lazarus/lcl/textstrings.pas
2009-02-20 11:14:43 +00:00

724 lines
20 KiB
ObjectPascal

{
/***************************************************************************
textstrings.pas
---------------
Component Library Code
***************************************************************************/
*****************************************************************************
* *
* This file is part of the Lazarus Component Library (LCL) *
* *
* See the file COPYING.modifiedLGPL.txt, included in this distribution, *
* for details about the copyright. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *
* *
*****************************************************************************
TTextStrings is a TStrings descendent that is optimized for handling the
complete text as whole (instead of as line by line as in TStringList).
}
unit TextStrings;
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, LCLStrConsts;
type
{ TTextStrings }
TTextLineRange = record
StartPos: integer; // start of line in Text
EndPos: integer; // end of line in Text (= start of newline character(s))
Line: string; // cached line as string
TheObject: TObject; // user data
end;
TTextStrings = class(TStrings)
private
FOnChange: TNotifyEvent;
FOnChanging: TNotifyEvent;
protected
FArraysValid: boolean;
FLineCount: integer;
FLineCapacity: integer;
FLineRanges: ^TTextLineRange;// array of TTextLineRange
FText: string;
FUpdateCount: integer;
FChangedWhileUpdate: boolean;
function GetTextStr: string; override;
procedure SetTextStr(const AValue: string); override;
procedure BuildArrays; virtual;
function GetCount: Integer; override;
procedure Changed; virtual;
procedure Changing; virtual;
function Get(Index: Integer): string; override;
procedure ClearArrays;
function GetObject(Index: Integer): TObject; override;
procedure Put(Index: Integer; const S: string); override;
procedure PutObject(Index: Integer; AnObject: TObject); override;
function GetLineLen(Index: integer; IncludeNewLineChars: boolean): integer; inline;
function GetLineEnd(Index: integer; IncludeNewLineChars: boolean): integer;
function HasObjects: boolean;
function CountLineEndings(const s: string): integer;
public
destructor Destroy; override;
procedure Clear; override;
procedure SetText(TheText: PChar); override;
procedure Insert(Index: Integer; const S: string); override;
procedure Delete(Index: Integer); override;
procedure Exchange(Index1, Index2: Integer); override;
procedure Move(CurIndex, NewIndex: Integer); override;
procedure MakeTextBufferUnique;
procedure BeginUpdate;
procedure EndUpdate;
function GetText: PChar; override;
function IndexOf(const S: string): Integer; override;
function Add(const S: string): Integer; override;
function AddObject(const S: string; AObject: TObject): Integer; override;
procedure AddStrings(TheStrings: TStrings); override;
public
property Text: string read FText write SetTextStr;
property OnChange: TNotifyEvent read FOnChange write FOnChange;
property OnChanging: TNotifyEvent read FOnChanging write FOnChanging;
end;
implementation
{ TTextStrings }
function TTextStrings.GetTextStr: string;
begin
Result:=FText;
end;
procedure TTextStrings.SetTextStr(const AValue: string);
begin
if FText=AValue then exit;
FText:=AValue;
FArraysValid:=false;
end;
procedure TTextStrings.BuildArrays;
var
p, line: integer;
l: Integer;
ArraySize: Integer;
begin
if FArraysValid then exit;
ClearArrays;
FArraysValid:=true;
// count line ends
FLineCount:=CountLineEndings(FText);
l:=length(FText);
if (FText<>'') and (not (FText[l] in [#10,#13])) then
inc(FLineCount);
FLineCapacity:=FLineCount;
// build line range list
if FLineCount>0 then begin
