contrib/src/stc/scintilla/src/CellBuffer.h

   1 // Scintilla source code edit control
   2 /** @file CellBuffer.h
   3  ** Manages the text of the document.
   4  **/
   5 // Copyright 1998-2001 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 /**
  12  * This holds the marker identifier and the marker type to display.
  13  * MarkerHandleNumbers are members of lists.
  14  */
  15 struct MarkerHandleNumber {
  16         int handle;
  17         int number;
  18         MarkerHandleNumber *next;
  19 };
  20
  21 /**
  22  * A marker handle set contains any number of MarkerHandleNumbers.
  23  */
  24 class MarkerHandleSet {
  25         MarkerHandleNumber *root;
  26
  27 public:
  28         MarkerHandleSet();
  29         ~MarkerHandleSet();
  30         int Length();
  31         int NumberFromHandle(int handle);
  32         int MarkValue();        ///< Bit set of marker numbers.
  33         bool Contains(int handle);
  34         bool InsertHandle(int handle, int markerNum);
  35         void RemoveHandle(int handle);
  36         void RemoveNumber(int markerNum);
  37         void CombineWith(MarkerHandleSet *other);
  38 };
  39
  40 /**
  41  * Each line stores the starting position of the first character of the line in the cell buffer
  42  * and potentially a marker handle set. Often a line will not have any attached markers.
  43  */
  44 struct LineData {
  45         int startPosition;
  46         MarkerHandleSet *handleSet;
  47         LineData() : startPosition(0), handleSet(0) {
  48         }
  49 };
  50
  51 /**
  52  * The line vector contains information about each of the lines in a cell buffer.
  53  */
  54 class LineVector {
  55 public:
  56         int growSize;
  57         int lines;
  58         LineData *linesData;
  59         int size;
  60         int *levels;
  61         int sizeLevels;
  62
  63         /// Handles are allocated sequentially and should never have to be reused as 32 bit ints are very big.
  64         int handleCurrent;
  65
  66         LineVector();
  67         ~LineVector();
  68         void Init();
  69
  70         void Expand(int sizeNew);
  71         void ExpandLevels(int sizeNew=-1);
  72         void ClearLevels();
  73         void InsertValue(int pos, int value);
  74         void SetValue(int pos, int value);
  75         void Remove(int pos);
  76         int LineFromPosition(int pos);
  77
  78         int AddMark(int line, int marker);
  79         void MergeMarkers(int pos);
  80         void DeleteMark(int line, int markerNum);
  81         void DeleteMarkFromHandle(int markerHandle);
  82         int LineFromHandle(int markerHandle);
  83 };
  84
  85 enum actionType { insertAction, removeAction, startAction };
  86
  87 /**
  88  * Actions are used to store all the information required to perform one undo/redo step.
  89  */
  90 class Action {
  91 public:
  92         actionType at;
  93         int position;
  94         char *data;
  95         int lenData;
  96         bool mayCoalesce;
  97
  98         Action();
  99         ~Action();
 100         void Create(actionType at_, int position_=0, char *data_=0, int lenData_=0, bool mayCoalesce_=true);
 101         void Destroy();
 102         void Grab(Action *source);
 103 };
 104
 105 /**
 106  *
 107  */
 108 class UndoHistory {
 109         Action *actions;
 110         int lenActions;
 111         int maxAction;
 112         int currentAction;
 113         int undoSequenceDepth;
 114         int savePoint;
 115
 116         void EnsureUndoRoom();
 117
 118 public:
 119         UndoHistory();
 120         ~UndoHistory();
 121
 122         void AppendAction(actionType at, int position, char *data, int length);
 123
 124         void BeginUndoAction();
 125         void EndUndoAction();
 126         void DropUndoSequence();
 127         void DeleteUndoHistory();
 128
 129         /// The save point is a marker in the undo stack where the container has stated that
 130         /// the buffer was saved. Undo and redo can move over the save point.
