[keyboard] Tidy up the debugging output, add docs

src/modules/keyboard/KeyboardLayoutModel.h

@@ -91,6 +91,11 @@ private:
     int m_defaultPC105 = -1;  ///< The index of pc105, if there is one
 };
 
+/** @brief A list of keyboard layouts (arrangements of keycaps)
+ *
+ * Layouts can have a list of associated Variants, so this
+ * is slightly more complicated than the "regular" XKBListModel.
+ */
 class KeyboardLayoutModel : public QAbstractListModel
 {
     Q_OBJECT
@@ -125,6 +130,12 @@ signals:
     void currentIndexChanged( int index );
 };
 
+/** @brief A list of variants (xkb id and human-readable)
+ *
+ * The variants that are available depend on the Layout that is used,
+ * so the `setVariants()` function can be used to update the variants
+ * when the two models are related.
+ */
 class KeyboardVariantsModel : public XKBListModel
 {
     Q_OBJECT

src/modules/keyboard/KeyboardPage.cpp

@@ -106,29 +106,25 @@ KeyboardPage::KeyboardPage( Config* config, QWidget* parent )
 void
 KeyboardPage::layoutChangedByUser( const QModelIndex& current, const QModelIndex& previous )
 {
-    cDebug() << "index ->" << current.row();
     m_config->keyboardLayouts()->setCurrentIndex( current.row() );
-    cDebug() << Logger::SubEntry << "variants now" << m_config->keyboardVariants()->rowCount();
 }
 
 void
 KeyboardPage::layoutChangedByConfig( int index )
 {
-    cDebug() << "index ->" << index;
     ui->layoutSelector->setCurrentIndex( m_config->keyboardLayouts()->index( index ) );
-    cDebug() << Logger::SubEntry << "variants now" << m_config->keyboardVariants()->rowCount();
 }
 
 void
 KeyboardPage::variantChangedByUser( const QModelIndex& current, const QModelIndex& previous )
 {
-    cDebug() << "index ->" << current.row();
+    m_config->keyboardVariants()->setCurrentIndex( current.row() );
 }
 
 void
 KeyboardPage::variantChangedByConfig( int index )
 {
-    cDebug() << "index ->" << index;
+    ui->variantSelector->setCurrentIndex( m_config->keyboardVariants()->index( index ) );
 }
 
 KeyboardPage::~KeyboardPage()