Configs for themes in Display Settings: hide themes options, hide custom themes, specific list of themes (#7173)

* Add configuration to enable or disable choosing themes in Display Settings. Only for Licensed servers.

* Add configuration to enable or disable choosing custom themes in Display Settings. Only for Licensed servers.

* Add configuration to enable or disable a specific list of themes to choose in Display Settings. Only for Licensed servers.

* Added config value and logic for "DefaultTheme"

* Fix problem with undefined values when the server is not licensed

model/config.go

@@ -132,6 +132,8 @@ const (
 	ANNOUNCEMENT_SETTINGS_DEFAULT_BANNER_COLOR      = "#f2a93b"
 	ANNOUNCEMENT_SETTINGS_DEFAULT_BANNER_TEXT_COLOR = "#333333"
 
+	TEAM_SETTINGS_DEFAULT_TEAM_TEXT = "default"
+
 	ELASTICSEARCH_SETTINGS_DEFAULT_CONNECTION_URL                  = ""
 	ELASTICSEARCH_SETTINGS_DEFAULT_USERNAME                        = ""
 	ELASTICSEARCH_SETTINGS_DEFAULT_PASSWORD                        = ""
@@ -335,6 +337,13 @@ type AnnouncementSettings struct {
 	AllowBannerDismissal *bool
 }
 
+type ThemeSettings struct {
+	EnableThemeSelection *bool
+	DefaultTheme         *string
+	AllowCustomThemes    *bool
+	AllowedThemes        []string
+}
+
 type TeamSettings struct {
 	SiteName                            string
 	MaxUsersPerTeam                     *int
@@ -500,6 +509,7 @@ type Config struct {
 	PrivacySettings       PrivacySettings
 	SupportSettings       SupportSettings
 	AnnouncementSettings  AnnouncementSettings
+	ThemeSettings         ThemeSettings
 	GitLabSettings        SSOSettings
 	GoogleSettings        SSOSettings
 	Office365Settings     SSOSettings
@@ -1003,6 +1013,25 @@ func (o *Config) SetDefaults() {
 		*o.AnnouncementSettings.AllowBannerDismissal = true
 	}
 
+	if o.ThemeSettings.EnableThemeSelection == nil {
+		o.ThemeSettings.EnableThemeSelection = new(bool)
+		*o.ThemeSettings.EnableThemeSelection = true
+	}
+
+	if o.ThemeSettings.DefaultTheme == nil {
+		o.ThemeSettings.DefaultTheme = new(string)
+		*o.ThemeSettings.DefaultTheme = TEAM_SETTINGS_DEFAULT_TEAM_TEXT
+	}
+
+	if o.ThemeSettings.AllowCustomThemes == nil {
+		o.ThemeSettings.AllowCustomThemes = new(bool)
+		*o.ThemeSettings.AllowCustomThemes = true
+	}
+
+	if o.ThemeSettings.AllowedThemes == nil {
+		o.ThemeSettings.AllowedThemes = []string{}
+	}
+
 	if o.LdapSettings.Enable == nil {
 		o.LdapSettings.Enable = new(bool)
 		*o.LdapSettings.Enable = false

model/license.go

@@ -51,6 +51,7 @@ type Features struct {
 	PasswordRequirements      *bool `json:"password_requirements"`
 	Elasticsearch             *bool `json:"elastic_search"`
 	Announcement              *bool `json:"announcement"`
+	ThemeManagement           *bool `json:"theme_management"`
 	EmailNotificationContents *bool `json:"email_notification_contents"`
 
 	// after we enabled more features for webrtc we'll need to control them with this
@@ -152,6 +153,11 @@ func (f *Features) SetDefaults() {
 		*f.Announcement = true
 	}
 
+	if f.ThemeManagement == nil {
+		f.ThemeManagement = new(bool)
+		*f.ThemeManagement = true
+	}
+
 	if f.EmailNotificationContents == nil {
 		f.EmailNotificationContents = new(bool)
 		*f.EmailNotificationContents = *f.FutureFeatures