ArraySize:=FLineCount*SizeOf(TTextLineRange);
GetMem(FLineRanges,ArraySize);
FillChar(FLineRanges^,ArraySize,0);
p:=1;
line:=0;
FLineRanges[line].StartPos:=1;
FLineRanges[FLineCount-1].EndPos:=l+1;
while (p<=l) do begin
if (not (FText[p] in [#10,#13])) then begin
inc(p);
end else begin
// new line
FLineRanges[line].EndPos:=p;
inc(line);
inc(p);
if (p<=l) and (FText[p] in [#10,#13])
and (FText[p]<>FText[p-1]) then
inc(p);
if line<FLineCount then
FLineRanges[line].StartPos:=p;
end;
end;
end;
end;
function TTextStrings.GetCount: Integer;
begin
if not FArraysValid then BuildArrays;
Result:=FLineCount;
end;
procedure TTextStrings.Changed;
// called after text changed
begin
if (FUpdateCount>0) then begin
FChangedWhileUpdate:=true;
exit;
end;
if Assigned(FOnChange) then
FOnChange(Self);
end;
procedure TTextStrings.Changing;
begin
if FUpdateCount=0 then
if Assigned(FOnChanging) then
FOnChanging(Self);
end;
function TTextStrings.Get(Index: Integer): string;
begin
if not FArraysValid then BuildArrays;
if (Index<0) or (Index>=FLineCount) then
Error(rsListIndexExceedsBounds, Index);
if (FLineRanges[Index].Line='')
and (FLineRanges[Index].StartPos<FLineRanges[Index].EndPos) then begin
FLineRanges[Index].Line:=copy(FText,FLineRanges[Index].StartPos,
FLineRanges[Index].EndPos-FLineRanges[Index].StartPos);
end;
Result:=FLineRanges[Index].Line;
end;
procedure TTextStrings.ClearArrays;
var
i: Integer;
begin
FArraysValid:=false;
if FLineRanges<>nil then begin
for i:=0 to FLineCount-1 do
FLineRanges[i].Line:='';
FreeMem(FLineRanges);
FLineRanges:=nil;
end;
FLineCapacity:=0;
end;
function TTextStrings.GetObject(Index: Integer): TObject;
begin
if FArraysValid then
Result:=FLineRanges[Index].TheObject
else
Result:=nil;
end;
procedure TTextStrings.Put(Index: Integer; const S: string);
var
OldLineLen: Integer;
NewLineLen: Integer;
Movement: Integer;
OldStartPos: LongInt;
OldEndPos: LongInt;
MoveLen: Integer;
i: Integer;
NewEndPos: Integer;
begin
if not FArraysValid then BuildArrays;
OldStartPos:=FLineRanges[Index].StartPos;
OldEndPos:=FLineRanges[Index].EndPos;
NewLineLen:=length(s);
OldLineLen:=OldEndPos-OldStartPos;
Movement:=NewLineLen-OldLineLen;
NewEndPos:=OldEndPos+Movement;
// move text behind
MoveLen:=length(FText)-OldEndPos;
if (Movement<>0) and (MoveLen>0) then begin
SetLength(FText,length(FText)+Movement);
System.Move(FText[OldEndPos],FText[NewEndPos],MoveLen);
for i:=Index+1 to FLineCount-1 do begin
inc(FLineRanges[i].StartPos,Movement);
inc(FLineRanges[i].EndPos,Movement);
end;
end;
FLineRanges[Index].EndPos:=NewEndPos;
// copy text
if NewLineLen>0 then
System.Move(S[1],FText[OldStartPos],NewLineLen);
FLineRanges[Index].Line:=S;
// check if arrays need rebuild
i:=NewLineLen;
while (i>0) and (not (S[i] in [#10,#13])) do dec(i);
if i>0 then begin
// S contains new line chars => rebuild needed
FArraysValid:=false;
end;
end;
procedure TTextStrings.PutObject(Index: Integer; AnObject: TObject);
begin
if not FArraysValid then BuildArrays;
FLineRanges[Index].TheObject:=AnObject;
end;
function TTextStrings.GetLineLen(Index: integer; IncludeNewLineChars: boolean
): integer;
begin
Result:=GetLineEnd(Index,IncludeNewLineChars)-FLineRanges[Index].StartPos;
end;
function TTextStrings.GetLineEnd(Index: integer; IncludeNewLineChars: boolean
): integer;
begin
if not FArraysValid then BuildArrays;
if not IncludeNewLineChars then
Result:=FLineRanges[Index].EndPos
else if Index=FLineCount-1 then
Result:=length(FText)+1
else
Result:=FLineRanges[Index+1].StartPos;
end;
function TTextStrings.HasObjects: boolean;
var
i: Integer;
begin
if FArraysValid then
for i:=0 to FLineCount-1 do
