contrib/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 InsertValue(int pos, int value);
  62         void SetValue(int pos, int value);
  63         void Remove(int pos);
  64         int LineFromPosition(int pos);
  65
  66         int AddMark(int line, int marker);
  67         void MergeMarkers(int pos);
  68         void DeleteMark(int line, int markerNum);
  69         void DeleteMarkFromHandle(int markerHandle);
  70         int LineFromHandle(int markerHandle);
  71 };
  72
  73 // Actions are used to store all the information required to perform one undo/redo step.
  74 enum actionType { insertAction, removeAction, startAction };
  75
  76 class Action {
  77 public:
  78         actionType at;
  79         int position;
  80         char *data;
  81         int lenData;
  82
  83         Action();
  84         ~Action();
  85         void Create(actionType at_, int position_=0, char *data_=0, int lenData_=0);
  86         void Destroy();
  87         void Grab(Action *source);
  88 };
  89
  90 enum undoCollectionType { undoCollectNone, undoCollectAutoStart, undoCollectManualStart };
  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 &UndoStep();
 123         bool CanRedo() const;
 124         int StartRedo();
 125         const Action &RedoStep();
 126 };
 127
 128 // Holder for an expandable array of characters that supports undo and line markers
 129 // Based on article "Data Structures in a Bit-Mapped Text Editor"
 130 // by Wilfred J. Hansen, Byte January 1987, page 183
 131 class CellBuffer {
 132 private:
 133         char *body;
 134         int size;
 135         int length;
 136         int part1len;
 137         int gaplen;
 138         char *part2body;
 139         bool readOnly;
 140
 141         undoCollectionType collectingUndo;
 142         UndoHistory uh;
 143
 144         LineVector lv;
 145
 146         SVector<int, 4000> lineStates;
 147
 148         void GapTo(int position);
 149         void RoomFor(int insertionLength);
 150
 151         inline char ByteAt(int position);
 152         void SetByteAt(int position, char ch);
 153
 154 public:
 155
 156         CellBuffer(int initialLength = 4000);
 157         ~CellBuffer();
 158
 159         // Retrieving positions outside the range of the buffer works and returns 0
 160         char CharAt(int position);
 161         void GetCharRange(char *buffer, int position, int lengthRetrieve);
 162         char StyleAt(int position);
 163
 164         int ByteLength();
 165         int Length();
 166         int Lines();
 167         int LineStart(int line);
 168         int LineFromPosition(int pos) { return lv.LineFromPosition(pos); }
 169         const char *InsertString(int position, char *s, int insertLength);
 170         void InsertCharStyle(int position, char ch, char style);
 171
 172         // Setting styles for positions outside the range of the buffer is safe and has no effect.
 173         // True is returned if the style of a character changed.
 174         bool SetStyleAt(int position, char style, char mask=(char)0xff);
 175         bool SetStyleFor(int position, int length, char style, char mask);
 176
 177         const char *DeleteChars(int position, int deleteLength);
 178
 179         bool IsReadOnly();
 180         void SetReadOnly(bool set);
 181
 182         // The save point is a marker in the undo stack where the container has stated that
 183         // the buffer was saved. Undo and redo can move over the save point.
 184         void SetSavePoint();
 185         bool IsSavePoint();
 186
 187         // Line marker functions
 188         int AddMark(int line, int markerNum);
 189         void DeleteMark(int line, int markerNum);
 190         void DeleteMarkFromHandle(int markerHandle);
 191         int GetMark(int line);
 192         void DeleteAllMarks(int markerNum);
 193         int LineFromHandle(int markerHandle);
 194
 195         // Without undo
 196         void BasicInsertString(int position, char *s, int insertLength);
 197         void BasicDeleteChars(int position, int deleteLength);
 198
 199         undoCollectionType SetUndoCollection(undoCollectionType collectUndo);
 200         bool IsCollectingUndo();
 201         void BeginUndoAction();
 202         void EndUndoAction();
 203         void DeleteUndoHistory();
 204
 205         // To perform an undo, StartUndo is called to retrieve the number of steps, then UndoStep is
 206         // called that many times. Similarly for redo.
 207         bool CanUndo();
 208         int StartUndo();
 209         const Action &UndoStep();
 210         bool CanRedo();
 211         int StartRedo();
 212         const Action &RedoStep();
 213
 214         int SetLineState(int line, int state);
 215         int GetLineState(int line);
 216         int GetMaxLineState();
 217
 218         int SetLevel(int line, int level);
 219         int GetLevel(int line);
 220 };
 221
 222 #define CELL_SIZE       2
 223
 224 #endif