{-------------------------------------------------------------------------------
The contents of this file are subject to the Mozilla Public License
Version 1.1 (the "License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.mozilla.org/MPL/

Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
the specific language governing rights and limitations under the License.

Alternatively, the contents of this file may be used under the terms of the
GNU General Public License Version 2 or later (the "GPL"), in which case
the provisions of the GPL are applicable instead of those above.
If you wish to allow use of your version of this file only under the terms
of the GPL and not to allow others to use your version of this file
under the MPL, indicate your decision by deleting the provisions above and
replace them with the notice and other provisions required by the GPL.
If you do not delete the provisions above, a recipient may use your version
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-------------------------------------------------------------------------------}

(* Naming Conventions:
  Byte = Logical: Refers to the location any TextToken has in the String.
         In Utf8String some TextToken can have more than one byte
  Char = Physical: Refers to the (x-)location on the screen matrix.
         Some TextToken (like tab) can spawn multiply char locations
*)

unit SynEditPointClasses;

{$I synedit.inc}

{off $DEFINE SynCaretDebug}

interface

uses
  Classes, SysUtils, Controls, LCLProc, LCLType, LCLIntf, ExtCtrls, Graphics, Forms,
  {$IFDEF SYN_MBCSSUPPORT}
  Imm,
  {$ENDIF}
  LazSynEditText, SynEditTypes, SynEditMiscProcs;//, SynEditTextBuffer;

type

  TInvalidateLines = procedure(FirstLine, LastLine: integer) of Object;
  TLinesCountChanged = procedure(FirstLine, Count: integer) of Object;
  TMaxLeftCharFunc = function: Integer of object;

  { TSynEditPointBase }

  TSynEditPointBase = class
  private
    function GetLocked: Boolean;
  protected
    FLines: TSynEditStrings;
    FOnChangeList: TMethodList;
    FLockCount: Integer;
    procedure SetLines(const AValue: TSynEditStrings); virtual;
    procedure DoLock; virtual;
    Procedure DoUnlock; virtual;
  public
    constructor Create;
    constructor Create(Lines: TSynEditStrings);
    destructor Destroy; override;
    procedure AddChangeHandler(AHandler: TNotifyEvent);
    procedure RemoveChangeHandler(AHandler: TNotifyEvent);
    procedure Lock;
    Procedure Unlock;
    property  Lines: TSynEditStrings read FLines write SetLines;
    property Locked: Boolean read GetLocked;
  end;

  TSynEditBaseCaret = class;
  TSynEditCaret = class;

  TSynBlockPersistMode = (
    sbpDefault,
    sbpWeak,     // selstart/end are treated as outside the block
    sbpStrong    // selstart/end are treated as inside the block
  );

  TSynBeforeSetSelTextEvent = procedure(Sender: TObject; AMode: TSynSelectionMode; ANewText: PChar) of object;

  { TSynBeforeSetSelTextList }

  TSynBeforeSetSelTextList = Class(TMethodList)
  public
    procedure CallBeforeSetSelTextHandlers(Sender: TObject; AMode: TSynSelectionMode; ANewText: PChar);
  end;

  { TSynEditSelection }

  TSynEditSelection = class(TSynEditPointBase)
  private
    FOnBeforeSetSelText: TSynBeforeSetSelTextList;
    FAutoExtend: Boolean;
    FCaret: TSynEditCaret;
    FHide: Boolean;
    FInternalCaret: TSynEditBaseCaret;
    FInvalidateLinesMethod: TInvalidateLines;
    FEnabled: Boolean;
    FHookedLines: Boolean;
    FIsSettingText: Boolean;
    FForceSingleLineSelected: Boolean;
    FActiveSelectionMode: TSynSelectionMode;
    FSelectionMode:       TSynSelectionMode;
    FStartLinePos: Integer; // 1 based
    FStartBytePos: Integer; // 1 based
    FAltStartLinePos, FAltStartBytePos: Integer; // 1 based // Alternate, for min selection
    FEndLinePos: Integer; // 1 based
    FEndBytePos: Integer; // 1 based
    FPersistent: Boolean;
    FPersistentLock, FWeakPersistentIdx, FStrongPersistentIdx: Integer;
    FIgnoreNextCaretMove: Boolean;
    (* On any modification, remember the position of the caret.
       If it gets moved from there to either end of the block, this should be ignored
       This happens, if Block and caret are adjusted directly
    *)
    FLastCarePos: TPoint;
    FStickyAutoExtend: Boolean;
    function  AdjustBytePosToCharacterStart(Line: integer; BytePos: integer): integer;
    function  GetFirstLineBytePos: TPoint;
    function  GetLastLineBytePos: TPoint;
    function GetLastLineHasSelection: Boolean;
    procedure SetAutoExtend(AValue: Boolean);
    procedure SetCaret(const AValue: TSynEditCaret);
    procedure SetEnabled(const Value : Boolean);
    procedure SetActiveSelectionMode(const Value: TSynSelectionMode);
    procedure SetForceSingleLineSelected(AValue: Boolean);
    procedure SetHide(const AValue: Boolean);
    procedure SetPersistent(const AValue: Boolean);
    procedure SetSelectionMode      (const AValue: TSynSelectionMode);
    function  GetStartLineBytePos: TPoint;
    procedure ConstrainStartLineBytePos(var Value: TPoint);
    procedure SetStartLineBytePos(Value: TPoint);
    procedure AdjustStartLineBytePos(Value: TPoint);
    function  GetEndLineBytePos: TPoint;
    procedure SetEndLineBytePos(Value: TPoint);
    function  GetSelText: string;
    procedure SetSelText(const Value: string);
    procedure DoCaretChanged(Sender: TObject);
    procedure AdjustAfterTrimming; // TODO: Move into TrimView?
  protected
    procedure DoLock; override;
    procedure DoUnlock; override;
    Procedure LineChanged(Sender: TSynEditStrings; AIndex, ACount : Integer);
    procedure DoLinesEdited(Sender: TSynEditStrings; aLinePos, aBytePos, aCount,
                            aLineBrkCnt: Integer; aText: String);
  public
    constructor Create(ALines: TSynEditStrings; aActOnLineChanges: Boolean);
    destructor Destroy; override;
    procedure AssignFrom(Src: TSynEditSelection);
    procedure SetSelTextPrimitive(PasteMode: TSynSelectionMode; Value: PChar; AReplace: Boolean = False);
    function  SelAvail: Boolean;
    function  SelCanContinue(ACaret: TSynEditCaret): Boolean;
    function  IsBackwardSel: Boolean; // SelStart < SelEnd ?
    procedure BeginMinimumSelection; // current selection will be minimum while follow caret (autoExtend) // until next setSelStart or end of follow
    procedure SortSelectionPoints;
    procedure IgnoreNextCaretMove;
    // Mode can NOT be changed in nested calls
    procedure IncPersistentLock(AMode: TSynBlockPersistMode = sbpDefault); // Weak: Do not extend (but rather move) block, if at start/end
    procedure DecPersistentLock;
    procedure Clear;
    procedure AddBeforeSetSelTextHandler(AHandler: TSynBeforeSetSelTextEvent);
    procedure RemoveBeforeSetSelTextHandler(AHandler: TSynBeforeSetSelTextEvent);
    property  Enabled: Boolean read FEnabled write SetEnabled;
    property  ForceSingleLineSelected: Boolean read FForceSingleLineSelected write SetForceSingleLineSelected;
    property  ActiveSelectionMode: TSynSelectionMode
                read FActiveSelectionMode write SetActiveSelectionMode;
    property  SelectionMode: TSynSelectionMode
                read FSelectionMode write SetSelectionMode;
    property  SelText: String read GetSelText write SetSelText;
    // Start and End positions are in the order they where defined
    // This may mean Startpos is behind EndPos in the text
    property  StartLineBytePos: TPoint
                read GetStartLineBytePos write SetStartLineBytePos;
    property  StartLineBytePosAdjusted: TPoint
                 write AdjustStartLineBytePos;
    property  EndLineBytePos: TPoint
                read GetEndLineBytePos write SetEndLineBytePos;
    property  StartLinePos: Integer read FStartLinePos;
    property  EndLinePos: Integer read FEndLinePos;
    property  StartBytePos: Integer read FStartBytePos;
    property  EndBytePos: Integer read FEndBytePos;
    // First and Last Pos are ordered according to the text flow (LTR)
    property  FirstLineBytePos: TPoint read GetFirstLineBytePos;
    property  LastLineBytePos: TPoint read GetLastLineBytePos;
    property  LastLineHasSelection: Boolean read GetLastLineHasSelection;
    property  InvalidateLinesMethod : TInvalidateLines write FInvalidateLinesMethod;
    property  Caret: TSynEditCaret read FCaret write SetCaret;
    property  Persistent: Boolean read FPersistent write SetPersistent;
    // automatically Start/Extend selection if caret moves
    // (depends if caret was at block border or not)
    property  AutoExtend: Boolean read FAutoExtend write SetAutoExtend;
    property  StickyAutoExtend: Boolean read FStickyAutoExtend write FStickyAutoExtend;
    property  Hide: Boolean read FHide write SetHide;
  end;

