1 files changed, 46 insertions, 0 deletions
diff --git a/packages/frontend/src/scripts/fullscreen.ts b/packages/frontend/src/scripts/fullscreen.ts
new file mode 100644
index 0000000000..7a0a018ef3
--- /dev/null
+++ b/packages/frontend/src/scripts/fullscreen.ts
@@ -0,0 +1,46 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+type PartiallyPartial<T, K extends keyof T> = Omit<T, K> & Partial<Pick<T, K>>;
+
+type VideoEl = PartiallyPartial<HTMLVideoElement, 'requestFullscreen'> & {
+	webkitEnterFullscreen?(): void;
+	webkitExitFullscreen?(): void;
+};
+
+type PlayerEl = PartiallyPartial<HTMLElement, 'requestFullscreen'>;
+
+type RequestFullscreenProps = {
+	readonly videoEl: VideoEl;
+	readonly playerEl: PlayerEl;
+	readonly options?: FullscreenOptions | null;
+};
+
+type ExitFullscreenProps = {
+	readonly videoEl: VideoEl;
+};
+
+export const requestFullscreen = ({ videoEl, playerEl, options }: RequestFullscreenProps) => {
+	if (playerEl.requestFullscreen != null) {
+		playerEl.requestFullscreen(options ?? undefined);
+		return;
+	}
+	if (videoEl.webkitEnterFullscreen != null) {
+		videoEl.webkitEnterFullscreen();
+		return;
+	}
+};
+
+export const exitFullscreen = ({ videoEl }: ExitFullscreenProps) => {
+	// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+	if (document.exitFullscreen != null) {
+		document.exitFullscreen();
+		return;
+	}
+	if (videoEl.webkitExitFullscreen != null) {
+		videoEl.webkitExitFullscreen();
+		return;
+	}
+};