Support selecting theme on the footer (#35741)

Fixes: https://github.com/go-gitea/gitea/pull/27576

modules/setting/session.go

@@ -10,6 +10,7 @@ import (
 
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
 )
 
 // SessionConfig defines Session settings
@@ -49,10 +50,8 @@ func loadSessionFrom(rootCfg ConfigProvider) {
 		checkOverlappedPath("[session].PROVIDER_CONFIG", SessionConfig.ProviderConfig)
 	}
 	SessionConfig.CookieName = sec.Key("COOKIE_NAME").MustString("i_like_gitea")
-	SessionConfig.CookiePath = AppSubURL
-	if SessionConfig.CookiePath == "" {
-		SessionConfig.CookiePath = "/"
-	}
+	// HINT: INSTALL-PAGE-COOKIE-INIT: the cookie system is not properly initialized on the Install page, so there is no CookiePath
+	SessionConfig.CookiePath = util.IfZero(AppSubURL, "/")
 	SessionConfig.Secure = sec.Key("COOKIE_SECURE").MustBool(strings.HasPrefix(strings.ToLower(AppURL), "https://"))
 	SessionConfig.Gclifetime = sec.Key("GC_INTERVAL_TIME").MustInt64(86400)
 	SessionConfig.Maxlifetime = sec.Key("SESSION_LIFE_TIME").MustInt64(86400)

modules/svg/svg.go

@@ -58,6 +58,9 @@ func MockIcon(icon string) func() {
 
 // RenderHTML renders icons - arguments icon name (string), size (int), class (string)
 func RenderHTML(icon string, others ...any) template.HTML {
+	if icon == "" {
+		return ""
+	}
 	size, class := gitea_html.ParseSizeAndClass(defaultSize, "", others...)
 	if svgStr, ok := svgIcons[icon]; ok {
 		// the code is somewhat hacky, but it just works, because the SVG contents are all normalized

modules/templates/helper.go

@@ -12,7 +12,6 @@ import (
 	"strings"
 	"time"
 
-	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/htmlutil"
 	"code.gitea.io/gitea/modules/markup"
@@ -21,7 +20,6 @@ import (
 	"code.gitea.io/gitea/modules/templates/eval"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/gitdiff"
-	"code.gitea.io/gitea/services/webtheme"
 )
 
 // NewFuncMap returns functions for injecting to templates
@@ -130,7 +128,6 @@ func NewFuncMap() template.FuncMap {
 		"DisableWebhooks": func() bool {
 			return setting.DisableWebhooks
 		},
-		"UserThemeName": userThemeName,
 		"NotificationSettings": func() map[string]any {
 			return map[string]any{
 				"MinTimeout":            int(setting.UI.Notification.MinTimeout / time.Millisecond),
@@ -217,16 +214,6 @@ func evalTokens(tokens ...any) (any, error) {
 	return n.Value, err
 }
 
-func userThemeName(user *user_model.User) string {
-	if user == nil || user.Theme == "" {
-		return setting.UI.DefaultTheme
-	}
-	if webtheme.IsThemeAvailable(user.Theme) {
-		return user.Theme
-	}
-	return setting.UI.DefaultTheme
-}
-
 func isQueryParamEmpty(v any) bool {
 	return v == nil || v == false || v == 0 || v == int64(0) || v == ""
 }

modules/templates/util_render.go

@@ -23,8 +23,10 @@ import (
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/reqctx"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/svg"
 	"code.gitea.io/gitea/modules/translation"
 	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/services/webtheme"
 )
 
 type RenderUtils struct {
@@ -259,3 +261,18 @@ func (ut *RenderUtils) RenderLabels(labels []*issues_model.Label, repoLink strin
 	htmlCode += "</span>"
 	return template.HTML(htmlCode)
 }
+
+func (ut *RenderUtils) RenderThemeItem(info *webtheme.ThemeMetaInfo, iconSize int) template.HTML {
+	svgName := "octicon-paintbrush"
+	switch info.ColorScheme {
+	case "dark":
+		svgName = "octicon-moon"
+	case "light":
+		svgName = "octicon-sun"
+	case "auto":
+		svgName = "gitea-eclipse"
+	}
+	icon := svg.RenderHTML(svgName, iconSize)
+	extraIcon := svg.RenderHTML(info.GetExtraIconName(), iconSize)
+	return htmlutil.HTMLFormat(`<div class="theme-menu-item" data-tooltip-content="%s">%s %s %s</div>`, info.GetDescription(), icon, info.DisplayName, extraIcon)
+}

modules/web/middleware/cookie.go

@@ -11,6 +11,7 @@ import (
 
 	"code.gitea.io/gitea/modules/session"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
 )
 
