feat: MIDI note duration inheritance & Ctrl+Shift+click split

app/static/js/app.jsx

@@ -6007,6 +6007,7 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, activeTracks, onClos
   notesRef.current = notes;
   React.useEffect(() => { if (!draggedNoteRef.current) setNotes(st.notes || []); }, [st.notes]);
   const brushVelocityRef = React.useRef(0.8);
+  const lastNoteDurationRef = React.useRef(null);
   const previewPitchRef = React.useRef(null);
   const previewNodesRef = React.useRef(null);
   var stopPreviewNote = function() {
@@ -6503,28 +6504,50 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, activeTracks, onClos
       }
     }
 
-    // Ctrl+Shift+click: duplicate selected + clicked notes
+    // Ctrl+Shift+click on note → split at click position
     if (e.ctrlKey && e.shiftKey) {
       if (clickedNoteIdx !== -1) {
+        const target = notes[clickedNoteIdx];
+        const splitBeat = getSnapBeat(beat, snapValue);
+        if (splitBeat > target.start_beat + 0.03125 && splitBeat < target.start_beat + target.duration_beats - 0.03125) {
+          pushToUndo(notes);
+          const noteA = {
+            ...JSON.parse(JSON.stringify(target)),
+            id: 'note_' + Date.now() + Math.random().toString(36).substr(2, 8),
+            duration_beats: splitBeat - target.start_beat
+          };
+          const noteB = {
+            ...JSON.parse(JSON.stringify(target)),
+            id: 'note_' + Date.now() + Math.random().toString(36).substr(2, 8),
+            start_beat: splitBeat,
+            duration_beats: target.start_beat + target.duration_beats - splitBeat
+          };
+          setNotes(prev => prev.map(n => n.id === target.id ? noteA : n).concat([noteB]));
+          setSelectedNoteIds([noteA.id, noteB.id]);
+          showToast('Đã tách nốt!', 'info');
+        }
+      } else {
+        // Ctrl+Shift+click on empty space → duplicate selected + clicked notes
         pushToUndo(notes);
-        const clickedNote = notes[clickedNoteIdx];
+        const clones = notes.filter(n => selectedNoteIds.includes(n.id)).map(n => ({
-        const idsToClone = [...new Set([...selectedNoteIds, clickedNote.id])];
-        const clones = notes.filter(n => idsToClone.includes(n.id)).map(n => ({
           ...JSON.parse(JSON.stringify(n)),
           id: 'note_' + Date.now() + Math.random().toString(36).substr(2, 8)
         }));
-        setNotes(prev => [...prev, ...clones]);
+        if (clones.length > 0) {
-        const cloneIds = clones.map(c => c.id);
+          setNotes(prev => [...prev, ...clones]);
-        setSelectedNoteIds(cloneIds);
+          const cloneIds = clones.map(c => c.id);
-        notesBeforeDragRef.current = JSON.parse(JSON.stringify(notes));
+          setSelectedNoteIds(cloneIds);
-        const cloneOffsets = clones.map(n => ({ id: n.id, originalStartBeat: n.start_beat, originalPitch: n.pitch }));
+          notesBeforeDragRef.current = JSON.parse(JSON.stringify(notes));
-        setDraggedNote({
+          const cloneOffsets = clones.map(n => ({ id: n.id, originalStartBeat: n.start_beat, originalPitch: n.pitch }));
-          mode: 'move',
+          setDraggedNote({
-          idx: -1,
+            mode: 'move',
-          startOffsetBeat: beat,
+            idx: -1,
-          startOffsetPitch: pitch,
+            startOffsetBeat: beat,
-          selectedNotesOffset: cloneOffsets
+            startOffsetPitch: pitch,
-        });
+            selectedNotesOffset: cloneOffsets
+          });
+          showToast('Đã nhân bản ' + clones.length + ' nốt!', 'info');
+        }
       }
       return;
     }
@@ -6589,7 +6612,7 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, activeTracks, onClos
       // Click on empty space with pen tool: DRAW a new note (brush mode with visitedPitches)
       pushToUndo(notes);
       const start = getSnapBeat(beat, snapValue);
-      const initialDur = getSnapDuration(snapValue);
+      const initialDur = lastNoteDurationRef.current || getSnapDuration(snapValue);
       const noteId = 'note_' + Date.now() + Math.random().toString(36).substr(2, 5);
       const newNote = {
         id: noteId,
@@ -6874,6 +6897,15 @@ const PianoRollTabEditor = ({ st, zoom, bpm, viewportWidth, activeTracks, onClos
   };
 
   const handleGridMouseUp = () => {
+    if (draggedNote && draggedNote.mode === 'draw') {
+      const dn = draggedNote;
+      const brushIds = dn.brushIds || [];
+      const lastBrushId = brushIds.length > 0 ? brushIds[brushIds.length - 1] : dn.drawNoteId;
+      if (lastBrushId) {
+        const lastNote = notes.find(n => n.id === lastBrushId);
+        if (lastNote) lastNoteDurationRef.current = lastNote.duration_beats;
+      }
+    }
     setDraggedNote(null);
     setSelectionMarquee(null);
     rightClickDragRef.current = { active: false, startX: 0, startY: 0 };