Improve theme display

docs/content/administration/customizing-gitea.en-us.md

@@ -383,13 +383,27 @@ To make a custom theme available to all users:
  The value of `$GITEA_CUSTOM` of your instance can be queried by calling `gitea help` and looking up the value of "CustomPath".
 2. Add `<theme-name>` to the comma-separated list of setting `THEMES` in `app.ini`, or leave `THEMES` empty to allow all themes.
 
+A custom theme file named `theme-my-theme.css` will be displayed as `my-theme` on the user's theme selection page.
+It could add theme meta information into the custom theme CSS file to provide more information about the theme.
+
+If a custom theme is a dark theme, please set the global css variable `--is-dark-theme: true` in the `:root` block.
+This allows Gitea to adjust the Monaco code editor's theme accordingly.
+
+```css
+gitea-theme-meta-info {
+ --theme-display-name: "My Awesome Theme"; /* this theme will be display as "My Awesome Theme" on the UI */
+}
+:root {
+ --is-dark-theme: true; /* if it is a dark theme */
+ --color-primary: #112233;
+ /* more custom theme variables ... */
+}
+```
+
 Community themes are listed in [gitea/awesome-gitea#themes](https://gitea.com/gitea/awesome-gitea#themes).
 
 The default theme sources can be found [here](https://github.com/go-gitea/gitea/blob/main/web_src/css/themes).
 
-If your custom theme is considered a dark theme, set the global css variable `--is-dark-theme` to `true`.
-This allows Gitea to adjust the Monaco code editor's theme accordingly.
-
 ## Customizing fonts
 
 Fonts can be customized using CSS variables:

routers/web/user/setting/profile.go

@@ -319,13 +319,7 @@ func Repos(ctx *context.Context) {
 func Appearance(ctx *context.Context) {
  ctx.Data["Title"] = ctx.Tr("settings.appearance")
  ctx.Data["PageIsSettingsAppearance"] = true
-
- allThemes := webtheme.GetAvailableThemes()
- if webtheme.IsThemeAvailable(setting.UI.DefaultTheme) {
- allThemes = util.SliceRemoveAll(allThemes, setting.UI.DefaultTheme)
- allThemes = append([]string{setting.UI.DefaultTheme}, allThemes...) // move the default theme to the top
- }
- ctx.Data["AllThemes"] = allThemes
+ ctx.Data["AllThemes"] = webtheme.GetAvailableThemes()
 
  var hiddenCommentTypes *big.Int
  val, err := user_model.GetUserSetting(ctx, ctx.Doer.ID, user_model.SettingsKeyHiddenCommentTypes)

services/webtheme/webtheme.go

@@ -4,6 +4,7 @@
 package webtheme
 
 import (
+ "regexp"
  "sort"
  "strings"
  "sync"
@@ -12,63 +13,146 @@ import (
  "code.gitea.io/gitea/modules/log"
  "code.gitea.io/gitea/modules/public"
  "code.gitea.io/gitea/modules/setting"
+ "code.gitea.io/gitea/modules/util"
 )
 
 var (
- availableThemes []string
- availableThemesSet container.Set[string]
- themeOnce sync.Once
+ availableThemes  []*ThemeMetaInfo
+ availableThemeInternalNames container.Set[string]
+ themeOnce  sync.Once
 )
 
