led2/.planning/phases/04-timeline-editor/04-04-SUMMARY.md

phase, plan, subsystem, tags, dependency_graph, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	dependency_graph	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
04-timeline-editor	04	ui	canvas timeline inspector color-picker command-pattern undo-redo	requires provides affects phase provides 04-timeline-editor/04-02 CommandHistory, DeleteBlockCommand, syncBlock, selectedBlock, _onSelectBlock callback UpdateParamsCommand (undoable color/speed/direction/length changes) BlockInspector class rendering compact strip with all param controls Inspector show/hide wired to block selection via _onSelectBlock Block canvas fill uses params.color for visual distinction Undo/redo refreshes inspector values via re-triggered _onSelectBlock	added patterns BlockInspector wired via callback: timeline._onSelectBlock = (block) => inspector.show(block) Inspector delete wires via _onDelete callback to fire DeleteBlockCommand through timeline.history UpdateParamsCommand uses module-level currentShowId (same pattern as existing commands) Color change committed on 'change' event not 'input' — avoids command flood during color drag Block canvas fill uses blockColor + '1a' hex suffix for ~10% opacity color accent	created modified lightsync/frontend/timeline/inspector.js lightsync/frontend/timeline/commands.js lightsync/frontend/timeline/timeline.js lightsync/frontend/app.js	UpdateParamsCommand uses currentShowId (module-level var) not this._showId — matches existing command pattern in commands.js Color input fires 'change' (not 'input') to create command — avoids flooding command history during native color picker drag	Inspector callbacks: _onSelectBlock and _onDelete on inspector — app.js wires both after creating inspector	TL-04	4min	2026-04-06

Phase 04 Plan 04: Block Inspector Panel Summary

Compact inspector strip between timeline and transport bar — shows animation label, color swatch, speed/direction/length controls — all param changes go through UpdateParamsCommand for full undo/redo support.

Performance

• Duration: ~4 min
• Started: 2026-04-06T23:51:12Z
• Completed: 2026-04-06T23:55:00Z
• Tasks: 2
• Files modified: 4 (1 created, 3 modified)

Accomplishments

• UpdateParamsCommand added to commands.js with execute/undo storing old/new params shallow copies
• BlockInspector class rendering inspector strip: animation label, color swatch → hidden color input, SPEED number, DIR select, LEN number, remove button
• Inspector show/hide wired to block selection via timeline._onSelectBlock callback in app.js
• Inspector delete wired via _onDelete → DeleteBlockCommand through timeline.history
• Block fill on canvas uses params.color + '1a' for subtle color accent — color changes visible immediately
• Undo/redo handlers re-trigger _onSelectBlock(selectedBlock) to refresh inspector values after command reversal
• Docker build: clean (no errors)

Task Commits

1. Task 1: UpdateParamsCommand + BlockInspector module - e82fc4a (feat)
2. Task 2: Wire inspector into timeline and app.js - 8e084ca (feat)

Files Created/Modified

• lightsync/frontend/timeline/inspector.js — BlockInspector class with show/hide/_render/_wireEvents, imports UpdateParamsCommand
• lightsync/frontend/timeline/commands.js — UpdateParamsCommand added with currentShowId-based sync
• lightsync/frontend/app.js — imports BlockInspector + DeleteBlockCommand, wires inspector to timeline
• lightsync/frontend/timeline/timeline.js — block color accent from params.color, undo/redo re-triggers inspector refresh

Decisions Made

Decision	Rationale
UpdateParamsCommand uses currentShowId not this._showId	The plan's code had this._showId which doesn't exist — commands.js uses module-level currentShowId, same as all other commands
Color change on change not input	Native color pickers fire input continuously during drag; committing on change prevents hundreds of undo steps for one color change

Deviations from Plan

Auto-fixed Issues

1. [Rule 1 - Bug] Fixed UpdateParamsCommand._showId → currentShowId

• Found during: Task 1 (UpdateParamsCommand implementation)
• Issue: Plan's code used this._showId in syncBlock call, but commands.js uses module-level currentShowId — this._showId is undefined
• Fix: Used currentShowId (module-level variable) matching the exact pattern of PlaceBlockCommand, MoveBlockCommand etc.
• Files modified: lightsync/frontend/timeline/commands.js
• Committed in: e82fc4a

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Total deviations: 1 auto-fixed (Rule 1 - Bug) Impact on plan: Essential fix — this._showId would be undefined at runtime, breaking backend sync for all param changes.

Issues Encountered

None — all other implementation matched the plan exactly.

Known Stubs

None — inspector is fully wired. All param changes route through UpdateParamsCommand. Color accent on canvas reflects actual block color. Remove button fires DeleteBlockCommand. Undo/redo refreshes inspector.

Self-Check: PASSED

• lightsync/frontend/timeline/inspector.js exists: YES (e82fc4a)
• inspector.js exports BlockInspector: YES
• commands.js has UpdateParamsCommand: YES (e82fc4a)
• app.js imports BlockInspector and DeleteBlockCommand: YES (8e084ca)
• app.js wires _onSelectBlock and _onDelete: YES (8e084ca)
• timeline.js uses blockColor + '1a' for fill: YES (8e084ca)
• timeline.js undo/redo re-triggers _onSelectBlock: YES (8e084ca)
• Docker build: SUCCESS (clean)

Next Phase Readiness

• Timeline editor is feature-complete: block place/move/resize/delete/params all undoable
• Inspector provides full visual feedback for selected block parameters
• Phase 04 is complete — all 4 plans done
• No blockers

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Phase: 04-timeline-editor Completed: 2026-04-06