diff --git a/components/powerpdf/PdfDoc.pas b/components/powerpdf/PdfDoc.pas
index 0d7638b49..24b37e6c3 100644
--- a/components/powerpdf/PdfDoc.pas
+++ b/components/powerpdf/PdfDoc.pas
@@ -53,8 +53,6 @@ uses
   SysUtils, Classes
   {$IFDEF UNIX}
   , Types
-  {$ELSE}
-  , Windows
   {$ENDIF}
   {$IFDEF LAZ_POWERPDF}
   , LCLProc
@@ -275,7 +273,7 @@ type
 
   TPdfXref = class(TPdfObjectMgr)
   private
-    FXrefEntries: TList;
+    FXrefEntries: TFpList;
     function GetItem(ObjectID: integer): TPdfXrefEntry;
     function GetItemCount: integer;
   protected
@@ -309,8 +307,8 @@ type
     FXref: TPdfXref;
     FInfo: TPdfInfo;
     FHasDoc: boolean;
-    FFontList: TList;
-    FObjectList: TList;
+    FFontList: TFpList;
+    FObjectList: TFpList;
     FOutlineRoot: TPdfOutlineRoot;
     FXObjectList: TPdfArray;
     FDefaultPageWidth: Word;
@@ -325,21 +323,21 @@ type
     procedure CreateInfo;
     procedure CreateOutlines;
     function CreateCatalog: TPdfDictionary;
-    function CreateFont(FontName: string): TPdfFont;
+    function CreateFont(const FontName: string): TPdfFont;
     function CreatePages(Parent: TPdfDictionary): TPdfDictionary;
   public
-    procedure RegisterXObject(AObject: TPdfXObject; AName: string);
+    procedure RegisterXObject(AObject: TPdfXObject; const AName: string);
     constructor Create;
     destructor Destroy; override;
     procedure NewDoc;
     procedure FreeDoc;
     procedure AddPage;
-    procedure AddXObject(AName: string; AXObject: TPdfXObject);
+    procedure AddXObject(const AName: string; AXObject: TPdfXObject);
     procedure SaveToStream(AStream: TStream);
     procedure SetVirtualMode;
-    function GetFont(FontName: string): TPdfFont;
-    function GetXObject(AName: string): TPdfXObject;
-    function CreateAnnotation(AType: TPdfAnnotationSubType; ARect: TPdfRect): TPdfDictionary;
+    function GetFont(const FontName: string): TPdfFont;
+    function GetXObject(const AName: string): TPdfXObject;
+    function CreateAnnotation(AType: TPdfAnnotationSubType; const ARect: TPdfRect): TPdfDictionary;
     function CreateDestination: TPdfDestination;
     property HasDoc: boolean read FHasDoc;
     property Canvas: TPdfCanvas read GetCanvas;
@@ -392,7 +390,7 @@ type
     FIsVirtual: boolean;
     procedure SetPageWidth(AValue: integer);
     procedure SetPageHeight(AValue: integer);
-    procedure WriteString(S: string);
+    procedure WriteString(const S: string);
     function GetDoc: TPdfDoc;
     function GetPage: TPdfDictionary;
     function GetPageWidth: Integer;
@@ -441,7 +439,7 @@ type
     procedure SetWordSpace(wordSpace: Single);                   {  Tw  }
     procedure SetHorizontalScaling(hScaling: Word);              {  Tz  }
     procedure SetLeading(leading: Single);                       {  TL  }
-    procedure SetFontAndSize(fontname: string; size: Single);    {  Tf  }
+    procedure SetFontAndSize(const fontname: string; size: Single);    {  Tf  }
     procedure SetTextRenderingMode(mode: TTextRenderingMode);    {  Tr  }
     procedure SetTextRise(rise: Word);                           {  Ts  }
     procedure BeginText;                                         {  BT  }
@@ -449,11 +447,11 @@ type
     procedure MoveTextPoint(tx, ty: Single);                     {  Td  }
     procedure SetTextMatrix(a, b, c, d, x, y: Single);           {  Tm  }
     procedure MoveToNextLine;                                    {  T*  }
-    procedure ShowText(s: string);                               {  Tj  }
-    procedure ShowTextNextLine(s: string);                       {  '   }
+    procedure ShowText(const s: string);                               {  Tj  }
+    procedure ShowTextNextLine(const s: string);                       {  '   }
 
     {* external objects *}
-    procedure ExecuteXObject(xObject: string);                   {  Do  }
+    procedure ExecuteXObject(const xObject: string);                   {  Do  }
 
     {* Device-dependent color space operators *}
     procedure SetRGBFillColor(Value: TPdfColor);                 {  rg  }
@@ -461,16 +459,16 @@ type
 
