[libcalamares] Regions and zones change to QList<Base*>

- By using QList< CStringPair* > consistently, we can save
   a bunch of model code at the cost of an occasional dynamic_cast;
   it's fairly rare for there to be a need for the derived pointer.

src/libcalamares/locale/TimeZone.cpp

@@ -130,16 +130,16 @@ TZRegion::~TZRegion()
     qDeleteAll( m_zones );
 }
 
-TZRegionList
+CStringPairList
 TZRegion::fromZoneTab()
 {
     return TZRegion::fromFile( TZ_DATA_FILE );
 }
 
-TZRegionList
+CStringPairList
 TZRegion::fromFile( const char* fileName )
 {
-    TZRegionList model;
+    CStringPairList model;
 
     QFile file( fileName );
     if ( !file.open( QIODevice::ReadOnly | QIODevice::Text ) )
@@ -176,11 +176,11 @@ TZRegion::fromFile( const char* fileName )
             continue;
         }
 
-        auto it
-            = std::find_if( model.begin(), model.end(), [&region]( const TZRegion* r ) { return r->m_key == region; } );
+        auto keyMatch = [&region]( const CStringPair* r ) { return r->key() == region; };
+        auto it = std::find_if( model.begin(), model.end(), keyMatch );
         if ( it != model.end() )
         {
-            thisRegion = *it;
+            thisRegion = dynamic_cast< TZRegion* >( *it );
         }
         else
         {
@@ -195,13 +195,19 @@ TZRegion::fromFile( const char* fileName )
         }
 
         timezoneParts.removeFirst();
-        thisRegion->m_zones.append( new TZZone( timezoneParts.join( '/' ).toUtf8().constData(), countryCode, list.at( 1 ) ) );
+        thisRegion->m_zones.append(
+            new TZZone( timezoneParts.join( '/' ).toUtf8().constData(), countryCode, list.at( 1 ) ) );
     }
 
-    std::sort( model.begin(), model.end(), []( const TZRegion* l, const TZRegion* r ) { return *l < *r; } );
-    for ( auto& r : model )
+    auto sorter = []( const CStringPair* l, const CStringPair* r ) { return *l < *r; };
+    std::sort( model.begin(), model.end(), sorter );
+    for ( auto& it : model )
     {
-        std::sort( r->m_zones.begin(), r->m_zones.end(), []( const TZZone* l, const TZZone* r ) { return *l < *r; } );
+        TZRegion* r = dynamic_cast< TZRegion* >( it );
+        if ( r )
+        {
+            std::sort( r->m_zones.begin(), r->m_zones.end(), sorter );
+        }
     }
 
     return model;
@@ -233,21 +239,21 @@ TZZone::print( QDebug& log ) const
 }
 
 
-TZRegionModel::TZRegionModel( TZRegionList l )
-    : m_regions( l )
+CStringListModel::CStringListModel( CStringPairList l )
+    : m_list( l )
 {
 }
 
-TZRegionModel::~TZRegionModel() {}
+CStringListModel::~CStringListModel() {}
 
 int
-TZRegionModel::rowCount( const QModelIndex& parent ) const
+CStringListModel::rowCount( const QModelIndex& parent ) const
 {
-    return m_regions.count();
+    return m_list.count();
 }
 
 QVariant
-TZRegionModel::data( const QModelIndex& index, int role ) const
+CStringListModel::data( const QModelIndex& index, int role ) const
 {
     if ( ( role != Qt::DisplayRole ) && ( role != Qt::UserRole ) )
     {
@@ -259,18 +265,18 @@ TZRegionModel::data( const QModelIndex& index, int role ) const
         return QVariant();
     }
 
-    const TZRegion* region = m_regions.at( index.row() );
-    return role == Qt::DisplayRole ? region->tr() : region->key();
+    const auto* item = m_list.at( index.row() );
+    return item ? ( role == Qt::DisplayRole ? item->tr() : item->key() ) : QVariant();
 }
 