if FLineRanges[i].TheObject<>nil then
exit(true);
Result:=false;
end;
function TTextStrings.CountLineEndings(const s: string): integer;
var
p: Integer;
l: Integer;
begin
Result:=0;
l:=length(s);
p:=1;
while p<=l do begin
if s[p] in [#10,#13] then
begin
inc(Result);
inc(p);
if (p<=l) and (s[p] in [#10,#13]) and (s[p-1]<>s[p]) then
inc(p);
end else begin
inc(p);
end;
end;
end;
destructor TTextStrings.Destroy;
begin
Clear;
inherited Destroy;
end;
procedure TTextStrings.Clear;
begin
ClearArrays;
FLineCount:=0;
FText:='';
end;
procedure TTextStrings.SetText(TheText: PChar);
begin
if FText=TheText then exit;
FText:=TheText;
FArraysValid:=false;
end;
procedure TTextStrings.Insert(Index: Integer; const S: string);
var
NewStartPos: Integer;
NewLineCharCount: Integer;
NewLineLen: Integer;
i: Integer;
SEndsInNewLine: boolean;
begin
if not FArraysValid then BuildArrays;
NewLineLen:=length(S);
SEndsInNewLine:=(S<>'') and (S[NewLineLen] in [#10,#13]);
if Index<FLineCount then
NewStartPos:=FLineRanges[Index].StartPos
else
NewStartPos:=length(FText);
NewLineCharCount:=0;
if SEndsInNewLine then begin
inc(NewLineCharCount);
if (NewLineLen>1)
and (S[NewLineLen-1] in [#10,#13])
and (S[NewLineLen-1]<>S[NewLineLen]) then
inc(NewLineCharCount);
System.Insert(S,FText,NewStartPos);
end else begin
// append missing newline char
System.Insert(S+LineEnding,FText,NewStartPos);
NewLineCharCount:=length(LineEnding);
inc(NewLineLen,NewLineCharCount);
end;
// adjust arrays
if FLineCount=FLineCapacity then begin
if FLineCapacity<8 then
FLineCapacity:=8
else
FLineCapacity:=FLineCapacity shl 1;
ReAllocMem(FLineRanges,SizeOf(TTextLineRange)*FLineCapacity);
end;
if Index<FLineCount then begin
System.Move(FLineRanges[Index],FLineRanges[Index+1],
(FLineCount-Index)*SizeOf(TTextLineRange));
for i:=Index+1 to FLineCount do begin
inc(FLineRanges[i].StartPos,NewLineLen);
inc(FLineRanges[i].EndPos,NewLineLen);
end;
end;
FLineRanges[Index].Line:=S;
FLineRanges[Index].EndPos:=NewStartPos+NewLineLen-NewLineCharCount;
inc(FLineCount);
end;
procedure TTextStrings.Delete(Index: Integer);
var
OldLineLen: Integer;
OldStartPos: Integer;
i: Integer;
begin
if not FArraysValid then BuildArrays;
// adjust text
OldLineLen:=GetLineLen(Index,true);
if OldLineLen>0 then begin
OldStartPos:=FLineRanges[Index].StartPos;
System.Delete(FText,OldStartPos,OldLineLen);
end;
// adjust arrays
dec(FLineCount);
FLineRanges[Index].Line:='';
if Index<FLineCount then begin
System.Move(FLineRanges[Index+1],FLineRanges[Index],
(FLineCount-Index)*SizeOf(TTextLineRange));
for i:=Index to FLineCount-1 do begin
dec(FLineRanges[i].StartPos,OldLineLen);
dec(FLineRanges[i].EndPos,OldLineLen);
end;
end;
end;
procedure TTextStrings.Exchange(Index1, Index2: Integer);
var
LineLen1: Integer;
LineLen2: Integer;
buf: Pointer;
Dummy: Integer;
OldBetweenStart: Integer;
NewBetweenStart: Integer;
BetweenLength: Integer;
StartPos1: LongInt;
StartPos2: LongInt;
i: Integer;
Movement: Integer;
Obj: TObject;
LineShortLen1: LongInt;
LineShortLen2: LongInt;
begin
// check values
if Index1=Index2 then exit;
if Index1<0 then
Error(rsListIndexExceedsBounds, Index1);
if Index2<0 then
Error(rsListIndexExceedsBounds, Index2);
if not FArraysValid then BuildArrays;
if Index1>=FLineCount then
Error(rsListIndexExceedsBounds, Index1);
if Index2>=FLineCount then
Error(rsListIndexExceedsBounds, Index2);
// make sure Index1<Index2
if Index1>Index2 then begin
Dummy:=Index1;
Index1:=Index2;
Index2:=Dummy;
end;
// adjust text
MakeTextBufferUnique;
if (Index2=FLineCount-1) and (FLineRanges[Index2].EndPos=length(FText))
then begin
// The last line should be exchanged,
// but Text has no new line character(s) at the end