  { TSynEditCaret }

  TSynEditCaretFlag = (
      scCharPosValid, scBytePosValid
    );
  TSynEditCaretFlags = set of TSynEditCaretFlag;

  TSynEditCaretUpdateFlag = (
      scuForceSet,                // Change even if equal to old
      scuChangedX, scuChangedY,   //
      scuNoInvalidate             // Keep the Char/Byte ValidFlags
    );
  TSynEditCaretUpdateFlags = set of TSynEditCaretUpdateFlag;


  { TSynEditBaseCaret
    No Checks at all.
    Caller MUST ensure at least not to set x to invalid pos (middle of char) (incl update x, after SetLine)
  }

  TSynEditBaseCaret = class(TSynEditPointBase)
  private
    FFlags: TSynEditCaretFlags;
    FLinePos: Integer;     // 1 based
    FCharPos: Integer;     // 1 based
    FBytePos, FBytePosOffset: Integer;     // 1 based

    function  GetBytePos: Integer;
    function  GetBytePosOffset: Integer;
    function  GetCharPos: Integer;
    function GetFullLogicalPos: TLogCaretPoint;
    function  GetLineBytePos: TPoint;
    function  GetLineCharPos: TPoint;
    procedure SetBytePos(AValue: Integer);
    procedure SetBytePosOffset(AValue: Integer);
    procedure SetCharPos(AValue: Integer);
    procedure SetFullLogicalPos(AValue: TLogCaretPoint);
    procedure SetLineBytePos(AValue: TPoint);
    procedure SetLineCharPos(AValue: TPoint);
    procedure SetLinePos(AValue: Integer);

    function  GetLineText: string;
    procedure SetLineText(AValue: string);
  protected
    procedure ValidateBytePos;
    procedure ValidateCharPos;

    procedure InternalSetLineCharPos(NewLine, NewCharPos: Integer;
                                     UpdFlags: TSynEditCaretUpdateFlags); virtual;
    procedure InternalSetLineByterPos(NewLine, NewBytePos, NewByteOffs: Integer;
                                     UpdFlags: TSynEditCaretUpdateFlags); virtual;
  public
    constructor Create;
    procedure AssignFrom(Src: TSynEditBaseCaret);
    procedure Invalidate; // force to 1,1
    procedure InvalidateBytePos; // 1,1 IF no validCharPos
    procedure InvalidateCharPos;

    function IsAtLineChar(aPoint: TPoint): Boolean;
    function IsAtLineByte(aPoint: TPoint; aByteOffset: Integer = -1): Boolean;
    function IsAtPos(aCaret: TSynEditCaret): Boolean;

    property LinePos: Integer read FLinePos write SetLinePos;
    property CharPos: Integer read GetCharPos write SetCharPos;
    property LineCharPos: TPoint read GetLineCharPos write SetLineCharPos;
    property BytePos: Integer read GetBytePos write SetBytePos;
    property BytePosOffset: Integer read GetBytePosOffset write SetBytePosOffset;
    property LineBytePos: TPoint read GetLineBytePos write SetLineBytePos;
    property FullLogicalPos: TLogCaretPoint read GetFullLogicalPos write SetFullLogicalPos;

    property LineText: string read GetLineText write SetLineText;
  end;

  { TSynEditCaret }

  TSynEditCaret = class(TSynEditBaseCaret)
  private
    FLinesEditedRegistered: Boolean;
    FAllowPastEOL: Boolean;
    FAutoMoveOnEdit: Integer;
    FForcePastEOL: Integer;
    FForceAdjustToNextChar: Integer;
    FKeepCaretX: Boolean;
    FLastCharPos: Integer; // used by KeepCaretX

    FOldLinePos: Integer; // 1 based
    FOldCharPos: Integer; // 1 based

    FAdjustToNextChar: Boolean;
    FMaxLeftChar: TMaxLeftCharFunc;
    FChangeOnTouch: Boolean;
    FSkipTabs: Boolean;
    FTouched: Boolean;

    procedure AdjustToChar;
    function GetMaxLeftPastEOL: Integer;

    function  GetOldLineCharPos: TPoint;
    function  GetOldLineBytePos: TPoint;
    function  GetOldFullLogicalPos: TLogCaretPoint;

    procedure SetAllowPastEOL(const AValue: Boolean);
    procedure SetSkipTabs(const AValue: Boolean);
    procedure SetKeepCaretX(const AValue: Boolean);

    procedure RegisterLinesEditedHandler;
  protected
    procedure InternalSetLineCharPos(NewLine, NewCharPos: Integer;
                                     UpdFlags: TSynEditCaretUpdateFlags); override;
    procedure InternalSetLineByterPos(NewLine, NewBytePos, NewByteOffs: Integer;
                                     UpdFlags: TSynEditCaretUpdateFlags); override;

    procedure DoLock; override;
    Procedure DoUnlock; override;
    procedure SetLines(const AValue: TSynEditStrings); override;
    procedure DoLinesEdited(Sender: TSynEditStrings; aLinePos, aBytePos, aCount,
                            aLineBrkCnt: Integer; aText: String);
  public
    constructor Create;
    destructor Destroy; override;
    procedure AssignFrom(Src: TSynEditBaseCaret);

    procedure IncForcePastEOL;
    procedure DecForcePastEOL;
    procedure IncForceAdjustToNextChar;
    procedure DecForceAdjustToNextChar;
    procedure IncAutoMoveOnEdit;
    procedure DecAutoMoveOnEdit;
    procedure ChangeOnTouch;
    procedure Touch(aChangeOnTouch: Boolean = False);

    function WasAtLineChar(aPoint: TPoint): Boolean;
    function WasAtLineByte(aPoint: TPoint): Boolean;
    function MoveHoriz(ACount: Integer): Boolean; // Logical // False, if past EOL (not mowed)/BOl

    property OldLinePos: Integer read FOldLinePos;
    property OldCharPos: Integer read FOldCharPos;
    property OldLineCharPos: TPoint read GetOldLineCharPos;
    property OldLineBytePos: TPoint read GetOldLineBytePos;
    property OldFullLogicalPos: TLogCaretPoint read GetOldFullLogicalPos;

    property AdjustToNextChar: Boolean read FAdjustToNextChar write FAdjustToNextChar; deprecated;
    property SkipTabs: Boolean read FSkipTabs write SetSkipTabs;
    property AllowPastEOL: Boolean read FAllowPastEOL write SetAllowPastEOL;
    property KeepCaretX: Boolean read FKeepCaretX write SetKeepCaretX;
    property KeepCaretXPos: Integer read FLastCharPos write FLastCharPos;
    property MaxLeftChar: TMaxLeftCharFunc read FMaxLeftChar write FMaxLeftChar;
  end;

