feat(web): add lightbox preview for chat images (#715)

web/src/components/AssistantChat/messages/MessageAttachments.tsx

@@ -1,6 +1,7 @@
 import type { AttachmentMetadata } from '@/types/api'
 import { FileIcon } from '@/components/FileIcon'
 import { isImageMimeType } from '@/lib/fileAttachments'
+import { ImagePreview } from '@/components/ImagePreview'
 
 function formatFileSize(bytes: number): string {
     if (bytes < 1024) return `${bytes} B`
@@ -11,18 +12,20 @@ function formatFileSize(bytes: number): string {
 function ImageAttachment(props: { attachment: AttachmentMetadata }) {
     const { attachment } = props
     return (
-        <div className="relative overflow-hidden rounded-lg">
+        <ImagePreview
-            <img
+            src={attachment.previewUrl ?? ''}
-                src={attachment.previewUrl}
+            fileName={attachment.filename}
-                alt={attachment.filename}
+            label={attachment.filename}
-                className="max-h-48 max-w-full object-contain"
+            buttonClassName="relative overflow-hidden rounded-lg text-left cursor-zoom-in"
-            />
+            imageClassName="max-h-48 max-w-full object-contain"
+            caption={(
                 <div className="absolute inset-x-0 bottom-0 bg-gradient-to-t from-black/60 to-transparent px-2 py-1.5">
                     <span className="text-xs text-white/90 line-clamp-1">
                         {attachment.filename}
                     </span>
                 </div>
-        </div>
+            )}
+        />
     )
 }
 

web/src/components/AssistantChat/messages/ToolMessage.tsx

@@ -14,6 +14,7 @@ import { ToolCard } from '@/components/ToolCard/ToolCard'
 import { useHappyChatContext } from '@/components/AssistantChat/context'
 import { CliOutputBlock } from '@/components/CliOutputBlock'
 import { UserBubbleContent, getUserBubbleClassName, shouldShowMessageStatus } from '@/components/AssistantChat/messages/user-bubble'
+import { ImagePreview } from '@/components/ImagePreview'
 
 function isToolCallBlock(value: unknown): value is ToolCallBlock {
     if (!isObject(value)) return false
@@ -84,11 +85,12 @@ function GeneratedImageCard(props: { block: GeneratedImageBlock }) {
                 Generated image · {props.block.fileName}
             </div>
             {objectUrl ? (
-                <img
+                <ImagePreview
                     src={objectUrl}
-                    alt={props.block.fileName}
+                    fileName={props.block.fileName}
-                    className="max-h-[min(28rem,60vh)] max-w-full rounded-xl object-contain"
+                    label={props.block.fileName}
-                    draggable={false}
+                    buttonClassName="block max-w-full cursor-zoom-in rounded-xl text-left"
+                    imageClassName="max-h-[min(28rem,60vh)] max-w-full rounded-xl object-contain"
                 />
             ) : error ? (
                 <div className="text-sm text-[var(--app-hint)]">