     {* utility routines *}
     procedure SetPage(APage: TPdfDictionary);
-    procedure SetFont(AName: string; ASize: Single);
-    procedure TextOut(X, Y: Single; Text: string);
+    procedure SetFont(const AName: string; ASize: Single);
+    procedure TextOut(X, Y: Single; const Text: string);
     procedure TextRect(ARect: TPdfRect; Text: string;
         Alignment: TPdfAlignment; Clipping: boolean);
     procedure MultilineTextRect(ARect: TPdfRect;
-        Text: string; WordWrap: boolean);
+        const Text: string; WordWrap: boolean);
     procedure DrawXObject(X, Y, AWidth, AHeight: Single;
-        AXObjectName: string);
+        const AXObjectName: string);
     procedure DrawXObjectEx(X, Y, AWidth, AHeight: Single;
-        ClipX, ClipY, ClipWidth, ClipHeight: Single; AXObjectName: string);
+        ClipX, ClipY, ClipWidth, ClipHeight: Single; const AXObjectName: string);
     procedure Ellipse(x, y, width, height: Single);
     procedure RoundRect(x, y, width, height, rx, ry: Single; SqrCorners:TPdfCorners=[]);
     function TextWidth(Text: string): Single;
@@ -485,7 +483,7 @@ type
     property PageHeight: integer read GetPageHeight write SetPageHeight;
 
     {* Text rotated up *}
-    procedure TextOutRotatedUp(X, Y: Single; Text: string);
+    procedure TextOutRotatedUp(X, Y: Single; const Text: string);
   end;
 
   TPdfDictionaryWrapper = class(TPersistent)
@@ -502,17 +500,17 @@ type
   TPdfInfo = class(TPdfDictionaryWrapper)
   private
     function GetAuthor: string;
-    procedure SetAuthor(Value: string);
+    procedure SetAuthor(const Value: string);
     function GetCreationDate: TDateTime;
     procedure SetCreationDate(Value: TDateTime);
     function GetCreator: string;
-    procedure SetCreator(Value: string);
+    procedure SetCreator(const Value: string);
     function GetKeywords: string;
-    procedure SetKeywords(Value: string);
+    procedure SetKeywords(const Value: string);
     function GetSubject: string;
-    procedure SetSubject(Value: string);
+    procedure SetSubject(const Value: string);
     function GetTitle: string;
-    procedure SetTitle(Value: string);
+    procedure SetTitle(const Value: string);
     function GetModDate: TDateTime;
     procedure SetModDate(Value: TDateTime);
   public
@@ -562,8 +560,8 @@ type
     procedure AddStrElements(ADic: TPdfDictionary; ATable: array of TPDF_STR_TBL);
     procedure AddIntElements(ADic: TPdfDictionary; ATable: array of TPDF_INT_TBL);
   public
-    constructor Create(AXref: TPdfXref; AName: string); virtual;
-    function GetCharWidth(AText: string; APos: integer): integer; virtual;
+    constructor Create(AXref: TPdfXref; const AName: string); virtual;
+    function GetCharWidth(const AText: string; APos: integer): integer; virtual;
     property Name: string read FName;
     property UnderlinePosition: Integer read FUnderlinePosition write FUnderlinePosition;
     property UnderlineThickness: Integer read FUnderlineThickness write FUnderlineThickness;
@@ -754,7 +752,7 @@ constructor TPdfXref.Create;
 var
   RootEntry: TPdfXrefEntry;
 begin
-  FXrefEntries := TList.Create;
+  FXrefEntries := TFpList.Create;
   RootEntry := TPdfXrefEntry.Create(nil);
   RootEntry.GenerationNumber := PDF_MAX_GENERATION_NUM;
   FXrefEntries.Add(RootEntry);
@@ -890,7 +888,7 @@ begin
 end;
 
 // CreateFont
-function TPdfDoc.CreateFont(FontName: string): TPdfFont;
+function TPdfDoc.CreateFont(const FontName: string): TPdfFont;
 var
   PdfFont: TPdfFont;
 begin
@@ -910,7 +908,7 @@ begin
 end;
 
 // RegisterXObject
-procedure TPdfDoc.RegisterXObject(AObject: TPdfXObject; AName: string);
+procedure TPdfDoc.RegisterXObject(AObject: TPdfXObject; const AName: string);
 begin
    // check object and register it.
    if AObject = nil then
@@ -969,7 +967,7 @@ begin
 end;
 
 // GetFont
-function TPdfDoc.GetFont(FontName: string): TPdfFont;
+function TPdfDoc.GetFont(const FontName: string): TPdfFont;
 var
   FFont: TPdfFont;
   i :integer;
@@ -993,7 +991,7 @@ begin
 end;
 
 // GetXObject
-function TPdfDoc.GetXObject(AName: string): TPdfXObject;
+function TPdfDoc.GetXObject(const AName: string): TPdfXObject;
 var
   FXObject: TPdfXObject;
   i :integer;
@@ -1012,7 +1010,7 @@ begin
 end;
 
