src/stc/scintilla/src/CellBuffer.h

   1 // Scintilla source code edit control
   2 // CellBuffer.h - manages the text of the document
   3 // Copyright 1998-2000 by Neil Hodgson <neilh@scintilla.org>
   4 // The License.txt file describes the conditions under which this software may be distributed.
   5
   6 #ifndef CELLBUFFER_H
   7 #define CELLBUFFER_H
   8
   9 // This holds the marker identifier and the marker type to display.
  10 // MarkerHandleNumbers are members of lists.
  11 struct MarkerHandleNumber {
  12         int handle;
  13         int number;
  14         MarkerHandleNumber *next;
  15 };
  16
  17 // A marker handle set contains any number of MarkerHandleNumbers
  18 class MarkerHandleSet {
  19         MarkerHandleNumber *root;
  20 public:
  21         MarkerHandleSet();
  22         ~MarkerHandleSet();
  23         int Length();
  24         int NumberFromHandle(int handle);
  25         int MarkValue();        // Bit set of marker numbers
  26         bool Contains(int handle);
  27         bool InsertHandle(int handle, int markerNum);
  28         void RemoveHandle(int handle);
  29         void RemoveNumber(int markerNum);
  30         void CombineWith(MarkerHandleSet *other);
  31 };
  32
  33 // Each line stores the starting position of the first character of the line in the cell buffer
  34 // and potentially a marker handle set. Often a line will not have any attached markers.
  35 struct LineData {
  36         int startPosition;
  37         MarkerHandleSet *handleSet;
  38         LineData() : startPosition(0), handleSet(0) {
  39         }
  40 };
  41
  42 // The line vector contains information about each of the lines in a cell buffer.
  43 class LineVector {
  44 public:
  45         enum { growSize = 4000 };
  46         int lines;
  47         LineData *linesData;
  48         int size;
  49         int *levels;
  50         int sizeLevels;
  51
  52         // Handles are allocated sequentially and should never have to be reused as 32 bit ints are very big.
  53         int handleCurrent;
  54
  55         LineVector();
  56         ~LineVector();
  57         void Init();
  58
  59         void Expand(int sizeNew);
  60         void ExpandLevels(int sizeNew=-1);
  61     void ClearLevels();
  62         void InsertValue(int pos, int value);
  63         void SetValue(int pos, int value);
  64         void Remove(int pos);
  65         int LineFromPosition(int pos);
  66
  67         int AddMark(int line, int marker);
  68         void MergeMarkers(int pos);
  69         void DeleteMark(int line, int markerNum);
  70         void DeleteMarkFromHandle(int markerHandle);
  71         int LineFromHandle(int markerHandle);
  72 };
  73
  74 // Actions are used to store all the information required to perform one undo/redo step.
  75 enum actionType { insertAction, removeAction, startAction };
  76
  77 class Action {
  78 public:
  79         actionType at;
  80         int position;
  81         char *data;
  82         int lenData;
  83         bool mayCoalesce;
  84
  85         Action();
  86         ~Action();
  87         void Create(actionType at_, int position_=0, char *data_=0, int lenData_=0, bool mayCoalesce_=true);
  88         void Destroy();
  89         void Grab(Action *source);
  90 };
  91
  92 class UndoHistory {
  93         Action *actions;
  94         int lenActions;
  95         int maxAction;
  96         int currentAction;
  97         int undoSequenceDepth;
  98         int savePoint;
  99
 100         void EnsureUndoRoom();
 101
 102 public:
 103         UndoHistory();
 104         ~UndoHistory();
 105
 106         void AppendAction(actionType at, int position, char *data, int length);
 107
 108         void BeginUndoAction();
 109         void EndUndoAction();
 110         void DropUndoSequence();
 111         void DeleteUndoHistory();
 112
 113         // The save point is a marker in the undo stack where the container has stated that
 114         // the buffer was saved. Undo and redo can move over the save point.
