Initial Commit

packages/ui/react/react-midi/src/hooks/use-midi-output/use-midi-output.ts

@@ -0,0 +1,39 @@
+import { useMemo } from "react";
+import type { MidiMessage } from "../../midi-contract/midi-message.types.js";
+import { adaptOutput } from "../../port/web-midi-port.js";
+import { useMidiContextOrThrow } from "../use-midi-context.js";
+import type { PortSelector } from "../use-midi-input/use-midi-input.js";
+
+export interface MidiOutputHandle {
+    readonly id: string;
+    readonly name: string;
+    readonly manufacturer: string | undefined;
+    readonly state: "connected" | "disconnected";
+    send(bytes: Uint8Array): void;
+    sendMessage(msg: MidiMessage): void;
+}
+
+/**
+ * Returns a typed output handle for the selected Web MIDI output, or
+ * `null` while access is loading / the selector misses. The handle's
+ * `sendMessage` encodes a `MidiMessage` via `encodeMessage` and
+ * forwards the resulting bytes to the underlying `MIDIOutput.send`;
+ * `send(bytes)` is the raw escape-hatch (typically used for SysEx
+ * pass-through).
+ */
+export function useMidiOutput(selector: PortSelector): MidiOutputHandle | null {
+    const ctx = useMidiContextOrThrow();
+    const stateVersion = ctx.stateVersion;
+    return useMemo<MidiOutputHandle | null>(() => {
+        void stateVersion;
+        if (ctx.access === null) {
+            return null;
+        }
+        if (selector === "first") {
+            const next = ctx.access.outputs.values().next();
+            return next.done === true ? null : adaptOutput(next.value);
+        }
+        const target = ctx.access.outputs.get(selector);
+        return target === undefined ? null : adaptOutput(target);
+    }, [ctx.access, stateVersion, selector]);
+}