+const (
+ fileNamePrefix = "theme-"
+ fileNameSuffix = ".css"
+)
+
+type ThemeMetaInfo struct {
+ FileName string
+ InternalName string
+ DisplayName string
+}
+
+func parseThemeMetaInfoToMap(cssContent string) map[string]string {
+ /*
+ The theme meta info is stored in the CSS file's variables of `gitea-theme-meta-info` element,
+ which is a privately defined and is only used by backend to extract the meta info.
+ Not using ":root" because it is difficult to parse various ":root" blocks when importing other files,
+ it is difficult to control the overriding, and it's difficult to avoid user's customized overridden styles.
+ */
+ metaInfoContent := cssContent
+ if pos := strings.LastIndex(metaInfoContent, "gitea-theme-meta-info"); pos >= 0 {
+ metaInfoContent = metaInfoContent[pos:]
+ }
+
+ reMetaInfoItem := `
+(
+\s*(--[-\w]+)
+\s*:
+\s*("(\\"|[^"])*")
+\s*;
+\s*
+)
+`
+ reMetaInfoItem = strings.ReplaceAll(reMetaInfoItem, "\n", "")
+ reMetaInfoBlock := `\bgitea-theme-meta-info\s*\{(` + reMetaInfoItem + `+)\}`
+ re := regexp.MustCompile(reMetaInfoBlock)
+ matchedMetaInfoBlock := re.FindAllStringSubmatch(metaInfoContent, -1)
+ if len(matchedMetaInfoBlock) == 0 {
+ return nil
+ }
+ re = regexp.MustCompile(strings.ReplaceAll(reMetaInfoItem, "\n", ""))
+ matchedItems := re.FindAllStringSubmatch(matchedMetaInfoBlock[0][1], -1)
+ m := map[string]string{}
+ for _, item := range matchedItems {
+ v := item[3]
+ v = strings.TrimPrefix(v, "\"")
+ v = strings.TrimSuffix(v, "\"")
+ v = strings.ReplaceAll(v, `\"`, `"`)
+ m[item[2]] = v
+ }
+ return m
+}
+
+func defaultThemeMetaInfoByFileName(fileName string) *ThemeMetaInfo {
+ themeInfo := &ThemeMetaInfo{
+ FileName: fileName,
+ InternalName: strings.TrimSuffix(strings.TrimPrefix(fileName, fileNamePrefix), fileNameSuffix),
+ }
+ themeInfo.DisplayName = themeInfo.InternalName
+ return themeInfo
+}
+
+func defaultThemeMetaInfoByInternalName(fileName string) *ThemeMetaInfo {
+ return defaultThemeMetaInfoByFileName(fileNamePrefix + fileName + fileNameSuffix)
+}
+
+func parseThemeMetaInfo(fileName, cssContent string) *ThemeMetaInfo {
+ themeInfo := defaultThemeMetaInfoByFileName(fileName)
+ m := parseThemeMetaInfoToMap(cssContent)
+ if m == nil {
+ return themeInfo
+ }
+ themeInfo.DisplayName = m["--theme-display-name"]
+ return themeInfo
+}
+
 func initThemes() {
  availableThemes = nil
  defer func() {
- availableThemesSet = container.SetOf(availableThemes...)
- if !availableThemesSet.Contains(setting.UI.DefaultTheme) {
+ availableThemeInternalNames = container.Set[string]{}
+ for _, theme := range availableThemes {
+ availableThemeInternalNames.Add(theme.InternalName)
+ }
+ if !availableThemeInternalNames.Contains(setting.UI.DefaultTheme) {
  setting.LogStartupProblem(1, log.ERROR, "Default theme %q is not available, please correct the '[ui].DEFAULT_THEME' setting in the config file", setting.UI.DefaultTheme)
  }
  }()
  cssFiles, err := public.AssetFS().ListFiles("/assets/css")
  if err != nil {
  log.Error("Failed to list themes: %v", err)
- availableThemes = []string{setting.UI.DefaultTheme}
+ availableThemes = []*ThemeMetaInfo{defaultThemeMetaInfoByInternalName(setting.UI.DefaultTheme)}
  return
  }
- var foundThemes []string
- for _, name := range cssFiles {
- name, ok := strings.CutPrefix(name, "theme-")
- if !ok {
- continue
- }
- name, ok = strings.CutSuffix(name, ".css")
- if !ok {
- continue
+ var foundThemes []*ThemeMetaInfo
+ for _, fileName := range cssFiles {
+ if strings.HasPrefix(fileName, fileNamePrefix) && strings.HasSuffix(fileName, fileNameSuffix) {
+  content, err := public.AssetFS().ReadFile("/assets/css/" + fileName)
+ if err != nil {
+  log.Error("Failed to read theme file %q: %v", fileName, err)
+  continue
+  }
+ foundThemes = append(foundThemes, parseThemeMetaInfo(fileName, util.UnsafeBytesToString(content)))
  }
- foundThemes = append(foundThemes, name)
  }
  if len(setting.UI.Themes) > 0 {
  allowedThemes := container.SetOf(setting.UI.Themes...)
  for _, theme := range foundThemes {
- if allowedThemes.Contains(theme) {
+ if allowedThemes.Contains(theme.InternalName) {
  availableThemes = append(availableThemes, theme)
  }
  }
  } else {
  availableThemes = foundThemes
  }
- sort.Strings(availableThemes)
+ sort.Slice(availableThemes, func(i, j int) bool {
+ if availableThemes[i].InternalName == setting.UI.DefaultTheme {
+ return true
+ }
+ return availableThemes[i].DisplayName < availableThemes[j].DisplayName
+ })
  if len(availableThemes) == 0 {
  setting.LogStartupProblem(1, log.ERROR, "No theme candidate in asset files, but Gitea requires there should be at least one usable theme")
- availableThemes = []string{setting.UI.DefaultTheme}
+ availableThemes = []*ThemeMetaInfo{defaultThemeMetaInfoByInternalName(setting.UI.DefaultTheme)}
  }
 }
 
