fix: random not able to exit piano roll hybrid mode issue when switching between different MIDI regions (introduced a region dragging start threshold)

src/stores/projectStore.test.ts

@@ -0,0 +1,78 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { act } from '@testing-library/react';
+import { KGMidiTrack } from '../core/track/KGMidiTrack';
+
+const mockProject = {
+  getTimeSignature: () => ({ numerator: 4, denominator: 4 }),
+  getMaxBars: () => 32,
+  getBarWidthMultiplier: () => 1,
+  getTracks: () => [new KGMidiTrack('Track 1', 0, 'acoustic_grand_piano')],
+  getBpm: () => 120,
+  getKeySignature: () => 'C major',
+  getName: () => 'Test Project',
+  getSelectedMode: () => 'major',
+  getIsLooping: () => false,
+  getLoopingRange: () => null,
+};
+
+const mockCore = {
+  getCurrentProject: () => mockProject,
+  setPlayheadUpdateCallback: vi.fn(),
+  setPlaybackStateChangeCallback: vi.fn(),
+  getSelectedItems: () => [],
+  onSelectionChanged: vi.fn(),
+  canUndo: () => false,
+  canRedo: () => false,
+  getUndoDescription: () => '',
+  getRedoDescription: () => '',
+  setOnCommandHistoryChanged: vi.fn(),
+  executeCommand: vi.fn(),
+  clearSelectedItems: vi.fn(),
+  getStatus: () => 'Ready',
+  getPlayheadPosition: () => 0,
+  getIsPlaying: () => false,
+};
+
+vi.mock('../core/KGCore', () => ({
+  KGCore: {
+    instance: () => mockCore,
+  },
+}));
+
+vi.mock('../core/config/ConfigManager', () => ({
+  ConfigManager: {
+    instance: () => ({
+      getIsInitialized: () => true,
+      get: () => false,
+    }),
+  },
+}));
+
+describe('projectStore piano roll state', () => {
+  beforeEach(() => {
+    vi.resetModules();
+  });
+
+  it('clears hybrid state when opening a MIDI region', async () => {
+    const { useProjectStore } = await import('./projectStore');
+
+    act(() => {
+      useProjectStore.getState().openHybridMode('midi-a', 'audio-a');
+    });
+
+    let state = useProjectStore.getState();
+    expect(state.pianoRollMode).toBe('hybrid');
+    expect(state.activeRegionId).toBe('midi-a');
+    expect(state.hybridAudioRegionId).toBe('audio-a');
+
+    act(() => {
+      useProjectStore.getState().openMidiPianoRoll('midi-b');
+    });
+
+    state = useProjectStore.getState();
+    expect(state.showPianoRoll).toBe(true);
+    expect(state.pianoRollMode).toBe('midi-edit');
+    expect(state.activeRegionId).toBe('midi-b');
+    expect(state.hybridAudioRegionId).toBeNull();
+  });
+});