third_party/blink/renderer/core/html/imports/html_import.h

/*
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#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_HTML_IMPORTS_HTML_IMPORT_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_HTML_IMPORTS_HTML_IMPORT_H_

#include "third_party/blink/renderer/core/html/imports/html_import_state.h"
#include "third_party/blink/renderer/platform/heap/handle.h"
#include "third_party/blink/renderer/platform/wtf/allocator.h"
#include "third_party/blink/renderer/platform/wtf/tree_node.h"

namespace blink {

class Document;
class HTMLImportLoader;

// The superclass of HTMLImportTreeRoot and HTMLImportChild
// This represents the import tree data structure.
class HTMLImport : public GarbageCollectedFinalized<HTMLImport>,
                   public TreeNode<HTMLImport> {
 public:
  enum SyncMode { kSync = 0, kAsync = 1 };

  virtual ~HTMLImport() = default;

  // FIXME: Consider returning HTMLImportTreeRoot.
  HTMLImport* Root();
  bool Precedes(HTMLImport*);
  bool IsRoot() const { return !Parent(); }
  bool IsSync() const { return SyncMode(sync_) == kSync; }
  bool FormsCycle() const;
  const HTMLImportState& GetState() const { return state_; }

  void AppendImport(HTMLImport*);

  virtual Document* GetDocument() const = 0;
  virtual bool HasFinishedLoading() const = 0;
  virtual HTMLImportLoader* Loader() const { return nullptr; }
  virtual void StateWillChange() {}
  virtual void StateDidChange();

  virtual void Trace(Visitor* visitor) {}

 protected:
  // Stating from most conservative state.
  // It will be corrected through state update flow.
  explicit HTMLImport(SyncMode sync) : sync_(sync) {}

  static void RecalcTreeState(HTMLImport* root);

 private:
  HTMLImportState state_;
  unsigned sync_ : 1;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_HTML_IMPORTS_HTML_IMPORT_H_