vikunja-api/pkg/modules/avatar/initials/initials.go

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// Vikunja is a to-do list application to facilitate your life.
// Copyright 2018-2020 Vikunja and contributors. All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package initials
import (
"code.vikunja.io/api/pkg/log"
"code.vikunja.io/api/pkg/user"
"github.com/disintegration/imaging"
"strconv"
"strings"
"sync"
"bytes"
"github.com/golang/freetype/truetype"
"golang.org/x/image/font"
"golang.org/x/image/font/gofont/goregular"
"golang.org/x/image/math/fixed"
"image"
"image/color"
"image/draw"
"image/png"
)
// Provider represents the provider implementation of the initials provider
type Provider struct {
}
var (
avatarBgColors = []*color.RGBA{
{69, 189, 243, 255},
{224, 143, 112, 255},
{77, 182, 172, 255},
{149, 117, 205, 255},
{176, 133, 94, 255},
{240, 98, 146, 255},
{163, 211, 108, 255},
{121, 134, 203, 255},
{241, 185, 29, 255},
}
// Contain the created avatars with a size of defaultSize
cache = map[int64]*image.RGBA64{}
cacheLock = sync.Mutex{}
cacheResized = map[string][]byte{}
cacheResizedLock = sync.Mutex{}
)
func init() {
cache = make(map[int64]*image.RGBA64)
cacheResized = make(map[string][]byte)
}
const (
dpi = 72
defaultSize = 1024
)
func drawImage(text rune, bg *color.RGBA) (img *image.RGBA64, err error) {
size := defaultSize
fontSize := float64(size) * 0.8
// Inspired by https://github.com/holys/initials-avatar
// Get the font
f, err := truetype.Parse(goregular.TTF)
if err != nil {
return img, err
}
// Build the image background
img = image.NewRGBA64(image.Rect(0, 0, size, size))
draw.Draw(img, img.Bounds(), &image.Uniform{C: bg}, image.Point{}, draw.Src)
// Add the text
drawer := &font.Drawer{
Dst: img,
Src: image.White,
Face: truetype.NewFace(f, &truetype.Options{
Size: fontSize,
DPI: dpi,
Hinting: font.HintingNone,
}),
}
// Font Index
fi := f.Index(text)
// Glyph example: http://www.freetype.org/freetype2/docs/tutorial/metrics.png
var gbuf truetype.GlyphBuf
fsize := fixed.Int26_6(fontSize * dpi * (64.0 / 72.0))
err = gbuf.Load(f, fsize, fi, font.HintingFull)
if err != nil {
drawer.DrawString("")
return img, err
}
// Center
dY := (size - int(gbuf.Bounds.Max.Y-gbuf.Bounds.Min.Y)>>6) / 2
dX := (size - int(gbuf.Bounds.Max.X-gbuf.Bounds.Min.X)>>6) / 2
y := int(gbuf.Bounds.Max.Y>>6) + dY
x := 0 - int(gbuf.Bounds.Min.X>>6) + dX
drawer.Dot = fixed.Point26_6{
X: fixed.I(x),
Y: fixed.I(y),
}
drawer.DrawString(string(text))
return img, err
}
func getAvatarForUser(u *user.User) (fullSizeAvatar *image.RGBA64, err error) {
var cached bool
fullSizeAvatar, cached = cache[u.ID]
if !cached {
log.Debugf("Initials avatar for user %d not cached, creating...", u.ID)
firstRune := []rune(strings.ToUpper(u.Username))[0]
bg := avatarBgColors[int(u.ID)%len(avatarBgColors)] // Random color based on the user id
fullSizeAvatar, err = drawImage(firstRune, bg)
if err != nil {
return nil, err
}
cacheLock.Lock()
cache[u.ID] = fullSizeAvatar
cacheLock.Unlock()
}
return fullSizeAvatar, err
}
// GetAvatar returns an initials avatar for a user
func (p *Provider) GetAvatar(u *user.User, size int64) (avatar []byte, mimeType string, err error) {
var cached bool
cacheKey := strconv.Itoa(int(u.ID)) + "_" + strconv.Itoa(int(size))
avatar, cached = cacheResized[cacheKey]
if !cached {
log.Debugf("Initials avatar for user %d and size %d not cached, creating...", u.ID, size)
fullAvatar, err := getAvatarForUser(u)
if err != nil {
return nil, "", err
}
img := imaging.Resize(fullAvatar, int(size), int(size), imaging.Lanczos)
buf := &bytes.Buffer{}
err = png.Encode(buf, img)
if err != nil {
return nil, "", err
}
avatar = buf.Bytes()
cacheResizedLock.Lock()
cacheResized[cacheKey] = avatar
cacheResizedLock.Unlock()
} else {
log.Debugf("Serving initials avatar for user %d and size %d from cache", u.ID, size)
}
return avatar, "image/png", err
}