 // SetRedirectToCookie convenience function to set the RedirectTo cookie consistently
@@ -39,11 +40,13 @@ func SetSiteCookie(resp http.ResponseWriter, name, value string, maxAge int) {
 	// These are more specific than cookies without a trailing /, so
 	// we need to delete these if they exist.
 	deleteLegacySiteCookie(resp, name)
+
+	// HINT: INSTALL-PAGE-COOKIE-INIT: the cookie system is not properly initialized on the Install page, so there is no CookiePath
 	cookie := &http.Cookie{
 		Name:     name,
 		Value:    url.QueryEscape(value),
 		MaxAge:   maxAge,
-		Path:     setting.SessionConfig.CookiePath,
+		Path:     util.IfZero(setting.SessionConfig.CookiePath, "/"),
 		Domain:   setting.SessionConfig.Domain,
 		Secure:   setting.SessionConfig.Secure,
 		HttpOnly: true,

public/assets/img/svg/gitea-colorblind-redgreen.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 40 40" class="svg gitea-colorblind-redgreen" width="16" height="16" aria-hidden="true"><g clip-path="url(#gitea-colorblind-redgreen__a)"><rect width="40" height="40" fill="#0000" rx="20"/><path fill="#0566d5" d="M34.284 34.284c7.81-7.81 7.81-20.474 0-28.284L6 34.284c7.81 7.81 20.474 7.81 28.284 0"/><path fill="#e7a100" d="M34.283 34.284c7.81-7.81 7.81-20.474 0-28.284L20.14 20.142z"/><circle cx="20" cy="20" r="18" fill="#0000" stroke="#aaa" stroke-width="4"/></g><defs><clipPath id="gitea-colorblind-redgreen__a"><rect width="40" height="40" fill="#0000" rx="20"/></clipPath></defs></svg>

public/assets/img/svg/gitea-eclipse.svg

@@ -0,0 +1 @@
+<svg viewBox="490 490 820 820" class="svg gitea-eclipse" xmlns="http://www.w3.org/2000/svg" width="16" height="16" aria-hidden="true"><path d="M866.7 582.1A321.3 321.3 0 0 0 738.6 623a317.3 317.3 0 0 0-109.1 108.5A418 418 0 0 0 609 772a335.3 335.3 0 0 0-19.6 71.5 205.2 205.2 0 0 0-2.8 45c0 25.8.2 29.3 2.8 45 4.1 25.4 9.9 46.4 19.6 71.5a314.2 314.2 0 0 0 111.6 137.3A306.8 306.8 0 0 0 893 1196a308.6 308.6 0 0 0 303.6-262.5c2.6-15.7 2.8-19.2 2.8-45s-.2-29.3-2.8-45A335.3 335.3 0 0 0 1177 772a314.2 314.2 0 0 0-111.6-137.3A308.3 308.3 0 0 0 918 582c-13-1.1-38.2-1.1-51.3.1M747 663.5l-2.4 16.7c-4 26.4-4.9 41.1-4.3 65.3a323.7 323.7 0 0 0 37.2 145c18.2 36 41.3 66.6 72 95.5a346.4 346.4 0 0 0 208.5 93.1l18 1.6 4.5.5-8.5 8a259.3 259.3 0 0 1-141.5 65.8 281 281 0 0 1-123.9-11.4 267.2 267.2 0 0 1-181.7-269.9c2-27.6 5.7-47.6 13.3-70.7a281.2 281.2 0 0 1 46.4-85c8-10.1 28-30.2 37.9-38.1 13.8-11.1 24.5-18.3 24.5-16.4"/></svg>

routers/common/errpage.go

@@ -35,7 +35,7 @@ func RenderPanicErrorPage(w http.ResponseWriter, req *http.Request, err any) {
 	httpcache.SetCacheControlInHeader(w.Header(), &httpcache.CacheControlOptions{NoTransform: true})
 	w.Header().Set(`X-Frame-Options`, setting.CORSConfig.XFrameOptions)
 
