initial public release.

src/hooks/useRegionOperations.ts

@@ -0,0 +1,115 @@
+import { useCallback } from 'react';
+import { DEBUG_MODE } from '../constants';
+import { KGMidiRegion } from '../core/region/KGMidiRegion';
+import { KGTrack } from '../core/track/KGTrack';
+import { KGCore } from '../core/KGCore';
+import type { RegionUI } from '../components/interfaces';
+import { DeleteMultipleRegionsCommand } from '../core/commands';
+
+interface UseRegionOperationsProps {
+  tracks: KGTrack[];
+  updateTrack: (track: KGTrack) => void;
+  setRegions: React.Dispatch<React.SetStateAction<RegionUI[]>>;
+  selectedRegionId: string | null;
+  setSelectedRegionId: React.Dispatch<React.SetStateAction<string | null>>;
+  showPianoRoll: boolean;
+  setShowPianoRoll: (show: boolean) => void;
+  activeRegionId: string | null;
+  setActiveRegionId: (regionId: string | null) => void;
+}
+
+export const useRegionOperations = ({
+  tracks,
+  updateTrack,
+  setRegions,
+  selectedRegionId,
+  setSelectedRegionId,
+  showPianoRoll,
+  setShowPianoRoll,
+  activeRegionId,
+  setActiveRegionId
+}: UseRegionOperationsProps) => {
+  // Get KGCore instance for accessing selected items
+  const core = KGCore.instance();
+
+  /**
+   * Utility function to delete selected regions using commands
+   * This function:
+   * 1. Gets all selected regions from KGCore
+   * 2. Creates a DeleteMultipleRegionsCommand with the region IDs
+   * 3. Executes the command (which handles the model updates)
+   * 4. Updates the UI state to reflect the deletion
+   * 5. Updates tracks in the store and manages UI state
+   * 
+   * @returns {boolean} True if regions were deleted, false if no regions were selected
+   */
+  const deleteSelectedRegions = useCallback(() => {
+    // Get all selected regions from KGCore
+    const selectedItems = core.getSelectedItems();
+    const selectedRegions = selectedItems.filter(item => 
+      item instanceof KGMidiRegion
+    ) as KGMidiRegion[];
+    
+    if (selectedRegions.length === 0) {
+      if (DEBUG_MODE.MAIN_CONTENT) {
+        console.log('No regions selected for deletion');
+      }
+      return false;
+    }
+    
+    if (DEBUG_MODE.MAIN_CONTENT) {
+      console.log(`Deleting ${selectedRegions.length} selected regions`);
+    }
+    
+    // Get the region IDs for the command
+    const regionIds = selectedRegions.map(region => region.getId());
+    
+    // Create and execute the delete command
+    const command = new DeleteMultipleRegionsCommand(regionIds);
+    core.executeCommand(command);
+    
+    // Update tracks in the store to reflect the changes
+    const deletedRegionData = command.getDeletedRegionData();
+    const uniqueTrackIds = new Set(deletedRegionData.map(data => data.trackId));
+    
+    uniqueTrackIds.forEach(trackId => {
+      const track = tracks.find(t => t.getId().toString() === trackId);
+      if (track) {
+        updateTrack(track);
+      }
+    });
+    
+    // Update regions state to reflect the deletion
+    setRegions(prevRegions => {
+      const selectedRegionIds = new Set(regionIds);
+      const filteredRegions = prevRegions.filter(region => !selectedRegionIds.has(region.id));
+      
+      if (DEBUG_MODE.MAIN_CONTENT) {
+        console.log(`Updated regions state: ${prevRegions.length} -> ${filteredRegions.length} regions`);
+      }
+      
+      return filteredRegions;
+    });
+    
+    // Clear selected region ID if it was deleted
+    if (selectedRegionId && regionIds.includes(selectedRegionId)) {
+      setSelectedRegionId(null);
+    }
+    
+    // Close piano roll if the active region was deleted
+    if (activeRegionId && regionIds.includes(activeRegionId)) {
+      setShowPianoRoll(false);
+      setActiveRegionId(null);
+    }
+    
+    if (DEBUG_MODE.MAIN_CONTENT) {
+      console.log(`Deleted ${selectedRegions.length} regions using command`);
+    }
+    
+    return true;
+  }, [tracks, selectedRegionId, activeRegionId, updateTrack, setRegions, setSelectedRegionId, setShowPianoRoll, setActiveRegionId, core]);
+
+  return {
+    deleteSelectedRegions
+  };
+};