  TSynCaretType = (ctVerticalLine, ctHorizontalLine, ctHalfBlock, ctBlock, ctCostum);
  TSynCaretLockFlags = set of (sclfUpdateDisplay, sclfUpdateDisplayType);

  { TSynEditScreenCaretTimer
    Allow sync between carets which use an internal painter
  }

  TSynEditScreenCaretTimer = class
  private
    FDisplayCycle: Boolean;
    FTimer: TTimer;
    FTimerList: TMethodList;
    FAfterPaintList: TMethodList;
    FLocCount: Integer;
    FLocFlags: set of (lfTimer, lfRestart);
    procedure DoTimer(Sender: TObject);
    procedure DoAfterPaint(Data: PtrInt);
  public
    constructor Create;
    destructor Destroy; override;
    procedure AddAfterPaintHandler(AHandler: TNotifyEvent); // called once
    procedure AddHandler(AHandler: TNotifyEvent);
    procedure RemoveHandler(AHandler: TNotifyEvent);
    procedure RemoveHandler(AHandlerOwner: TObject);
    procedure IncLock;
    procedure DecLock;
    procedure AfterPaintEvent;

    procedure RestartCycle;
    property DisplayCycle: Boolean read FDisplayCycle;
  end;

  TSynEditScreenCaret = class;

  { TSynEditScreenCaretPainter }

  TSynEditScreenCaretPainter = class
  private
    FLeft, FTop, FHeight, FWidth: Integer;
    FCreated, FShowing: Boolean;
    FInPaint, FInScroll: Boolean;
    FPaintClip: TRect;
    FScrollX, FScrollY: Integer;
    FScrollRect, FScrollClip: TRect;

    function GetHandle: HWND;
    function GetHandleAllocated: Boolean;
  protected
    FHandleOwner: TWinControl;
    FOwner: TSynEditScreenCaret;
    FNeedPositionConfirmed: boolean;
    procedure Init; virtual;
    property Handle: HWND read GetHandle;
    property HandleAllocated: Boolean read GetHandleAllocated;

    procedure BeginScroll(dx, dy: Integer; const rcScroll, rcClip: TRect); virtual;
    procedure FinishScroll(dx, dy: Integer; const rcScroll, rcClip: TRect; Success: Boolean); virtual;
    procedure BeginPaint(rcClip: TRect); virtual;
    procedure FinishPaint(rcClip: TRect); virtual;
  public
    constructor Create(AHandleOwner: TWinControl; AOwner: TSynEditScreenCaret);
    function CreateCaret(w, h: Integer): Boolean; virtual;
    function DestroyCaret: Boolean; virtual;
    function HideCaret: Boolean; virtual;
    function ShowCaret: Boolean; virtual;
    function SetCaretPosEx(x, y: Integer): Boolean; virtual;

    property Left: Integer read FLeft;
    property Top: Integer read FTop;
    property Width: Integer read FWidth;
    property Height: Integer read FHeight;
    property Created: Boolean read FCreated;
    property Showing: Boolean read FShowing;
    property InPaint: Boolean read FInPaint;
    property InScroll: Boolean read FInScroll;
    property NeedPositionConfirmed: boolean read FNeedPositionConfirmed;
  end;

  TSynEditScreenCaretPainterClass = class of TSynEditScreenCaretPainter;

  { TSynEditScreenCaretPainterSystem }

  TSynEditScreenCaretPainterSystem = class(TSynEditScreenCaretPainter)
  protected
    //procedure BeginScroll(dx, dy: Integer; const rcScroll, rcClip: TRect); override;
    procedure FinishScroll(dx, dy: Integer; const rcScroll, rcClip: TRect; Success: Boolean); override;
    procedure BeginPaint(rcClip: TRect); override;
    //procedure FinishPaint(rcClip: TRect); override; // unhide, currently done by editor
  public
    function CreateCaret(w, h: Integer): Boolean; override;
    function DestroyCaret: Boolean; override;
    function HideCaret: Boolean; override;
    function ShowCaret: Boolean; override;
    function SetCaretPosEx(x, y: Integer): Boolean; override;
  end;

  { TSynEditScreenCaretPainterInternal }

  TSynEditScreenCaretPainterInternal = class(TSynEditScreenCaretPainter)
  private type
    TIsInRectState = (irInside, irPartInside, irOutside);
    TPainterState = (psAfterPaintAdded, psCleanOld, psRemoveTimer);
    TPainterStates = set of TPainterState;
  private
    FColor: TColor;
    FForcePaintEvents: Boolean;
    FIsDrawn: Boolean;
    FSavePen: TPen;
    FOldX, FOldY, FOldW, FOldH: Integer;
    FState: TPainterStates;
    FCanPaint: Boolean;

    procedure DoTimer(Sender: TObject);
    procedure DoPaint(ACanvas: TCanvas; X, Y, H, W: Integer);
    procedure Paint;
    procedure Invalidate;
    procedure AddAfterPaint(AStates: TPainterStates = []);
    procedure DoAfterPaint(Sender: TObject);
    procedure ExecAfterPaint;
    function CurrentCanvas: TCanvas;
    procedure SetColor(AValue: TColor);
    function IsInRect(ARect: TRect): TIsInRectState;
    function IsInRect(ARect: TRect; X, Y, W, H: Integer): TIsInRectState;
  protected
    procedure Init; override;

    procedure BeginScroll(dx, dy: Integer; const rcScroll, rcClip: TRect); override;
    procedure FinishScroll(dx, dy: Integer; const rcScroll, rcClip: TRect; Success: Boolean); override;
    procedure BeginPaint(rcClip: TRect); override;
    procedure FinishPaint(rcClip: TRect); override;
  public
    destructor Destroy; override;
    function CreateCaret(w, h: Integer): Boolean; override;
    function DestroyCaret: Boolean; override;
    function HideCaret: Boolean; override;
    function ShowCaret: Boolean; override;
    function SetCaretPosEx(x, y: Integer): Boolean; override;
    property Color: TColor read FColor write SetColor;
    property ForcePaintEvents: Boolean read FForcePaintEvents write FForcePaintEvents;
  end;

  // relative dimensions in percent from 0 to 1024 (=100%)
  TSynCustomCaretSizeFlag = (ccsRelativeLeft, ccsRelativeTop, ccsRelativeWidth, ccsRelativeHeight);
  TSynCustomCaretSizeFlags = set of TSynCustomCaretSizeFlag;

