[plasmalnf] Allow filtering the selectable lnf themes

- empty list allows all of them
 - always suppress hidden, invalid themes, and those named

src/modules/plasmalnf/PlasmaLnfPage.cpp

@@ -34,11 +34,11 @@ static PlasmaLnfList plasma_themes()
 
     for ( const KPluginMetaData& data : pkgs )
     {
-        packages << PlasmaLnfDescriptor{ data.pluginId(), data.name() };
+        if ( data.isValid() && !data.isHidden() && !data.name().isEmpty() )
-        cDebug() << "LNF Package" << data.pluginId();
+        {
-        cDebug() << "  .." << data.name();
+            packages << PlasmaLnfDescriptor{ data.pluginId(), data.name() };
-        cDebug() << "  .." << data.description();
+            cDebug() << "LNF Package" << data.pluginId();
-        cDebug() << "  .." << 'V' << data.isValid() << 'H' << data.isHidden() << 'D' << data.isEnabledByDefault();
+        }
     }
 
     return packages;
@@ -55,9 +55,7 @@ PlasmaLnfPage::PlasmaLnfPage( QWidget* parent )
         ui->retranslateUi( this );
         ui->generalExplanation->setText( tr( "Please choose a look-and-feel for the KDE Plasma Desktop, below." ) );
         m_availableLnf = plasma_themes();
-        ui->lnfCombo->clear();
+        winnowThemes();
-        for ( const auto& p : m_availableLnf )
-            ui->lnfCombo->addItem( p.name );
     }
     )
 
@@ -83,3 +81,18 @@ PlasmaLnfPage::setLnfPath( const QString& path )
 {
     m_lnfPath = path;
 }
+
+void
+PlasmaLnfPage::setEnabledThemes(const QStringList& themes)
+{
+    m_enabledThemes = themes;
+    winnowThemes();
+}
+
+void PlasmaLnfPage::winnowThemes()
+{
+    ui->lnfCombo->clear();
+    for ( const auto& p : m_availableLnf )
+        if ( m_enabledThemes.isEmpty() || m_enabledThemes.contains( p.id ) )
+            ui->lnfCombo->addItem( p.name );
+}

src/modules/plasmalnf/PlasmaLnfPage.h

@@ -21,6 +21,7 @@
 
 #include <QList>
 #include <QString>
+#include <QStringList>
 #include <QWidget>
 
 namespace Ui
@@ -43,6 +44,7 @@ public:
     explicit PlasmaLnfPage( QWidget* parent = nullptr );
 
     void setLnfPath( const QString& path );
+    void setEnabledThemes( const QStringList& themes );
 
 public slots:
     void activated( int index );
@@ -51,8 +53,11 @@ signals:
     void plasmaThemeSelected( const QString& id );
 
 private:
+    void winnowThemes();
+
     Ui::PlasmaLnfPage* ui;
     QString m_lnfPath;
+    QStringList m_enabledThemes;
     PlasmaLnfList m_availableLnf;
 };
 

src/modules/plasmalnf/PlasmaLnfViewStep.cpp

@@ -135,6 +135,15 @@ PlasmaLnfViewStep::setConfigurationMap( const QVariantMap& configurationMap )
     if ( configurationMap.contains( "liveuser" ) && configurationMap.value( "liveuser" ).type() == QVariant::String )
         liveUser = configurationMap.value( "liveuser" ).toString();
     m_liveUser = liveUser;
+
+    if ( configurationMap.contains( "themes" ) &&
+        configurationMap.value( "themes" ).type() == QVariant::List )
+    {
+        QStringList enabledThemes( configurationMap.value( "themes" ).toStringList() );
+        if ( enabledThemes.length() == 1 )
+            cDebug() << "WARNING: only one theme enabled in plasmalnf";
+        m_widget->setEnabledThemes( enabledThemes );
+    }
 }
 
 void

src/modules/plasmalnf/plasmalnf.conf

@@ -1,10 +1,22 @@
 ---
 # Full path to the Plasma look-and-feel tool (CLI program
-# for querying and applying Plasma themes).
+# for querying and applying Plasma themes). If this is not
+# set, no LNF setting will happen.
 lnftool:	"/usr/bin/lookandfeeltool"
 
 # For systems where the user Calamares runs as (usually root,
 # via either sudo or pkexec) has a clean environment, set this
 # to the originating username; the lnftool will be run through
 # "sudo -H -u <liveuser>" instead of directly.
-liveuser:	"live"
+#
+# liveuser:	"live"
+
+# You can limit the list of Plasma look-and-feel themes by listing ids
+# here. If this key is not present, or the list is empty, all of the
+# installed themes are listed. If only one theme is listed, why are
+# you using this module at all?
+#
+themes:
+    - org.kde.breeze.desktop
+    # - org.kde.breezedark.desktop
+