web/src/components/ImagePreview.tsx

@@ -0,0 +1,268 @@
+import { useCallback, useEffect, useRef, useState, type PointerEvent, type ReactNode, type WheelEvent } from 'react'
+import { CloseIcon } from '@/components/icons'
+
+const MIN_IMAGE_SCALE = 0.25
+const MAX_IMAGE_SCALE = 8
+const IMAGE_SCALE_STEP = 0.25
+
+function clampImageScale(value: number): number {
+    return Math.min(MAX_IMAGE_SCALE, Math.max(MIN_IMAGE_SCALE, value))
+}
+
+type ImagePoint = { x: number; y: number }
+
+function getPointDistance(a: ImagePoint, b: ImagePoint): number {
+    return Math.hypot(a.x - b.x, a.y - b.y)
+}
+
+function getPointCenter(a: ImagePoint, b: ImagePoint): ImagePoint {
+    return {
+        x: (a.x + b.x) / 2,
+        y: (a.y + b.y) / 2
+    }
+}
+
+export function ImagePreview(props: {
+    src: string
+    fileName: string
+    label: string
+    buttonClassName?: string
+    imageClassName?: string
+    caption?: ReactNode
+}) {
+    const [viewerOpen, setViewerOpen] = useState(false)
+    const [scale, setScale] = useState(1)
+    const [offset, setOffset] = useState({ x: 0, y: 0 })
+    const scaleRef = useRef(scale)
+    const offsetRef = useRef(offset)
+    const activePointersRef = useRef(new Map<number, ImagePoint>())
+    const dragRef = useRef<{ pointerId: number; startX: number; startY: number; originX: number; originY: number } | null>(null)
+    const pinchRef = useRef<{ startDistance: number; startScale: number; startCenter: ImagePoint; origin: ImagePoint } | null>(null)
+
+    const updateScale = useCallback((next: number | ((current: number) => number)) => {
+        setScale((current) => {
+            const value = typeof next === 'function' ? next(current) : next
+            scaleRef.current = value
+            return value
+        })
+    }, [])
+
+    const updateOffset = useCallback((next: ImagePoint) => {
+        offsetRef.current = next
+        setOffset(next)
+    }, [])
+
+    const resetView = useCallback(() => {
+        updateScale(1)
+        updateOffset({ x: 0, y: 0 })
+    }, [updateOffset, updateScale])
+
+    const closeViewer = useCallback(() => {
+        setViewerOpen(false)
+        activePointersRef.current.clear()
+        dragRef.current = null
+        pinchRef.current = null
+        resetView()
+    }, [resetView])
+
+    const zoomBy = useCallback((delta: number) => {
+        updateScale((current) => clampImageScale(current + delta))
+    }, [updateScale])
+
+    const handleWheel = useCallback((event: WheelEvent<HTMLDivElement>) => {
+        event.preventDefault()
+        const delta = event.deltaY < 0 ? IMAGE_SCALE_STEP : -IMAGE_SCALE_STEP
+        zoomBy(delta)
+    }, [zoomBy])
+
+    const beginPinch = useCallback(() => {
+        const pointers = Array.from(activePointersRef.current.values())
+        if (pointers.length < 2) return
+
+        const [first, second] = pointers
+        pinchRef.current = {
+            startDistance: getPointDistance(first, second),
+            startScale: scaleRef.current,
+            startCenter: getPointCenter(first, second),
+            origin: offsetRef.current
+        }
+        dragRef.current = null
+    }, [])
+
+    const handlePointerDown = useCallback((event: PointerEvent<HTMLDivElement>) => {
+        if (event.button !== 0) return
+        event.currentTarget.setPointerCapture(event.pointerId)
+        activePointersRef.current.set(event.pointerId, { x: event.clientX, y: event.clientY })
+
+        if (activePointersRef.current.size >= 2) {
+            beginPinch()
+            return
+        }
+
+        dragRef.current = {
+            pointerId: event.pointerId,
+            startX: event.clientX,
+            startY: event.clientY,
+            originX: offsetRef.current.x,
+            originY: offsetRef.current.y
+        }
+    }, [beginPinch])
+
+    const handlePointerMove = useCallback((event: PointerEvent<HTMLDivElement>) => {
+        if (!activePointersRef.current.has(event.pointerId)) return
+        activePointersRef.current.set(event.pointerId, { x: event.clientX, y: event.clientY })
+
+        if (activePointersRef.current.size >= 2 && pinchRef.current) {
+            const pointers = Array.from(activePointersRef.current.values())
+            const [first, second] = pointers
+            const distance = getPointDistance(first, second)
+            const center = getPointCenter(first, second)
+            const pinch = pinchRef.current
+            const nextScale = pinch.startDistance > 0
+                ? clampImageScale(pinch.startScale * (distance / pinch.startDistance))
+                : pinch.startScale
+
+            updateScale(nextScale)
+            updateOffset({
+                x: pinch.origin.x + center.x - pinch.startCenter.x,
+                y: pinch.origin.y + center.y - pinch.startCenter.y
+            })
+            return
+        }
+
+        const drag = dragRef.current
+        if (!drag || drag.pointerId !== event.pointerId) return
+        updateOffset({
+            x: drag.originX + event.clientX - drag.startX,
+            y: drag.originY + event.clientY - drag.startY
+        })
+    }, [updateOffset, updateScale])
+
+    const handlePointerUp = useCallback((event: PointerEvent<HTMLDivElement>) => {
+        activePointersRef.current.delete(event.pointerId)
+        if (dragRef.current?.pointerId === event.pointerId) {
+            dragRef.current = null
+        }
+        pinchRef.current = null
