From a74abbb0b3bb1d12a3d8e35e93c9822639878a6e Mon Sep 17 00:00:00 2001
From: Ilia Mashkov <hikkikomori7@gmail.com>
Date: Mon, 13 Apr 2026 13:23:03 +0300
Subject: [PATCH] feat: wire createFontRowSizeResolver into SampleList for
 pretext-backed row heights

---
 .../ui/SampleList/SampleList.svelte           | 47 +++++++++++++++++--
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/src/widgets/SampleList/ui/SampleList/SampleList.svelte b/src/widgets/SampleList/ui/SampleList/SampleList.svelte
index f38815b..69f4b3f 100644
--- a/src/widgets/SampleList/ui/SampleList/SampleList.svelte
+++ b/src/widgets/SampleList/ui/SampleList/SampleList.svelte
@@ -5,7 +5,12 @@
     - Provides a typography menu for font setup.
 -->
 <script lang="ts">
-import { FontVirtualList } from '$entities/Font';
+import {
+    FontVirtualList,
+    appliedFontsManager,
+    createFontRowSizeResolver,
+    fontStore,
+} from '$entities/Font';
 import { FontSampler } from '$features/DisplayFont';
 import {
     TypographyMenu,
@@ -15,12 +20,30 @@ import { throttle } from '$shared/lib/utils';
 import { Skeleton } from '$shared/ui';
 import { layoutManager } from '../../model';
 
+// FontSampler chrome heights — derived from Tailwind classes in FontSampler.svelte.
+// Header: py-3 (12+12px padding) + ~32px content row ≈ 56px.
+// Only the header is counted; the mobile footer (md:hidden) is excluded because
+// on desktop, where container widths are wide and estimates matter most, it is invisible.
+// Over-estimating chrome is safe (row is slightly taller than text needs, never cut off).
+const SAMPLER_CHROME_HEIGHT = 56;
+
+// p-4 = 16px per side = 32px total horizontal padding in FontSampler's content area.
+// Using the smallest breakpoint (mobile) ensures contentWidth is never over-estimated:
+// wider actual padding → more text wrapping → pretext height ≥ rendered height → safe.
+const SAMPLER_CONTENT_PADDING_X = 32;
+
+// Fallback row height used when the font has not loaded yet.
+// Matches the previous hardcoded itemHeight={220} value to avoid regressions.
+const SAMPLER_FALLBACK_HEIGHT = 220;
+
 let text = $state('The quick brown fox jumps over the lazy dog...');
 let wrapper = $state<HTMLDivElement | null>(null);
 // Binds to the actual window height
 let innerHeight = $state(0);
 // Is the component above the middle of the viewport?
 let isAboveMiddle = $state(false);
+// Inner width of the wrapper div — updated by bind:clientWidth on mount and resize.
+let containerWidth = $state(0);
 
 const checkPosition = throttle(() => {
     if (!wrapper) return;
@@ -30,6 +53,24 @@ const checkPosition = throttle(() => {
 
     isAboveMiddle = rect.top < viewportMiddle;
 }, 100);
+
+// Resolver recreated when typography values change. The returned closure reads
+// appliedFontsManager.statuses (a SvelteMap) on every call, so any font status
+// change triggers a full offsets recompute in createVirtualizer — no DOM snap.
+const fontRowHeight = $derived.by(() =>
+    createFontRowSizeResolver({
+        getFonts: () => fontStore.fonts,
+        getWeight: () => controlManager.weight,
+        getPreviewText: () => text,
+        getContainerWidth: () => containerWidth,
+        getFontSizePx: () => controlManager.renderedSize,
+        getLineHeightPx: () => controlManager.height * controlManager.renderedSize,
+        getStatus: key => appliedFontsManager.statuses.get(key),
+        contentHorizontalPadding: SAMPLER_CONTENT_PADDING_X,
+        chromeHeight: SAMPLER_CHROME_HEIGHT,
+        fallbackHeight: SAMPLER_FALLBACK_HEIGHT,
+    })
+);
 </script>
 
 {#snippet skeleton()}
@@ -52,9 +93,9 @@ const checkPosition = throttle(() => {
     onresize={checkPosition}
 />
 
-<div bind:this={wrapper}>
+<div bind:this={wrapper} bind:clientWidth={containerWidth}>
     <FontVirtualList
-        itemHeight={220}
+        itemHeight={fontRowHeight}
         useWindowScroll={true}
         weight={controlManager.weight}
         columns={layoutManager.columns}