From 75a9c16070709bc45b2c44c0993edb724a806d54 Mon Sep 17 00:00:00 2001
From: Ilia Mashkov <hikkikomori7@gmail.com>
Date: Mon, 26 Jan 2026 12:54:01 +0300
Subject: [PATCH] feat(ComparisonWrapper): remove props and add checks for
 fonts absence

---
 .../ComparisonSlider/ComparisonSlider.svelte  | 170 +++++++++---------
 1 file changed, 81 insertions(+), 89 deletions(-)

diff --git a/src/widgets/ComparisonSlider/ui/ComparisonSlider/ComparisonSlider.svelte b/src/widgets/ComparisonSlider/ui/ComparisonSlider/ComparisonSlider.svelte
index e259a97..a9c00b8 100644
--- a/src/widgets/ComparisonSlider/ui/ComparisonSlider/ComparisonSlider.svelte
+++ b/src/widgets/ComparisonSlider/ui/ComparisonSlider/ComparisonSlider.svelte
@@ -9,38 +9,26 @@
     - Responsive layout with Tailwind breakpoints for font sizing.
     - Performance optimized using offscreen canvas for measurements and transform-based animations.
 -->
-<script lang="ts" generics="T extends { name: string; id: string }">
+<script lang="ts">
+import { displayedFontsStore } from '$features/DisplayFont';
 import {
     createCharacterComparison,
     createTypographyControl,
 } from '$shared/lib';
 import type { LineData } from '$shared/lib';
+import { cubicOut } from 'svelte/easing';
 import { Spring } from 'svelte/motion';
+import { fly } from 'svelte/transition';
 import CharacterSlot from './components/CharacterSlot.svelte';
 import ControlsWrapper from './components/ControlsWrapper.svelte';
 import Labels from './components/Labels.svelte';
 import SliderLine from './components/SliderLine.svelte';
 
-interface Props<T extends { name: string; id: string }> {
-    /**
-     * First font definition ({name, id})
-     */
-    fontA: T;
-    /**
-     * Second font definition ({name, id})
-     */
-    fontB: T;
-    /**
-     * Text to display and compare
-     */
-    text?: string;
-}
-
-let {
-    fontA,
-    fontB,
-    text = $bindable('The quick brown fox jumps over the lazy dog'),
-}: Props<T> = $props();
+// Displayed text
+let text = $state('The quick brown fox jumps over the lazy dog...');
+// Pair of fonts to compare
+const fontA = $derived(displayedFontsStore.fontA);
+const fontB = $derived(displayedFontsStore.fontB);
 
 let container: HTMLElement | undefined = $state();
 let controlsWrapperElement = $state<HTMLDivElement | null>(null);
@@ -98,7 +86,6 @@ function handleMove(e: PointerEvent) {
 
 function startDragging(e: PointerEvent) {
     if (e.target === controlsWrapperElement || controlsWrapperElement?.contains(e.target as Node)) {
-        console.log('Pointer down on controls wrapper');
         e.stopPropagation();
         return;
     }
@@ -162,82 +149,87 @@ $effect(() => {
                 - Font Family switches based on `isPast`
                 - Transitions/Transforms provide the "morph" feel
             -->
-            <CharacterSlot
-                {char}
-                {proximity}
-                {isPast}
-                weight={weightControl.value}
-                size={sizeControl.value}
-                fontAName={fontA.name}
-                fontBName={fontB.name}
-            />
+            {#if fontA && fontB}
+                <CharacterSlot
+                    {char}
+                    {proximity}
+                    {isPast}
+                    weight={weightControl.value}
+                    size={sizeControl.value}
+                    fontAName={fontA.name}
+                    fontBName={fontB.name}
+                />
+            {/if}
         {/each}
     </div>
 {/snippet}
 
-<!-- Hidden canvas used for text measurement by the helper -->
-<canvas bind:this={measureCanvas} class="hidden" width="1" height="1"></canvas>
+{#if fontA && fontB}
+    <!-- Hidden canvas used for text measurement by the helper -->
+    <canvas bind:this={measureCanvas} class="hidden" width="1" height="1"></canvas>
 