+
+        const remainingPointer = activePointersRef.current.entries().next().value as [number, ImagePoint] | undefined
+        if (remainingPointer) {
+            dragRef.current = {
+                pointerId: remainingPointer[0],
+                startX: remainingPointer[1].x,
+                startY: remainingPointer[1].y,
+                originX: offsetRef.current.x,
+                originY: offsetRef.current.y
+            }
+        }
+    }, [])
+
+    useEffect(() => {
+        if (!viewerOpen) return
+
+        const handleKeyDown = (event: KeyboardEvent) => {
+            if (event.key === 'Escape') {
+                closeViewer()
+            }
+            if (event.key === '0') {
+                resetView()
+            }
+            if (event.key === '+' || event.key === '=') {
+                zoomBy(IMAGE_SCALE_STEP)
+            }
+            if (event.key === '-') {
+                zoomBy(-IMAGE_SCALE_STEP)
+            }
+        }
+
+        window.addEventListener('keydown', handleKeyDown)
+        return () => window.removeEventListener('keydown', handleKeyDown)
+    }, [closeViewer, resetView, viewerOpen, zoomBy])
+
+    return (
+        <>
+            <button
+                type="button"
+                onClick={() => setViewerOpen(true)}
+                className={props.buttonClassName ?? 'group flex min-h-[18rem] w-full items-center justify-center overflow-auto rounded-md border border-[var(--app-border)] bg-[var(--app-code-bg)] p-3 text-left'}
+                title="Click to zoom"
+            >
+                <img
+                    src={props.src}
+                    alt={props.label}
+                    className={props.imageClassName ?? 'max-h-[calc(100vh-14rem)] max-w-full object-contain transition-transform group-hover:scale-[1.01]'}
+                    draggable={false}
+                />
+                {props.caption}
+                <span className="sr-only">{props.fileName}</span>
+            </button>
+
+            {viewerOpen ? (
+                <div
+                    className="fixed inset-0 z-50 flex flex-col bg-black/90 text-white"
+                    role="dialog"
+                    aria-modal="true"
+                    aria-label={props.label}
+                >
+                    <div className="flex items-center gap-2 border-b border-white/10 bg-black/50 px-3 py-2">
+                        <div className="min-w-0 flex-1 truncate text-sm font-medium">{props.fileName}</div>
+                        <button
+                            type="button"
+                            onClick={() => zoomBy(-IMAGE_SCALE_STEP)}
+                            className="rounded bg-white/10 px-3 py-1 text-sm hover:bg-white/20 disabled:opacity-40"
+                            disabled={scale <= MIN_IMAGE_SCALE}
+                            title="Zoom out"
+                        >
+                            −
+                        </button>
+                        <button
+                            type="button"
+                            onClick={resetView}
+                            className="rounded bg-white/10 px-3 py-1 text-sm hover:bg-white/20"
+                            title="Reset zoom"
+                        >
+                            {Math.round(scale * 100)}%
+                        </button>
+                        <button
+                            type="button"
+                            onClick={() => zoomBy(IMAGE_SCALE_STEP)}
+                            className="rounded bg-white/10 px-3 py-1 text-sm hover:bg-white/20 disabled:opacity-40"
+                            disabled={scale >= MAX_IMAGE_SCALE}
+                            title="Zoom in"
+                        >
+                            +
+                        </button>
+                        <button
+                            type="button"
+                            onClick={closeViewer}
+                            className="flex h-8 w-8 items-center justify-center rounded bg-white/10 hover:bg-white/20"
+                            title="Close"
+                        >
+                            <CloseIcon className="h-4 w-4" />
+                        </button>
+                    </div>
+                    <div
+                        className="relative min-h-0 flex-1 cursor-grab touch-none overflow-hidden active:cursor-grabbing"
+                        onWheel={handleWheel}
+                        onPointerDown={handlePointerDown}
+                        onPointerMove={handlePointerMove}
+                        onPointerUp={handlePointerUp}
+                        onPointerCancel={handlePointerUp}
+                        onDoubleClick={resetView}
+                    >
+                        <img
+                            src={props.src}
+                            alt={props.label}
+                            draggable={false}
+                            className="absolute left-1/2 top-1/2 max-h-[90vh] max-w-[90vw] select-none object-contain"
+                            style={{
+                                transform: `translate(calc(-50% + ${offset.x}px), calc(-50% + ${offset.y}px)) scale(${scale})`,
+                                transformOrigin: 'center center'
+                            }}
+                        />
+                    </div>
+                </div>
+            ) : null}
+        </>
+    )
+}