-	tmplCtx := context.TemplateContext{}
+	tmplCtx := context.NewTemplateContext(req.Context(), req)
 	tmplCtx["Locale"] = middleware.Locale(w, req)
 	ctxData := middleware.GetContextData(req.Context())
 

routers/common/qos.go

@@ -133,7 +133,7 @@ func renderServiceUnavailable(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	tmplCtx := giteacontext.TemplateContext{}
+	tmplCtx := giteacontext.NewTemplateContext(req.Context(), req)
 	tmplCtx["Locale"] = middleware.Locale(w, req)
 	ctxData := middleware.GetContextData(req.Context())
 	err := templates.HTMLRenderer().HTML(w, http.StatusServiceUnavailable, tplStatus503, ctxData, tmplCtx)

routers/install/routes.go

@@ -14,6 +14,7 @@ import (
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/routers/common"
 	"code.gitea.io/gitea/routers/web/healthcheck"
+	"code.gitea.io/gitea/routers/web/misc"
 	"code.gitea.io/gitea/services/forms"
 )
 
@@ -32,7 +33,11 @@ func Routes() *web.Router {
 	r.Get("/", Install) // it must be on the root, because the "install.js" use the window.location to replace the "localhost" AppURL
 	r.Post("/", web.Bind(forms.InstallForm{}), SubmitInstall)
 	r.Get("/post-install", InstallDone)
+
+	r.Get("/-/web-theme/list", misc.WebThemeList)
+	r.Post("/-/web-theme/apply", misc.WebThemeApply)
 	r.Get("/api/healthz", healthcheck.Check)
+
 	r.NotFound(installNotFound)
 
 	base.Mount("", r)

routers/web/misc/webtheme.go

@@ -0,0 +1,42 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package misc
+
+import (
+	"net/http"
+
+	"code.gitea.io/gitea/modules/optional"
+	"code.gitea.io/gitea/modules/templates"
+	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/modules/web/middleware"
+	"code.gitea.io/gitea/services/context"
+	user_service "code.gitea.io/gitea/services/user"
+	"code.gitea.io/gitea/services/webtheme"
+)
+
+func WebThemeList(ctx *context.Context) {
+	curWebTheme := ctx.TemplateContext.CurrentWebTheme()
+	renderUtils := templates.NewRenderUtils(ctx)
+	allThemes := webtheme.GetAvailableThemes()
+
+	var results []map[string]any
+	for _, theme := range allThemes {
+		results = append(results, map[string]any{
+			"name":  renderUtils.RenderThemeItem(theme, 14),
+			"value": theme.InternalName,
+			"class": "item js-aria-clickable" + util.Iif(theme.InternalName == curWebTheme.InternalName, " selected", ""),
+		})
+	}
+	ctx.JSON(http.StatusOK, map[string]any{"results": results})
+}
+
+func WebThemeApply(ctx *context.Context) {
+	themeName := ctx.FormString("theme")
+	if ctx.Doer != nil {
+		opts := &user_service.UpdateOptions{Theme: optional.Some(themeName)}
+		_ = user_service.UpdateUser(ctx, ctx.Doer, opts)
+	} else {
+		middleware.SetSiteCookie(ctx.Resp, "gitea_theme", themeName, 0)
+	}
+}

routers/web/user/setting/profile.go

@@ -369,7 +369,7 @@ func UpdateUIThemePost(ctx *context.Context) {
 		return
 	}
 
-	if !webtheme.IsThemeAvailable(form.Theme) {
+	if webtheme.GetThemeMetaInfo(form.Theme) == nil {
 		ctx.Flash.Error(ctx.Tr("settings.theme_update_error"))
 		ctx.Redirect(setting.AppSubURL + "/user/settings/appearance")
 		return

routers/web/web.go

@@ -490,6 +490,9 @@ func registerWebRoutes(m *web.Router) {
 
 	m.Post("/-/markup", reqSignIn, web.Bind(structs.MarkupOption{}), misc.Markup)
 
