I18N: support localised local aircraft strings

Allows us to localize aircraft names/descriptions, especially for the
UFO and C172

src/GUI/AircraftModel.cxx

@@ -277,11 +277,11 @@ QVariant AircraftItemModel::dataFromItem(AircraftItemPtr item, const DelegateSta
     if (role >= AircraftVariantDescriptionRole) {
         int variantIndex = role - AircraftVariantDescriptionRole;
         if (variantIndex == 0) {
-            return item->description;
+            return item->name();
         }
 
         Q_ASSERT(variantIndex < item->variants.size());
-        return item->variants.at(variantIndex)->description;
+        return item->variants.at(variantIndex)->name();
     }
 
     if (state.variant) {
@@ -292,11 +292,11 @@ QVariant AircraftItemModel::dataFromItem(AircraftItemPtr item, const DelegateSta
     }
 
     if (role == Qt::DisplayRole) {
-        if (item->description.isEmpty()) {
+        if (item->name().isEmpty()) {
             return tr("Missing description for: %1").arg(item->baseName());
         }
 
-        return item->description;
+        return item->name();
     } else if (role == AircraftPathRole) {
         return item->path;
     } else if (role == AircraftAuthorsRole) {
@@ -318,7 +318,7 @@ QVariant AircraftItemModel::dataFromItem(AircraftItemPtr item, const DelegateSta
         }
         return have;
     } else if (role == AircraftLongDescriptionRole) {
-        return item->longDescription;
+        return item->description();
     } else if (role == AircraftIsHelicopterRole) {
         return item->usesHeliports;
     } else if (role == AircraftIsSeaplaneRole) {
@@ -564,14 +564,14 @@ QString AircraftItemModel::nameForAircraftURI(QUrl uri) const
 
         const QString path = uri.toLocalFile();
         if (item->path == path) {
-            return item->description;
+            return item->name();
         }
 
         // check variants too
         for (int vr=0; vr < item->variants.size(); ++vr) {
             auto variant = item->variants.at(vr);
             if (variant->path == path) {
-                return variant->description;
+                return variant->name();
             }
         }
     } else if (uri.scheme() == "package") {

src/GUI/LocalAircraftCache.cxx

@@ -31,17 +31,28 @@
 #include <QSettings>
 #include <QDebug>
 
-#include <Main/globals.hxx>
 #include <Include/version.h>
+#include <Main/globals.hxx>
+#include <Main/locale.hxx>
 
 #include <simgear/misc/ResourceManager.hxx>
 #include <simgear/props/props_io.hxx>
 #include <simgear/structure/exception.hxx>
 
-static quint32 CACHE_VERSION = 12;
+static quint32 CACHE_VERSION = 13;
 
-AircraftItem::AircraftItem()
+const std::vector<QByteArray> static_localizedStringTags = {"name", "desc"};
+
+QDataStream& operator<<(QDataStream& ds, const AircraftItem::LocalizedStrings& ls)
 {
+    ds << ls.locale << ls.strings;
+    return ds;
+}
+
+QDataStream& operator>>(QDataStream& ds, AircraftItem::LocalizedStrings& ls)
+{
+    ds >> ls.locale >> ls.strings;
+    return ds;
 }
 
 AircraftItem::AircraftItem(QDir dir, QString filePath)
@@ -62,10 +73,9 @@ AircraftItem::AircraftItem(QDir dir, QString filePath)
         return;
     }
 
-    description = sim->getStringValue("description");
+    LocalizedStrings ls;
-	// trim the description to ensure the alphabetical sort
+    ls.locale = "en";
-	// doesn't get thrown off by leading whitespace
+    ls.strings["name"] = QString::fromStdString(sim->getStringValue("description")).trimmed();
-	description = description.trimmed();
     authors = sim->getStringValue("author");
 
     if (sim->hasChild("rating")) {
@@ -77,7 +87,7 @@ AircraftItem::AircraftItem(QDir dir, QString filePath)
 
     if (sim->hasChild("long-description")) {
         // clean up any XML whitspace in the text.
-        longDescription = QString(sim->getStringValue("long-description")).simplified();
+        ls.strings["desc"] = QString(sim->getStringValue("long-description")).simplified();
     }
 