// => add LineEnding
FText:=FText+LineEnding;
end;
// get line lengths including new line chars
LineLen1:=GetLineLen(Index1,true);
LineLen2:=GetLineLen(Index2,true);
if (LineLen1<1) and (LineLen2<1) then exit;
LineShortLen1:=GetLineLen(Index1,false);
LineShortLen2:=GetLineLen(Index2,false);
// save the bigger line
StartPos1:=FLineRanges[Index1].StartPos;
StartPos2:=FLineRanges[Index2].StartPos;
if LineLen1>=LineLen2 then begin
GetMem(buf,LineLen1);
System.Move(FText[StartPos1],buf^,LineLen1);
end else begin
GetMem(buf,LineLen2);
System.Move(FText[StartPos2],buf^,LineLen2);
end;
// move text in between
OldBetweenStart:=StartPos1+LineLen1;
BetweenLength:=StartPos2-OldBetweenStart;
NewBetweenStart:=StartPos1+LineLen2;
if (BetweenLength>0) and (OldBetweenStart<>NewBetweenStart) then
System.Move(FText[OldBetweenStart],FText[NewBetweenStart],BetweenLength);
// move both lines
if LineLen1>=LineLen2 then begin
System.Move(FText[StartPos2],FText[StartPos1],LineLen2);
System.Move(buf^,FText[StartPos2],LineLen1);
end else begin
System.Move(FText[StartPos1],FText[StartPos2],LineLen1);
System.Move(buf^,FText[StartPos1],LineLen2);
end;
// adjust line ranges
Movement:=NewBetweenStart-OldBetweenStart;
FLineRanges[Index1].EndPos:=FLineRanges[Index1].StartPos+LineShortLen2;
inc(FLineRanges[Index2].StartPos,Movement);
FLineRanges[Index2].EndPos:=FLineRanges[Index2].StartPos+LineShortLen1;
if (BetweenLength>0) and (OldBetweenStart<>NewBetweenStart) then begin
for i:=Index1+1 to Index2-1 do begin
inc(FLineRanges[i].StartPos,Movement);
inc(FLineRanges[i].EndPos,Movement);
end;
end;
// exchange TheObject
Obj:=FLineRanges[Index1].TheObject;
FLineRanges[Index1].TheObject:=FLineRanges[Index2].TheObject;
FLineRanges[Index2].TheObject:=Obj;
// clean up
FreeMem(buf);
end;
procedure TTextStrings.Move(CurIndex, NewIndex: Integer);
var
SrcPos1: LongInt;
SrcPos2: LongInt;
SrcPos3: LongInt;
LineStr: String;
LineLen: Integer;
i: LongInt;
Obj: TObject;
LineShortLen: LongInt;
begin
// check values
if CurIndex=NewIndex then exit;
if CurIndex<0 then
Error(rsListIndexExceedsBounds, CurIndex);
if NewIndex<0 then
Error(rsListIndexExceedsBounds, NewIndex);
if not FArraysValid then BuildArrays;
if CurIndex>=FLineCount then
Error(rsListIndexExceedsBounds, CurIndex);
if NewIndex>=FLineCount then
Error(rsListIndexExceedsBounds, NewIndex);
// adjust text
MakeTextBufferUnique;
if CurIndex<NewIndex then
begin
// move to higher index
if (NewIndex=FLineCount-1) and (FLineRanges[NewIndex].EndPos>length(FText))
then begin
// CurIndex should be moved to the end,
// but Text has no new line character(s) at the end
// => add LineEnding
FText:=FText+LineEnding;
end;
SrcPos1:=FLineRanges[CurIndex].StartPos;
SrcPos2:=FLineRanges[CurIndex+1].StartPos;
SrcPos3:=GetLineEnd(NewIndex,true);
// store current line with line end
LineLen:=SrcPos2-SrcPos1;
LineShortLen:=GetLineLen(CurIndex,false);
LineStr:=copy(FText,SrcPos1,LineLen);
Obj:=FLineRanges[CurIndex].TheObject;
// move lines -1
System.Move(FText[SrcPos2],FText[SrcPos1],SrcPos3-SrcPos2);
for i:=CurIndex+1 to NewIndex do begin
dec(FLineRanges[i].StartPos,LineLen);
dec(FLineRanges[i].EndPos,LineLen);
end;
System.Move(FLineRanges[CurIndex+1],FLineRanges[CurIndex],
SizeOf(TTextLineRange)*(NewIndex-CurIndex));
// put current line at new position
i:=SrcPos3-LineLen;
System.Move(LineStr[1],FText[i],LineLen);
FLineRanges[NewIndex].StartPos:=i;
FLineRanges[NewIndex].EndPos:=i+LineShortLen;
FLineRanges[NewIndex].Line:=''; // this will be updated on demand
FLineRanges[NewIndex].TheObject:=Obj;
end else begin
// move to lower index
if (CurIndex=FLineCount-1) and (FLineRanges[CurIndex].EndPos>length(FText))