+	m.Get("/-/web-theme/list", misc.WebThemeList)
+	m.Post("/-/web-theme/apply", optSignInIgnoreCsrf, misc.WebThemeApply)
+
 	m.Group("/explore", func() {
 		m.Get("", func(ctx *context.Context) {
 			ctx.Redirect(setting.AppSubURL + "/explore/repos")

services/context/context.go

@@ -103,7 +103,7 @@ func GetValidateContext(req *http.Request) (ctx *ValidateContext) {
 }
 
 func NewTemplateContextForWeb(ctx *Context) TemplateContext {
-	tmplCtx := NewTemplateContext(ctx)
+	tmplCtx := NewTemplateContext(ctx, ctx.Req)
 	tmplCtx["Locale"] = ctx.Base.Locale
 	tmplCtx["AvatarUtils"] = templates.NewAvatarUtils(ctx)
 	tmplCtx["RenderUtils"] = templates.NewRenderUtils(ctx)

services/context/context_template.go

@@ -5,13 +5,16 @@ package context
 
 import (
 	"context"
+	"net/http"
 	"time"
+
+	"code.gitea.io/gitea/services/webtheme"
 )
 
 var _ context.Context = TemplateContext(nil)
 
-func NewTemplateContext(ctx context.Context) TemplateContext {
-	return TemplateContext{"_ctx": ctx}
+func NewTemplateContext(ctx context.Context, req *http.Request) TemplateContext {
+	return TemplateContext{"_ctx": ctx, "_req": req}
 }
 
 func (c TemplateContext) parentContext() context.Context {
@@ -33,3 +36,19 @@ func (c TemplateContext) Err() error {
 func (c TemplateContext) Value(key any) any {
 	return c.parentContext().Value(key)
 }
+
+func (c TemplateContext) CurrentWebTheme() *webtheme.ThemeMetaInfo {
+	req := c["_req"].(*http.Request)
+	var themeName string
+	if webCtx := GetWebContext(c); webCtx != nil {
+		if webCtx.Doer != nil {
+			themeName = webCtx.Doer.Theme
+		}
+	}
+	if themeName == "" {
+		if cookieTheme, _ := req.Cookie("gitea_theme"); cookieTheme != nil {
+			themeName = cookieTheme.Value
+		}
+	}
+	return webtheme.GuaranteeGetThemeMetaInfo(themeName)
+}

services/webtheme/webtheme.go

@@ -17,9 +17,9 @@ import (
 )
 
 var (
-	availableThemes             []*ThemeMetaInfo
-	availableThemeInternalNames container.Set[string]
-	themeOnce                   sync.Once
+	availableThemes   []*ThemeMetaInfo
+	availableThemeMap map[string]*ThemeMetaInfo
+	themeOnce         sync.Once
 )
 
 const (
@@ -28,9 +28,25 @@ const (
 )
 
 type ThemeMetaInfo struct {
-	FileName     string
-	InternalName string
-	DisplayName  string
+	FileName       string
+	InternalName   string
+	DisplayName    string
+	ColorblindType string
+	ColorScheme    string
+}
+
+func (info *ThemeMetaInfo) GetDescription() string {
+	if info.ColorblindType == "red-green" {
+		return "Red-green colorblind friendly"
+	}
+	return ""
+}
+
+func (info *ThemeMetaInfo) GetExtraIconName() string {
+	if info.ColorblindType == "red-green" {
+		return "gitea-colorblind-redgreen"
+	}
+	return ""
 }
 
 func parseThemeMetaInfoToMap(cssContent string) map[string]string {
@@ -54,7 +70,7 @@ func parseThemeMetaInfoToMap(cssContent string) map[string]string {
 |('(\\'|[^'])*')
 |([^'";]+)
 )
-\s*;
+\s*;?
 \s*
 )
 `
@@ -102,17 +118,19 @@ func parseThemeMetaInfo(fileName, cssContent string) *ThemeMetaInfo {
 		return themeInfo
 	}
 	themeInfo.DisplayName = m["--theme-display-name"]
+	themeInfo.ColorblindType = m["--theme-colorblind-type"]
+	themeInfo.ColorScheme = m["--theme-color-scheme"]
 	return themeInfo
 }
 
