1 files changed, 67 insertions, 0 deletions
diff --git a/frontend/src/components/Chart.svelte b/frontend/src/components/Chart.svelte
new file mode 100644
index 0000000..ca8f4f8
--- /dev/null
+++ b/frontend/src/components/Chart.svelte
@@ -0,0 +1,67 @@
+<script lang="ts">
+  import { onMount, onDestroy } from 'svelte';
+  import type * as echartsNS from 'echarts';
+
+  interface Props {
+    option: echartsNS.EChartsOption;
+    height?: number;
+    ariaLabel?: string;
+  }
+  let { option, height = 360, ariaLabel = '图表' }: Props = $props();
+
+  let host: HTMLDivElement;
+  let chart: echartsNS.ECharts | null = null;
+  let observer: ResizeObserver | null = null;
+
+  onMount(async () => {
+    // ECharts chunk loads lazily when a result/comparison view is opened.
+    const echarts = (await import('echarts')) as typeof echartsNS;
+    if (!host) return;
+    // Pass explicit sizes when the host has no layout yet (jsdom regression
+    // tests report 0×0 and ECharts warns "Can't get DOM width or height").
+    // In a real browser clientWidth/clientHeight are non-zero, so the measured
+    // size is used exactly as before; responsive resizing still works through
+    // the ResizeObserver below.
+    chart = echarts.init(host, undefined, {
+      renderer: 'svg',
+      width: host.clientWidth || 640,
+      height: host.clientHeight || height
+    });
+    observer = new ResizeObserver(() => {
+      if (!chart) return;
+      // re-measure on EVERY resize callback and pass the measured size
+      // explicitly: echarts keeps the width given at init/resize, so a
+      // desktop->mobile viewport change would otherwise leave the SVG at the
+      // old width and overflow the page (real, re-verified live bug).
+      const w = host.clientWidth || undefined;
+      const h = host.clientHeight || undefined;
+      if (w === undefined && h === undefined) return;
+      chart.resize({ width: w, height: h });
+    });
+    observer.observe(host);
+    chart?.setOption(option, { notMerge: true });
+  });
+
+  onDestroy(() => {
+    observer?.disconnect();
+    chart?.dispose();
+    chart = null;
+  });
+
+  $effect(() => {
+    chart?.setOption(option, { notMerge: true });
+  });
+</script>
+
+<div
+  bind:this={host}
+  style="height:{height}px; width:100%; min-width:0;"
+  role="img"
+  aria-label={ariaLabel}
+></div>
+
+<style>
+  div {
+    display: block;
+  }
+</style>