  { TSynEditScreenCaret }

  TSynEditScreenCaret = class
  private
    FCharHeight: Integer;
    FCharWidth: Integer;
    FClipRight: Integer;
    FClipBottom: Integer;
    FClipLeft: Integer;
    FClipTop: Integer;
    FDisplayPos: TPoint;
    FDisplayType: TSynCaretType;
    FExtraLinePixel, FExtraLineChars: Integer;
    FOnExtraLineCharsChanged: TNotifyEvent;
    FVisible: Boolean;
    FHandleOwner: TWinControl;
    FCaretPainter: TSynEditScreenCaretPainter;
    FPaintTimer: TSynEditScreenCaretTimer;
    FPaintTimerOwned: Boolean;
    function GetHandle: HWND;
    function GetHandleAllocated: Boolean;
    procedure SetCharHeight(const AValue: Integer);
    procedure SetCharWidth(const AValue: Integer);
    procedure SetClipRight(const AValue: Integer);
    procedure SetDisplayPos(const AValue: TPoint);
    procedure SetDisplayType(const AType: TSynCaretType);
    procedure SetVisible(const AValue: Boolean);
  private
    FClipExtraPixel: Integer;
    {$IFDeF SynCaretDebug}
    FDebugShowCount: Integer;
    {$ENDIF}
    FPixelWidth, FPixelHeight: Integer;
    FOffsetX, FOffsetY: Integer;
    FCustomPixelWidth, FCustomPixelHeight: Array [TSynCaretType] of Integer;
    FCustomOffsetX, FCustomOffsetY: Array [TSynCaretType] of Integer;
    FCustomFlags: Array [TSynCaretType] of TSynCustomCaretSizeFlags;
    FLockCount: Integer;
    FLockFlags: TSynCaretLockFlags;
    function GetHasPaintTimer: Boolean;
    function GetPaintTimer: TSynEditScreenCaretTimer;
    procedure SetClipBottom(const AValue: Integer);
    procedure SetClipExtraPixel(AValue: Integer);
    procedure SetClipLeft(const AValue: Integer);
    procedure SetClipRect(const AValue: TRect);
    procedure SetClipTop(const AValue: Integer);
    procedure CalcExtraLineChars;
    procedure SetPaintTimer(AValue: TSynEditScreenCaretTimer);
    procedure UpdateDisplayType;
    procedure UpdateDisplay;
    procedure ShowCaret;
    procedure HideCaret;
    property HandleAllocated: Boolean read GetHandleAllocated;
  protected
    property Handle: HWND read GetHandle;
  public
    constructor Create(AHandleOwner: TWinControl);
    constructor Create(AHandleOwner: TWinControl; APainterClass: TSynEditScreenCaretPainterClass);
    procedure ChangePainter(APainterClass: TSynEditScreenCaretPainterClass);
    destructor Destroy; override;

    procedure BeginScroll(dx, dy: Integer; const rcScroll, rcClip: TRect);
    procedure FinishScroll(dx, dy: Integer; const rcScroll, rcClip: TRect; Success: Boolean);
    procedure BeginPaint(rcClip: TRect);
    procedure FinishPaint(rcClip: TRect);
    procedure Lock;
    procedure UnLock;
    procedure AfterPaintEvent;  // next async

    procedure  Hide; // Keep visible = true
    procedure  DestroyCaret(SkipHide: boolean = False);
    procedure ResetCaretTypeSizes;
    procedure SetCaretTypeSize(AType: TSynCaretType; AWidth, AHeight, AXOffs, AYOffs: Integer;
                               AFlags: TSynCustomCaretSizeFlags = []);
    property HandleOwner: TWinControl read FHandleOwner;
    property PaintTimer: TSynEditScreenCaretTimer read GetPaintTimer write SetPaintTimer;
    property HasPaintTimer: Boolean read GetHasPaintTimer;
    property Painter: TSynEditScreenCaretPainter read FCaretPainter;
    property CharWidth:   Integer read FCharWidth write SetCharWidth;
    property CharHeight:  Integer read FCharHeight write SetCharHeight;
    property ClipLeft:    Integer read FClipLeft write SetClipLeft;
    property ClipRight:   Integer read FClipRight write SetClipRight;           // First pixel outside the allowed area
    property ClipTop:     Integer read FClipTop write SetClipTop;
    property ClipRect:    TRect write SetClipRect;
    property ClipBottom:  Integer read FClipBottom write SetClipBottom;
    property ClipExtraPixel: Integer read FClipExtraPixel write SetClipExtraPixel; // Amount of pixels, after  the last full char (half visible char width)
    property Visible:     Boolean read FVisible write SetVisible;
    property DisplayType: TSynCaretType read FDisplayType write SetDisplayType;
    property DisplayPos:  TPoint  read FDisplayPos write SetDisplayPos;
    property ExtraLineChars: Integer read FExtraLineChars; // Extend the longest line by x chars
    property OnExtraLineCharsChanged: TNotifyEvent
             read FOnExtraLineCharsChanged write FOnExtraLineCharsChanged;
  end;

implementation

{ TSynBeforeSetSelTextList }

procedure TSynBeforeSetSelTextList.CallBeforeSetSelTextHandlers(Sender: TObject;
  AMode: TSynSelectionMode; ANewText: PChar);
var
  i: Integer;
begin
  i:=Count;
  while NextDownIndex(i) do
    TSynBeforeSetSelTextEvent(Items[i])(Sender, AMode, ANewText);
end;

{ TSynEditBaseCaret }

function TSynEditBaseCaret.GetBytePos: Integer;
begin
  ValidateBytePos;
  Result := FBytePos;
end;

function TSynEditBaseCaret.GetBytePosOffset: Integer;
begin
  ValidateBytePos;
  Result := FBytePosOffset;
end;

function TSynEditBaseCaret.GetCharPos: Integer;
begin
  ValidateCharPos;
  Result := FCharPos;
end;

function TSynEditBaseCaret.GetFullLogicalPos: TLogCaretPoint;
begin
  ValidateBytePos;
  Result.Y := FLinePos;
  Result.X := FBytePos;
  Result.Offs := FBytePosOffset;
end;

function TSynEditBaseCaret.GetLineBytePos: TPoint;
begin
  ValidateBytePos;
  Result := Point(FBytePos, FLinePos);
end;

function TSynEditBaseCaret.GetLineCharPos: TPoint;
begin
  ValidateCharPos;
  Result := Point(FCharPos, FLinePos);
end;

procedure TSynEditBaseCaret.SetBytePos(AValue: Integer);
begin
  InternalSetLineByterPos(FLinePos, AValue, 0, [scuChangedX]);
end;

procedure TSynEditBaseCaret.SetBytePosOffset(AValue: Integer);
begin
  ValidateBytePos;
  InternalSetLineByterPos(FLinePos, FBytePos, AValue, [scuChangedX]);
end;

procedure TSynEditBaseCaret.SetCharPos(AValue: Integer);
begin
  InternalSetLineCharPos(FLinePos, AValue, [scuChangedX]);
end;

procedure TSynEditBaseCaret.SetFullLogicalPos(AValue: TLogCaretPoint);
begin
  InternalSetLineByterPos(AValue.y, AValue.x, AValue.Offs, [scuChangedX, scuChangedY]);
end;

procedure TSynEditBaseCaret.SetLineBytePos(AValue: TPoint);
begin
  InternalSetLineByterPos(AValue.y, AValue.x, 0, [scuChangedX, scuChangedY]);
end;

procedure TSynEditBaseCaret.SetLineCharPos(AValue: TPoint);
begin
  InternalSetLineCharPos(AValue.y, AValue.X, [scuChangedX, scuChangedY]);
end;

