初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumJsonReader/JsonReaderOptions.h

@@ -0,0 +1,165 @@
+#pragma once
+
+#include "IExtensionJsonHandler.h"
+#include "Library.h"
+
+#include <functional>
+#include <map>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace CesiumJsonReader {
+
+/**
+ * @brief The state of an extension.
+ */
+enum class ExtensionState {
+  /**
+   * @brief The extension is enabled.
+   *
+   * If a statically-typed class is available for the extension, it will be
+   * used. Otherwise the extension will be represented as a
+   * {@link CesiumUtility::JsonValue}.
+   */
+  Enabled,
+
+  /**
+   * @brief The extension is enabled but will always be deserialized as a
+   * {@link CesiumUtility::JsonValue}.
+   *
+   * Even if a statically-typed class is available for the extension, it will
+   * not be used.
+   */
+  JsonOnly,
+
+  /**
+   * @brief The extension is disabled.
+   *
+   * It will not be represented in the loaded model at all.
+   */
+  Disabled
+};
+
+/**
+ * @brief Holds options for reading statically-typed data structures from JSON.
+ */
+class CESIUMJSONREADER_API JsonReaderOptions {
+public:
+  /**
+   * @brief Gets a value indicating whether the values of unknown properties are
+   * captured in the {@link CesiumUtility::ExtensibleObject::unknownProperties} field.
+   *
+   * If this is false, unknown properties are completely ignored.
+   */
+  bool getCaptureUnknownProperties() const {
+    return this->_captureUnknownProperties;
+  }
+
+  /**
+   * @brief Sets a value indicating whether the values of unknown properties are
+   * captured in the {@link CesiumUtility::ExtensibleObject::unknownProperties} field.
+   *
+   * If this is false, unknown properties are completely ignored.
+   */
+  void setCaptureUnknownProperties(bool value) {
+    this->_captureUnknownProperties = value;
+  }
+
+  /**
+   * @brief Registers an extension for an object.
+   *
+   * @tparam TExtended The object to extend.
+   * @tparam TExtensionHandler The extension's
+   * {@link CesiumJsonReader::JsonHandler}.
+   * @param extensionName The name of the extension.
+   */
+  template <typename TExtended, typename TExtensionHandler>
+  void registerExtension(const std::string& extensionName) {
+    auto it =
+        this->_extensions.emplace(extensionName, ObjectTypeToHandler()).first;
+    it->second.insert_or_assign(
+        TExtended::TypeName,
+        ExtensionReaderFactory([](const JsonReaderOptions& context) {
+          return std::make_unique<TExtensionHandler>(context);
+        }));
+  }
+
+  /**
+   * @brief Registers an extension for an object.
+   *
+   * The extension name is obtained from `TExtensionHandler::ExtensionName`.
+   *
+   * @tparam TExtended The object to extend.
+   * @tparam TExtensionHandler The extension's
+   * {@link CesiumJsonReader::JsonHandler}.
+   */
+  template <typename TExtended, typename TExtensionHandler>
+  void registerExtension() {
+    auto it =
+        this->_extensions
+            .emplace(TExtensionHandler::ExtensionName, ObjectTypeToHandler())
+            .first;
+    it->second.insert_or_assign(
+        TExtended::TypeName,
+        ExtensionHandlerFactory([](const JsonReaderOptions& context) {
+          return std::make_unique<TExtensionHandler>(context);
+        }));
+  }
+
+  /**
+   * @brief Returns whether an extension is enabled or disabled.
+   *
+   * By default, all extensions are enabled.
+   *
+   * @param extensionName The name of the extension.
+   */
+  ExtensionState getExtensionState(const std::string& extensionName) const;
+
+  /**
+   * @brief Enables or disables an extension.
+   *
+   * By default, all extensions are enabled. When an enabled extension is
+   * encountered in the source JSON, it is read into a statically-typed
+   * extension class, if one is registered, or into a
+   * {@link CesiumUtility::JsonValue} if not.
+   *
+   * When a disabled extension is encountered in the source JSON, it is ignored
+   * completely.
+   *
+   * An extension may also be set to `ExtensionState::JsonOnly`, in which case
+   * it will be read into a {@link CesiumUtility::JsonValue} even if a
+   * statically-typed extension class is registered.
+   *
+   * @param extensionName The name of the extension to be enabled or disabled.
+   * @param newState The new state for the extension.
+   */
+  void
+  setExtensionState(const std::string& extensionName, ExtensionState newState);
+
+  /**
+   * @brief Creates an extension handler for the given extension.
+   *
+   * @param extensionName The name of the extension to create a handler for.
+   * @param extendedObjectType The name of the type of the object that is being
+   * extended.
+   * @returns An \ref IExtensionJsonHandler to read the extension.
+   */
+  std::unique_ptr<IExtensionJsonHandler> createExtensionHandler(
+      const std::string_view& extensionName,
+      const std::string& extendedObjectType) const;
+
+private:
+  using ExtensionHandlerFactory =
+      std::function<std::unique_ptr<IExtensionJsonHandler>(
+          const JsonReaderOptions&)>;
+  using ObjectTypeToHandler = std::map<std::string, ExtensionHandlerFactory>;
+  using ExtensionNameMap = std::map<std::string, ObjectTypeToHandler>;
+
+  ExtensionNameMap _extensions;
+  std::unordered_map<std::string, ExtensionState> _extensionStates;
+  bool _captureUnknownProperties = true;
+};
+
+} // namespace CesiumJsonReader