enhance(frontend): ウィジェットの設定画面を改良 (#17033)

* enhance(frontend): ウィジェットの設定画面を改良

* Update Changelog

* fix lint

packages/frontend/src/components/MkPreviewWithControls.vue

@@ -0,0 +1,93 @@
+<!--
+SPDX-FileCopyrightText: syuilo and misskey-project
+SPDX-License-Identifier: AGPL-3.0-only
+-->
+
+<template>
+<div :class="$style.root">
+	<div :class="$style.container">
+		<div :class="[$style.preview, prefer.s.animation ? $style.animatedBg : null]">
+			<div :class="$style.previewContent">
+				<slot name="preview"></slot>
+			</div>
+			<div v-if="previewLoading" :class="$style.previewLoading">
+				<MkLoading :class="$style.previewLoadingSpinner"/>
+			</div>
+		</div>
+		<div :class="$style.controls">
+			<slot name="controls"></slot>
+		</div>
+	</div>
+</div>
+</template>
+
+<script lang="ts" setup>
+import { prefer } from '@/preferences.js';
+
+const props = withDefaults(defineProps<{
+	previewLoading?: boolean;
+}>(), {
+	previewLoading: false,
+});
+
+defineSlots<{
+	preview: () => any;
+	controls: () => any;
+}>();
+</script>
+
+<style lang="scss" module>
+.root {
+	container-type: inline-size;
+	height: 100%;
+}
+
+.container {
+	height: 100%;
+	display: grid;
+	grid-template-columns: 1fr 400px;
+}
+
+.preview {
+	position: relative;
+	background-color: var(--MI_THEME-bg);
+	background-image: linear-gradient(135deg, transparent 30%, var(--MI_THEME-panel) 30%, var(--MI_THEME-panel) 50%, transparent 50%, transparent 80%, var(--MI_THEME-panel) 80%, var(--MI_THEME-panel) 100%);
+	background-size: 20px 20px;
+}
+
+.previewContent {
+	position: relative;
+	width: 100%;
+	height: 100%;
+	overflow: clip;
+}
+
+.previewLoading {
+	position: absolute;
+	inset: 0;
+	background-color: color(from var(--MI_THEME-panel) srgb r g b / 0.7);
+	display: flex;
+	justify-content: center;
+	align-items: center;
+}
+
+.animatedBg {
+	animation: bg 1.2s linear infinite;
+}
+
+@keyframes bg {
+	0% { background-position: 0 0; }
+	100% { background-position: -20px -20px; }
+}
+
+.controls {
+	overflow-y: scroll;
+}
+
+@container (max-width: 800px) {
+	.container {
+		grid-template-columns: 1fr;
+		grid-template-rows: 1fr 1fr;
+	}
+}
+</style>