dify

dify/web/app/components/base/app-icon-picker/utils.ts

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+export const createImage = (url: string) =>
+  new Promise<HTMLImageElement>((resolve, reject) => {
+    const image = new Image()
+    image.addEventListener('load', () => resolve(image))
+    image.addEventListener('error', error => reject(error))
+    image.setAttribute('crossOrigin', 'anonymous') // needed to avoid cross-origin issues on CodeSandbox
+    image.src = url
+  })
+
+export function getRadianAngle(degreeValue: number) {
+  return (degreeValue * Math.PI) / 180
+}
+
+export function getMimeType(fileName: string): string {
+  const extension = fileName.split('.').pop()?.toLowerCase()
+  switch (extension) {
+    case 'png':
+      return 'image/png'
+    case 'jpg':
+    case 'jpeg':
+      return 'image/jpeg'
+    case 'gif':
+      return 'image/gif'
+    case 'webp':
+      return 'image/webp'
+    default:
+      return 'image/jpeg'
+  }
+}
+
+/**
+ * Returns the new bounding area of a rotated rectangle.
+ */
+export function rotateSize(width: number, height: number, rotation: number) {
+  const rotRad = getRadianAngle(rotation)
+
+  return {
+    width:
+            Math.abs(Math.cos(rotRad) * width) + Math.abs(Math.sin(rotRad) * height),
+    height:
+            Math.abs(Math.sin(rotRad) * width) + Math.abs(Math.cos(rotRad) * height),
+  }
+}
+
+/**
+ * This function was adapted from the one in the ReadMe of https://github.com/DominicTobias/react-image-crop
+ */
+export default async function getCroppedImg(
+  imageSrc: string,
+  pixelCrop: { x: number; y: number; width: number; height: number },
+  fileName: string,
+  rotation = 0,
+  flip = { horizontal: false, vertical: false },
+): Promise<Blob> {
+  const image = await createImage(imageSrc)
+  const canvas = document.createElement('canvas')
+  const ctx = canvas.getContext('2d')
+  const mimeType = getMimeType(fileName)
+
+  if (!ctx)
+    throw new Error('Could not create a canvas context')
+
+  const rotRad = getRadianAngle(rotation)
+
+  // calculate bounding box of the rotated image
+  const { width: bBoxWidth, height: bBoxHeight } = rotateSize(
+    image.width,
+    image.height,
+    rotation,
+  )
+
+  // set canvas size to match the bounding box
+  canvas.width = bBoxWidth
+  canvas.height = bBoxHeight
+
+  // translate canvas context to a central location to allow rotating and flipping around the center
+  ctx.translate(bBoxWidth / 2, bBoxHeight / 2)
+  ctx.rotate(rotRad)
+  ctx.scale(flip.horizontal ? -1 : 1, flip.vertical ? -1 : 1)
+  ctx.translate(-image.width / 2, -image.height / 2)
+
+  // draw rotated image
+  ctx.drawImage(image, 0, 0)
+
+  const croppedCanvas = document.createElement('canvas')
+
+  const croppedCtx = croppedCanvas.getContext('2d')
+
+  if (!croppedCtx)
+    throw new Error('Could not create a canvas context')
+
+  // Set the size of the cropped canvas
+  croppedCanvas.width = pixelCrop.width
+  croppedCanvas.height = pixelCrop.height
+
+  // Draw the cropped image onto the new canvas
+  croppedCtx.drawImage(
+    canvas,
+    pixelCrop.x,
+    pixelCrop.y,
+    pixelCrop.width,
+    pixelCrop.height,
+    0,
+    0,
+    pixelCrop.width,
+    pixelCrop.height,
+  )
+
+  return new Promise((resolve, reject) => {
+    croppedCanvas.toBlob((file) => {
+      if (file)
+        resolve(file)
+      else
+        reject(new Error('Could not create a blob'))
+    }, mimeType)
+  })
+}
+
+export function checkIsAnimatedImage(file: File): Promise<boolean> {
+  return new Promise((resolve, reject) => {
+    const fileReader = new FileReader()
+
+    fileReader.onload = function (e) {
+      const arr = new Uint8Array(e.target?.result as ArrayBuffer)
+
+      // Check file extension
+      const fileName = file.name.toLowerCase()
+      if (fileName.endsWith('.gif')) {
+        // If file is a GIF, assume it's animated
+        resolve(true)
+      }
+      // Check for WebP signature (RIFF and WEBP)
+      else if (isWebP(arr)) {
+        resolve(checkWebPAnimation(arr)) // Check if it's animated
+      }
+      else {
+        resolve(false) // Not a GIF or WebP
+      }
+    }
+
+    fileReader.onerror = function (err) {
+      reject(err) // Reject the promise on error
+    }
+
+    // Read the file as an array buffer
+    fileReader.readAsArrayBuffer(file)
+  })
+}
+
+// Function to check for WebP signature
+function isWebP(arr: Uint8Array) {
+  return (
+    arr[0] === 0x52 && arr[1] === 0x49 && arr[2] === 0x46 && arr[3] === 0x46
+    && arr[8] === 0x57 && arr[9] === 0x45 && arr[10] === 0x42 && arr[11] === 0x50
+  ) // "WEBP"
+}
+
+// Function to check if the WebP is animated (contains ANIM chunk)
+function checkWebPAnimation(arr: Uint8Array) {
+  // Search for the ANIM chunk in WebP to determine if it's animated
+  for (let i = 12; i < arr.length - 4; i++) {
+    if (arr[i] === 0x41 && arr[i + 1] === 0x4E && arr[i + 2] === 0x49 && arr[i + 3] === 0x4D)
+      return true // Found animation
+  }
+  return false // No animation chunk found
+}