288 lines
10 KiB
Markdown
288 lines
10 KiB
Markdown
# Plan: MIDI Ghost Notes + Dropdown Item Switcher + Session Sync Mode
|
|
|
|
## Overview
|
|
Three features built on each other:
|
|
1. **Dropdown** at tab title position listing ALL MIDI items across all tracks
|
|
2. **Item switching** — selected item becomes editable, all others become ghost notes
|
|
3. **Session sync mode toggle** — viewport aligns with session bars (ghost visible) or resets to bar 0 (isolated, no ghost)
|
|
|
|
---
|
|
|
|
## Key Design Decisions
|
|
|
|
### A. Ghost note scope = all items except the selected one
|
|
Not just "other tracks" — ALL MIDI items in `activeTracks` except the one matching `targetItemId` contribute ghost notes if overlapping.
|
|
|
|
### B. Two viewport modes, togglable
|
|
| Mode | Viewport origin | Ghost notes | Bar labels |
|
|
|------|----------------|-------------|------------|
|
|
| **Session Sync** (default) | `item.startTime / secondsPerBar` | Visible | `Bar N` (session-absolute) |
|
|
| **Isolated** | bar 0 | Hidden | `Bar N` (0-based) |
|
|
|
|
### C. Ghost notes computed (not persisted)
|
|
No schema changes. Extraction runs in `useMemo` inside `PianoRollTabEditor`.
|
|
|
|
### D. Hit-testing exclusion is automatic
|
|
Ghost notes are in separate `ghostLayers` state; mouse handlers only iterate `notes`.
|
|
|
|
---
|
|
|
|
## Files to Modify
|
|
|
|
| File | Change |
|
|
|------|--------|
|
|
| **NEW** `app/static/js/services/ghostNoteExtractor.js` | Extraction logic |
|
|
| `app/static/js/app.jsx` (~16113) | Pass `activeTracks` prop to `PianoRollTabEditor` |
|
|
| `app/static/js/app.jsx` (~4563-6070) | All PianoRollTabEditor changes below |
|
|
|
|
---
|
|
|
|
## Step-by-Step Implementation
|
|
|
|
### Step 1: Create `ghostNoteExtractor.js`
|
|
|
|
`app/static/js/services/ghostNoteExtractor.js`
|
|
|
|
```js
|
|
export function extractGhostLayers(activeTracks, targetTrackId, targetItemId, bpm)
|
|
```
|
|
|
|
Algorithm:
|
|
1. `secondsPerBeat = 60 / bpm`
|
|
2. Find `targetItem` across all tracks → `windowStartBeat = targetItem.startTime / secondsPerBeat`, `windowEndBeat = (targetItem.startTime + targetItem.duration) / secondsPerBeat`
|
|
3. Iterate ALL tracks, ALL MIDI items:
|
|
- Skip non-MIDI tracks (`!t.midiItems || !t.midiItems.length`)
|
|
- Skip muted tracks (`t.muted`)
|
|
- Skip item matching `targetItemId` (the active item)
|
|
4. For each candidate item:
|
|
- `itemStartBeat = item.startTime / secondsPerBeat`
|
|
- `itemEndBeat = (item.startTime + item.duration) / secondsPerBeat`
|
|
- Overlap test: `itemStartBeat < windowEndBeat && itemEndBeat > windowStartBeat`
|
|
- For each overlapping note:
|
|
- `noteAbsStart = itemStartBeat + note.start_beat`
|
|
- `noteAbsEnd = noteAbsStart + note.duration_beats`
|
|
- Clip: keep if `noteAbsStart < windowEndBeat && noteAbsEnd > windowStartBeat`
|
|
- `clampedDur = Math.min(noteAbsEnd, windowEndBeat) - Math.max(noteAbsStart, windowStartBeat)`
|
|
- Push: `{ id: ghost_${note.id}, pitch, relative_start_beat: noteAbsStart - windowStartBeat, duration_beats: clampedDur, velocity, original_track_name: t.name, original_track_color: t.color || '#888' }`
|
|
5. Group by track → `ghostLayers: [{ track_id, track_name, track_color, notes }]`
|
|
6. Return `ghostLayers`
|
|
|
|
### Step 2: Pass `activeTracks` to PianoRollTabEditor
|
|
|
|
At render site (~line 16113), add:
|
|
```js
|
|
activeTracks: activeTracks,
|
|
```
|
|
|
|
Add `activeTracks` to destructured props in `PianoRollTabEditor` function signature (~line 4563).