web/src/routes/sessions/file.tsx

@@ -1,9 +1,9 @@
-import { useCallback, useEffect, useMemo, useRef, useState, type PointerEvent, type WheelEvent } from 'react'
+import { useEffect, useMemo, useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
 import { useParams, useSearch } from '@tanstack/react-router'
 import type { GitCommandResponse } from '@/types/api'
 import { FileIcon } from '@/components/FileIcon'
-import { CopyIcon, CheckIcon, CloseIcon } from '@/components/icons'
+import { CopyIcon, CheckIcon } from '@/components/icons'
 import { useAppContext } from '@/lib/app-context'
 import { useAppGoBack } from '@/hooks/useAppGoBack'
 import { useCopyToClipboard } from '@/hooks/useCopyToClipboard'
@@ -12,11 +12,9 @@ import { queryKeys } from '@/lib/query-keys'
 import { langAlias, useShikiHighlighter } from '@/lib/shiki'
 import { useTranslation } from '@/lib/use-translation'
 import { decodeBase64 } from '@/lib/utils'
+import { ImagePreview } from '@/components/ImagePreview'
 
 const MAX_COPYABLE_FILE_BYTES = 1_000_000
-const MIN_IMAGE_SCALE = 0.25
-const MAX_IMAGE_SCALE = 8
-const IMAGE_SCALE_STEP = 0.25
 const IMAGE_MIME_BY_EXTENSION: Record<string, string> = {
     apng: 'image/apng',
     avif: 'image/avif',
@@ -143,260 +141,6 @@ function extractCommandError(result: GitCommandResponse | undefined): string | n
     return result.error ?? result.stderr ?? 'Failed to load diff'
 }
 
