feat: add migration to create BlurHash strings for all list backgrounds

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/ThreeDotsLabs/watermill v1.1.1
 	github.com/adlio/trello v1.9.0
 	github.com/asaskevich/govalidator v0.0.0-20200907205600-7a23bdc65eef
+	github.com/bbrks/go-blurhash v1.1.1 // indirect
 	github.com/beevik/etree v1.1.0 // indirect
 	github.com/c2h5oh/datasize v0.0.0-20200825124411-48ed595a09d2
 	github.com/coreos/go-oidc/v3 v3.1.0

go.sum

@@ -99,6 +99,8 @@ github.com/armon/go-radix v1.0.0/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgI
 github.com/asaskevich/govalidator v0.0.0-20200907205600-7a23bdc65eef h1:46PFijGLmAjMPwCCCo7Jf0W6f9slllCkkv7vyc1yOSg=
 github.com/asaskevich/govalidator v0.0.0-20200907205600-7a23bdc65eef/go.mod h1:WaHUgvxTVq04UNunO+XhnAqY/wQc+bxr74GqbsZ/Jqw=
 github.com/aymerick/raymond v2.0.3-0.20180322193309-b565731e1464+incompatible/go.mod h1:osfaiScAUVup+UC9Nfq76eWqDhXlp+4UYaA8uhTBO6g=
+github.com/bbrks/go-blurhash v1.1.1 h1:uoXOxRPDca9zHYabUTwvS4KnY++KKUbwFo+Yxb8ME4M=
+github.com/bbrks/go-blurhash v1.1.1/go.mod h1:lkAsdyXp+EhARcUo85yS2G1o+Sh43I2ebF5togC4bAY=
 github.com/beevik/etree v1.1.0 h1:T0xke/WvNtMoCqgzPhkX2r4rjY3GDZFi+FjpRZY2Jbs=
 github.com/beevik/etree v1.1.0/go.mod h1:r8Aw8JqVegEf0w2fDnATrX9VpkMcyFeM0FhwO62wh+A=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
@@ -531,6 +533,7 @@ github.com/mailru/easyjson v0.0.0-20190614124828-94de47d64c63/go.mod h1:C1wdFJiN
 github.com/mailru/easyjson v0.0.0-20190626092158-b2ccc519800e/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
 github.com/mailru/easyjson v0.7.6 h1:8yTIVnZgCoiM1TgqoeTl+LfU5Jg6/xL3QhGQnimLYnA=
 github.com/mailru/easyjson v0.7.6/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
+github.com/matryer/is v1.2.0/go.mod h1:2fLPjFQM9rhQ15aVEtbuwhJinnOqrmgXPNdZsdwlWXA=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=

pkg/initialize/init.go

@@ -78,15 +78,15 @@ func FullInit() {
 
 	LightInit()
 
+	// Initialize the files handler
+	files.InitFileHandler()
+
 	// Run the migrations
 	migration.Migrate(nil)
 
 	// Set Engine
 	InitEngines()
 
-	// Initialize the files handler
-	files.InitFileHandler()
-
 	// Start the mail daemon
 	mail.StartMailDaemon()
 

pkg/migration/20211212210054.go

@@ -0,0 +1,94 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2021 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 Affero General Public Licensee 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 Affero General Public Licensee for more details.
+//
+// You should have received a copy of the GNU Affero General Public Licensee
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package migration
+
+import (
+	"code.vikunja.io/api/pkg/files"
+	"code.vikunja.io/api/pkg/log"
+	"github.com/bbrks/go-blurhash"
+	"golang.org/x/image/draw"
+	"image"
+	"src.techknowlogick.com/xormigrate"
+	"xorm.io/xorm"
+)
+
+type lists20211212210054 struct {
+	ID                 int64  `xorm:"bigint autoincr not null unique pk" json:"id" param:"list"`
+	BackgroundFileID   int64  `xorm:"null" json:"-"`
+	BackgroundBlurHash string `xorm:"varchar(50) null" json:"background_blur_hash"`
+}
+
+func (lists20211212210054) TableName() string {
+	return "lists"
+}
+
+func init() {
+	migrations = append(migrations, &xormigrate.Migration{
+		ID:          "20211212210054",
+		Description: "Add blurHash to list backgrounds.",
+		Migrate: func(tx *xorm.Engine) error {
+			err := tx.Sync2(lists20211212210054{})
+			if err != nil {
+				return err
+			}
+
+			lists := []*lists20211212210054{}
+			err = tx.Where("background_file_id is not null AND background_file_id != ?", 0).Find(&lists)
+			if err != nil {
+				return err
+			}
+
+			log.Infof("Creating BlurHash for %d list backgrounds, this might take a while...", len(lists))
+
+			for _, l := range lists {
+				bgFile := &files.File{
+					ID: l.BackgroundFileID,
+				}
+				if err := bgFile.LoadFileByID(); err != nil {
+					return err
+				}
+
+				src, _, err := image.Decode(bgFile.File)
+				if err != nil {
+					return err
+				}
+
+				dst := image.NewRGBA(image.Rect(0, 0, 32, 32))
+				draw.NearestNeighbor.Scale(dst, dst.Rect, src, src.Bounds(), draw.Over, nil)
+
+				hash, err := blurhash.Encode(4, 3, dst)
+				if err != nil {
+					return err
+				}
+
+				l.BackgroundBlurHash = hash
+				_, err = tx.Where("id = ?", l.ID).
+					Cols("background_blur_hash").
+					Update(l)
+				if err != nil {
+					return err
+				}
+				log.Debugf("Created BlurHash for list %d", l.ID)
+			}
+
+			return nil
+		},
+		Rollback: func(tx *xorm.Engine) error {
+			return nil
+		},
+	})
+}

pkg/models/list.go

@@ -59,6 +59,8 @@ type List struct {
 	BackgroundFileID int64 `xorm:"null" json:"-"`
 	// Holds extra information about the background set since some background providers require attribution or similar. If not null, the background can be accessed at /lists/{listID}/background
 	BackgroundInformation interface{} `xorm:"-" json:"background_information"`
+	// Contains a very small version of the list background to use as a blurry preview until the actual background is loaded. Check out https://blurha.sh/ to learn how it works.
+	BackgroundBlurHash string `xorm:"varchar(50) null" json:"background_blur_hash"`
 
 	// True if a list is a favorite. Favorite lists show up in a separate namespace. This value depends on the user making the call to the api.
 	IsFavorite bool `xorm:"-" json:"is_favorite"`