 func initThemes() {
 	availableThemes = nil
 	defer func() {
-		availableThemeInternalNames = container.Set[string]{}
+		availableThemeMap = map[string]*ThemeMetaInfo{}
 		for _, theme := range availableThemes {
-			availableThemeInternalNames.Add(theme.InternalName)
+			availableThemeMap[theme.InternalName] = theme
 		}
-		if !availableThemeInternalNames.Contains(setting.UI.DefaultTheme) {
+		if availableThemeMap[setting.UI.DefaultTheme] == nil {
 			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)
 		}
 	}()
@@ -147,6 +165,9 @@ func initThemes() {
 		if availableThemes[i].InternalName == setting.UI.DefaultTheme {
 			return true
 		}
+		if availableThemes[i].ColorblindType != availableThemes[j].ColorblindType {
+			return availableThemes[i].ColorblindType < availableThemes[j].ColorblindType
+		}
 		return availableThemes[i].DisplayName < availableThemes[j].DisplayName
 	})
 	if len(availableThemes) == 0 {
@@ -160,7 +181,21 @@ func GetAvailableThemes() []*ThemeMetaInfo {
 	return availableThemes
 }
 
-func IsThemeAvailable(internalName string) bool {
+func GetThemeMetaInfo(internalName string) *ThemeMetaInfo {
 	themeOnce.Do(initThemes)
-	return availableThemeInternalNames.Contains(internalName)
+	return availableThemeMap[internalName]
+}
+
+// GuaranteeGetThemeMetaInfo guarantees to return a non-nil ThemeMetaInfo,
+// to simplify the caller's logic, especially for templates.
+// There are already enough warnings messages if the default theme is not available.
+func GuaranteeGetThemeMetaInfo(internalName string) *ThemeMetaInfo {
+	info := GetThemeMetaInfo(internalName)
+	if info == nil {
+		info = GetThemeMetaInfo(setting.UI.DefaultTheme)
+	}
+	if info == nil {
+		info = &ThemeMetaInfo{DisplayName: "unavailable", InternalName: "unavailable", FileName: "unavailable"}
+	}
+	return info
 }

services/webtheme/webtheme_test.go

@@ -34,4 +34,10 @@ gitea-theme-meta-info {
 	--k2: real;
 }`)
 	assert.Equal(t, map[string]string{"--k2": "real"}, m)
+
+	// compressed CSS, no trailing semicolon
+	m = parseThemeMetaInfoToMap(`gitea-theme-meta-info{--k1:"v1"}`)
+	assert.Equal(t, map[string]string{"--k1": "v1"}, m)
+	m = parseThemeMetaInfoToMap(`gitea-theme-meta-info{--k1:"v1";--k2:"v2"}`)
+	assert.Equal(t, map[string]string{"--k1": "v1", "--k2": "v2"}, m)
 }

templates/base/footer_content.tmpl

@@ -17,6 +17,10 @@
 		{{end}}
 	</div>
 	<div class="right-links" role="group" aria-label="{{ctx.Locale.Tr "aria.footer.links"}}">
+		<div class="ui dropdown custom" id="footer-theme-selector">
+			<span class="default-text">{{ctx.RenderUtils.RenderThemeItem ctx.CurrentWebTheme 16}}</span>
+			<div class="menu theme-menu"></div>
+		</div>
 		<div class="ui dropdown upward">
 			<span class="flex-text-inline">{{svg "octicon-globe" 14}} {{ctx.Locale.LangName}}</span>
 			<div class="menu language-menu">

templates/base/head.tmpl

@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html lang="{{ctx.Locale.Lang}}" data-theme="{{UserThemeName .SignedUser}}">
+<html lang="{{ctx.Locale.Lang}}" data-theme="{{ctx.CurrentWebTheme.InternalName}}">
 <head>
 	<meta name="viewport" content="width=device-width, initial-scale=1">
 	<title>{{if .Title}}{{.Title}} - {{end}}{{if .Repository.Name}}{{.Repository.Name}} - {{end}}{{AppName}}</title>