|
|
|
|
### Step 3: New state & derived data
|
|
|
|
Inside `PianoRollTabEditor` (~line 4570), after existing `React.useState` declarations:
|
|
|
|
```js
|
|
const [showGhostNotes, setShowGhostNotes] = React.useState(true);
|
|
const [sessionSyncMode, setSessionSyncMode] = React.useState(true);
|
|
|
|
// Compute all MIDI items for dropdown
|
|
const allMidiItems = React.useMemo(() => {
|
|
const result = [];
|
|
(activeTracks || []).forEach(t => {
|
|
if (!t.midiItems || !t.midiItems.length) return;
|
|
t.midiItems.forEach(m => {
|
|
result.push({ ...m, _trackId: t.id, _trackName: t.name });
|
|
});
|
|
});
|
|
return result;
|
|
}, [activeTracks]);
|
|
|
|
// Compute ghost layers
|
|
const ghostLayers = React.useMemo(() => {
|
|
if (!activeTracks || !st || !st.target_id) return [];
|
|
return extractGhostLayers(activeTracks, st.trackId, st.target_id, parseInt(bpm) || 120);
|
|
}, [activeTracks, st.trackId, st.target_id, bpm]);
|
|
|
|
// Compute session offset for bar labels
|
|
const secondsPerBar = (60.0 / (parseInt(bpm) || 120)) * 4;
|
|
const targetTrack = React.useMemo(
|
|
() => (activeTracks || []).find(t => t.id === st.trackId),
|
|
[activeTracks, st.trackId]
|
|
);
|
|
const activeTargetItem = React.useMemo(
|
|
() => targetTrack ? (targetTrack.midiItems || []).find(m => m.id === st.target_id) : null,
|
|
[targetTrack, st.target_id]
|
|
);
|
|
const sessionStartBar = sessionSyncMode && activeTargetItem
|
|
? (activeTargetItem.startTime / secondsPerBar) : 0;
|
|
```
|
|
|
|
### Step 4: Dropdown at tab title position
|
|
|
|
Replace the static title (line 5748-5752) with a dropdown:
|
|
|
|
```js
|
|
/* 1a. TAB TITLE DROPDOWN */
|
|
React.createElement("div", { className: "relative inline-block text-xs" },
|
|
React.createElement("select", {
|
|
value: st.target_id,
|
|
onChange: e => handleSwitchMidiItem(e.target.value),
|
|
className: "bg-zinc-800 border border-zinc-700 text-yellow-500 font-bold rounded px-1.5 py-0.5 outline-none focus:border-yellow-500 max-w-[200px]"
|
|
}, allMidiItems.map(m =>
|
|
React.createElement("option", {
|
|
key: m.id,
|
|
value: m.id
|
|
}, `${m._trackName} - ${m.name || 'MIDI'}`)
|
|
))
|
|
)
|
|
```
|
|
|
|
### Step 5: Switch handler function
|
|
|
|
Add before the return statement:
|
|
|
|
```js
|
|
const handleSwitchMidiItem = (itemId) => {
|
|
if (itemId === st.target_id) return;
|
|
|
|
// Save current notes first
|
|
onSaveNotes(st.id, st.trackId, st.target_id, notes);
|
|
|
|
// Find selected item
|
|
const match = allMidiItems.find(m => m.id === itemId);
|
|
if (!match) return;
|
|
|
|
// Update subTab state (triggers ghost re-compute via useMemo)
|
|
setSubTabs(prev => prev.map(s => s.id === st.id ? {
|
|
...s,
|
|
trackId: match._trackId,
|
|
target_id: match.id,
|
|
label: `Piano Roll: ${match.name || 'MIDI'}`,
|
|
notes: match.notes || [],
|
|
duration: match.duration || 4,
|
|
instrumentProgram: activeTracks.find(t => t.id === match._trackId)?.instrumentProgram,
|
|
instrumentName: activeTracks.find(t => t.id === match._trackId)?.instrumentName,
|
|
note_selection: [],
|
|
currentTime: 0,
|
|
} : s));
|
|
|
|
// Reset local state
|
|
setSelectedNoteIds([]);
|
|
setLoopStartBeat(null);
|
|
setLoopEndBeat(null);
|
|
};
|
|
```
|
|
|
|
### Step 6: Session sync toggle button
|
|
|
|
In toolbar (~line 5798, near CC toggle), add:
|
|
|
|
```js
|
|
/* Session sync mode toggle */
|
|
React.createElement("button", {
|
|
onClick: () => setSessionSyncMode(!sessionSyncMode),
|
|
className: `px-2 py-1 rounded text-xs ${sessionSyncMode ? 'bg-cyan-900/60 text-cyan-300 border border-cyan-700' : 'text-zinc-500 hover:text-zinc-300'}`,
|
|
title: sessionSyncMode ? "Session-synced mode (ghost visible)" : "Isolated mode (bar 0, no ghost)"
|
|
}, sessionSyncMode ? "🌐 Session" : "📋 Isolated")
|
|
```
|
|
|
|
And the Ghost toggle:
|
|
|
|
```js
|
|
React.createElement("button", {
|
|
onClick: () => setShowGhostNotes(!showGhostNotes),
|
|
disabled: !sessionSyncMode,
|
|
className: `px-2 py-1 rounded text-xs ${!sessionSyncMode ? 'opacity-30 cursor-not-allowed' : showGhostNotes ? 'bg-purple-900/60 text-purple-300 border border-purple-700' : 'text-zinc-500 hover:text-zinc-300'}`,
|
|
title: "Toggle ghost notes visibility"
|
|
}, "👻 Ghost")
|
|
```
|
|
|
|
Ghost toggle disabled in isolated mode (no ghost notes to show).
