notepad-plus-plus/scintilla/src/ChangeHistory.h

125 lines
4.2 KiB
C++

// Scintilla source code edit control
/** @file ChangeHistory.h
** Manages a history of changes in a document.
**/
// Copyright 2022 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
#ifndef CHANGEHISTORY_H
#define CHANGEHISTORY_H
namespace Scintilla::Internal {
constexpr int changeOriginal = 0;
constexpr int changeRevertedOriginal = 1;
constexpr int changeSaved = 2;
constexpr int changeModified = 3;
constexpr int changeRevertedToChange = 4;
// As bit flags
constexpr unsigned int bitRevertedToOriginal = 1;
constexpr unsigned int bitSaved = 2;
constexpr unsigned int bitModified = 4;
constexpr unsigned int bitRevertedToModified = 8;
struct ChangeSpan {
Sci::Position start;
Sci::Position length;
int edition;
int count;
enum class Direction { insertion, deletion } direction;
};
struct EditionCount {
int edition;
int count;
// Used in tests.
constexpr bool operator==(const EditionCount &other) const noexcept {
return (edition == other.edition) && (count == other.count);
}
};
// EditionSet is ordered from oldest to newest, its not really a set
using EditionSet = std::vector<EditionCount>;
using EditionSetOwned = std::unique_ptr<EditionSet>;
class ChangeStack {
std::vector<int> steps;
std::vector<ChangeSpan> changes;
public:
void Clear() noexcept;
void AddStep();
void PushDeletion(Sci::Position positionDeletion, const EditionCount &ec);
void PushInsertion(Sci::Position positionInsertion, Sci::Position length, int edition);
[[nodiscard]] int PopStep() noexcept;
[[nodiscard]] ChangeSpan PopSpan(int maxSteps) noexcept;
void SetSavePoint() noexcept;
void Check() const noexcept;
};
struct ChangeLog {
ChangeStack changeStack;
RunStyles<Sci::Position, int> insertEdition;
SparseVector<EditionSetOwned> deleteEdition;
void Clear(Sci::Position length);
void InsertSpace(Sci::Position position, Sci::Position insertLength);
void DeleteRange(Sci::Position position, Sci::Position deleteLength);
void Insert(Sci::Position start, Sci::Position length, int edition);
void CollapseRange(Sci::Position position, Sci::Position deleteLength);
void PushDeletionAt(Sci::Position position, EditionCount ec);
void InsertFrontDeletionAt(Sci::Position position, EditionCount ec);
void SaveRange(Sci::Position position, Sci::Position length);
void PopDeletion(Sci::Position position, Sci::Position deleteLength);
void SaveHistoryForDelete(Sci::Position position, Sci::Position deleteLength);
void DeleteRangeSavingHistory(Sci::Position position, Sci::Position deleteLength);
void SetSavePoint();
Sci::Position Length() const noexcept;
[[nodiscard]] size_t DeletionCount(Sci::Position start, Sci::Position length) const noexcept;
void Check() const noexcept;
};
enum class ReversionState { clear, reverting, detached };
class ChangeHistory {
ChangeLog changeLog;
std::unique_ptr<ChangeLog> changeLogReversions;
int historicEpoch = -1;
public:
ChangeHistory(Sci::Position length=0);
void Insert(Sci::Position position, Sci::Position insertLength, bool collectingUndo, bool beforeSave);
void DeleteRange(Sci::Position position, Sci::Position deleteLength, bool reverting);
void DeleteRangeSavingHistory(Sci::Position position, Sci::Position deleteLength, bool beforeSave, bool isDetached);
void StartReversion();
void EndReversion() noexcept;
void SetSavePoint();
void UndoDeleteStep(Sci::Position position, Sci::Position deleteLength, bool isDetached);
[[nodiscard]] Sci::Position Length() const noexcept;
// Setting up history before this session
void SetEpoch(int epoch) noexcept;
void EditionCreateHistory(Sci::Position start, Sci::Position length);
// Queries for drawing
[[nodiscard]] int EditionAt(Sci::Position pos) const noexcept;
[[nodiscard]] Sci::Position EditionEndRun(Sci::Position pos) const noexcept;
[[nodiscard]] unsigned int EditionDeletesAt(Sci::Position pos) const noexcept;
[[nodiscard]] Sci::Position EditionNextDelete(Sci::Position pos) const noexcept;
// Testing - not used by Scintilla
[[nodiscard]] size_t DeletionCount(Sci::Position start, Sci::Position length) const noexcept;
EditionSet DeletionsAt(Sci::Position pos) const;
void Check() noexcept;
};
}
#endif