-func GetAvailableThemes() []string {
+func GetAvailableThemes() []*ThemeMetaInfo {
  themeOnce.Do(initThemes)
  return availableThemes
 }
 
-func IsThemeAvailable(name string) bool {
+func IsThemeAvailable(internalName string) bool {
  themeOnce.Do(initThemes)
- return availableThemesSet.Contains(name)
+ return availableThemeInternalNames.Contains(internalName)
 }

services/webtheme/webtheme_test.go

@@ -0,0 +1,15 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package webtheme
+
+import (
+ "testing"
+
+ "github.com/stretchr/testify/assert"
+)
+
+func TestParseThemeMetaInfo(t *testing.T) {
+ m := parseThemeMetaInfoToMap(`gitea-theme-meta-info { --k1: "v1"; --k2: "a\"b"; }`)
+ assert.Equal(t, map[string]string{"--k1": "v1", "--k2": `a"b`}, m)
+}

templates/user/settings/appearance.tmpl

@@ -18,7 +18,7 @@
  <label>{{ctx.Locale.Tr "settings.ui"}}</label>
  <select name="theme" class="ui dropdown">
  {{range $theme := .AllThemes}}
- <option value="{{$theme}}" {{Iif (eq $.SignedUser.Theme $theme) "selected"}}>{{$theme}}</option>
+ <option value="{{$theme.InternalName}}" {{Iif (eq $.SignedUser.Theme $theme.InternalName) "selected"}}>{{$theme.DisplayName}}</option>
  {{end}}
  </select>
  </div>

web_src/css/themes/theme-gitea-auto.css

@@ -1,2 +1,6 @@
 @import "./theme-gitea-light.css" (prefers-color-scheme: light);
 @import "./theme-gitea-dark.css" (prefers-color-scheme: dark);
+
+gitea-theme-meta-info {
+ --theme-display-name: "Auto";
+}

web_src/css/themes/theme-gitea-dark-protanopia-deuteranopia.css

@@ -1,5 +1,9 @@
 @import "./theme-gitea-dark.css";
 
+gitea-theme-meta-info {
+ --theme-display-name: "Dark (Red/Green Colorblind-Friendly)";
+}
+
 /* red/green colorblind-friendly colors */
 /* from GitHub: --diffBlob-addition-*, --diffBlob-deletion-*, etc */
 :root {

web_src/css/themes/theme-gitea-dark.css

@@ -1,6 +1,10 @@
 @import "../chroma/dark.css";
 @import "../codemirror/dark.css";
 
+gitea-theme-meta-info {
+ --theme-display-name: "Dark";
+}
+
 :root {
  --is-dark-theme: true;
  --color-primary: #4183c4;

web_src/css/themes/theme-gitea-light-protanopia-deuteranopia.css

@@ -1,5 +1,9 @@
 @import "./theme-gitea-light.css";
 
+gitea-theme-meta-info {
+ --theme-display-name: "Light (Red/Green Colorblind-Friendly)";
+}
+
 /* red/green colorblind-friendly colors */
 /* from GitHub: --diffBlob-addition-*, --diffBlob-deletion-*, etc */
 :root {

web_src/css/themes/theme-gitea-light.css

@@ -1,6 +1,10 @@
 @import "../chroma/light.css";
 @import "../codemirror/light.css";
 
+gitea-theme-meta-info {
+ --theme-display-name: "Light";
+}
+
 :root {
  --is-dark-theme: false;
  --color-primary: #4183c4;