ext/scintilla/src/CellBuffer.h

   1 // Scintilla source code edit control
   2 /** @file CellBuffer.h
   3  ** Manages the text of the document.
   4  **/
   5 // Copyright 1998-2004 by Neil Hodgson <neilh@scintilla.org>
   6 // The License.txt file describes the conditions under which this software may be distributed.
   7
   8 #ifndef CELLBUFFER_H
   9 #define CELLBUFFER_H
  10
  11 #ifdef SCI_NAMESPACE
  12 namespace Scintilla {
  13 #endif
  14
  15 // Interface to per-line data that wants to see each line insertion and deletion
  16 class PerLine {
  17 public:
  18         virtual ~PerLine() {}
  19         virtual void Init()=0;
  20         virtual void InsertLine(int line)=0;
  21         virtual void RemoveLine(int line)=0;
  22 };
  23
  24 /**
  25  * The line vector contains information about each of the lines in a cell buffer.
  26  */
  27 class LineVector {
  28
  29         Partitioning starts;
  30         PerLine *perLine;
  31
  32 public:
  33
  34         LineVector();
  35         ~LineVector();
  36         void Init();
  37         void SetPerLine(PerLine *pl);
  38
  39         void InsertText(int line, int delta);
  40         void InsertLine(int line, int position, bool lineStart);
  41         void SetLineStart(int line, int position);
  42         void RemoveLine(int line);
  43         int Lines() const {
  44                 return starts.Partitions();
  45         }
  46         int LineFromPosition(int pos) const;
  47         int LineStart(int line) const {
  48                 return starts.PositionFromPartition(line);
  49         }
  50
  51         int MarkValue(int line);
  52         int AddMark(int line, int marker);
  53         void MergeMarkers(int pos);
  54         void DeleteMark(int line, int markerNum, bool all);
  55         void DeleteMarkFromHandle(int markerHandle);
  56         int LineFromHandle(int markerHandle);
  57
  58         void ClearLevels();
  59         int SetLevel(int line, int level);
  60         int GetLevel(int line);
  61
  62         int SetLineState(int line, int state);
  63         int GetLineState(int line);
  64         int GetMaxLineState();
  65
  66 };
  67
  68 enum actionType { insertAction, removeAction, startAction, containerAction };
  69
  70 /**
  71  * Actions are used to store all the information required to perform one undo/redo step.
  72  */
  73 class Action {
  74 public:
  75         actionType at;
  76         int position;
  77         char *data;
  78         int lenData;
  79         bool mayCoalesce;
  80
  81         Action();
  82         ~Action();
  83         void Create(actionType at_, int position_=0, const char *data_=0, int lenData_=0, bool mayCoalesce_=true);
  84         void Destroy();
  85         void Grab(Action *source);
  86 };
  87
  88 /**
  89  *
  90  */
  91 class UndoHistory {
  92         Action *actions;
  93         int lenActions;
  94         int maxAction;
  95         int currentAction;
  96         int undoSequenceDepth;
  97         int savePoint;
  98         int tentativePoint;
  99
 100         void EnsureUndoRoom();
 101
 102         // Private so UndoHistory objects can not be copied
 103         UndoHistory(const UndoHistory &);
 104
 105 public:
 106         UndoHistory();
 107         ~UndoHistory();
 108
 109         const char *AppendAction(actionType at, int position, const char *data, int length, bool &startSequence, bool mayCoalesce=true);
 110
 111         void BeginUndoAction();
 112         void EndUndoAction();
 113         void DropUndoSequence();
 114         void DeleteUndoHistory();
 115
 116         /// The save point is a marker in the undo stack where the container has stated that
 117         /// the buffer was saved. Undo and redo can move over the save point.
 118         void SetSavePoint();
 119         bool IsSavePoint() const;
 120
 121         // Tentative actions are used for input composition so that it can be undone cleanly
 122         void TentativeStart();
 123         void TentativeCommit();
 124         bool TentativeActive() const { return tentativePoint >= 0; }
 125         int TentativeSteps();
 126
 127         /// To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 128         /// called that many times. Similarly for redo.
