basic react package

packages/react/src/hooks/useHighlighting.mjs

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+import { useEffect } from 'react';
+import { setHighlights } from '../components/CodeMirror6';
+import { Tone } from '@strudel.cycles/tone';
+
+let highlights = []; // actively highlighted events
+let lastEnd;
+
+function useHighlighting({ view, pattern, active }) {
+  useEffect(() => {
+    if (view) {
+      if (pattern && active) {
+        let frame = requestAnimationFrame(updateHighlights);
+
+        function updateHighlights() {
+          try {
+            const audioTime = Tone.getTransport().seconds;
+            const span = [lastEnd || audioTime, audioTime + 1 / 60];
+            lastEnd = audioTime + 1 / 60;
+            highlights = highlights.filter((hap) => hap.whole.end > audioTime); // keep only highlights that are still active
+            const haps = pattern.queryArc(...span).filter((hap) => hap.hasOnset());
+            highlights = highlights.concat(haps); // add potential new onsets
+            view.dispatch({ effects: setHighlights.of(highlights) }); // highlight all still active + new active haps
+          } catch (err) {
+            // console.log('error in updateHighlights', err);
+            view.dispatch({ effects: setHighlights.of([]) });
+          }
+          frame = requestAnimationFrame(updateHighlights);
+        }
+
+        return () => {
+          cancelAnimationFrame(frame);
+        };
+      } else {
+        highlights = [];
+        view.dispatch({ effects: setHighlights.of([]) });
+      }
+    }
+  }, [pattern, active, view]);
+}
+
+export default useHighlighting;