OcdFileImport: Handle graphic objects

OCD format recognizes symbol-less map objects that, however, render in
map colors. They are called "graphic objects". We create synthetic
symbols for graphic objects on import. All the Mapper symbols have the
same name and number reflecting the anonymous nature of the source
graphic objects.

Closes OpenOrienteeringGH-959.

src/fileformats/ocd_file_import.cpp

@@ -1884,13 +1884,92 @@ void OcdFileImport::setupPointSymbolPattern(PointSymbol* symbol, std::size_t dat
 	}
 }
 
+
+Symbol* OcdFileImport::getGraphicObjectSymbol(const Ocd::ObjectV8& ocd_object)
+{
+	Q_UNUSED(ocd_object);
+	return nullptr;
+}
+
+
+template< class O >
+Symbol* OcdFileImport::getGraphicObjectSymbol(const O& ocd_object)
+{
+	Symbol* symbol = nullptr;
+	auto symbol_setup_common = [](Symbol& symbol) {
+		symbol.setName(QLatin1String("helper symbol for graphic objects"));
+		symbol.setNumberComponent(0, 999);
+		symbol.setNumberComponent(1, -1);
+		symbol.setNumberComponent(2, -1);				
+	};
+
+	auto get_cached_symbol = [this](const quint64 key) {
+		return graphic_symbol_index.contains(key) ?
+		            graphic_symbol_index[key] : nullptr;
+	};
+
+	auto store_cached_symbol = [this](const quint64 key, Symbol* symbol) {
+		map->addSymbol(symbol, map->getNumSymbols());
+		graphic_symbol_index[key] = symbol;
+	};
+
+	switch (ocd_object.type)
+	{
+	case Ocd::ObjectTypeLine:
+		{
+			const auto g_key = quint64(ocd_object.color) 
+			                   | quint64(ocd_object.line_width) << 32
+			                   | quint64(Ocd::ObjectTypeLine) << 56;
+			symbol = get_cached_symbol(g_key);
+			if (!symbol)
+			{
+				auto* line_symbol = new OcdImportedLineSymbol();
+				symbol_setup_common(*line_symbol);
+				line_symbol->color = convertColor(ocd_object.color);
+				line_symbol->line_width = convertLength(ocd_object.line_width);
+				symbol = line_symbol;
+				store_cached_symbol(g_key, symbol);
+			}
+		}
+		break;
+	case Ocd::ObjectTypeArea:
+		{
+			const auto g_key = quint64(ocd_object.color)
+			                   | quint64(Ocd::ObjectTypeArea) << 56;
+			symbol = get_cached_symbol(g_key);
+			if (!symbol)
+			{
+				auto* area_symbol = new OcdImportedAreaSymbol();
+				symbol_setup_common(*area_symbol);
+				area_symbol->color = convertColor(ocd_object.color);		
+				symbol = area_symbol;
+				store_cached_symbol(g_key, symbol);
+			}
+		}
+		break;
+	default:
+	         addWarning(tr("Encountered an unsupported type of graphic object (%1). Skipping.").arg(ocd_object.type));
+	         break;
+	}
+
+	return symbol;
+}
+
+
 template< class O >
 Object* OcdFileImport::importObject(const O& ocd_object, MapPart* part)
 {
 	Symbol* symbol = nullptr;
-	if (ocd_object.symbol >= 0)
+	switch (ocd_object.symbol)
 	{
-		symbol = symbol_index[ocd_object.symbol];
+	case -2: // graphic object
+		symbol = getGraphicObjectSymbol(ocd_object);
+		break;
+	default:
+		if (ocd_object.symbol >= 0)
+		{
+			symbol = symbol_index[ocd_object.symbol];
+		}
 	}
 
 	if (!symbol)

src/fileformats/ocd_file_import.h

@@ -306,6 +306,11 @@ class OcdFileImport : public Importer
 	template< class O >
 	Object* importObject(const O& ocd_object, MapPart* part);
 
+	Symbol* getGraphicObjectSymbol(const Ocd::ObjectV8& ocd_object);
+
+	template< class O >
+	Symbol* getGraphicObjectSymbol(const O& ocd_object);
+
 	QString getObjectText(const Ocd::ObjectV8& ocd_object) const;
 
 	template< class O >
@@ -350,6 +355,9 @@ class OcdFileImport : public Importer
 	/// maps OCD symbol number to oo-mapper symbol object
 	QHash<unsigned int, Symbol *> symbol_index;
 
+	/// maps OCD graphic object properties to oo-mapper synthetic symbol object
+	QHash<quint64, Symbol *> graphic_symbol_index;
+
 	/// maps OO Mapper text symbol pointer to OCD defined horizontal alignment (stored in objects instead of symbols in OO Mapper)
 	QHash<Symbol*, TextObject::HorizontalAlignment> text_halign_map;
 

src/fileformats/ocd_types.h

@@ -280,6 +280,20 @@ namespace Ocd
 		SymbolHidden    = 2
 	};
 
+	/**
+	 * Object type values.
+	 */
+	enum ObjectType
+	{
+		ObjectTypePoint = 1,
+		ObjectTypeLine = 2,
+		ObjectTypeArea = 3,
+		ObjectTypeUnformattedText = 4,
+		ObjectTypeFormattedText = 5,
+		ObjectTypeLineText = 6,
+		ObjectTypeRectangle = 7,
+	};
+
 	/**
 	 * Status values for objects.
 	 */