procedure TSynEditBaseCaret.SetLinePos(AValue: Integer);
begin
  // TODO: may temporary lead to invalid x bytepos. Must be adjusted *before* calculating char
  //if scBytePosValid in FFlags then
  //  InternalSetLineByterPos(AValue, FBytePos, FBytePosOffset, [scuChangedY])
  //else
    ValidateCharPos;
    InternalSetLineCharPos(AValue, FCharPos, [scuChangedY]);
end;

function TSynEditBaseCaret.GetLineText: string;
begin
  if (LinePos >= 1) and (LinePos <= FLines.Count) then
    Result := FLines[LinePos - 1]
  else
    Result := '';
end;

procedure TSynEditBaseCaret.SetLineText(AValue: string);
begin
  if (LinePos >= 1) and (LinePos <= Max(1, FLines.Count)) then
    FLines[LinePos - 1] := AValue;
end;

procedure TSynEditBaseCaret.ValidateBytePos;
begin
  if scBytePosValid in FFlags then
    exit;
  assert(scCharPosValid in FFlags, 'ValidateBytePos: no charpos set');
  Include(FFlags, scBytePosValid);
  FBytePos := FLines.LogPhysConvertor.PhysicalToLogical(FLinePos-1, FCharPos, FBytePosOffset);
end;

procedure TSynEditBaseCaret.ValidateCharPos;
begin
  if scCharPosValid in FFlags then
    exit;
  assert(scBytePosValid in FFlags, 'ValidateCharPos: no bytepos set');
  Include(FFlags, scCharPosValid);
  FCharPos := FLines.LogPhysConvertor.LogicalToPhysical(FLinePos-1, FBytePos, FBytePosOffset);
end;

procedure TSynEditBaseCaret.InternalSetLineCharPos(NewLine, NewCharPos: Integer;
  UpdFlags: TSynEditCaretUpdateFlags);
begin
  if (fCharPos = NewCharPos) and (fLinePos = NewLine) and
     (scCharPosValid in FFlags) and not (scuForceSet in UpdFlags)
  then
    exit;

  if not (scuNoInvalidate in UpdFlags) then
    Exclude(FFlags, scBytePosValid);
  Include(FFlags, scCharPosValid);

  if NewLine < 1 then begin
    NewLine := 1;
    Exclude(FFlags, scBytePosValid);
  end;

  if NewCharPos < 1 then begin
    NewCharPos := 1;
    Exclude(FFlags, scBytePosValid);
  end;

  FCharPos := NewCharPos;
  FLinePos := NewLine;
end;

procedure TSynEditBaseCaret.InternalSetLineByterPos(NewLine, NewBytePos, NewByteOffs: Integer;
  UpdFlags: TSynEditCaretUpdateFlags);
begin
  if (FBytePos = NewBytePos) and (FBytePosOffset = NewByteOffs) and
     (FLinePos = NewLine) and (scBytePosValid in FFlags) and not (scuForceSet in UpdFlags)
  then
    exit;

  if not (scuNoInvalidate in UpdFlags) then
    Exclude(FFlags, scCharPosValid);
  Include(FFlags, scBytePosValid);

  if NewLine < 1 then begin
    NewLine := 1;
    Exclude(FFlags, scCharPosValid);
  end;

  if NewBytePos < 1 then begin
    NewBytePos := 1;
    Exclude(FFlags, scCharPosValid);
  end;

  FBytePos       := NewBytePos;
  FBytePosOffset := NewByteOffs;
  FLinePos       := NewLine;
end;

constructor TSynEditBaseCaret.Create;
begin
  inherited Create;
  fLinePos       := 1;
  fCharPos       := 1;
  FBytePos       := 1;
  FBytePosOffset := 0;
  FFlags := [scCharPosValid, scBytePosValid];
end;

procedure TSynEditBaseCaret.AssignFrom(Src: TSynEditBaseCaret);
begin
  FLinePos       := Src.FLinePos;
  FCharPos       := Src.FCharPos;
  FBytePos       := Src.FBytePos;
  FBytePosOffset := Src.FBytePosOffset;
  FFlags         := Src.FFlags;
  SetLines(Src.FLines);
end;

procedure TSynEditBaseCaret.Invalidate;
begin
  FLinePos := 1;
  FCharPos := 1;
  FBytePos := 1;
  FFlags := [];
end;

procedure TSynEditBaseCaret.InvalidateBytePos;
begin
  if not (scCharPosValid in FFlags) then
    Invalidate
  else
    Exclude(FFlags, scBytePosValid);
end;

procedure TSynEditBaseCaret.InvalidateCharPos;
begin
  if not (scBytePosValid in FFlags) then
    Invalidate
  else
    Exclude(FFlags, scCharPosValid);
end;

function TSynEditBaseCaret.IsAtLineChar(aPoint: TPoint): Boolean;
begin
  ValidateCharPos;
  Result := (FLinePos = aPoint.y) and (FCharPos = aPoint.x);
end;

function TSynEditBaseCaret.IsAtLineByte(aPoint: TPoint; aByteOffset: Integer): Boolean;
begin
  ValidateBytePos;
  Result := (FLinePos = aPoint.y) and (BytePos = aPoint.x) and
            ( (aByteOffset < 0) or (FBytePosOffset = aByteOffset) );
end;

function TSynEditBaseCaret.IsAtPos(aCaret: TSynEditCaret): Boolean;
begin
  if (scBytePosValid in FFlags) or (scBytePosValid in aCaret.FFlags) then
    Result := IsAtLineByte(aCaret.LineBytePos, aCaret.BytePosOffset)
  else
    Result := IsAtLineChar(aCaret.LineCharPos);
end;

{ TSynEditPointBase }

function TSynEditPointBase.GetLocked: Boolean;
begin
  Result := FLockCount > 0;
end;

procedure TSynEditPointBase.SetLines(const AValue: TSynEditStrings);
begin
  FLines := AValue;
end;

procedure TSynEditPointBase.DoLock;
begin
end;

procedure TSynEditPointBase.DoUnlock;
begin
end;

constructor TSynEditPointBase.Create;
begin
  FOnChangeList := TMethodList.Create;
end;

constructor TSynEditPointBase.Create(Lines : TSynEditStrings);
begin
  Create;
  FLines := Lines;
end;

destructor TSynEditPointBase.Destroy;
begin
  FreeAndNil(FOnChangeList);
  inherited Destroy;
end;

procedure TSynEditPointBase.AddChangeHandler(AHandler : TNotifyEvent);
begin
  FOnChangeList.Add(TMethod(AHandler));
end;

procedure TSynEditPointBase.RemoveChangeHandler(AHandler : TNotifyEvent);
begin
  FOnChangeList.Remove(TMethod(AHandler));
end;

procedure TSynEditPointBase.Lock;
begin
  if FLockCount = 0 then
    DoLock;
  inc(FLockCount);
end;

procedure TSynEditPointBase.Unlock;
begin
  dec(FLockCount);
  if FLockCount = 0 then
    DoUnLock;
end;

