初始提交: UE5.3项目基础框架

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

@@ -0,0 +1,101 @@
+#pragma once
+
+#include "JsonHandler.h"
+#include "Library.h"
+
+#include <CesiumUtility/IntrusivePointer.h>
+
+#include <optional>
+
+namespace CesiumJsonReader {
+/**
+ * @brief \ref IJsonHandler for handling JSON objects.
+ */
+class CESIUMJSONREADER_API ObjectJsonHandler : public JsonHandler {
+public:
+  ObjectJsonHandler() noexcept : JsonHandler() {}
+
+  /** @copydoc IJsonHandler::readObjectStart */
+  virtual IJsonHandler* readObjectStart() override /* final */;
+  /** @copydoc IJsonHandler::readObjectEnd */
+  virtual IJsonHandler* readObjectEnd() override /* final */;
+
+protected:
+  /**
+   * @brief Called when \ref readObjectStart is called when the depth of the
+   * \ref ObjectJsonHandler is greater than 0.
+   */
+  virtual IJsonHandler* StartSubObject() noexcept;
+  /**
+   * @brief Called when \ref readObjectEnd is called when the depth of the
+   * \ref ObjectJsonHandler is greater than 0.
+   */
+  virtual IJsonHandler* EndSubObject() noexcept;
+
+  /**
+   * @brief Called from \ref IJsonHandler::readObjectKey to read a property into
+   * an object.
+   *
+   * @param currentKey The key that's currently being read.
+   * @param accessor An \ref IJsonHandler that can read the type of this
+   * property.
+   * @param value A reference to the location to store the read value.
+   * @returns The `accessor` \ref IJsonHandler that will read the next token
+   * into `value`.
+   */
+  template <typename TAccessor, typename TProperty>
+  IJsonHandler*
+  property(const char* currentKey, TAccessor& accessor, TProperty& value) {
+    this->_currentKey = currentKey;
+
+    if constexpr (isOptional<TProperty>::value) {
+      value.emplace();
+      accessor.reset(this, &value.value());
+    } else if constexpr (isIntrusivePointer<TProperty>::value) {
+      value.emplace();
+      accessor.reset(this, value.get());
+    } else {
+      accessor.reset(this, &value);
+    }
+
+    return &accessor;
+  }
+
+  /**
+   * @brief Obtains the most recent key handled by this JsonHandler.
+   */
+  const char* getCurrentKey() const noexcept;
+
+  /** @copydoc IJsonHandler::reportWarning */
+  virtual void reportWarning(
+      const std::string& warning,
+      std::vector<std::string>&& context = std::vector<std::string>()) override;
+
+protected:
+  /**
+   * @brief Sets the most recent key handled by this JsonHandler.
+   */
+  void setCurrentKey(const char* key) noexcept;
+
+private:
+  template <typename T> struct isOptional {
+    static constexpr bool value = false;
+  };
+
+  template <typename T> struct isOptional<std::optional<T>> {
+    static constexpr bool value = true;
+  };
+
+  template <typename T> struct isIntrusivePointer {
+    static constexpr bool value = false;
+  };
+
+  template <typename T>
+  struct isIntrusivePointer<CesiumUtility::IntrusivePointer<T>> {
+    static constexpr bool value = true;
+  };
+
+  int32_t _depth = 0;
+  const char* _currentKey = nullptr;
+};
+} // namespace CesiumJsonReader