|
|
|
|
### Step 7: Bar labels with session offset
|
|
|
|
Modify `renderBarLabels()` (~line 5711-5734):
|
|
|
|
Replace `Bar ${bar}` with:
|
|
```js
|
|
const displayBar = bar + Math.floor(sessionStartBar);
|
|
`Bar ${displayBar}`
|
|
```
|
|
|
|
And the seek click handler:
|
|
```js
|
|
const barTime = (bar + Math.floor(sessionStartBar)) * 4 * beatSec;
|
|
```
|
|
|
|
### Step 8: Auto-scroll to session position
|
|
|
|
Add `useEffect`:
|
|
|
|
```js
|
|
React.useEffect(() => {
|
|
if (sessionSyncMode && gridScrollRef.current && activeTargetItem) {
|
|
const scrollTargetBeats = sessionStartBar * 4;
|
|
gridScrollRef.current.scrollLeft = scrollTargetBeats * pixelsPerBeat;
|
|
}
|
|
}, [sessionSyncMode, sessionStartBar, st.target_id, pixelsPerBeat]);
|
|
```
|
|
|
|
### Step 9: Ghost note canvas layer
|
|
|
|
In the note-drawing `useLayoutEffect` (~line 4834), insert **before** active note rendering:
|
|
|
|
```js
|
|
/* Layer 2: Ghost Notes */
|
|
if (showGhostNotes && sessionSyncMode && ghostLayers.length > 0) {
|
|
ghostLayers.forEach(layer => {
|
|
ctx.save();
|
|
ctx.globalAlpha = 0.25;
|
|
ctx.fillStyle = layer.track_color || '#888';
|
|
ctx.strokeStyle = layer.track_color || '#888';
|
|
layer.notes.forEach(note => {
|
|
const x = note.relative_start_beat * pixelsPerBeat;
|
|
const y = (127 - note.pitch) * NoteHeight;
|
|
const w = note.duration_beats * pixelsPerBeat;
|
|
const h = NoteHeight - 1;
|
|
ctx.fillRect(x, y, w, h);
|
|
ctx.setLineDash([2, 2]);
|
|
ctx.lineWidth = 1;
|
|
ctx.strokeRect(x, y, w, h);
|
|
ctx.setLineDash([]);
|
|
});
|
|
ctx.restore();
|
|
});
|
|
}
|
|
```
|
|
|
|
Add `showGhostNotes`, `sessionSyncMode`, `ghostLayers` to dependency array.
|
|
|
|
### Step 10: Ghost notes in CC Lane
|
|
|
|
Skip ghost notes in CC lane (only active notes). CC lane already only iterates `notes`, not `ghostLayers`. No changes needed.
|
|
|
|
---
|
|
|
|
## Edge Cases
|
|
|
|
- **Dropdown with single MIDI item**: Only one option, no ghost notes (nothing to ghost).
|
|
- **Item deleted while piano roll is open**: `handleSwitchMidiItem` fails gracefully (item not found → no-op). `ghostLayers` `useMemo` returns `[]`.
|
|
- **BPM change mid-edit**: All beat computations update via `useMemo`/React reactivity.
|
|
- **Session sync → Isolated switch**: Scroll resets to 0, bar labels change to 0-based, ghost notes disappear.
|
|
- **Isolated → Session sync switch**: Scroll jumps to session position, ghost notes reappear.
|
|
- **Color fallback**: Use track's `color` prop; if `#888` as default.
|
|
|
|
---
|
|
|
|
## Validation
|
|
|
|
1. Open MIDI item → dropdown shows all MIDI items across all tracks
|
|
2. Select different item from dropdown → active notes switch, ghost notes re-compute
|
|
3. Ghost notes from ALL non-selected items appear (same track + other tracks)
|
|
4. Ghost toggle hides/shows ghost notes (disabled in isolated mode)
|
|
5. Session sync mode shows correct bar labels (e.g. `Bar 2` if item starts at bar 2)
|
|
6. Isolated mode shows `Bar 0, 1, 2...` regardless of item's session position
|
|
7. Switching items in isolated mode: notes change, viewport stays at bar 0
|
|
8. Ghost notes cannot be clicked/dragged (excluded from hit-testing)
|
|
9. Muted tracks' MIDI items are excluded from ghost notes
|
|
10. Items outside target window are excluded from ghost notes
|