 115         void SetSavePoint();
 116         bool IsSavePoint() const;
 117
 118         // To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 119         // called that many times. Similarly for redo.
 120         bool CanUndo() const;
 121         int StartUndo();
 122         const Action &GetUndoStep() const;
 123         void CompletedUndoStep();
 124         bool CanRedo() const;
 125         int StartRedo();
 126         const Action &GetRedoStep() const;
 127         void CompletedRedoStep();
 128 };
 129
 130 // Holder for an expandable array of characters that supports undo and line markers
 131 // Based on article "Data Structures in a Bit-Mapped Text Editor"
 132 // by Wilfred J. Hansen, Byte January 1987, page 183
 133 class CellBuffer {
 134 private:
 135         char *body;
 136         int size;
 137         int length;
 138         int part1len;
 139         int gaplen;
 140         char *part2body;
 141         bool readOnly;
 142
 143         bool collectingUndo;
 144         UndoHistory uh;
 145
 146         LineVector lv;
 147
 148         SVector lineStates;
 149
 150         void GapTo(int position);
 151         void RoomFor(int insertionLength);
 152
 153         inline char ByteAt(int position);
 154         void SetByteAt(int position, char ch);
 155
 156 public:
 157
 158         CellBuffer(int initialLength = 4000);
 159         ~CellBuffer();
 160
 161         // Retrieving positions outside the range of the buffer works and returns 0
 162         char CharAt(int position);
 163         void GetCharRange(char *buffer, int position, int lengthRetrieve);
 164         char StyleAt(int position);
 165
 166         int ByteLength();
 167         int Length();
 168         int Lines();
 169         int LineStart(int line);
 170         int LineFromPosition(int pos) { return lv.LineFromPosition(pos); }
 171         const char *InsertString(int position, char *s, int insertLength);
 172         void InsertCharStyle(int position, char ch, char style);
 173
 174         // Setting styles for positions outside the range of the buffer is safe and has no effect.
 175         // True is returned if the style of a character changed.
 176         bool SetStyleAt(int position, char style, char mask='\377');
 177         bool SetStyleFor(int position, int length, char style, char mask);
 178
 179         const char *DeleteChars(int position, int deleteLength);
 180
 181         bool IsReadOnly();
 182         void SetReadOnly(bool set);
 183
 184         // The save point is a marker in the undo stack where the container has stated that
 185         // the buffer was saved. Undo and redo can move over the save point.
 186         void SetSavePoint();
 187         bool IsSavePoint();
 188
 189         // Line marker functions
 190         int AddMark(int line, int markerNum);
 191         void DeleteMark(int line, int markerNum);
 192         void DeleteMarkFromHandle(int markerHandle);
 193         int GetMark(int line);
 194         void DeleteAllMarks(int markerNum);
 195         int LineFromHandle(int markerHandle);
 196
 197         // Without undo
 198         void BasicInsertString(int position, char *s, int insertLength);
 199         void BasicDeleteChars(int position, int deleteLength);
 200
 201         bool SetUndoCollection(bool collectUndo);
 202         bool IsCollectingUndo();
 203         void BeginUndoAction();
 204         void EndUndoAction();
 205         void DeleteUndoHistory();
 206
 207         // To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 208         // called that many times. Similarly for redo.
 209         bool CanUndo();
 210         int StartUndo();
 211         const Action &GetUndoStep() const;
 212         void PerformUndoStep();
 213         bool CanRedo();
 214         int StartRedo();
 215         const Action &GetRedoStep() const;
 216         void PerformRedoStep();
 217
 218         int SetLineState(int line, int state);
 219         int GetLineState(int line);
 220         int GetMaxLineState();
 221
 222         int SetLevel(int line, int level);
 223         int GetLevel(int line);
 224     void ClearLevels();
 225 };
 226
 227 #define CELL_SIZE       2
 228
 229 #endif