 129         bool CanUndo() const;
 130         int StartUndo();
 131         const Action &GetUndoStep() const;
 132         void CompletedUndoStep();
 133         bool CanRedo() const;
 134         int StartRedo();
 135         const Action &GetRedoStep() const;
 136         void CompletedRedoStep();
 137 };
 138
 139 /**
 140  * Holder for an expandable array of characters that supports undo and line markers.
 141  * Based on article "Data Structures in a Bit-Mapped Text Editor"
 142  * by Wilfred J. Hansen, Byte January 1987, page 183.
 143  */
 144 class CellBuffer {
 145 private:
 146         SplitVector<char> substance;
 147         SplitVector<char> style;
 148         bool readOnly;
 149         int utf8LineEnds;
 150
 151         bool collectingUndo;
 152         UndoHistory uh;
 153
 154         LineVector lv;
 155
 156         bool UTF8LineEndOverlaps(int position) const;
 157         void ResetLineEnds();
 158         /// Actions without undo
 159         void BasicInsertString(int position, const char *s, int insertLength);
 160         void BasicDeleteChars(int position, int deleteLength);
 161
 162 public:
 163
 164         CellBuffer();
 165         ~CellBuffer();
 166
 167         /// Retrieving positions outside the range of the buffer works and returns 0
 168         char CharAt(int position) const;
 169         void GetCharRange(char *buffer, int position, int lengthRetrieve) const;
 170         char StyleAt(int position) const;
 171         void GetStyleRange(unsigned char *buffer, int position, int lengthRetrieve) const;
 172         const char *BufferPointer();
 173         const char *RangePointer(int position, int rangeLength);
 174         int GapPosition() const;
 175
 176         int Length() const;
 177         void Allocate(int newSize);
 178         int GetLineEndTypes() const { return utf8LineEnds; }
 179         void SetLineEndTypes(int utf8LineEnds_);
 180         void SetPerLine(PerLine *pl);
 181         int Lines() const;
 182         int LineStart(int line) const;
 183         int LineFromPosition(int pos) const { return lv.LineFromPosition(pos); }
 184         void InsertLine(int line, int position, bool lineStart);
 185         void RemoveLine(int line);
 186         const char *InsertString(int position, const char *s, int insertLength, bool &startSequence);
 187
 188         /// Setting styles for positions outside the range of the buffer is safe and has no effect.
 189         /// @return true if the style of a character is changed.
 190         bool SetStyleAt(int position, char styleValue);
 191         bool SetStyleFor(int position, int length, char styleValue);
 192
 193         const char *DeleteChars(int position, int deleteLength, bool &startSequence);
 194
 195         bool IsReadOnly() const;
 196         void SetReadOnly(bool set);
 197
 198         /// The save point is a marker in the undo stack where the container has stated that
 199         /// the buffer was saved. Undo and redo can move over the save point.
 200         void SetSavePoint();
 201         bool IsSavePoint() const;
 202
 203         void TentativeStart();
 204         void TentativeCommit();
 205         bool TentativeActive() const;
 206         int TentativeSteps();
 207
 208         bool SetUndoCollection(bool collectUndo);
 209         bool IsCollectingUndo() const;
 210         void BeginUndoAction();
 211         void EndUndoAction();
 212         void AddUndoAction(int token, bool mayCoalesce);
 213         void DeleteUndoHistory();
 214
 215         /// To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 216         /// called that many times. Similarly for redo.
 217         bool CanUndo() const;
 218         int StartUndo();
 219         const Action &GetUndoStep() const;
 220         void PerformUndoStep();
 221         bool CanRedo() const;
 222         int StartRedo();
 223         const Action &GetRedoStep() const;
 224         void PerformRedoStep();
 225 };
 226
 227 #ifdef SCI_NAMESPACE
 228 }
 229 #endif
 230
 231 #endif