-function clampImageScale(value: number): number {
-    return Math.min(MAX_IMAGE_SCALE, Math.max(MIN_IMAGE_SCALE, value))
-}
-
-type ImagePoint = { x: number; y: number }
-
-function getPointDistance(a: ImagePoint, b: ImagePoint): number {
-    return Math.hypot(a.x - b.x, a.y - b.y)
-}
-
-function getPointCenter(a: ImagePoint, b: ImagePoint): ImagePoint {
-    return {
-        x: (a.x + b.x) / 2,
-        y: (a.y + b.y) / 2
-    }
-}
-
-function ImagePreview(props: { dataUrl: string; fileName: string; label: string }) {
-    const [viewerOpen, setViewerOpen] = useState(false)
-    const [scale, setScale] = useState(1)
-    const [offset, setOffset] = useState({ x: 0, y: 0 })
-    const scaleRef = useRef(scale)
-    const offsetRef = useRef(offset)
-    const activePointersRef = useRef(new Map<number, ImagePoint>())
-    const dragRef = useRef<{ pointerId: number; startX: number; startY: number; originX: number; originY: number } | null>(null)
-    const pinchRef = useRef<{ startDistance: number; startScale: number; startCenter: ImagePoint; origin: ImagePoint } | null>(null)
-
-    const updateScale = useCallback((next: number | ((current: number) => number)) => {
-        setScale((current) => {
-            const value = typeof next === 'function' ? next(current) : next
-            scaleRef.current = value
-            return value
-        })
-    }, [])
-
-    const updateOffset = useCallback((next: ImagePoint) => {
-        offsetRef.current = next
-        setOffset(next)
-    }, [])
-
-    const resetView = useCallback(() => {
-        updateScale(1)
-        updateOffset({ x: 0, y: 0 })
-    }, [updateOffset, updateScale])
-
-    const closeViewer = useCallback(() => {
-        setViewerOpen(false)
-        activePointersRef.current.clear()
-        dragRef.current = null
-        pinchRef.current = null
-        resetView()
-    }, [resetView])
-
-    const zoomBy = useCallback((delta: number) => {
-        updateScale((current) => clampImageScale(current + delta))
-    }, [updateScale])
-
-    const handleWheel = useCallback((event: WheelEvent<HTMLDivElement>) => {
-        event.preventDefault()
-        const delta = event.deltaY < 0 ? IMAGE_SCALE_STEP : -IMAGE_SCALE_STEP
-        zoomBy(delta)
-    }, [zoomBy])
-
-    const beginPinch = useCallback(() => {
-        const pointers = Array.from(activePointersRef.current.values())
-        if (pointers.length < 2) return
-
-        const [first, second] = pointers
-        pinchRef.current = {
-            startDistance: getPointDistance(first, second),
-            startScale: scaleRef.current,
-            startCenter: getPointCenter(first, second),
-            origin: offsetRef.current
-        }
-        dragRef.current = null
-    }, [])
-
-    const handlePointerDown = useCallback((event: PointerEvent<HTMLDivElement>) => {
-        if (event.button !== 0) return
-        event.currentTarget.setPointerCapture(event.pointerId)
-        activePointersRef.current.set(event.pointerId, { x: event.clientX, y: event.clientY })
-
-        if (activePointersRef.current.size >= 2) {
-            beginPinch()
-            return
-        }
-
-        dragRef.current = {
-            pointerId: event.pointerId,
-            startX: event.clientX,
-            startY: event.clientY,
-            originX: offsetRef.current.x,
-            originY: offsetRef.current.y
-        }
-    }, [beginPinch])
-
-    const handlePointerMove = useCallback((event: PointerEvent<HTMLDivElement>) => {
-        if (!activePointersRef.current.has(event.pointerId)) return
-        activePointersRef.current.set(event.pointerId, { x: event.clientX, y: event.clientY })
-
-        if (activePointersRef.current.size >= 2 && pinchRef.current) {
-            const pointers = Array.from(activePointersRef.current.values())
-            const [first, second] = pointers
-            const distance = getPointDistance(first, second)
-            const center = getPointCenter(first, second)
-            const pinch = pinchRef.current
-            const nextScale = pinch.startDistance > 0
-                ? clampImageScale(pinch.startScale * (distance / pinch.startDistance))
-                : pinch.startScale
-
-            updateScale(nextScale)
-            updateOffset({
-                x: pinch.origin.x + center.x - pinch.startCenter.x,
-                y: pinch.origin.y + center.y - pinch.startCenter.y
-            })
-            return
-        }
-
-        const drag = dragRef.current
-        if (!drag || drag.pointerId !== event.pointerId) return
-        updateOffset({
-            x: drag.originX + event.clientX - drag.startX,
-            y: drag.originY + event.clientY - drag.startY
-        })
-    }, [updateOffset, updateScale])
-
-    const handlePointerUp = useCallback((event: PointerEvent<HTMLDivElement>) => {
-        activePointersRef.current.delete(event.pointerId)
-        if (dragRef.current?.pointerId === event.pointerId) {
-            dragRef.current = null
-        }
-        pinchRef.current = null
-
-        const remainingPointer = activePointersRef.current.entries().next().value as [number, ImagePoint] | undefined
-        if (remainingPointer) {
-            dragRef.current = {
-                pointerId: remainingPointer[0],
-                startX: remainingPointer[1].x,
-                startY: remainingPointer[1].y,
-                originX: offsetRef.current.x,
-                originY: offsetRef.current.y
-            }
-        }
-    }, [])
