# Resize & Rotate/Flip UX Redesign Implementation Plan
> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
**Goal:** Replace the before/after slider with intuitive side-by-side comparison for resize and live CSS preview for rotate/flip.
**Architecture:** Frontend-only changes. Resize gets a tab-based settings panel (Presets/Custom Size/Scale) and a new SideBySideComparison result view. Rotate/flip gets live CSS transform preview on the ImageViewer with an "Apply" button. The tool-page.tsx conditionally renders the appropriate result view per tool. No backend changes.
**Tech Stack:** React, TypeScript, Tailwind CSS, Zustand, lucide-react
**Spec:** `docs/superpowers/specs/2026-03-23-resize-rotate-redesign.md`
---
### Task 1: Create SideBySideComparison Component
**Files:**
- Create: `apps/web/src/components/common/side-by-side-comparison.tsx`
- [ ] **Step 1: Create the component file**
```tsx
import { useState } from "react";
interface SideBySideComparisonProps {
beforeSrc: string;
afterSrc: string;
beforeSize?: number;
afterSize?: number;
}
function formatSize(bytes: number): string {
if (bytes < 1024) return `${bytes} B`;
if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
return `${(bytes / (1024 * 1024)).toFixed(2)} MB`;
}
export function SideBySideComparison({
beforeSrc,
afterSrc,
beforeSize,
afterSize,
}: SideBySideComparisonProps) {
const [beforeDims, setBeforeDims] = useState<{ w: number; h: number } | null>(null);
const [afterDims, setAfterDims] = useState<{ w: number; h: number } | null>(null);
const savingsPercent =
beforeSize && afterSize && beforeSize > 0
? ((1 - afterSize / beforeSize) * 100).toFixed(1)
: null;
const checkerboard = {
backgroundImage: `linear-gradient(45deg, #ccc 25%, transparent 25%),
linear-gradient(-45deg, #ccc 25%, transparent 25%),
linear-gradient(45deg, transparent 75%, #ccc 75%),
linear-gradient(-45deg, transparent 75%, #ccc 75%)`,
backgroundSize: "16px 16px",
backgroundPosition: "0 0, 0 8px, 8px -8px, -8px 0px",
};
return (
{/* Side-by-side images */}
{/* Original */}
Original

{
const img = e.currentTarget;
setBeforeDims({ w: img.naturalWidth, h: img.naturalHeight });
}}
/>
{beforeDims && (
{beforeDims.w} × {beforeDims.h}
)}
{beforeSize != null &&
{formatSize(beforeSize)}
}
{/* Resized */}
Resized

{
const img = e.currentTarget;
setAfterDims({ w: img.naturalWidth, h: img.naturalHeight });
}}
/>
{afterDims && (
{afterDims.w} × {afterDims.h}
)}
{afterSize != null &&
{formatSize(afterSize)}
}
{/* Size savings */}
{savingsPercent !== null && (
0 ? "text-green-600 dark:text-green-400" : "text-red-500"}`}
>
{Number(savingsPercent) > 0
? `${savingsPercent}% smaller`
: `${Math.abs(Number(savingsPercent))}% larger`}
)}
);
}
```
- [ ] **Step 2: Verify it compiles**
Run: `cd /Users/sidd/Desktop/Personal/Projects/Stirling-Image && pnpm --filter @stirling-image/web build 2>&1 | tail -5`
Expected: Build succeeds
- [ ] **Step 3: Commit**
```bash
git add apps/web/src/components/common/side-by-side-comparison.tsx
git commit -m "feat: add SideBySideComparison component for resize results"
```
---
### Task 2: Rewrite ResizeSettings with Tab-Based UI
**Files:**
- Modify: `apps/web/src/components/tools/resize-settings.tsx`
- [ ] **Step 1: Rewrite resize-settings.tsx with three tabs**
Replace the entire file content with:
```tsx
import { useState } from "react";
import { SOCIAL_MEDIA_PRESETS } from "@stirling-image/shared";
import { useFileStore } from "@/stores/file-store";
import { useToolProcessor } from "@/hooks/use-tool-processor";
import { Download, Link, Unlink } from "lucide-react";
import { ProgressCard } from "@/components/common/progress-card";
type ResizeTab = "presets" | "custom" | "scale";
type FitMode = "cover" | "contain" | "fill";
const FIT_LABELS: Record = {
cover: "Crop to fit",
contain: "Fit inside",
fill: "Stretch",
};
// Group presets by platform
const platforms = [...new Set(SOCIAL_MEDIA_PRESETS.map((p) => p.platform))];
export function ResizeSettings() {
const { files } = useFileStore();
const { processFiles, processing, error, downloadUrl, progress } =
useToolProcessor("resize");
const [tab, setTab] = useState("presets");
const [selectedPreset, setSelectedPreset] = useState(null);
const [width, setWidth] = useState("");
const [height, setHeight] = useState("");
const [percentage, setPercentage] = useState("50");
const [fit, setFit] = useState("cover");
const [lockAspect, setLockAspect] = useState(true);
