File size: 3,875 Bytes
80bcac8 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 | import { useCallback, useRef, useEffect, useState, useReducer } from 'react'
export function useImageLoader() {
const fileInputRef = useRef<HTMLInputElement>(null)
const loadImage = useCallback(
(file: File): Promise<{ image: HTMLImageElement; imageData: ImageData }> => {
return new Promise((resolve, reject) => {
const url = URL.createObjectURL(file)
const img = new Image()
img.onload = () => {
const canvas = document.createElement('canvas')
canvas.width = img.width
canvas.height = img.height
const ctx = canvas.getContext('2d')
if (!ctx) {
URL.revokeObjectURL(url)
reject(new Error('Failed to get canvas context'))
return
}
ctx.drawImage(img, 0, 0)
const imageData = ctx.getImageData(0, 0, img.width, img.height)
URL.revokeObjectURL(url)
resolve({ image: img, imageData })
}
img.onerror = () => {
URL.revokeObjectURL(url)
reject(new Error('Failed to load image'))
}
img.src = url
})
},
[]
)
const openFileDialog = useCallback(() => {
fileInputRef.current?.click()
}, [])
const handleFileSelect = useCallback(
(event: React.ChangeEvent<HTMLInputElement>, onLoad: (data: { image: HTMLImageElement; imageData: ImageData }) => void) => {
const file = event.target.files?.[0]
if (!file) return
if (!file.type.startsWith('image/')) {
alert('Please select an image file')
return
}
loadImage(file).then(onLoad).catch((error) => {
alert(`Failed to load image: ${error.message}`)
})
},
[loadImage]
)
return {
fileInputRef,
loadImage,
openFileDialog,
handleFileSelect,
}
}
export function useDragAndDrop(onLoad: (image: HTMLImageElement, imageData: ImageData) => void) {
const [isDragging, setIsDragging] = useState(false)
const loadImageFromFile = useCallback(
(file: File): Promise<{ image: HTMLImageElement; imageData: ImageData }> => {
return new Promise((resolve, reject) => {
const url = URL.createObjectURL(file)
const img = new Image()
img.onload = () => {
const canvas = document.createElement('canvas')
canvas.width = img.width
canvas.height = img.height
const ctx = canvas.getContext('2d')
if (!ctx) {
URL.revokeObjectURL(url)
reject(new Error('Failed to get canvas context'))
return
}
ctx.drawImage(img, 0, 0)
const imageData = ctx.getImageData(0, 0, img.width, img.height)
URL.revokeObjectURL(url)
resolve({ image: img, imageData })
}
img.onerror = () => {
URL.revokeObjectURL(url)
reject(new Error('Failed to load image'))
}
img.src = url
})
},
[]
)
const handleDragOver = useCallback((e: React.DragEvent) => {
e.preventDefault()
e.stopPropagation()
setIsDragging(true)
}, [])
const handleDragLeave = useCallback((e: React.DragEvent) => {
e.preventDefault()
e.stopPropagation()
setIsDragging(false)
}, [])
const handleDrop = useCallback(
async (e: React.DragEvent) => {
e.preventDefault()
e.stopPropagation()
setIsDragging(false)
const file = e.dataTransfer.files[0]
if (!file || !file.type.startsWith('image/')) return
try {
const { image, imageData } = await loadImageFromFile(file)
onLoad(image, imageData)
} catch (error) {
alert(`Failed to load image: ${error instanceof Error ? error.message : 'Unknown error'}`)
}
},
[onLoad, loadImageFromFile]
)
return {
handleDragOver,
handleDragLeave,
handleDrop,
isDragging,
}
} |