{ TSynEditCaret }

constructor TSynEditCaret.Create;
begin
  inherited Create;
  FMaxLeftChar := nil;
  FAllowPastEOL := True;
  FForcePastEOL := 0;
  FAutoMoveOnEdit := 0;
  if FLines <> nil then
    FLines.AddEditHandler(@DoLinesEdited);
end;

destructor TSynEditCaret.Destroy;
begin
  if FLines <> nil then
    FLines.RemoveEditHandler(@DoLinesEdited);
  inherited Destroy;
end;

procedure TSynEditCaret.AssignFrom(Src: TSynEditBaseCaret);
begin
  FOldCharPos := FCharPos;
  FOldLinePos := FLinePos;

  inherited AssignFrom(Src);

  if Src is TSynEditCaret then begin
    FMaxLeftChar   := TSynEditCaret(Src).FMaxLeftChar;
    FAllowPastEOL  := TSynEditCaret(Src).FAllowPastEOL;
    FKeepCaretX    := TSynEditCaret(Src).FKeepCaretX;
    FLastCharPos   := TSynEditCaret(Src).FLastCharPos;
  end
  else begin
    AdjustToChar;
    FLastCharPos   := FCharPos;
  end;
end;

procedure TSynEditCaret.DoLock;
begin
  FTouched := False;
  ValidateCharPos;
  //ValidateBytePos;
  FOldCharPos := FCharPos;
  FOldLinePos := FLinePos;
end;

procedure TSynEditCaret.DoUnlock;
begin
  if not FChangeOnTouch then
    FTouched := False;
  FChangeOnTouch := False;
  ValidateCharPos;
  //ValidateBytePos;
  if (FOldCharPos <> FCharPos) or (FOldLinePos <> FLinePos) or FTouched then
    fOnChangeList.CallNotifyEvents(self);
  // All notifications called, reset oldpos
  FTouched := False;
  FOldCharPos := FCharPos;
  FOldLinePos := FLinePos;
end;

procedure TSynEditCaret.SetLines(const AValue: TSynEditStrings);
begin
  if FLines = AValue then exit;
  // Do not check flag. It will be cleared in Assign
  if (FLines <> nil) then
    FLines.RemoveEditHandler(@DoLinesEdited);
  FLinesEditedRegistered := False;
  inherited SetLines(AValue);
  if FAutoMoveOnEdit > 0 then
    RegisterLinesEditedHandler;
end;

procedure TSynEditCaret.RegisterLinesEditedHandler;
begin
  if FLinesEditedRegistered or (FLines = nil) then
    exit;
  FLinesEditedRegistered := True;
  FLines.AddEditHandler(@DoLinesEdited);
end;

procedure TSynEditCaret.DoLinesEdited(Sender: TSynEditStrings; aLinePos, aBytePos, aCount,
  aLineBrkCnt: Integer; aText: String);
  // Todo: refactor / this is a copy from selection
  function AdjustPoint(aPoint: Tpoint): TPoint; inline;
  begin
    Result := aPoint;
    if aLineBrkCnt < 0 then begin
      (* Lines Deleted *)
      if aPoint.y > aLinePos then begin
        Result.y := Max(aLinePos, Result.y + aLineBrkCnt);
        if Result.y = aLinePos then
          Result.x := Result.x + aBytePos - 1;
      end;
    end
    else
    if aLineBrkCnt > 0 then begin
      (* Lines Inserted *)
      if (aPoint.y = aLinePos) and (aPoint.x >= aBytePos) then begin
        Result.x := Result.x - aBytePos + 1;
        Result.y := Result.y + aLineBrkCnt;
      end;
      if aPoint.y > aLinePos then begin
        Result.y := Result.y + aLineBrkCnt;
      end;
    end
    else
    if aCount <> 0 then begin
      (* Chars Insert/Deleted *)
      if (aPoint.y = aLinePos) and (aPoint.x >= aBytePos) then
        Result.x := Max(aBytePos, Result.x + aCount);
    end;
  end;

var
  p: TPoint;
begin
  if (FAutoMoveOnEdit > 0) and
     ( (aLineBrkCnt <> 0) or (aLinePos = FLinePos) )
  then begin
    IncForcePastEOL;
    ValidateBytePos;
    p :=  AdjustPoint(Point(FBytePos, FLinePos));
    InternalSetLineByterPos(p.y, p.x, FBytePosOffset, [scuChangedX, scuChangedY, scuForceSet]);
    DecForcePastEOL;
  end;
end;

procedure TSynEditCaret.AdjustToChar;
var
  CharWidthsArr: TPhysicalCharWidths;
  CharWidths: PPhysicalCharWidth;
  i, LogLen: Integer;
  ScreenPos: Integer;
  LogPos: Integer;
  L: String;
begin
  ValidateCharPos;
  L := LineText;
  if FLines.LogPhysConvertor.CurrentLine = FLinePos then begin
    CharWidths := FLines.LogPhysConvertor.CurrentWidths;
    LogLen     := FLines.LogPhysConvertor.CurrentWidthsCount;
  end
  else begin
    CharWidthsArr := FLines.GetPhysicalCharWidths(Pchar(L), length(L), FLinePos-1);
    LogLen        := Length(CharWidthsArr);
    if LogLen > 0 then
      CharWidths := @CharWidthsArr[0];
  end;

  ScreenPos := 1;
  LogPos := 0;

  while LogPos < LogLen do begin
    if ScreenPos = FCharPos then exit;
    if ScreenPos + (CharWidths[LogPos] and PCWMask) > FCharPos then begin
      if (L[LogPos+1] = #9) and (not FSkipTabs) then exit;
      i := FCharPos;
      if FAdjustToNextChar or (FForceAdjustToNextChar > 0) then
        FCharPos := ScreenPos + (CharWidths[LogPos] and PCWMask)
      else
        FCharPos := ScreenPos;
      if FCharPos <> i then
        Exclude(FFlags, scBytePosValid);
      exit;
    end;
    ScreenPos := ScreenPos + (CharWidths[LogPos] and PCWMask);
    inc(LogPos);
  end;
end;

function TSynEditCaret.GetMaxLeftPastEOL: Integer;
begin
  if FMaxLeftChar <> nil then
    Result := FMaxLeftChar()
  else
    Result := MaxInt;
end;

procedure TSynEditCaret.InternalSetLineCharPos(NewLine, NewCharPos: Integer;
  UpdFlags: TSynEditCaretUpdateFlags);
var
  LogEolPos, MaxPhysX, NewLogCharPos, Offs: Integer;
  L: String;
begin
  if not (scuChangedX in UpdFlags) and FKeepCaretX then
    NewCharPos := FLastCharPos;

  Lock;
  FTouched := True;
  try
    if (fCharPos = NewCharPos) and (fLinePos = NewLine) and
       (scCharPosValid in FFlags) and not (scuForceSet in UpdFlags)
    then begin
      // Lines may have changed, so the other pos can be invalid
      if not (scuNoInvalidate in UpdFlags) then
        Exclude(FFlags, scBytePosValid);
      exit;
    end;

    if NewLine > FLines.Count then begin
      NewLine := FLines.Count;
      Exclude(UpdFlags, scuNoInvalidate);
    end;

    if NewLine < 1 then begin // Only allowed, if Lines.Count = 0
      NewLine := 1;
      if (NewCharPos > 1) and (FAllowPastEOL or (FForcePastEOL > 0))
      then MaxPhysX := GetMaxLeftPastEOL
      else MaxPhysX := 1;

      if NewCharPos > MaxPhysX then
        NewCharPos := MaxPhysX;

      NewLogCharPos := NewCharPos;
      Offs := 0;
      Exclude(UpdFlags, scuNoInvalidate);
    end else begin
      if FAdjustToNextChar or (FForceAdjustToNextChar > 0) then
        NewLogCharPos := Lines.LogPhysConvertor.PhysicalToLogical(NewLine-1, NewCharPos, Offs, cspDefault, [lpfAdjustToNextChar])
      else
        NewLogCharPos := Lines.LogPhysConvertor.PhysicalToLogical(NewLine-1, NewCharPos, Offs, cspDefault, [lpfAdjustToCharBegin]);
      Offs := Lines.LogPhysConvertor.UnAdjustedPhysToLogColOffs;
      L := Lines[NewLine - 1];

      if (Offs > 0) and (not FSkipTabs) and (L[NewLogCharPos] = #9) then begin
        // get the unadjusted result
        NewLogCharPos  := Lines.LogPhysConvertor.UnAdjustedPhysToLogResult
      end
      else begin
        // get adjusted Result
        NewCharPos := Lines.LogPhysConvertor.AdjustedPhysToLogOrigin;
        Offs := 0;
      end;