const [withoutEnlargement, setWithoutEnlargement] = useState(false);
const handlePreset = (preset: (typeof SOCIAL_MEDIA_PRESETS)[number]) => {
const key = `${preset.platform}-${preset.name}`;
if (selectedPreset === key) {
setSelectedPreset(null);
setWidth("");
setHeight("");
} else {
setSelectedPreset(key);
setWidth(String(preset.width));
setHeight(String(preset.height));
}
};
const handleProcess = () => {
const settings: Record = {};
if (tab === "scale") {
settings.percentage = Number(percentage);
} else {
if (width) settings.width = Number(width);
if (height) settings.height = Number(height);
settings.fit = tab === "presets" ? "cover" : fit;
settings.withoutEnlargement = withoutEnlargement;
}
processFiles(files, settings);
};
const hasFile = files.length > 0;
const canProcess =
hasFile &&
!processing &&
(tab === "scale"
? Number(percentage) > 0
: Boolean(width) || Boolean(height));
const handleSubmit = (e: React.FormEvent) => {
e.preventDefault();
if (canProcess) handleProcess();
};
const tabClass = (t: ResizeTab) =>
`flex-1 text-xs py-1.5 rounded ${tab === t ? "bg-primary text-primary-foreground" : "bg-muted text-muted-foreground"}`;
return (
);
}
```
- [ ] **Step 2: Verify it compiles**
Run: `cd /Users/sidd/Desktop/Personal/Projects/Stirling-Image && pnpm --filter @stirling-image/web build 2>&1 | tail -5`
Expected: Build succeeds
- [ ] **Step 3: Commit**
```bash
git add apps/web/src/components/tools/resize-settings.tsx
git commit -m "feat: rewrite resize settings with tab-based UI (presets, custom, scale)"
```
---
### Task 3: Add CSS Transform Props to ImageViewer
**Files:**
- Modify: `apps/web/src/components/common/image-viewer.tsx`
- [ ] **Step 1: Add optional CSS transform props to the ImageViewer interface and apply them**
Add `cssRotate`, `cssFlipH`, `cssFlipV` optional props to the `ImageViewerProps` interface. In the `imageStyle` computation, compose CSS transforms when these props are provided.
Changes to make:
1. Update the interface (line 5-8):
```tsx
interface ImageViewerProps {
src: string;
filename: string;
fileSize: number;
cssRotate?: number;
cssFlipH?: boolean;
cssFlipV?: boolean;
}
```
2. Update the component destructuring (line 14):
```tsx
export function ImageViewer({ src, filename, fileSize, cssRotate, cssFlipH, cssFlipV }: ImageViewerProps) {
```
3. Update the `imageStyle` computation (lines 65-68) to compose CSS transforms:
```tsx
const previewTransform = [
cssRotate ? `rotate(${cssRotate}deg)` : "",
cssFlipH ? "scaleX(-1)" : "",
cssFlipV ? "scaleY(-1)" : "",
]
.filter(Boolean)
.join(" ");
const imageStyle =
fitMode === "fit"
? {
maxWidth: "100%",
maxHeight: "100%",
objectFit: "contain" as const,
...(previewTransform && { transform: previewTransform }),
}
: {
transform: `scale(${zoom / 100})${previewTransform ? ` ${previewTransform}` : ""}`,
transformOrigin: "center center",
};
```
- [ ] **Step 2: Verify it compiles**
Run: `cd /Users/sidd/Desktop/Personal/Projects/Stirling-Image && pnpm --filter @stirling-image/web build 2>&1 | tail -5`
Expected: Build succeeds
- [ ] **Step 3: Commit**
```bash
git add apps/web/src/components/common/image-viewer.tsx
git commit -m "feat: add CSS transform props to ImageViewer for live rotate/flip preview"
```
---
### Task 4: Update RotateSettings with Live Preview Callback
**Files:**
- Modify: `apps/web/src/components/tools/rotate-settings.tsx`
- [ ] **Step 1: Add onPreviewTransform callback prop and change button label**
The component needs to:
1. Accept an optional `onPreviewTransform` callback
2. Call it on every state change (angle, flipH, flipV) via useEffect
3. Change the submit button label from "Rotate" to "Apply"
Replace the entire file:
```tsx
import { useState, useEffect } from "react";
import { useFileStore } from "@/stores/file-store";
import { useToolProcessor } from "@/hooks/use-tool-processor";
import {
Download,
RotateCcw,
RotateCw,
FlipHorizontal,
FlipVertical,
} from "lucide-react";
import { ProgressCard } from "@/components/common/progress-card";
export interface PreviewTransform {
rotate: number;
flipH: boolean;
flipV: boolean;
}
interface RotateSettingsProps {
onPreviewTransform?: (transform: PreviewTransform) => void;
}
export function RotateSettings({ onPreviewTransform }: RotateSettingsProps) {
const { files } = useFileStore();
const { processFiles, processing, error, downloadUrl, progress } =
useToolProcessor("rotate");
const [angle, setAngle] = useState(0);