then begin
// CurIndex should be moved from the end,
// but Text has no new line character(s) at the end
// => add LineEnding
FText:=FText+LineEnding;
end;
SrcPos1:=FLineRanges[NewIndex].StartPos;
SrcPos2:=FLineRanges[CurIndex].StartPos;
SrcPos3:=GetLineEnd(CurIndex,true);
// store current line with line end
LineLen:=SrcPos3-SrcPos2;
LineShortLen:=GetLineLen(CurIndex,false);
LineStr:=copy(FText,SrcPos2,LineLen);
Obj:=FLineRanges[CurIndex].TheObject;
// move lines +1
System.Move(FText[SrcPos1],FText[SrcPos1+LineLen],SrcPos2-SrcPos1);
for i:=CurIndex-1 downto NewIndex do begin
inc(FLineRanges[i].StartPos,LineLen);
inc(FLineRanges[i].EndPos,LineLen);
end;
System.Move(FLineRanges[NewIndex],FLineRanges[NewIndex+1],
SizeOf(TTextLineRange)*(CurIndex-NewIndex));
// put current line at new position
System.Move(LineStr[1],FText[SrcPos1],LineLen);
FLineRanges[NewIndex].StartPos:=SrcPos1;
FLineRanges[NewIndex].EndPos:=SrcPos1+LineShortLen;
FLineRanges[NewIndex].Line:=''; // this will be updated on demand
FLineRanges[NewIndex].TheObject:=Obj;
end;
end;
procedure TTextStrings.MakeTextBufferUnique;
begin
// make string unique (refcount=1) to be able to edit it directly
UniqueString(FText);
end;
procedure TTextStrings.BeginUpdate;
begin
inc(FUpdateCount);
end;
procedure TTextStrings.EndUpdate;
procedure RaiseUpdateCount;
begin
raise Exception.Create('TTextStrings.EndUpdate');
end;
begin
if FUpdateCount<=0 then RaiseUpdateCount;
dec(FUpdateCount);
if FUpdateCount=0 then begin
if FChangedWhileUpdate then
Changed;
end;
end;
function TTextStrings.GetText: PChar;
begin
Result:=PChar(FText);
end;
function TTextStrings.IndexOf(const S: string): Integer;
begin
Result:=inherited IndexOf(S);
end;
function TTextStrings.Add(const S: string): Integer;
begin
Result:=AddObject(S,nil);
end;
function TTextStrings.AddObject(const S: string; AObject: TObject): Integer;
var
e: String;
NewLineCount: Integer;
OldTxtLen: Integer;
p: Integer;
l: Integer;
begin
Result:=Count;
if (FText<>'') and (not (FText[length(FText)] in [#10,#13])) then
e:=LineEnding
else
e:='';
OldTxtLen:=length(FText);
FText:=Text+e+S+LineEnding;
if AObject<>nil then
BuildArrays;
if FArraysValid then
begin
// update FLineRanges
NewLineCount:=FLineCount+CountLineEndings(S)+1;
if NewLineCount>FLineCapacity then begin
FLineCapacity:=FLineCapacity*2+10;
if FLineCapacity<NewLineCount then
FLineCapacity:=NewLineCount;
ReAllocMem(FLineRanges,SizeOf(TTextLineRange)*FLineCapacity);
FillByte(FLineRanges[FLineCount],SizeOf(TTextLineRange)*(FLineCapacity-FLineCount),0);
end;
FLineRanges[FLineCount].TheObject:=AObject;
p:=OldTxtLen+length(e)+1;
l:=length(FText);
while FLineCount<NewLineCount do begin
FLineRanges[FLineCount].StartPos:=p;
while (p<=l) and (not (FText[p] in [#10,#13])) do
inc(p);
FLineRanges[FLineCount].EndPos:=p;
inc(p);
if (p<=l) and (FText[p] in [#10,#13]) and (FText[p]<>FText[p-1]) then
inc(p);
inc(FLineCount);
end;
end;
end;
procedure TTextStrings.AddStrings(TheStrings: TStrings);
function MustAddObjects: boolean;
var
i: Integer;
begin
if HasObjects then exit(true);
if TheStrings is TTextStrings then
Result:=TTextStrings(TheStrings).HasObjects
else
begin
for i:=0 to TheStrings.Count-1 do
if TheStrings.Objects[i]<>nil then
exit(true);
Result:=false;
end;
end;
var
s: String;
i: Integer;
begin
if TheStrings.Count=0 then exit;
if MustAddObjects then
begin
for i:=0 to TheStrings.Count-1 do
AddObject(TheStrings[i],TheStrings.Objects[i]);
end else begin
if (FText<>'') and (not (FText[length(FText)] in [#10,#13])) then
s:=LineEnding
else
s:='';
FArraysValid:=false;
FText:=FText+s+TheStrings.Text;
end;
end;
end.