     if (sim->hasChild("variant-of")) {
@@ -132,6 +142,65 @@ AircraftItem::AircraftItem(QDir dir, QString filePath)
     homepageUrl = QUrl(QString::fromStdString(sim->getStringValue("urls/home-page")));
     supportUrl = QUrl(QString::fromStdString(sim->getStringValue("urls/support")));
     wikipediaUrl = QUrl(QString::fromStdString(sim->getStringValue("urls/wikipedia")));
+
+    _localized.push_front(ls);
+    readLocalizedStrings(sim);
+    doLocalizeStrings();
+}
+
+void AircraftItem::readLocalizedStrings(SGPropertyNode_ptr simNode)
+{
+    if (!simNode->hasChild("localized"))
+        return;
+
+    auto localeNode = simNode->getChild("localized");
+    const auto num = localeNode->nChildren();
+    for (int i = 0; i < num; i++) {
+        const SGPropertyNode* c = localeNode->getChild(i);
+
+        LocalizedStrings ls;
+        ls.locale = QString::fromStdString(c->getNameString());
+        if (c->hasChild("description")) {
+            ls.strings["name"] = QString::fromStdString(c->getStringValue("description"));
+        }
+        if (c->hasChild("long-description")) {
+            ls.strings["desc"] = QString::fromStdString(c->getStringValue("long-description")).simplified();
+        }
+
+        _localized.push_back(ls);
+    }
+}
+
+void AircraftItem::doLocalizeStrings()
+{
+    // default strings are always at the front
+    _currentStrings = _localized.front().strings;
+
+    const auto lang = QString::fromStdString(globals->get_locale()->getPreferredLanguage());
+    // find the matching locale
+    auto it = std::find_if(_localized.begin(), _localized.end(), [lang](const LocalizedStrings& ls) {
+        return ls.locale == lang;
+    });
+
+    if (it == _localized.end())
+        return; // nothing else to do
+
+    for (auto t : static_localizedStringTags) {
+        if (it->strings.contains(t)) {
+            // copy the value we found
+            _currentStrings[t] = it->strings.value(t);
+        }
+    } // of strings iteration
+}
+
+QString AircraftItem::name() const
+{
+    return _currentStrings.value("name");
+}
+
+QString AircraftItem::description() const
+{
+    return _currentStrings.value("desc");
 }
 
 QString AircraftItem::baseName() const
@@ -148,7 +217,7 @@ void AircraftItem::fromDataStream(QDataStream& ds)
         return;
     }
 
-    ds >> description >> longDescription >> authors >> variantOf >> isPrimary;
+    ds >> authors >> variantOf >> isPrimary;
     for (int i=0; i<4; ++i) ds >> ratings[i];
     ds >> previews;
     ds >> thumbnailPath;
@@ -156,6 +225,9 @@ void AircraftItem::fromDataStream(QDataStream& ds)
     ds >> needsMaintenance >> usesHeliports >> usesSeaports;
     ds >> homepageUrl >> supportUrl >> wikipediaUrl;
     ds >> tags;
+    ds >> _localized;
+
+    doLocalizeStrings();
 }
 
 void AircraftItem::toDataStream(QDataStream& ds) const
@@ -165,7 +237,7 @@ void AircraftItem::toDataStream(QDataStream& ds) const
         return;
     }
 
-    ds << description << longDescription << authors << variantOf << isPrimary;
+    ds << authors << variantOf << isPrimary;
     for (int i=0; i<4; ++i) ds << ratings[i];
     ds << previews;
     ds << thumbnailPath;
@@ -173,6 +245,7 @@ void AircraftItem::toDataStream(QDataStream& ds) const
     ds << needsMaintenance << usesHeliports << usesSeaports;
     ds << homepageUrl << supportUrl << wikipediaUrl;
     ds << tags;
+    ds << _localized;
 }
 
 int AircraftItem::indexOfVariant(QUrl uri) const
@@ -216,6 +289,7 @@ public:
 