 131         void SetSavePoint();
 132         bool IsSavePoint() const;
 133
 134         /// To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 135         /// called that many times. Similarly for redo.
 136         bool CanUndo() const;
 137         int StartUndo();
 138         const Action &GetUndoStep() const;
 139         void CompletedUndoStep();
 140         bool CanRedo() const;
 141         int StartRedo();
 142         const Action &GetRedoStep() const;
 143         void CompletedRedoStep();
 144 };
 145
 146 /**
 147  * Holder for an expandable array of characters that supports undo and line markers.
 148  * Based on article "Data Structures in a Bit-Mapped Text Editor"
 149  * by Wilfred J. Hansen, Byte January 1987, page 183.
 150  */
 151 class CellBuffer {
 152 private:
 153         char *body;
 154         int size;
 155         int length;
 156         int part1len;
 157         int gaplen;
 158         char *part2body;
 159         bool readOnly;
 160         int growSize;
 161
 162         bool collectingUndo;
 163         UndoHistory uh;
 164
 165         LineVector lv;
 166
 167         SVector lineStates;
 168
 169         void GapTo(int position);
 170         void RoomFor(int insertionLength);
 171
 172         inline char ByteAt(int position);
 173         void SetByteAt(int position, char ch);
 174
 175 public:
 176
 177         CellBuffer(int initialLength = 4000);
 178         ~CellBuffer();
 179
 180         /// Retrieving positions outside the range of the buffer works and returns 0
 181         char CharAt(int position);
 182         void GetCharRange(char *buffer, int position, int lengthRetrieve);
 183         char StyleAt(int position);
 184
 185         int ByteLength();
 186         int Length();
 187         int Lines();
 188         int LineStart(int line);
 189         int LineFromPosition(int pos) { return lv.LineFromPosition(pos); }
 190         const char *InsertString(int position, char *s, int insertLength);
 191         void InsertCharStyle(int position, char ch, char style);
 192
 193         /// Setting styles for positions outside the range of the buffer is safe and has no effect.
 194         /// @return true if the style of a character is changed.
 195         bool SetStyleAt(int position, char style, char mask='\377');
 196         bool SetStyleFor(int position, int length, char style, char mask);
 197
 198         const char *DeleteChars(int position, int deleteLength);
 199
 200         bool IsReadOnly();
 201         void SetReadOnly(bool set);
 202
 203         /// The save point is a marker in the undo stack where the container has stated that
 204         /// the buffer was saved. Undo and redo can move over the save point.
 205         void SetSavePoint();
 206         bool IsSavePoint();
 207
 208         /// Line marker functions
 209         int AddMark(int line, int markerNum);
 210         void DeleteMark(int line, int markerNum);
 211         void DeleteMarkFromHandle(int markerHandle);
 212         int GetMark(int line);
 213         void DeleteAllMarks(int markerNum);
 214         int LineFromHandle(int markerHandle);
 215
 216         /// Actions without undo
 217         void BasicInsertString(int position, char *s, int insertLength);
 218         void BasicDeleteChars(int position, int deleteLength);
 219
 220         bool SetUndoCollection(bool collectUndo);
 221         bool IsCollectingUndo();
 222         void BeginUndoAction();
 223         void EndUndoAction();
 224         void DeleteUndoHistory();
 225
 226         /// To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 227         /// called that many times. Similarly for redo.
 228         bool CanUndo();
 229         int StartUndo();
 230         const Action &GetUndoStep() const;
 231         void PerformUndoStep();
 232         bool CanRedo();
 233         int StartRedo();
 234         const Action &GetRedoStep() const;
 235         void PerformRedoStep();
 236
 237         int SetLineState(int line, int state);
 238         int GetLineState(int line);
 239         int GetMaxLineState();
 240
 241         int SetLevel(int line, int level);
 242         int GetLevel(int line);
 243         void ClearLevels();
 244 };
 245
 246 #define CELL_SIZE       2
 247
 248 #endif