      LogEolPos := length(L)+1;
      if NewLogCharPos > LogEolPos then begin
        if FAllowPastEOL or (FForcePastEOL > 0) then begin
          MaxPhysX := GetMaxLeftPastEOL;
          if NewCharPos > MaxPhysX then begin
            NewLogCharPos := NewLogCharPos - (NewCharPos - MaxPhysX);
            NewCharPos := MaxPhysX;
            Exclude(UpdFlags, scuNoInvalidate);
          end;
        end
        else begin
          NewCharPos := NewCharPos - (NewLogCharPos - LogEolPos);
          NewLogCharPos := LogEolPos;
          Exclude(UpdFlags, scuNoInvalidate);
        end;
      end;

    end;

    if NewCharPos < 1 then begin
      NewCharPos := 1;
      Exclude(UpdFlags, scuNoInvalidate);
    end;

    inherited InternalSetLineCharPos(NewLine, NewCharPos, UpdFlags);
    inherited InternalSetLineByterPos(NewLine, NewLogCharPos, Offs, [scuNoInvalidate, scuChangedX]);

    if (scuChangedX in UpdFlags) or (not FKeepCaretX) then
      FLastCharPos := FCharPos;
  finally
    Unlock;
  end;
end;

procedure TSynEditCaret.InternalSetLineByterPos(NewLine, NewBytePos, NewByteOffs: Integer;
  UpdFlags: TSynEditCaretUpdateFlags);
var
  MaxPhysX, NewCharPos, LogEolPos: Integer;
  L: String;
begin
  if not (scuChangedX in UpdFlags) and FKeepCaretX then begin
    Exclude(UpdFlags, scuNoInvalidate);
    InternalSetLineCharPos(NewLine, FLastCharPos, UpdFlags);
    exit;
  end;

  Lock;
  FTouched := True;
  try
    if (FBytePos = NewBytePos) and (FBytePosOffset = NewByteOffs) and
       (FLinePos = NewLine) and (scBytePosValid in FFlags) and not (scuForceSet in UpdFlags)
    then begin
      // Lines may have changed, so the other pos can be invalid
      if not (scuNoInvalidate in UpdFlags) then
        Exclude(FFlags, scCharPosValid);
      exit;
    end;

    if NewLine > FLines.Count then begin
      NewLine := FLines.Count;
      Exclude(UpdFlags, scuNoInvalidate);
    end;

    if NewLine < 1 then begin // Only allowed, if Lines.Count = 0
      L := '';
      NewLine := 1;
      LogEolPos := 1;
      if (NewBytePos > 1) and (FAllowPastEOL or (FForcePastEOL > 0))
      then MaxPhysX := GetMaxLeftPastEOL
      else MaxPhysX := 1;
      if NewBytePos > MaxPhysX then
        NewBytePos := MaxPhysX;
      NewByteOffs := 0;
      NewCharPos := NewBytePos;
      Exclude(UpdFlags, scuNoInvalidate);
    end else begin
      L := Lines[NewLine - 1];
      LogEolPos := length(L)+1;

      if (NewBytePos > LogEolPos) then begin
        if not(FAllowPastEOL or (FForcePastEOL > 0)) then
          NewBytePos := LogEolPos;
        NewByteOffs := 0;
      end
      else
      if (NewByteOffs > 0) and ( (FSkipTabs) or (L[NewBytePos] <> #9) ) then
        NewByteOffs := 0;


      if FAdjustToNextChar or (FForceAdjustToNextChar > 0) then
        NewCharPos := Lines.LogPhysConvertor.LogicalToPhysical(NewLine-1, NewBytePos, NewByteOffs, cslDefault, [lpfAdjustToNextChar])
      else
        NewCharPos := Lines.LogPhysConvertor.LogicalToPhysical(NewLine-1, NewBytePos, NewByteOffs, cslDefault, [lpfAdjustToCharBegin]);
      NewBytePos := Lines.LogPhysConvertor.AdjustedLogToPhysOrigin;

      if (NewBytePos > LogEolPos) then begin
        MaxPhysX := GetMaxLeftPastEOL;
        if NewCharPos > MaxPhysX then begin
          NewBytePos := NewBytePos - (NewCharPos - MaxPhysX);
          NewCharPos := MaxPhysX;
          Exclude(UpdFlags, scuNoInvalidate);
        end;
      end;

    end;

    if NewBytePos < 1 then begin
      NewBytePos := 1;
      Exclude(UpdFlags, scuNoInvalidate);
    end;

    inherited InternalSetLineByterPos(NewLine, NewBytePos, NewByteOffs, UpdFlags);
    inherited InternalSetLineCharPos(NewLine, NewCharPos, [scuNoInvalidate, scuChangedX]);

    if (scuChangedX in UpdFlags) and FKeepCaretX then
      FLastCharPos := FCharPos;
  finally
    Unlock;
  end;
end;

function TSynEditCaret.GetOldLineCharPos: TPoint;
begin
  Result := Point(FOldCharPos, FOldLinePos);
end;

function TSynEditCaret.GetOldLineBytePos: TPoint;
begin
  Result := FLines.PhysicalToLogicalPos(OldLineCharPos);
end;

function TSynEditCaret.GetOldFullLogicalPos: TLogCaretPoint;
begin
  Result.Y := FOldLinePos;
  Result.X := FLines.LogPhysConvertor.PhysicalToLogical(ToIdx(FOldLinePos), FOldCharPos, Result.Offs);
end;

procedure TSynEditCaret.SetAllowPastEOL(const AValue: Boolean);
begin
  if FAllowPastEOL = AValue then exit;
  FAllowPastEOL := AValue;
  if not FAllowPastEOL then begin
    // TODO: this would set x=LastX
    //if scBytePosValid in FFlags then
    //  InternalSetLineByterPos(FLinePos, FBytePos, FBytePosOffset, [scuForceSet]); // NO scuChangedX => FLastCharPos is kept
    //else
    ValidateCharPos;
    InternalSetLineCharPos(FLinePos, FCharPos, [scuForceSet]); // NO scuChangedX => FLastCharPos is kept
  end;
end;

procedure TSynEditCaret.SetKeepCaretX(const AValue: Boolean);
begin
  if FKeepCaretX = AValue then exit;
  FKeepCaretX := AValue;
  if FKeepCaretX then begin
    ValidateCharPos;
    FLastCharPos := FCharPos;
  end;
end;

procedure TSynEditCaret.SetSkipTabs(const AValue: Boolean);
begin
  if FSkipTabs = AValue then exit;
  FSkipTabs := AValue;
  if FSkipTabs then begin
    Lock;
    AdjustToChar;
    Unlock;
  end;
end;

procedure TSynEditCaret.IncForcePastEOL;
begin
  inc(FForcePastEOL);
end;

procedure TSynEditCaret.DecForcePastEOL;
begin
  dec(FForcePastEOL);
end;

procedure TSynEditCaret.IncForceAdjustToNextChar;
begin
  Inc(FForceAdjustToNextChar);
end;

procedure TSynEditCaret.DecForceAdjustToNextChar;
begin
  Dec(FForceAdjustToNextChar);
end;

