Refactor refreshAvatar()

object/user_avatar_identicon.go

@@ -0,0 +1,80 @@
+// Copyright 2023 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package object
+
+import (
+	"bytes"
+	"crypto/md5"
+	"fmt"
+	"image"
+	"image/color"
+	"image/png"
+	"io"
+	"strings"
+
+	"github.com/fogleman/gg"
+)
+
+func getColor(data []byte) color.RGBA {
+	r := int(data[0]) % 256
+	g := int(data[1]) % 256
+	b := int(data[2]) % 256
+	return color.RGBA{uint8(r), uint8(g), uint8(b), 255}
+}
+
+func getIdenticonFileBuffer(username string) (*bytes.Buffer, string, error) {
+	username = strings.TrimSpace(strings.ToLower(username))
+
+	hash := md5.New()
+	io.WriteString(hash, username)
+	hashedUsername := hash.Sum(nil)
+
+	// Define the size of the image
+	const imageSize = 420
+	const cellSize = imageSize / 7
+
+	// Create a new image
+	img := image.NewRGBA(image.Rect(0, 0, imageSize, imageSize))
+
+	// Create a context
+	dc := gg.NewContextForRGBA(img)
+
+	// Set a background color
+	dc.SetColor(color.RGBA{240, 240, 240, 255})
+	dc.Clear()
+
+	// Get avatar color
+	avatarColor := getColor(hashedUsername)
+
+	// Draw cells
+	for i := 0; i < 7; i++ {
+		for j := 0; j < 7; j++ {
+			if (hashedUsername[i] >> uint(j) & 1) == 1 {
+				dc.SetColor(avatarColor)
+				dc.DrawRectangle(float64(j*cellSize), float64(i*cellSize), float64(cellSize), float64(cellSize))
+				dc.Fill()
+			}
+		}
+	}
+
+	// Save image to a bytes.Buffer
+	buffer := &bytes.Buffer{}
+	err := png.Encode(buffer, img)
+	if err != nil {
+		return nil, "", fmt.Errorf("failed to save image: %w", err)
+	}
+
+	return buffer, ".png", nil
+}