-const TZRegion*
-TZRegionModel::region( int index ) const
+const CStringPair*
+CStringListModel::item( int index ) const
 {
-    if ( ( index < 0 ) || ( index >= m_regions.count() ) )
+    if ( ( index < 0 ) || ( index >= m_list.count() ) )
     {
         return nullptr;
     }
-    return m_regions[ index ];
+    return m_list[ index ];
 }
 
 }  // namespace Locale

src/libcalamares/locale/TimeZone.h

@@ -57,7 +57,6 @@ public:
 
     /// @brief Give the localized human-readable form
     virtual QString tr() const = 0;
-
     QString key() const { return m_key; }
 
     bool operator<( const CStringPair& other ) const { return m_key < other.m_key; }
@@ -67,10 +66,7 @@ protected:
     QString m_key;
 };
 
-class TZZone;
-class TZRegion;
-using TZZoneList = QList< TZZone* >;
-using TZRegionList = QList< TZRegion* >;
+using CStringPairList = QList< CStringPair* >;
 
 /// @brief A pair of strings for timezone regions (e.g. "America")
 class TZRegion : public CStringPair
@@ -80,20 +76,22 @@ public:
     virtual ~TZRegion();
     QString tr() const override;
 
-    /** @brief Create model from a zone.tab-like file
+    /** @brief Create list from a zone.tab-like file
      *
      * Returns a list of all the regions; each region has a list
-     * of zones within that region.
+     * of zones within that region. Dyamically, the items in the
+     * returned list are TZRegions; their zones dynamically are
+     * TZZones even though all those lists have type CStringPairList.
      *
      * The list owns the regions, and the regions own their own list of zones.
      * When getting rid of the list, remember to qDeleteAll() on it.
      */
-    static TZRegionList fromFile( const char* fileName );
+    static CStringPairList fromFile( const char* fileName );
     /// @brief Calls fromFile with the standard zone.tab name
-    static TZRegionList fromZoneTab();
+    static CStringPairList fromZoneTab();
 
 private:
-    TZZoneList m_zones;
+    CStringPairList m_zones;
 };
 
 /// @brief A pair of strings for specific timezone names (e.g. "New_York")
@@ -119,23 +117,23 @@ operator<<( QDebug& log, const TZZone& z )
     return log;
 }
 
-class DLLEXPORT TZRegionModel : public QAbstractListModel
+class CStringListModel : public QAbstractListModel
 {
 public:
     /// @brief Create empty model
-    TZRegionModel();
+    CStringListModel();
     /// @brief Create model from list (non-owning)
-    TZRegionModel( TZRegionList );
-    virtual ~TZRegionModel() override;
+    CStringListModel( CStringPairList );
+    virtual ~CStringListModel() override;
 
     int rowCount( const QModelIndex& parent ) const override;
 
     QVariant data( const QModelIndex& index, int role ) const override;
 
-    const TZRegion* region( int index ) const;
+    const CStringPair* item( int index ) const;
 
 private:
-    TZRegionList m_regions;
+    CStringPairList m_list;
 };
 
 }  // namespace Locale

src/modules/locale/LocalePage.cpp

@@ -148,7 +148,7 @@ void
 LocalePage::init( const QString& initialRegion, const QString& initialZone, const QString& localeGenPath )
 {
     m_regionList = CalamaresUtils::Locale::TZRegion::fromZoneTab();
-    m_regionModel = std::make_unique< CalamaresUtils::Locale::TZRegionModel >( m_regionList );
+    m_regionModel = std::make_unique< CalamaresUtils::Locale::CStringListModel >( m_regionList );
     m_regionCombo->setModel( m_regionModel.get() );
 
     // Setup locations

src/modules/locale/LocalePage.h

@@ -74,8 +74,9 @@ private:
     void changeLocale();
     void changeFormats();
 
-    CalamaresUtils::Locale::TZRegionList m_regionList;
-    std::unique_ptr< CalamaresUtils::Locale::TZRegionModel > m_regionModel;
+    // Dynamically, QList< TZRegion* >
+    CalamaresUtils::Locale::CStringPairList m_regionList;
+    std::unique_ptr< CalamaresUtils::Locale::CStringListModel > m_regionModel;
 
     TimeZoneWidget* m_tzWidget;
     QComboBox* m_regionCombo;