-
-    useEffect(() => {
-        if (!viewerOpen) return
-
-        const handleKeyDown = (event: KeyboardEvent) => {
-            if (event.key === 'Escape') {
-                closeViewer()
-            }
-            if (event.key === '0') {
-                resetView()
-            }
-            if (event.key === '+' || event.key === '=') {
-                zoomBy(IMAGE_SCALE_STEP)
-            }
-            if (event.key === '-') {
-                zoomBy(-IMAGE_SCALE_STEP)
-            }
-        }
-
-        window.addEventListener('keydown', handleKeyDown)
-        return () => window.removeEventListener('keydown', handleKeyDown)
-    }, [closeViewer, resetView, viewerOpen, zoomBy])
-
-    return (
-        <>
-            <button
-                type="button"
-                onClick={() => setViewerOpen(true)}
-                className="group flex min-h-[18rem] w-full items-center justify-center overflow-auto rounded-md border border-[var(--app-border)] bg-[var(--app-code-bg)] p-3 text-left"
-                title="Click to zoom"
-            >
-                <img
-                    src={props.dataUrl}
-                    alt={props.label}
-                    className="max-h-[calc(100vh-14rem)] max-w-full object-contain transition-transform group-hover:scale-[1.01]"
-                    draggable={false}
-                />
-                <span className="sr-only">{props.fileName}</span>
-            </button>
-
-            {viewerOpen ? (
-                <div
-                    className="fixed inset-0 z-50 flex flex-col bg-black/90 text-white"
-                    role="dialog"
-                    aria-modal="true"
-                    aria-label={props.label}
-                >
-                    <div className="flex items-center gap-2 border-b border-white/10 bg-black/50 px-3 py-2">
-                        <div className="min-w-0 flex-1 truncate text-sm font-medium">{props.fileName}</div>
-                        <button
-                            type="button"
-                            onClick={() => zoomBy(-IMAGE_SCALE_STEP)}
-                            className="rounded bg-white/10 px-3 py-1 text-sm hover:bg-white/20 disabled:opacity-40"
-                            disabled={scale <= MIN_IMAGE_SCALE}
-                            title="Zoom out"
-                        >
-                            −
-                        </button>
-                        <button
-                            type="button"
-                            onClick={resetView}
-                            className="rounded bg-white/10 px-3 py-1 text-sm hover:bg-white/20"
-                            title="Reset zoom"
-                        >
-                            {Math.round(scale * 100)}%
-                        </button>
-                        <button
-                            type="button"
-                            onClick={() => zoomBy(IMAGE_SCALE_STEP)}
-                            className="rounded bg-white/10 px-3 py-1 text-sm hover:bg-white/20 disabled:opacity-40"
-                            disabled={scale >= MAX_IMAGE_SCALE}
-                            title="Zoom in"
-                        >
-                            +
-                        </button>
-                        <button
-                            type="button"
-                            onClick={closeViewer}
-                            className="flex h-8 w-8 items-center justify-center rounded bg-white/10 hover:bg-white/20"
-                            title="Close"
-                        >
-                            <CloseIcon className="h-4 w-4" />
-                        </button>
-                    </div>
-                    <div
-                        className="relative min-h-0 flex-1 cursor-grab touch-none overflow-hidden active:cursor-grabbing"
-                        onWheel={handleWheel}
-                        onPointerDown={handlePointerDown}
-                        onPointerMove={handlePointerMove}
-                        onPointerUp={handlePointerUp}
-                        onPointerCancel={handlePointerUp}
-                        onDoubleClick={resetView}
-                    >
-                        <img
-                            src={props.dataUrl}
-                            alt={props.label}
-                            draggable={false}
-                            className="absolute left-1/2 top-1/2 max-h-[90vh] max-w-[90vw] select-none object-contain"
-                            style={{
-                                transform: `translate(calc(-50% + ${offset.x}px), calc(-50% + ${offset.y}px)) scale(${scale})`,
-                                transformOrigin: 'center center'
-                            }}
-                        />
-                    </div>
-                </div>
-            ) : null}
-        </>
-    )
-}
-
 export default function FilePage() {
     const { api } = useAppContext()
     const { t } = useTranslation()
@@ -560,7 +304,7 @@ export default function FilePage() {
                     ) : displayMode === 'file' ? (
                         imagePreviewUrl ? (
                             <ImagePreview
-                                dataUrl={imagePreviewUrl}
+                                src={imagePreviewUrl}
                                 fileName={fileName}
                                 label={t('file.page.imagePreviewAlt', { name: fileName })}
                             />