procedure TSynEditCaret.IncAutoMoveOnEdit;
begin
  if FAutoMoveOnEdit = 0 then begin
    RegisterLinesEditedHandler;
    ValidateBytePos;
  end;
  inc(FAutoMoveOnEdit);
end;

procedure TSynEditCaret.DecAutoMoveOnEdit;
begin
  dec(FAutoMoveOnEdit);
end;

procedure TSynEditCaret.ChangeOnTouch;
begin
  FChangeOnTouch := True;
  if not Locked then
    FTouched := False;
end;

procedure TSynEditCaret.Touch(aChangeOnTouch: Boolean);
begin
  if aChangeOnTouch then
    ChangeOnTouch;
  FTouched := True;
end;


function TSynEditCaret.WasAtLineChar(aPoint: TPoint): Boolean;
begin
  Result := (FOldLinePos = aPoint.y) and (FOldCharPos = aPoint.x);
end;

function TSynEditCaret.WasAtLineByte(aPoint: TPoint): Boolean;
begin
  Result := (FOldLinePos = aPoint.y) and
            (FLines.PhysicalToLogicalPos(Point(FOldCharPos, FOldLinePos)).X = aPoint.x);
end;

function TSynEditCaret.MoveHoriz(ACount: Integer): Boolean;
var
  L: String;
  CharWidths: TPhysicalCharWidths;
  GotCharWidths: Boolean;
  MaxOffs: Integer;
  p: Integer;
  NC: Boolean;
  NF: Integer;

  function GetMaxOffs(AlogPos: Integer): Integer;
  begin
    if not GotCharWidths then
      CharWidths := FLines.GetPhysicalCharWidths(Pchar(L), length(L), FLinePos-1);
    GotCharWidths := True;
    Result := CharWidths[AlogPos-1];
  end;

begin
  GotCharWidths := False;
  L := LineText;
  ValidateBytePos;

  If ACount > 0 then begin
    if (FBytePos <= length(L)) and (L[FBytePos] = #9) and (not FSkipTabs) then
      MaxOffs := GetMaxOffs(FBytePos) - 1
    else
      MaxOffs := 0;

    while ACount > 0 do begin
      if FBytePosOffset < MaxOffs then
        inc(FBytePosOffset)
      else begin
        if (FBytePos > length(L)) and not (FAllowPastEOL or (FForcePastEOL > 0)) then
          break;
        FBytePos := FLines.LogicPosAddChars(L, FBytePos, 1, True);
        FBytePosOffset := 0;
        if (FBytePos <= length(L)) and (L[FBytePos] = #9) and (not FSkipTabs) then
          MaxOffs := GetMaxOffs(FBytePos) - 1
        else
          MaxOffs := 0;
      end;
      dec(ACount);
    end;
    Result := ACount = 0;

    p := FBytePos;
    IncForceAdjustToNextChar;
    InternalSetLineByterPos(FLinePos, FBytePos, FBytePosOffset, [scuChangedX, scuForceSet]);
    DecForceAdjustToNextChar;
    if p > FBytePos then
      Result := False; // MaxLeftChar
  end
  else begin
    while ACount < 0 do begin
      if FBytePosOffset > 0 then
        dec(FBytePosOffset)
      else begin
        if FBytePos = 1 then
          break;
        FBytePos := FLines.LogicPosAddChars(L, FBytePos, -1, True);
        if (FBytePos <= length(L)) and (L[FBytePos] = #9) and (not FSkipTabs) then
          FBytePosOffset := GetMaxOffs(FBytePos) - 1
        else
          FBytePosOffset := 0;
      end;
      inc(ACount);
    end;
    Result := ACount = 0;

    NC := FAdjustToNextChar;
    NF := FForceAdjustToNextChar;
    FAdjustToNextChar      := False;
    FForceAdjustToNextChar := 0;
    InternalSetLineByterPos(FLinePos, FBytePos, FBytePosOffset, [scuChangedX, scuForceSet]);
    FAdjustToNextChar      := NC;
    FForceAdjustToNextChar := NF;
  end;
end;

{ TSynEditSelection }

constructor TSynEditSelection.Create(ALines : TSynEditStrings; aActOnLineChanges: Boolean);
begin
  Inherited Create(ALines);
  FOnBeforeSetSelText := TSynBeforeSetSelTextList.Create;
  FInternalCaret := TSynEditBaseCaret.Create;
  FInternalCaret.Lines := FLines;

  FActiveSelectionMode := smNormal;
  FStartLinePos := 1;
  FStartBytePos := 1;
  FAltStartLinePos := -1;
  FAltStartBytePos := -1;
  FEndLinePos := 1;
  FEndBytePos := 1;
  FEnabled := True;
  FHookedLines := aActOnLineChanges;
  FIsSettingText := False;
  if FHookedLines then begin
    FLines.AddEditHandler(@DoLinesEdited);
    FLines.AddChangeHandler(senrLineChange, @LineChanged);
  end;
end;

destructor TSynEditSelection.Destroy;
begin
  FreeAndNil(FOnBeforeSetSelText);
  FreeAndNil(FInternalCaret);
  if FHookedLines then begin
    FLines.RemoveEditHandler(@DoLinesEdited);
    FLines.RemoveChangeHandler(senrLineChange, @LineChanged);
  end;
  inherited Destroy;
end;

procedure TSynEditSelection.AssignFrom(Src: TSynEditSelection);
begin
  //FEnabled             := src.FEnabled;
  FHide                := src.FHide;
  FActiveSelectionMode := src.FActiveSelectionMode;
  FSelectionMode       := src.FSelectionMode;
  FStartLinePos        := src.FStartLinePos; // 1 based
  FStartBytePos        := src.FStartBytePos; // 1 based
  FEndLinePos          := src.FEndLinePos; // 1 based
  FEndBytePos          := src.FEndBytePos; // 1 based
  FPersistent          := src.FPersistent;
end;

procedure TSynEditSelection.AdjustAfterTrimming;
begin
  if FStartBytePos > Length(FLines[FStartLinePos-1]) + 1 then
    FStartBytePos := Length(FLines[FStartLinePos-1]) + 1;
  if FEndBytePos > Length(FLines[FEndLinePos-1]) + 1 then
    FEndBytePos := Length(FLines[FEndLinePos-1]) + 1;
  // Todo: Call ChangeNotification
end;

procedure TSynEditSelection.DoLock;
begin
  inherited DoLock;
  FLastCarePos := Point(-1, -1);
end;

procedure TSynEditSelection.DoUnlock;
begin
  inherited DoUnlock;
  FLastCarePos := Point(-1, -1);
end;

function TSynEditSelection.GetSelText : string;

  function CopyPadded(const S: string; Index, Count: integer): string;
  var
    SrcLen: Integer;
    DstLen: integer;
    P: PChar;
  begin
    SrcLen := Length(S);
    DstLen := Index + Count;
    if SrcLen >= DstLen then
      Result := Copy(S, Index, Count)
    else begin
      SetLength(Result, DstLen);
      P := PChar(Pointer(Result));
      StrPCopy(P, Copy(S, Index, Count));
      Inc(P, SrcLen);
      FillChar(P^, DstLen - Srclen, $20);
    end;
  end;

  procedure CopyAndForward(const S: string; Index, Count: Integer; var P:
    PChar);
  var
    pSrc: PChar;
    SrcLen: Integer;
    DstLen: Integer;
  begin
    SrcLen := Length(S);
    if (Index <= SrcLen) and (Count > 0) then begin
      Dec(In…