Generate random avatar based on e-mail when disable Gravatar

.gopmfile

@@ -14,6 +14,7 @@ github.com/go-xorm/core =
 github.com/go-xorm/xorm = 
 github.com/gogits/chardet = commit:2404f77725
 github.com/gogits/go-gogs-client = commit:92e76d616a
+github.com/issue9/identicon = 
 github.com/lib/pq = commit:0dad96c0b9
 github.com/macaron-contrib/binding = commit:de6ed78668
 github.com/macaron-contrib/cache = commit:cd824f6f2d

models/user.go

@@ -13,7 +13,9 @@ import (
 	"fmt"
 	"image"
 	"image/jpeg"
+	_ "image/jpeg"
 	"os"
+	"path"
 	"path/filepath"
 	"strings"
 	"time"
@@ -116,11 +118,39 @@ func (u *User) HomeLink() string {
 
 // AvatarLink returns user gravatar link.
 func (u *User) AvatarLink() string {
+	defaultImgUrl := setting.AppSubUrl + "/img/avatar_default.jpg"
+	imgPath := path.Join(setting.AvatarUploadPath, com.ToStr(u.Id))
 	switch {
 	case u.UseCustomAvatar:
+		if !com.IsExist(imgPath) {
+			return defaultImgUrl
+		}
 		return setting.AppSubUrl + "/avatars/" + com.ToStr(u.Id)
 	case setting.DisableGravatar, setting.OfflineMode:
-		return setting.AppSubUrl + "/img/avatar_default.jpg"
+		if !com.IsExist(imgPath) {
+			img, err := avatar.RandomImage([]byte(u.Email))
+			if err != nil {
+				log.Error(3, "RandomImage: %v", err)
+				return defaultImgUrl
+			}
+			if err = os.MkdirAll(path.Dir(imgPath), os.ModePerm); err != nil {
+				log.Error(3, "Create: %v", err)
+				return defaultImgUrl
+			}
+			fw, err := os.Create(imgPath)
+			if err != nil {
+				log.Error(3, "Create: %v", err)
+				return defaultImgUrl
+			}
+			defer fw.Close()
+
+			if err = jpeg.Encode(fw, img, nil); err != nil {
+				log.Error(3, "Encode: %v", err)
+				return defaultImgUrl
+			}
+		}
+
+		return setting.AppSubUrl + "/avatars/" + com.ToStr(u.Id)
 	case setting.Service.EnableCacheAvatar:
 		return setting.AppSubUrl + "/avatar/" + u.Avatar
 	}

modules/avatar/avatar.go

@@ -19,9 +19,11 @@ import (
 	"errors"
 	"fmt"
 	"image"
+	"image/color/palette"
 	"image/jpeg"
 	"image/png"
 	"io"
+	"math/rand"
 	"net/http"
 	"net/url"
 	"os"
@@ -30,6 +32,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/issue9/identicon"
 	"github.com/nfnt/resize"
 
 	"github.com/gogits/gogs/modules/log"
@@ -59,6 +62,27 @@ func HashEmail(email string) string {
 	return hex.EncodeToString(h.Sum(nil))
 }
 
+const _RANDOM_AVATAR_SIZE = 200
+
+// RandomImage generates and returns a random avatar image.
+func RandomImage(data []byte) (image.Image, error) {
+	randExtent := len(palette.WebSafe) - 32
+	rand.Seed(time.Now().UnixNano())
+	colorIndex := rand.Intn(randExtent)
+	backColorIndex := colorIndex - 1
+	if backColorIndex < 0 {
+		backColorIndex = randExtent - 1
+	}
+
+	// Size, background, forecolor
+	imgMaker, err := identicon.New(_RANDOM_AVATAR_SIZE,
+		palette.WebSafe[backColorIndex], palette.WebSafe[colorIndex:colorIndex+32]...)
+	if err != nil {
+		return nil, err
+	}
+	return imgMaker.Make(data), nil
+}
+
 // Avatar represents the avatar object.
 type Avatar struct {
 	Hash           string

templates/repo/pulls/fork.tmpl

@@ -14,19 +14,19 @@
 			      <div class="ui selection dropdown">
 			        <input type="hidden" id="uid" name="uid" value="{{.ContextUser.Id}}" required>
 			        <span class="text">
-			        	<img class="ui mini avatar image" src="{{.ContextUser.AvatarLink}}">
+			        	<img class="ui mini image" src="{{.ContextUser.AvatarLink}}">
             		{{.ContextUser.Name}}
             	</span>
 			        <i class="dropdown icon"></i>
 			        <div class="menu">
 			        	<div class="item" data-value="{{.SignedUser.Id}}">
-				        	<img class="ui mini avatar image" src="{{.SignedUser.AvatarLink}}">
+				        	<img class="ui mini image" src="{{.SignedUser.AvatarLink}}">
 	            		{{.SignedUser.Name}}
 			        	</div>
 			        	{{range .Orgs}}
 			        	{{if .IsOwnedBy $.SignedUser.Id}}
 			        	<div class="item" data-value="{{.Id}}">
-				        	<img class="ui mini avatar image" src="{{.AvatarLink}}">
+				        	<img class="ui mini image" src="{{.AvatarLink}}">
 	            		{{.Name}}
 			        	</div>
 			        	{{end}}