const [flipH, setFlipH] = useState(false);
const [flipV, setFlipV] = useState(false);
// Emit preview transform on every change
useEffect(() => {
onPreviewTransform?.({ rotate: angle, flipH, flipV });
}, [angle, flipH, flipV, onPreviewTransform]);
const rotateLeft = () => setAngle((a) => (a - 90 + 360) % 360);
const rotateRight = () => setAngle((a) => (a + 90) % 360);
const handleProcess = () => {
processFiles(files, {
angle,
horizontal: flipH,
vertical: flipV,
});
};
const hasFile = files.length > 0;
const hasChanges = angle !== 0 || flipH || flipV;
const handleSubmit = (e: React.FormEvent) => {
e.preventDefault();
if (hasFile && hasChanges && !processing) handleProcess();
};
return (
);
}
```
- [ ] **Step 2: Verify it compiles**
Run: `cd /Users/sidd/Desktop/Personal/Projects/Stirling-Image && pnpm --filter @stirling-image/web build 2>&1 | tail -5`
Expected: Build succeeds
- [ ] **Step 3: Commit**
```bash
git add apps/web/src/components/tools/rotate-settings.tsx
git commit -m "feat: add live preview callback to RotateSettings, rename button to Apply"
```
---
### Task 5: Update tool-page.tsx for Conditional Rendering
**Files:**
- Modify: `apps/web/src/pages/tool-page.tsx`
- [ ] **Step 1: Add imports, preview transform state, and conditional result rendering**
Changes to make in `tool-page.tsx`:
1. Add imports at the top (after existing imports, around line 8):
```tsx
import { SideBySideComparison } from "@/components/common/side-by-side-comparison";
import type { PreviewTransform } from "@/components/tools/rotate-settings";
```
2. Add a set for tools that use alternate result views (after `NO_DROPZONE_TOOLS` on line 63):
```tsx
const SIDE_BY_SIDE_TOOLS = new Set(["resize"]);
const LIVE_PREVIEW_TOOLS = new Set(["rotate"]);
```
3. Update `ToolSettingsPanel` to accept and pass through the preview transform callback (replace the function starting at line 65):
```tsx
function ToolSettingsPanel({
toolId,
onPreviewTransform,
}: {
toolId: string;
onPreviewTransform?: (t: PreviewTransform) => void;
}) {
// Phase 2: Core tools
if (toolId === "resize") return ;
if (toolId === "crop") return ;
if (toolId === "rotate") return ;
```
(Rest of ToolSettingsPanel stays identical)
4. In the `ToolPage` component, add preview transform state (after `const [mobileSettingsOpen, setMobileSettingsOpen]` on line 177):
```tsx
const [previewTransform, setPreviewTransform] = useState(null);
```
5. Update ToolSettingsPanel usage in both mobile and desktop layouts — pass the callback:
```tsx
```
6. Replace the result rendering logic in the main area for **both mobile and desktop layouts**. Replace the entire conditional block (from `{isNoDropzone ?` through the closing `}`). Apply this **identically** in both the mobile layout (around line 286) and the desktop layout (around line 372):
```tsx
{isNoDropzone ? (
Configure settings and generate.
) : hasProcessed && originalBlobUrl && SIDE_BY_SIDE_TOOLS.has(tool.id) ? (
) : hasProcessed && originalBlobUrl && LIVE_PREVIEW_TOOLS.has(tool.id) ? (
) : hasProcessed && originalBlobUrl ? (
) : hasFile && originalBlobUrl ? (
) : (
)}
```
**Important:** The `BeforeAfterSlider` is kept for all tools except resize (SideBySideComparison) and rotate (ImageViewer). The `BeforeAfterSlider` import must NOT be removed.
- [ ] **Step 2: Verify it compiles**
Run: `cd /Users/sidd/Desktop/Personal/Projects/Stirling-Image && pnpm --filter @stirling-image/web build 2>&1 | tail -5`
Expected: Build succeeds
- [ ] **Step 3: Commit**
```bash
git add apps/web/src/pages/tool-page.tsx
git commit -m "feat: conditional result views — side-by-side for resize, live preview for rotate"
```
---
### Task 6: Docker Rebuild and Test
**Files:**
- No file changes — build and run existing Docker setup
- [ ] **Step 1: Build Docker image**
```bash
cd /Users/sidd/Desktop/Personal/Projects/Stirling-Image
docker compose -f docker/docker-compose.yml build
```
- [ ] **Step 2: Start the container**
```bash
docker compose -f docker/docker-compose.yml up -d
```
- [ ] **Step 3: Verify the app is running**
```bash
curl -f http://localhost:1349/api/v1/health
```
Expected: Health check passes
- [ ] **Step 4: Report to user for UI testing**
App is running at `http://localhost:1349`. User can test:
- Resize tool: tab-based settings (Presets, Custom Size, Scale), side-by-side result view
- Rotate tool: live CSS preview as controls change, "Apply" button, processed result in standard viewer