     SGPath resolve(const std::string& aResource, SGPath& aContext) const override
     {
+        Q_UNUSED(aContext)
         string_list pieces(sgPathBranchSplit(aResource));
         if ((pieces.size() < 3) || (pieces.front() != "Aircraft")) {
             return SGPath{}; // not an Aircraft path

src/GUI/LocalAircraftCache.hxx

@@ -29,6 +29,8 @@
 #include <QDir>
 #include <QVariant>
 
+#include <simgear/props/props.hxx>
+
 class QDataStream;
 struct AircraftItem;
 class AircraftScanThread;
@@ -38,13 +40,17 @@ typedef QSharedPointer<AircraftItem> AircraftItemPtr;
 
 struct AircraftItem
 {
-    AircraftItem();
+    AircraftItem() = default;
 
     AircraftItem(QDir dir, QString filePath);
 
     // the file-name without -set.xml suffix
     QString baseName() const;
 
+    QString name() const;
+
+    QString description() const;
+
     void fromDataStream(QDataStream& ds);
 
     void toDataStream(QDataStream& ds) const;
@@ -53,8 +59,7 @@ struct AircraftItem
 
     bool excluded = false;
     QString path;
-    QString description;
+
-    QString longDescription;
     QString authors; // legacy authors data only
     int ratings[4] = {0, 0, 0, 0};
     QString variantOf;
@@ -72,7 +77,31 @@ struct AircraftItem
     QUrl wikipediaUrl;
     QUrl supportUrl;
     QVariant status(int variant);
+
+
 private:
+    struct LocalizedStrings {
+        QString locale;
+        QMap<QByteArray, QString> strings;
+    };
+
+    friend QDataStream& operator<<(QDataStream&, const LocalizedStrings&);
+    friend QDataStream& operator>>(QDataStream&, LocalizedStrings&);
+
+    using LocalizedStringsVec = QVector<LocalizedStrings>;
+
+    // store all localized strings. We need this to avoid rebuilding
+    // the cache when switching languages.
+    LocalizedStringsVec _localized;
+
+    // the resolved values for our strings, based on QLocale
+    // if we support dynamic switching of language, this would need to
+    // be flushed and re-computed
+    QMap<QByteArray, QString> _currentStrings;
+
+    void doLocalizeStrings();
+
+    void readLocalizedStrings(SGPropertyNode_ptr simNode);
 };
 
 class LocalAircraftCache : public QObject

src/GUI/QmlAircraftInfo.cxx

@@ -342,7 +342,7 @@ quint32 QmlAircraftInfo::numVariants() const
 QString QmlAircraftInfo::name() const
 {
     if (_item) {
-        return resolveItem()->description;
+        return resolveItem()->name();
     } else if (_package) {
         return QString::fromStdString(_package->nameForVariant(_variant));
     }
@@ -353,7 +353,7 @@ QString QmlAircraftInfo::name() const
 QString QmlAircraftInfo::description() const
 {
     if (_item) {
-        return resolveItem()->longDescription;
+        return resolveItem()->description();
     } else if (_package) {
         std::string longDesc = _package->getLocalisedProp("description", _variant);
         return QString::fromStdString(longDesc).simplified();
@@ -773,12 +773,12 @@ QStringList QmlAircraftInfo::variantNames() const
 {
     QStringList result;
     if (_item) {
-        result.append(_item->description);
+        result.append(_item->name());
         Q_FOREACH(auto v, _item->variants) {
-            if (v->description.isEmpty()) {
+            if (v->name().isEmpty()) {
                 qWarning() << Q_FUNC_INFO << "missing description for " << v->path;
             }
-            result.append(v->description);
+            result.append(v->name());
         }
     } else if (_package) {
         for (quint32 vindex = 0; vindex < _package->variants().size(); ++vindex) {

src/GUI/QtLauncher.cxx

@@ -462,7 +462,7 @@ bool runLauncherDialog()
     // we will re-do this later, but we want to access translated strings
     // from within the launcher
     globals->get_locale()->selectLanguage(lang);
-    globals->packageRoot()->setLocale(lang);
+    globals->packageRoot()->setLocale(globals->get_locale()->getPreferredLanguage());
 
     // startup the HTTP system now since packages needs it
     FGHTTPClient* http = globals->add_new_subsystem<FGHTTPClient>();