templates/base/head_style.tmpl

@@ -1,2 +1,2 @@
 <link rel="stylesheet" href="{{AssetUrlPrefix}}/css/index.css?v={{AssetVersion}}">
-<link rel="stylesheet" href="{{AssetUrlPrefix}}/css/theme-{{UserThemeName .SignedUser | PathEscape}}.css?v={{AssetVersion}}">
+<link rel="stylesheet" href="{{AssetUrlPrefix}}/css/theme-{{ctx.CurrentWebTheme.InternalName | PathEscape}}.css?v={{AssetVersion}}">

templates/status/500.tmpl

@@ -1,12 +1,12 @@
 {{/* This page should only depend the minimal template functions/variables, to avoid triggering new panics.
-* base template functions: AppName, AssetUrlPrefix, AssetVersion, AppSubUrl, UserThemeName
+* base template functions: AppName, AssetUrlPrefix, AssetVersion, AppSubUrl
 * ctx.Locale
 * .Flash
 * .ErrorMsg
 * .SignedUser (optional)
 */}}
 <!DOCTYPE html>
-<html lang="{{ctx.Locale.Lang}}" data-theme="{{UserThemeName .SignedUser}}">
+<html lang="{{ctx.Locale.Lang}}" data-theme="{{ctx.CurrentWebTheme.InternalName}}">
 <head>
 	<meta name="viewport" content="width=device-width, initial-scale=1">
 	<title>Internal Server Error - {{AppName}}</title>

templates/user/settings/appearance.tmpl

@@ -16,11 +16,19 @@
 				</div>
 				<div class="field">
 					<label>{{ctx.Locale.Tr "settings.ui"}}</label>
-					<select name="theme" class="ui dropdown">
-						{{range $theme := .AllThemes}}
-						<option value="{{$theme.InternalName}}" {{Iif (eq $.SignedUser.Theme $theme.InternalName) "selected"}}>{{$theme.DisplayName}}</option>
-						{{end}}
-					</select>
+					<div class="ui selection dropdown">
+						<input type="hidden" name="theme" value="{{$.SignedUser.Theme}}">
+						<div class="text"></div> {{svg "octicon-triangle-down" 14 "dropdown icon"}}
+						<div class="menu flex-items-menu">
+							{{range $theme := .AllThemes}}
+								{{$extraIconName := $theme.GetExtraIconName}}
+								<div class="item" data-value="{{$theme.InternalName}}">
+									{{$theme.DisplayName}} {{svg $extraIconName}}
+									<div class="description">{{$theme.GetDescription}}</div>
+								</div>
+							{{end}}
+						</div>
+					</div>
 				</div>
 				<div class="field">
 					<button class="ui primary button">{{ctx.Locale.Tr "settings.update_theme"}}</button>

web_src/css/home.css

@@ -65,15 +65,34 @@
   flex-wrap: wrap;
   align-items: center;
   justify-content: center;
+  gap: 1em;
 }
 
 .page-footer .right-links > a {
   border-left: 1px solid var(--color-secondary-dark-1);
-  padding-left: 8px;
-  margin-left: 5px;
+  padding-left: 1em;
 }
 
-.page-footer .ui.dropdown .menu.language-menu {
+/* the theme item is also used for the menu's "default text" display */
+.page-footer .ui.dropdown .theme-menu-item {
+  display: flex;
+  align-items: center;
+  gap: 0.5em;
+}
+
+/* Fomantic UI dropdown "remote items by API" can't change parent "item" element,
+so we use "theme-menu-item" in the "item" and add tooltip to the inner one.
+Then the inner one needs to get padding and parent "item" padding needs to be removed */
+.page-footer .menu.theme-menu > .item {
+  padding: 0 !important;
+}
+
+.page-footer .menu.theme-menu > .item > .theme-menu-item {
+  padding: 11px 16px;
+}
+
+.page-footer .ui.dropdown .menu.language-menu,
+.page-footer .ui.dropdown .menu.theme-menu {
   max-height: min(500px, calc(100vh - 60px));
   overflow-y: auto;
   margin-bottom: 10px;

