[libcalamares] Add a find() to ZonesModel

- Look up TZ data by region and zone name.

src/libcalamares/locale/Tests.cpp

@@ -50,6 +50,7 @@ private Q_SLOTS:
     void testRegions();
     void testSimpleZones();
     void testComplexZones();
+    void testTZLookup();
 };
 
 LocaleTests::LocaleTests() {}
@@ -345,6 +346,21 @@ LocaleTests::testComplexZones()
     QVERIFY( names.contains( "Abidjan" ) );
 }
 
+void
+LocaleTests::testTZLookup()
+{
+    using namespace CalamaresUtils::Locale;
+    ZonesModel zones;
+
+    QVERIFY( zones.find( "America", "New_York" ) );
+    QCOMPARE( zones.find( "America", "New_York" )->zone(), QStringLiteral( "New_York" ) );
+    QCOMPARE( zones.find( "America", "New_York" )->tr(), QStringLiteral( "New York" ) );
+
+    QVERIFY( !zones.find( "Europe", "New_York" ) );
+    QVERIFY( !zones.find( "America", "New York" ) );
+}
+
+
 QTEST_GUILESS_MAIN( LocaleTests )
 
 #include "utils/moc-warnings.h"

src/libcalamares/locale/TimeZone.cpp

@@ -279,6 +279,19 @@ ZonesModel::roleNames() const
     return { { NameRole, "name" }, { KeyRole, "key" } };
 }
 
+const TimeZoneData*
+ZonesModel::find( const QString& region, const QString& zone )
+{
+    for ( const auto* p : m_private->m_zones )
+    {
+        if ( p->region() == region && p->zone() == zone )
+        {
+            return p;
+        }
+    }
+    return nullptr;
+}
+
 RegionalZonesModel::RegionalZonesModel( CalamaresUtils::Locale::ZonesModel* source, QObject* parent )
     : QSortFilterProxyModel( parent )
     , m_private( privateInstance() )

src/libcalamares/locale/TimeZone.h

@@ -57,6 +57,7 @@ public:
     QString tr() const override;
 
     QString region() const { return m_region; }
+    QString zone() const { return key(); }
 
 private:
     QString m_region;
@@ -113,6 +114,12 @@ public:
 
     QHash< int, QByteArray > roleNames() const override;
 
+    /** @brief Look up TZ data based on its name.
+     *
+     * Returns @c nullptr if not found.
+     */
+    const TimeZoneData* find( const QString& region, const QString& zone );
+
 private:
     Private* m_private;
 };