1 files changed, 116 insertions, 0 deletions
diff --git a/include/ricochet/tui/position.hh b/include/ricochet/tui/position.hh
new file mode 100644
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+++ b/include/ricochet/tui/position.hh
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+/*
+ * Ricochet - A minimalist CLI web browser for fast, distraction-free navigation.
+ * Copyright (C) 2026  Richard Qin
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "ricochet/tui/identity.hh"
+
+#include <cstddef>
+#include <cstdint>
+#include <variant>
+
+namespace ricochet::tui {
+
+// UTF-8 byte ranges are half-open. Text operations use grapheme boundaries.
+struct ByteRange
+{
+  std::size_t start { 0 };
+  std::size_t end { 0 };
+
+  bool operator==( const ByteRange& ) const = default;
+};
+
+struct TextPosition
+{
+  BlockId block {};
+  std::size_t byte_offset { 0 };
+
+  bool operator==( const TextPosition& ) const = default;
+};
+
+struct ControlTextPosition
+{
+  ControlId control {};
+  DraftRevision revision {};
+  // Offset in display text; password offsets refer only to its mask.
+  std::size_t byte_offset { 0 };
+
+  bool operator==( const ControlTextPosition& ) const = default;
+};
+
+enum class BoundarySide : std::uint8_t
+{
+  Before,
+  After
+};
+
+struct ObjectPosition
+{
+  std::variant<BlockId, ControlId> object {};
+  BoundarySide side { BoundarySide::Before };
+
+  bool operator==( const ObjectPosition& ) const = default;
+};
+
+struct DocumentStart
+{ bool operator==( const DocumentStart& ) const = default; };
+
+// Local to a document snapshot. Stored anchors cannot depend on mutable drafts.
+using ContentPoint = std::variant<DocumentStart, TextPosition, ObjectPosition>;
+using DocumentPoint = std::variant<DocumentStart, TextPosition, ControlTextPosition, ObjectPosition>;
+
+struct LogicalPosition
+{
+  DocumentScope scope {};
+  DocumentPoint point {};
+
+  bool operator==( const LogicalPosition& ) const = default;
+};
+
+// Endpoints follow reading order, never the numeric order of their IDs.
+struct DocumentRange
+{
+  DocumentPoint start {};
+  DocumentPoint end {};
+
+  bool operator==( const DocumentRange& ) const = default;
+};
+
+struct TextRange
+{
+  BlockId block {};
+  ByteRange bytes {};
+
+  bool operator==( const TextRange& ) const = default;
+};
+
+enum class WrapAffinity : std::uint8_t
+{
+  PreviousLine,
+  NextLine
+};
+
+struct DisplayPosition
+{
+  DocumentPoint point {};
+  WrapAffinity affinity { WrapAffinity::NextLine };
+
+  bool operator==( const DisplayPosition& ) const = default;
+};
+
+} // namespace ricochet::tui