel without stepping on each other.

Hard dependencies

Only two kinds exist:

1. The issue 7 signal (Core::undo_index_changed) — required by issues 9, 11, 15, 16 (and used by 10/12/13/17 for undo refresh). ✅ Already landed in a030f2da2 (issue 7 / #55). No longer blocks anything.

2. The issue 15 "project load finished" hook (Core broadcasts after TaskDialog load success). Explicitly reused by:

   • issue 13 (#38) — "re-read uniformly after undo/load"
   • issue 17 (#42) — "undo and load rebuild uniformly"
   • issue 19 (#44) — "on load completion do a uniform model reset (reuse the issue 15 hook)"

Everything else has no ordering constraints.

Dependency graph

issue 7 (done) ──┬─> 9, 10, 11, 12, 16        (undo refresh signal, available now)
                 └─> 15 ──┬─> 13              (project-load hook)
                          ├─> 17
                          └─> 19
14, 18, 20 — fully independent

File-overlap (merge-conflict) risks

Pair	Overlap	Severity
15 / 16	both in app/widget/nodeview/ (+ mainwindow.cpp in 16)	low — different files
17 / 18	both in app/widget/timelinewidget/ (17 heavily edits timelinewidget.cpp)	medium — keep in the same person's queue
12 / 13 / 14	all under app/widget/nodeparamview/	low — different files
9 / 10	marker/workarea pattern is identical; not the same files	none, but cheap to do together

Suggested split

Person A — "signals already available" batch (start immediately):

• issue 9 (#34) — seekablewidget marker/workarea
• issue 10 (#35) — resizabletimelinescrollbar marker/workarea (same pattern as 9)
• issue 11 (#36) — nodeviewitem label/color/message/array
• issue 12 (#37) — NodeParamViewItem / arraywidget / keyframecontrol
• issue 14 (#39) — NodeParamView group passthrough / context
• issue 20 (#45) — misc leftovers

Person B — "project-load hook" chain (15 first, then its dependents):

• issue 15 (#40) — nodeviewcontext structure core + add the load hook
• issue 16 (#41) — nodeview NODE_REMOVED_FROM_GRAPH (same area as 15)
• issue 13 (#38) — nodeparamviewwidgetbridge values (needs the hook)
• issue 17 (#42) — timelinewidget track/block structure (needs the hook; keeps 18's neighbor in one queue)
• issue 18 (#43) — trackviewitem index/muted
• issue 19 (#44) — projectviewmodel folder/label (needs the hook)

Rationale: B owns everything that consumes the issue 15 hook, so the hook's API is designed and used by one person with no cross-team blocking. A's batch only needs the already-landed issue 7 signal, so both can start today. Workload is ~6 × 0.5 day each side.

Ground rules still apply per issue: cmake --build cmake-build-debug -j8 && cd cmake-build-debug && ctest -j4 must be green (122/122) before shipping, and remove the matching bridge_->subscribe / oakengine_event_subscribe calls when done.