-<div class="relative">
-    <div
-        bind:this={container}
-        role="slider"
-        tabindex="0"
-        aria-valuenow={Math.round(sliderPos)}
-        aria-label="Font comparison slider"
-        onpointerdown={startDragging}
-        class="
-            group relative w-full py-16 px-6 sm:py-24 sm:px-12 overflow-hidden
-            bg-indigo-50 rounded-[2.5rem] border border-slate-100 shadow-2xl
-            select-none touch-none cursor-ew-resize min-h-100 flex flex-col justify-center
-        "
-        class:box-shadow={'-20px 20px 60px #bebebe, 20px -20px 60px #ffffff;'}
-    >
-        <!-- Background Gradient Accent -->
+    <div class="relative">
         <div
+            bind:this={container}
+            role="slider"
+            tabindex="0"
+            aria-valuenow={Math.round(sliderPos)}
+            aria-label="Font comparison slider"
+            onpointerdown={startDragging}
             class="
-                absolute inset-0 bg-linear-to-br
-                from-slate-50/50 via-white to-slate-100/50
-                opacity-50 pointer-events-none
+                group relative w-full py-16 px-6 sm:py-24 sm:px-12 overflow-hidden
+                bg-indigo-50 rounded-[2.5rem] border border-slate-100 shadow-2xl
+                select-none touch-none cursor-ew-resize min-h-100 flex flex-col justify-center
             "
+            class:box-shadow={'-20px 20px 60px #bebebe, 20px -20px 60px #ffffff;'}
+            in:fly={{ y: 0, x: -50, duration: 300, easing: cubicOut, opacity: 0.2 }}
         >
+            <!-- Background Gradient Accent -->
+            <div
+                class="
+                    absolute inset-0 bg-linear-to-br
+                    from-slate-50/50 via-white to-slate-100/50
+                    opacity-50 pointer-events-none
+                "
+            >
+            </div>
+
+            <!-- Text Rendering Container -->
+            <div
+                class="
+                    relative flex flex-col items-center gap-4
+                    text-4xl sm:text-5xl md:text-6xl lg:text-7xl font-bold leading-[1.15]
+                    z-10 pointer-events-none text-center
+                "
+                style:perspective="1000px"
+            >
+                {#each charComparison.lines as line, lineIndex}
+                    <div
+                        class="relative w-full whitespace-nowrap"
+                        style:height={`${heightControl.value}em`}
+                        style:display="flex"
+                        style:align-items="center"
+                        style:justify-content="center"
+                    >
+                        {@render renderLine(line, lineIndex)}
+                    </div>
+                {/each}
+            </div>
+
+            <SliderLine {sliderPos} {isDragging} />
         </div>
 
-        <!-- Text Rendering Container -->
-        <div
-            class="
-                relative flex flex-col items-center gap-4
-                text-4xl sm:text-5xl md:text-6xl lg:text-7xl font-bold leading-[1.15]
-                z-10 pointer-events-none text-center
-            "
-            style:perspective="1000px"
-        >
-            {#each charComparison.lines as line, lineIndex}
-                <div
-                    class="relative w-full whitespace-nowrap"
-                    style:height={`${heightControl.value}em`}
-                    style:display="flex"
-                    style:align-items="center"
-                    style:justify-content="center"
-                >
-                    {@render renderLine(line, lineIndex)}
-                </div>
-            {/each}
-        </div>
-
-        <!-- Visual Components -->
-        <SliderLine {sliderPos} {isDragging} />
-        <Labels {fontA} {fontB} {sliderPos} />
+        <Labels fontA={fontA} fontB={fontB} {sliderPos} />
+        <!-- Since there're slider controls inside we put them outside the main one -->
+        <ControlsWrapper
+            bind:wrapper={controlsWrapperElement}
+            {sliderPos}
+            {isDragging}
+            bind:text={text}
+            containerWidth={container?.clientWidth}
+            weightControl={weightControl}
+            sizeControl={sizeControl}
+            heightControl={heightControl}
+        />
     </div>
-    <!-- Since there're slider controls inside we put them outside the main one -->
-    <ControlsWrapper
-        bind:wrapper={controlsWrapperElement}
-        {sliderPos}
-        {isDragging}
-        bind:text={text}
-        containerWidth={container?.clientWidth}
-        weightControl={weightControl}
-        sizeControl={sizeControl}
-        heightControl={heightControl}
-    />
-</div>
+{/if}