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

@@ -2,5 +2,7 @@
 @import "./theme-gitea-dark-protanopia-deuteranopia.css" (prefers-color-scheme: dark);
 
 gitea-theme-meta-info {
-  --theme-display-name: "Auto (Red/Green Colorblind-friendly)";
+  --theme-display-name: "Auto";
+  --theme-colorblind-type: "red-green";
+  --theme-color-scheme: "auto";
 }

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

@@ -3,4 +3,5 @@
 
 gitea-theme-meta-info {
   --theme-display-name: "Auto";
+  --theme-color-scheme: "auto";
 }

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

@@ -1,7 +1,9 @@
 @import "./theme-gitea-dark.css";
 
 gitea-theme-meta-info {
-  --theme-display-name: "Dark (Red/Green Colorblind-friendly)";
+  --theme-display-name: "Dark";
+  --theme-colorblind-type: "red-green";
+  --theme-color-scheme: "dark";
 }
 
 /* red/green colorblind-friendly colors */

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

@@ -3,6 +3,7 @@
 
 gitea-theme-meta-info {
   --theme-display-name: "Dark";
+  --theme-color-scheme: "dark";
 }
 
 :root {

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

@@ -1,7 +1,9 @@
 @import "./theme-gitea-light.css";
 
 gitea-theme-meta-info {
-  --theme-display-name: "Light (Red/Green Colorblind-friendly)";
+  --theme-display-name: "Light";
+  --theme-colorblind-type: "red-green";
+  --theme-color-scheme: "light";
 }
 
 /* red/green colorblind-friendly colors */

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

@@ -3,6 +3,7 @@
 
 gitea-theme-meta-info {
   --theme-display-name: "Light";
+  --theme-color-scheme: "light";
 }
 
 :root {

web_src/js/features/common-page.ts

@@ -1,14 +1,14 @@
-import {GET} from '../modules/fetch.ts';
+import {GET, POST} from '../modules/fetch.ts';
 import {showGlobalErrorMessage} from '../bootstrap.ts';
 import {fomanticQuery} from '../modules/fomantic/base.ts';
-import {queryElems} from '../utils/dom.ts';
+import {addDelegatedEventListener, queryElems} from '../utils/dom.ts';
 import {registerGlobalInitFunc, registerGlobalSelectorFunc} from '../modules/observer.ts';
 import {initAvatarUploaderWithCropper} from './comp/Cropper.ts';
 import {initCompSearchRepoBox} from './comp/SearchRepoBox.ts';
 
-const {appUrl} = window.config;
+const {appUrl, appSubUrl} = window.config;
 
-export function initHeadNavbarContentToggle() {
+function initHeadNavbarContentToggle() {
   const navbar = document.querySelector('#navbar');
   const btn = document.querySelector('#navbar-expand-toggle');
   if (!navbar || !btn) return;
@@ -20,7 +20,7 @@ export function initHeadNavbarContentToggle() {
   });
 }
 
-export function initFootLanguageMenu() {
+function initFooterLanguageMenu() {
   document.querySelector('.ui.dropdown .menu.language-menu')?.addEventListener('click', async (e) => {
     const item = (e.target as HTMLElement).closest('.item');
     if (!item) return;
@@ -30,6 +30,27 @@ export function initFootLanguageMenu() {
   });
 }
 
+function initFooterThemeSelector() {
+  const elDropdown = document.querySelector('#footer-theme-selector');
+  if (!elDropdown) return; // some pages don't have footer, for example: 500.tmpl
+  const $dropdown = fomanticQuery(elDropdown);
+  $dropdown.dropdown({
+    direction: 'upward',
+    apiSettings: {url: `${appSubUrl}/-/web-theme/list`, cache: false},
+  });
+  addDelegatedEventListener(elDropdown, 'click', '.menu > .item', async (el) => {
+    const themeName = el.getAttribute('data-value');
+    await POST(`${appSubUrl}/-/web-theme/apply?theme=${encodeURIComponent(themeName)}`);
+    window.location.reload();
+  });
+}
+
+export function initCommmPageComponents() {
+  initHeadNavbarContentToggle();
+  initFooterLanguageMenu();
+  initFooterThemeSelector();
+}
+
 export function initGlobalDropdown() {
   // do not init "custom" dropdowns, "custom" dropdowns are managed by their own code.
   registerGlobalSelectorFunc('.ui.dropdown:not(.custom)', (el) => {

