Initial import.

Buffer.h

@@ -0,0 +1,165 @@
+/*
+ * Buffer.h - editor buffer representing an open document
+ */
+#ifndef KTE_BUFFER_H
+#define KTE_BUFFER_H
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+class Buffer {
+public:
+	Buffer();
+
+	explicit Buffer(const std::string &path);
+
+	// File operations
+	bool OpenFromFile(const std::string &path, std::string &err);
+
+	bool Save(std::string &err) const; // saves to existing filename; returns false if not file-backed
+	bool SaveAs(const std::string &path, std::string &err); // saves to path and makes buffer file-backed
+
+	// Accessors
+	[[nodiscard]] std::size_t Curx() const
+	{
+		return curx_;
+	}
+
+
+	[[nodiscard]] std::size_t Cury() const
+	{
+		return cury_;
+	}
+
+
+	[[nodiscard]] std::size_t Rx() const
+	{
+		return rx_;
+	}
+
+
+	[[nodiscard]] std::size_t Nrows() const
+	{
+		return nrows_;
+	}
+
+
+	[[nodiscard]] std::size_t Rowoffs() const
+	{
+		return rowoffs_;
+	}
+
+
+	[[nodiscard]] std::size_t Coloffs() const
+	{
+		return coloffs_;
+	}
+
+
+	[[nodiscard]] const std::vector<std::string> &Rows() const
+	{
+		return rows_;
+	}
+
+
+	[[nodiscard]] std::vector<std::string> &Rows()
+	{
+		return rows_;
+	}
+
+
+	[[nodiscard]] const std::string &Filename() const
+	{
+		return filename_;
+	}
+
+
+	[[nodiscard]] bool IsFileBacked() const
+	{
+		return is_file_backed_;
+	}
+
+
+	[[nodiscard]] bool Dirty() const
+	{
+		return dirty_;
+	}
+
+
+	void SetCursor(std::size_t x, std::size_t y)
+	{
+		curx_ = x;
+		cury_ = y;
+	}
+
+
+	void SetRenderX(std::size_t rx)
+	{
+		rx_ = rx;
+	}
+
+
+	void SetOffsets(std::size_t row, std::size_t col)
+	{
+		rowoffs_ = row;
+		coloffs_ = col;
+	}
+
+
+	void SetDirty(bool d)
+	{
+		dirty_ = d;
+	}
+
+
+	// Mark support
+	void ClearMark()
+	{
+		mark_set_ = false;
+	}
+
+
+	void SetMark(std::size_t x, std::size_t y)
+	{
+		mark_set_  = true;
+		mark_curx_ = x;
+		mark_cury_ = y;
+	}
+
+
+	[[nodiscard]] bool MarkSet() const
+	{
+		return mark_set_;
+	}
+
+
+	[[nodiscard]] std::size_t MarkCurx() const
+	{
+		return mark_curx_;
+	}
+
+
+	[[nodiscard]] std::size_t MarkCury() const
+	{
+		return mark_cury_;
+	}
+
+
+	[[nodiscard]] std::string AsString() const;
+
+private:
+	// State mirroring original C struct (without undo_tree)
+	std::size_t curx_    = 0, cury_ = 0; // cursor position in characters
+	std::size_t rx_      = 0; // render x (tabs expanded)
+	std::size_t nrows_   = 0; // number of rows
+	std::size_t rowoffs_ = 0, coloffs_ = 0; // viewport offsets
+	std::vector<std::string> rows_; // buffer rows (without trailing newlines)
+	std::string filename_;
+	bool is_file_backed_   = false;
+	bool dirty_            = false;
+	bool mark_set_         = false;
+	std::size_t mark_curx_ = 0, mark_cury_ = 0;
+};
+
+#endif // KTE_BUFFER_H