TSpStringList - Enhanced Delphi String List

uSpStringList.pas

unit uSpStringList;

interface

uses
  System.SysUtils,
  System.Classes;

type
  { TSpStringList }
  TSpStringList = class(TStringList)
  protected
    function ValidIndex(aIndex: Integer): Boolean;
  public
    function GetLineIndex(aOccurrence: Cardinal; const aLine: string): Integer;
    function ReplaceLine(aOccurrence: Cardinal; const aOldLine: string; const aNewLine: string; aOffset: Integer): Boolean;
    function RemoveLines(aOccurrence: Cardinal; const aReferenceLine: string; aOffset: Integer; aCount: Cardinal): Boolean;
    function InsertLine(aOccurrence: Cardinal; const aReferenceLine: string; aOffset: Integer; const aNewLine: string): Boolean;
  end;
  
implementation
  
uses
  System.StrUtils;
  
{ TSpStringList }
function TSpStringList.ValidIndex(aIndex: Integer): Boolean;
begin
  Result := False;
  if aIndex < 0 then Exit;
  if aIndex > Self.Count-1 then Exit;
  Result := True;
end;

function TSpStringList.GetLineIndex(aOccurrence: Cardinal; const aLine: string): Integer;
var
  LIndex: Integer;
  LText: string;
  LOccurence: Cardinal;
begin
  Result := -1;
  if aOccurrence = 0 then Exit;
  LOccurence := 0;
  for LIndex := 0 to Self.Count-1 do
  begin
    LText := Self[LIndex].Trim;
    if SameText(aLine, LText) then
    begin
      Inc(LOccurence);
      if LOccurance = aOccurence then
      begin
        Result := LIndex;
        Exit;
      end;
    end;
  end;
end;

function TSpStringList.ReplaceLine(aOccurence: Cardinal; const aOldLine: string; const aNewLine: string; aOffset: Integer): Boolean;
var
  LIndex: Integer;
begin
  Result := False;
  LIndex := GetLineIndex(aOccurance, aOldLine);
  if LIndex = -1 then Exit;
  LIndex := LIndex + aOffset;
  if not ValidIndex(LIndex) then Exit;
  Self[LIndex] := aNewLine;
  Result := True;
end;

function TSpStringList.RemoveLines(aOccurence: Cardinal; const aReferenceLine: string; aOffset: Integer; aCount: Cardinal): Boolean;
var
  LIndex: Integer;
  LStartIndex: Integer;
begin
  LStartIndex := GetLineIndex(aOccurance, aReferenceLine);
  if LStartIndex = -1 then Exit;
  LStartIndex := LStartIndex + aOffset;
  if not ValidIndex(LStartIndex) then Exit;
  for LIndex := 1 to aCount do
    Self.Delete(LStartIndex);
  Result := True;
end;

function TSpStringList.InsertLine(aOccurence: Cardinal; const aReferenceLine: string; aOffset: Integer; const aNewLine: string): Boolean;
var
  LIndex: Integer;
begin
  Result := False;
  LIndex := GetLineIndex(aOccurance, aReferenceLine);
  if LIndex = -1 then Exit;
  LIndex := LIndex + aOffset;
  if not ValidIndex(LIndex) then Exit;
  Self.Insert(LIndex, aNewLine)
end;  
  
end.