1 files changed, 86 insertions, 0 deletions
diff --git a/packages/frontend/src/scripts/use-tooltip.ts b/packages/frontend/src/scripts/use-tooltip.ts
new file mode 100644
index 0000000000..1f6e0fb6ce
--- /dev/null
+++ b/packages/frontend/src/scripts/use-tooltip.ts
@@ -0,0 +1,86 @@
+import { Ref, ref, watch, onUnmounted } from 'vue';
+
+export function useTooltip(
+	elRef: Ref<HTMLElement | { $el: HTMLElement } | null | undefined>,
+	onShow: (showing: Ref<boolean>) => void,
+	delay = 300,
+): void {
+	let isHovering = false;
+
+	// iOS(Androidも？)では、要素をタップした直後に(おせっかいで)mouseoverイベントを発火させたりするため、それを無視するためのフラグ
+	// 無視しないと、画面に触れてないのにツールチップが出たりし、ユーザビリティが損なわれる
+	// TODO: 一度でもタップすると二度とマウスでツールチップ出せなくなるのをどうにかする 定期的にfalseに戻すとか...？
+	let shouldIgnoreMouseover = false;
+
+	let timeoutId: number;
+
+	let changeShowingState: (() => void) | null;
+
+	const open = () => {
+		close();
+		if (!isHovering) return;
+		if (elRef.value == null) return;
+		const el = elRef.value instanceof Element ? elRef.value : elRef.value.$el;
+		if (!document.body.contains(el)) return; // openしようとしたときに既に元要素がDOMから消えている場合があるため
+
+		const showing = ref(true);
+		onShow(showing);
+		changeShowingState = () => {
+			showing.value = false;
+		};
+	};
+
+	const close = () => {
+		if (changeShowingState != null) {
+			changeShowingState();
+			changeShowingState = null;
+		}
+	};
+
+	const onMouseover = () => {
+		if (isHovering) return;
+		if (shouldIgnoreMouseover) return;
+		isHovering = true;
+		timeoutId = window.setTimeout(open, delay);
+	};
+
+	const onMouseleave = () => {
+		if (!isHovering) return;
+		isHovering = false;
+		window.clearTimeout(timeoutId);
+		close();
+	};
+
+	const onTouchstart = () => {
+		shouldIgnoreMouseover = true;
+		if (isHovering) return;
+		isHovering = true;
+		timeoutId = window.setTimeout(open, delay);
+	};
+
+	const onTouchend = () => {
+		if (!isHovering) return;
+		isHovering = false;
+		window.clearTimeout(timeoutId);
+		close();
+	};
+
+	const stop = watch(elRef, () => {
+		if (elRef.value) {
+			stop();
+			const el = elRef.value instanceof Element ? elRef.value : elRef.value.$el;
+			el.addEventListener('mouseover', onMouseover, { passive: true });
+			el.addEventListener('mouseleave', onMouseleave, { passive: true });
+			el.addEventListener('touchstart', onTouchstart, { passive: true });
+			el.addEventListener('touchend', onTouchend, { passive: true });
+			el.addEventListener('click', close, { passive: true });
+		}
+	}, {
+		immediate: true,
+		flush: 'post',
+	});
+
+	onUnmounted(() => {
+		close();
+	});
+}