fix: keep the display awake while a recording runs

electron/main.ts

@@ -65,6 +65,7 @@ import {
 	showPermissionsWindow,
 	showPermissionsWindowIfNeeded,
 } from "./permissions";
+import { setDisplaySleepBlocked } from "./recording/displaySleepBlocker";
 import { offersStarPrompt, REPO_URL, storeReviewUrl } from "./star-prompt";
 import { registerSttIpc, shutdownStt } from "./stt";
 import { checkLatestRelease } from "./update-checker";
@@ -1372,6 +1373,7 @@ appReady?.then(async () => {
 		(recording: boolean, sourceName: string) => {
 			selectedSourceName = sourceName;
 			isRecording = recording;
+			setDisplaySleepBlocked(recording);
 			if (!tray) createTray();
 			updateTrayMenu(recording);
 			// `canOfferUpdateCheck()` now answers "not mid-take" too, and the app/Help menus are

electron/recording/displaySleepBlocker.test.ts

@@ -0,0 +1,52 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const { start, stop } = vi.hoisted(() => {
+	let nextId = 1;
+	return { start: vi.fn(() => nextId++), stop: vi.fn() };
+});
+
+vi.mock("electron", () => ({ powerSaveBlocker: { start, stop } }));
+
+describe("setDisplaySleepBlocked", () => {
+	let setDisplaySleepBlocked: (recording: boolean) => void;
+
+	beforeEach(async () => {
+		vi.resetModules();
+		start.mockClear();
+		stop.mockClear();
+		({ setDisplaySleepBlocked } = await import("./displaySleepBlocker"));
+	});
+
+	it("starts one display-sleep blocker per recording and stops that same one", () => {
+		setDisplaySleepBlocked(true);
+		expect(start).toHaveBeenCalledOnce();
+		expect(start).toHaveBeenCalledWith("prevent-display-sleep");
+
+		setDisplaySleepBlocked(false);
+		expect(stop).toHaveBeenCalledOnce();
+		expect(stop).toHaveBeenCalledWith(start.mock.results[0].value);
+	});
+
+	it("never stacks a second blocker when a start is reported twice", () => {
+		setDisplaySleepBlocked(true);
+		setDisplaySleepBlocked(true);
+		setDisplaySleepBlocked(false);
+		expect(start).toHaveBeenCalledOnce();
+		expect(stop).toHaveBeenCalledOnce();
+	});
+
+	it("ignores a stop with nothing started, as a failed start then cancel reports", () => {
+		setDisplaySleepBlocked(false);
+		expect(stop).not.toHaveBeenCalled();
+	});
+
+	it("leaves nothing running across consecutive takes", () => {
+		for (let take = 0; take < 3; take++) {
+			setDisplaySleepBlocked(true);
+			setDisplaySleepBlocked(false);
+			setDisplaySleepBlocked(false);
+		}
+		expect(start).toHaveBeenCalledTimes(3);
+		expect(stop.mock.calls.map(([id]) => id)).toEqual(start.mock.results.map((r) => r.value));
+	});
+});

electron/recording/displaySleepBlocker.ts

@@ -0,0 +1,18 @@
+import { powerSaveBlocker } from "electron";
+
+let blockerId: number | null = null;
+
+/**
+ * Keeps the display awake for the whole take, pauses included (#935). Driven by the
+ * same recording flag as the tray, which every backend's start and every stop,
+ * cancel and failure path already report, so it is idempotent in both directions:
+ * a repeated `true` never stacks a second blocker, a stray `false` is a no-op.
+ */
+export function setDisplaySleepBlocked(recording: boolean) {
+	if (recording && blockerId === null) {
+		blockerId = powerSaveBlocker.start("prevent-display-sleep");
+	} else if (!recording && blockerId !== null) {
+		powerSaveBlocker.stop(blockerId);
+		blockerId = null;
+	}
+}

src/hooks/useScreenRecorder.ts

@@ -2028,6 +2028,9 @@ export function useScreenRecorder(): UseScreenRecorderReturn {
 				"error",
 				() => {
 					setRecording(false);
+					// The main process was told a take started (below), so it has to hear
+					// that it ended too, or the tray and the display-sleep blocker stay on.
+					window.electronAPI?.setRecordingState(false);
 				},
 				{ once: true },
 			);