feat: show recording input meter

src/recorder/AudioRecorder.ts

@@ -33,6 +33,12 @@ export class NativeAudioRecorder implements AudioRecorder {
 	private recorder: MediaRecorder | null = null;
 	private mimeType: string | undefined;
 	private deviceId: string | null = null;
+	private audioContext: AudioContext | null = null;
+	private analyser: AnalyserNode | null = null;
+	private inputSource: MediaStreamAudioSourceNode | null = null;
+	private inputSamples: Uint8Array | null = null;
+	private animationFrameId: number | null = null;
+	private onInputLevel: ((level: number) => void) | null = null;
 
 	getRecordingState(): "inactive" | "recording" | "paused" | undefined {
 		return this.recorder?.state;
@@ -46,6 +52,10 @@ export class NativeAudioRecorder implements AudioRecorder {
 		this.deviceId = deviceId;
 	}
 
+	setInputLevelCallback(callback: ((level: number) => void) | null): void {
+		this.onInputLevel = callback;
+	}
+
 	async startRecording(): Promise<void> {
 		if (!this.recorder) {
 			try {
@@ -70,6 +80,7 @@ export class NativeAudioRecorder implements AudioRecorder {
 				});
 
 				this.recorder = recorder;
+				this.startInputMeter(stream);
 			} catch (err) {
 				new Notice("✘ Couldn't access microphone");
 				console.error("Error initializing recorder:", err);
@@ -87,6 +98,7 @@ export class NativeAudioRecorder implements AudioRecorder {
 
 		if (this.recorder.state === "recording") {
 			this.recorder.pause();
+			this.onInputLevel?.(0);
 		} else if (this.recorder.state === "paused") {
 			this.recorder.resume();
 		}
@@ -97,6 +109,7 @@ export class NativeAudioRecorder implements AudioRecorder {
 			if (!this.recorder || this.recorder.state === "inactive") {
 				const blob = new Blob(this.chunks, { type: this.mimeType });
 				this.chunks.length = 0;
+				this.stopInputMeter();
 				resolve(blob);
 			} else {
 				this.recorder.addEventListener(
@@ -113,6 +126,7 @@ export class NativeAudioRecorder implements AudioRecorder {
 								.forEach((track) => track.stop());
 							this.recorder = null;
 						}
+						this.stopInputMeter();
 
 						resolve(blob);
 					},
@@ -123,4 +137,54 @@ export class NativeAudioRecorder implements AudioRecorder {
 			}
 		});
 	}
+
+	private startInputMeter(stream: MediaStream): void {
+		this.stopInputMeter();
+
+		this.audioContext = new AudioContext();
+		this.analyser = this.audioContext.createAnalyser();
+		this.analyser.fftSize = 256;
+		this.inputSamples = new Uint8Array(this.analyser.fftSize);
+
+		this.inputSource = this.audioContext.createMediaStreamSource(stream);
+		this.inputSource.connect(this.analyser);
+		this.tickInputMeter();
+	}
+
+	private tickInputMeter(): void {
+		if (!this.analyser || !this.inputSamples) return;
+
+		if (this.recorder?.state === "recording") {
+			this.analyser.getByteTimeDomainData(this.inputSamples);
+
+			let sum = 0;
+			for (let i = 0; i < this.inputSamples.length; i++) {
+				const centeredSample = (this.inputSamples[i] - 128) / 128;
+				sum += centeredSample * centeredSample;
+			}
+
+			const rms = Math.sqrt(sum / this.inputSamples.length);
+			this.onInputLevel?.(Math.min(1, rms * 6));
+		} else {
+			this.onInputLevel?.(0);
+		}
+
+		this.animationFrameId = requestAnimationFrame(() =>
+			this.tickInputMeter()
+		);
+	}
+
+	private stopInputMeter(): void {
+		if (this.animationFrameId !== null) {
+			cancelAnimationFrame(this.animationFrameId);
+			this.animationFrameId = null;
+		}
+
+		void this.audioContext?.close();
+		this.audioContext = null;
+		this.analyser = null;
+		this.inputSource = null;
+		this.inputSamples = null;
+		this.onInputLevel?.(0);
+	}
 }

src/recorder/StatusBar.ts

@@ -12,6 +12,7 @@ export class StatusBar {
 	statusBarItem: HTMLElement | null = null;
 	status: RecordingStatus = RecordingStatus.Idle;
 	private listeners: Array<(status: RecordingStatus) => void> = [];
+	private meterBars: HTMLElement[] = [];
 
 	constructor(plugin: Plugin) {
 		this.plugin = plugin;
@@ -33,27 +34,61 @@ export class StatusBar {
 		this.listeners.forEach((fn) => fn(status));
 	}
 
+	updateInputLevel(level: number): void {
+		if (this.status !== RecordingStatus.Recording) return;
+
+		const clampedLevel = Math.max(0, Math.min(1, level));
+		const activeBars = Math.round(clampedLevel * this.meterBars.length);
+
+		this.meterBars.forEach((bar, index) => {
+			bar.toggleClass("nibbleai-meter-bar-active", index < activeBars);
+		});
+	}
+
 	updateStatusBarItem() {
-		if (this.statusBarItem) {
-			switch (this.status) {
-				case RecordingStatus.Recording:
-					this.statusBarItem.textContent = "NibbleAI Recording...";
-					this.statusBarItem.style.color = "red";
-					break;
-				case RecordingStatus.Paused:
-					this.statusBarItem.textContent = "NibbleAI Paused";
-					this.statusBarItem.style.color = "yellow";
-					break;
-				case RecordingStatus.Processing:
-					this.statusBarItem.textContent = "NibbleAI Processing...";
-					this.statusBarItem.style.color = "gray";
-					break;
-				case RecordingStatus.Idle:
-				default:
-					this.statusBarItem.textContent = "NibbleAI Idle";
-					this.statusBarItem.style.color = "green";
-					break;
-			}
+		if (!this.statusBarItem) return;
+
+		this.statusBarItem.empty();
+		this.statusBarItem.removeClass("nibbleai-status-recording");
+		this.statusBarItem.removeClass("nibbleai-status-paused");
+		this.statusBarItem.removeClass("nibbleai-status-processing");
+		this.statusBarItem.removeClass("nibbleai-status-idle");
+		this.meterBars = [];
+
+		switch (this.status) {
+			case RecordingStatus.Recording:
+				this.statusBarItem.addClass("nibbleai-status-recording");
+				this.statusBarItem.createSpan({ text: "NibbleAI " });
+				this.createInputMeter();
+				break;
+			case RecordingStatus.Paused:
+				this.statusBarItem.addClass("nibbleai-status-paused");
+				this.statusBarItem.setText("NibbleAI Paused");
+				break;
+			case RecordingStatus.Processing:
+				this.statusBarItem.addClass("nibbleai-status-processing");
+				this.statusBarItem.setText("NibbleAI Processing...");
+				break;
+			case RecordingStatus.Idle:
+			default:
+				this.statusBarItem.addClass("nibbleai-status-idle");
+				this.statusBarItem.setText("NibbleAI Idle");
+				break;
+		}
+	}
+
+	private createInputMeter(): void {
+		if (!this.statusBarItem) return;
+
+		const meter = this.statusBarItem.createSpan({
+			cls: "nibbleai-input-meter",
+			attr: { "aria-label": "Recording input level" },
+		});
+
+		for (let i = 0; i < 8; i++) {
+			this.meterBars.push(
+				meter.createSpan({ cls: "nibbleai-meter-bar" })
+			);
 		}
 	}