web_src/js/index-domready.ts

@@ -60,7 +60,7 @@ import {initColorPickers} from './features/colorpicker.ts';
 import {initAdminSelfCheck} from './features/admin/selfcheck.ts';
 import {initOAuth2SettingsDisableCheckbox} from './features/oauth2-settings.ts';
 import {initGlobalFetchAction} from './features/common-fetch-action.ts';
-import {initFootLanguageMenu, initGlobalComponent, initGlobalDropdown, initGlobalInput, initHeadNavbarContentToggle} from './features/common-page.ts';
+import {initCommmPageComponents, initGlobalComponent, initGlobalDropdown, initGlobalInput} from './features/common-page.ts';
 import {initGlobalButtonClickOnEnter, initGlobalButtons, initGlobalDeleteButton} from './features/common-button.ts';
 import {initGlobalComboMarkdownEditor, initGlobalEnterQuickSubmit, initGlobalFormDirtyLeaveConfirm} from './features/common-form.ts';
 import {callInitFunctions} from './modules/init.ts';
@@ -93,8 +93,7 @@ const initPerformanceTracer = callInitFunctions([
 
   initInstall,
 
-  initHeadNavbarContentToggle,
-  initFootLanguageMenu,
+  initCommmPageComponents,
 
   initHeatmap,
   initImageDiff,

web_src/svg/gitea-colorblind-redgreen.svg

@@ -0,0 +1,13 @@
+<svg width="40" height="40" viewBox="0 0 40 40" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <g clip-path="url(#clip0)">
+    <rect width="40" height="40" rx="20" fill="#0000"/>
+    <path d="M34.2843 34.2842C42.0948 26.4737 42.0948 13.8104 34.2843 5.9999L6 34.2842C13.8105 42.0947 26.4738 42.0947 34.2843 34.2842Z" fill="#0566D5"/>
+    <path d="M34.2828 34.2842C42.0932 26.4737 42.0932 13.8104 34.2828 5.99995L20.1406 20.1421L34.2828 34.2842Z" fill="#E7A100"/>
+    <circle cx="20" cy="20" r="18" fill="#0000" stroke="#aaa" stroke-width="4"/>
+  </g>
+  <defs>
+    <clipPath id="clip0">
+      <rect width="40" height="40" rx="20" fill="#0000"/>
+    </clipPath>
+  </defs>
+</svg>

web_src/svg/gitea-eclipse.svg

@@ -0,0 +1 @@
+<svg viewBox="490 490 820 820"><path d="M866.7 582.1A321.3 321.3 0 0 0 738.6 623a317.3 317.3 0 0 0-109.1 108.5A418 418 0 0 0 609 772a335.3 335.3 0 0 0-19.6 71.5 205.2 205.2 0 0 0-2.8 45c0 25.8.2 29.3 2.8 45 4.1 25.4 9.9 46.4 19.6 71.5a314.2 314.2 0 0 0 111.6 137.3A306.8 306.8 0 0 0 893 1196a308.6 308.6 0 0 0 303.6-262.5c2.6-15.7 2.8-19.2 2.8-45s-.2-29.3-2.8-45A335.3 335.3 0 0 0 1177 772a314.2 314.2 0 0 0-111.6-137.3A308.3 308.3 0 0 0 918 582c-13-1.1-38.2-1.1-51.3.1zM747 663.5l-2.4 16.7c-4 26.4-4.9 41.1-4.3 65.3a323.7 323.7 0 0 0 37.2 145c18.2 36 41.3 66.6 72 95.5a346.4 346.4 0 0 0 208.5 93.1l18 1.6 4.5.5-8.5 8a259.3 259.3 0 0 1-141.5 65.8 281 281 0 0 1-123.9-11.4 267.2 267.2 0 0 1-181.7-269.9c2-27.6 5.7-47.6 13.3-70.7a281.2 281.2 0 0 1 46.4-85c8-10.1 28-30.2 37.9-38.1 13.8-11.1 24.5-18.3 24.5-16.4z"/></svg>