[welcome] Allow theming the international language-select icon

src/modules/welcome/WelcomePage.cpp

@@ -270,6 +270,12 @@ WelcomePage::externallySelectedLanguage( int row )
         ui->languageWidget->setCurrentIndex( row );
 }
 
+void
+WelcomePage::setLanguageIcon( QIcon i )
+{
+    ui->languageIcon->setPixmap( i.pixmap(48) );
+}
+
 
 void
 LocaleTwoColumnDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const

src/modules/welcome/WelcomePage.h

@@ -42,6 +42,8 @@ public:
     void setUpLinks( bool showSupportUrl,
                      bool showKnownIssuesUrl,
                      bool showReleaseNotesUrl );
+    /// @brief Set international language-selector icon
+    void setLanguageIcon( QIcon );
 
     /// @brief Results of requirements checking
     bool verdict() const;

src/modules/welcome/WelcomePage.ui

@@ -67,7 +67,7 @@
         </spacer>
        </item>
        <item>
-        <widget class="QLabel" name="label_2">
+        <widget class="QLabel" name="languageIcon">
          <property name="toolTip">
           <string>Select language</string>
          </property>

src/modules/welcome/WelcomeViewStep.cpp

@@ -137,6 +137,15 @@ WelcomeViewStep::setConfigurationMap( const QVariantMap& configurationMap )
         } );
         future->setFuture( handler->queryRaw() );
     }
+
+
+    QString language = CalamaresUtils::getString( configurationMap, "languageIcon" );
+    if ( !language.isEmpty() )
+    {
+        auto icon = QIcon::fromTheme( language );
+        if ( !icon.isNull() )
+            m_widget->setLanguageIcon( icon );
+    }
 }
 
 Calamares::RequirementsList

src/modules/welcome/welcome.conf

@@ -64,3 +64,16 @@ geoip:
     style:  "none"
     url:    "https://geoip.kde.org/v1/ubiquity"  # extended XML format
     selector: "CountryCode"  # blank uses default, which is wrong
+
+# User interface
+#
+# The "select language" icon is an international standard, but it
+# might not theme very well with your desktop environment.
+# Fill in an icon name (following FreeDesktop standards) to
+# use that named icon instead of the usual one.
+#
+# Leave blank or unset to use the international standard.
+#
+# Known icons in this space are "set-language" and "config-language".
+#
+# languageIcon: set-language