[packagechooser] Enforce selection mode on the next-button

src/modules/packagechooser/PackageChooserPage.cpp

@@ -80,6 +80,7 @@ PackageChooserPage::updateLabels()
     {
         currentChanged( QModelIndex() );
     }
+    emit selectionChanged();
 }
 
 void
@@ -91,3 +92,9 @@ PackageChooserPage::setModel( QAbstractItemModel* model )
              this,
              &PackageChooserPage::updateLabels );
 }
+
+bool
+PackageChooserPage::hasSelection() const
+{
+    return ui && ui->products && ui->products->selectionModel() && ui->products->selectionModel()->hasSelection();
+}

src/modules/packagechooser/PackageChooserPage.h

@@ -37,10 +37,15 @@ public:
 
     void setModel( QAbstractItemModel* model );
 
+    bool hasSelection() const;
+
 public slots:
     void currentChanged( const QModelIndex& index );
     void updateLabels();
 
+signals:
+    void selectionChanged();
+
 private:
     Ui::PackageChooserPage* ui;
     PackageItem m_introduction;

src/modules/packagechooser/PackageChooserViewStep.cpp

@@ -37,7 +37,7 @@ PackageChooserViewStep::PackageChooserViewStep( QObject* parent )
     : Calamares::ViewStep( parent )
     , m_widget( nullptr )
     , m_model( nullptr )
-    , m_mode( PackageChooserMode::Optional )
+    , m_mode( PackageChooserMode::Exclusive )
 {
     emit nextStatusChanged( false );
 }
@@ -66,6 +66,10 @@ PackageChooserViewStep::widget()
     if ( !m_widget )
     {
         m_widget = new PackageChooserPage( m_mode, nullptr );
+        connect( m_widget, &PackageChooserPage::selectionChanged, [=]() {
+            emit nextStatusChanged( this->isNextEnabled() );
+        } );
+
         if ( m_model )
         {
             hookupModel();
@@ -96,17 +100,13 @@ PackageChooserViewStep::isNextEnabled() const
     switch ( m_mode )
     {
     case PackageChooserMode::Optional:
-        // zero or one
-        return false;
-    case PackageChooserMode::Exclusive:
-        // exactly one
-        return false;
     case PackageChooserMode::Multiple:
-        // zero or more
+        // zero or one OR zero or more
         return true;
+    case PackageChooserMode::Exclusive:
     case PackageChooserMode::RequiredMultiple:
-        // one or more
+        // exactly one OR one or more
-        return false;
+        return m_widget->hasSelection();
     }
 
     NOTREACHED return true;