 // CreateAnnotation
-function TPdfDoc.CreateAnnotation(AType: TPdfAnnotationSubType; ARect: TPdfRect): TPdfDictionary;
+function TPdfDoc.CreateAnnotation(AType: TPdfAnnotationSubType; const ARect: TPdfRect): TPdfDictionary;
 var
   FAnnotation: TPdfDictionary;
   FArray: TPdfArray;
@@ -1069,9 +1067,9 @@ begin
   FXref := TPdfXref.Create;
   FHeader := TPdfHeader.Create;
   FTrailer := TPdfTrailer.Create(FXref);
-  FFontList := TList.Create;
+  FFontList := TFpList.Create;
   FXObjectList := TPdfArray.CreateArray(FXref);
-  FObjectList := TList.Create;
+  FObjectList := TFpList.Create;
 
   FRoot := TPdfCatalog.Create;
   FRoot.SetData(CreateCatalog);
@@ -1090,7 +1088,7 @@ begin
 end;
 
 // AddXObject
-procedure TPdfDoc.AddXObject(AName: string; AXObject: TPdfXObject);
+procedure TPdfDoc.AddXObject(const AName: string; AXObject: TPdfXObject);
 begin
   if GetXObject(AName) <> nil then
     raise Exception.CreateFmt('AddImage --the image named %s is already exists..', [AName]);
@@ -1402,7 +1400,7 @@ begin
 end;
 
 // WriteString
-procedure TPdfCanvas.WriteString(S: string);
+procedure TPdfCanvas.WriteString(const S: string);
 begin
   if (not FIsVirtual) and (FContents <> nil) then
     _WriteString(S, FContents.Stream);
@@ -1502,7 +1500,7 @@ begin
 end;
 
 // SetFont
-procedure TPdfCanvas.SetFont(AName: string; ASize: Single);
+procedure TPdfCanvas.SetFont(const AName: string; ASize: Single);
 var
   FFont: TPdfFont;
   FFontList: TPdfDictionary;
@@ -1523,7 +1521,7 @@ begin
 end;
 
 // TextOut
-procedure TPdfCanvas.TextOut(X, Y: Single; Text: string);
+procedure TPdfCanvas.TextOut(X, Y: Single; const Text: string);
 var
   UPos, UWidth: Single;
 begin
@@ -1595,7 +1593,7 @@ begin
 end;
 
 // MultilineTextRect
-procedure TPdfCanvas.MultilineTextRect(ARect: TPdfRect; Text: string;
+procedure TPdfCanvas.MultilineTextRect(ARect: TPdfRect; const Text: string;
   WordWrap: boolean);
 var
   i: integer;
@@ -1702,7 +1700,7 @@ end;
 
 // DrawXObject
 procedure TPdfCanvas.DrawXObject(X, Y, AWidth, AHeight: Single;
-    AXObjectName: string);
+    const AXObjectName: string);
 var
   XObject: TPdfXObject;
   FXObjectList: TPdfDictionary;
@@ -1724,7 +1722,7 @@ end;
 
 // DrawXObjectEx
 procedure TPdfCanvas.DrawXObjectEx(X, Y, AWidth, AHeight: Single;
-      ClipX, ClipY, ClipWidth, ClipHeight: Single; AXObjectName: string);
+      ClipX, ClipY, ClipWidth, ClipHeight: Single; const AXObjectName: string);
 var
   XObject: TPdfXObject;
   FXObjectList: TPdfDictionary;
@@ -2015,7 +2013,7 @@ begin
 end;
 
 // SetFontAndSize
-procedure TPdfCanvas.SetFontAndSize(fontname: string; size: Single);
+procedure TPdfCanvas.SetFontAndSize(const fontname: string; size: Single);
 var
   S: string;
 begin
@@ -2079,7 +2077,7 @@ begin
 end;
 
 // ShowText
-procedure TPdfCanvas.ShowText(s: string);
+procedure TPdfCanvas.ShowText(const s: string);
 var
   FString: string;
 begin
@@ -2091,7 +2089,7 @@ begin
 end;
 
 // ShowTextNextLine
-procedure TPdfCanvas.ShowTextNextLine(s: string);
+procedure TPdfCanvas.ShowTextNextLine(const s: string);
 var
   FString: string;
 begin
@@ -2105,7 +2103,7 @@ end;
 {* external objects *}
 
 // ExecuteXObject
-procedure TPdfCanvas.ExecuteXObject(xObject: string);
+procedure TPdfCanvas.ExecuteXObject(const xObject: string);
 var
   S: string;
 begin
@@ -2262,7 +2260,7 @@ begin
    Index := i + 1;
 end;
 
-procedure TPdfCanvas.TextOutRotatedUp(X, Y: Single; Text: string);
+procedure TPdfCanvas.TextOutRotatedUp(X, Y: Single; const Text: string);
 begin
   BeginText;
   SetTextMatrix(0, 1, -1, 0, X, Y); //  down to up
@@ -2297,7 +2295,7 @@ end;
 { TPdfInfo }
 
 // SetAuthor
-procedure TPdfInfo.SetAuthor(Value: string);
+procedure TPdfInfo.SetAuthor(const Value: string);
 begin
   FData.AddItem('Author', TPdfText.CreateText(Value));
 end;
@@ -2315,25 +2313,25 @@ begin
 end;
 
 // SetCreator
-procedure TPdfInfo.SetCreator(Value: string);
+procedure TPdfInfo.SetCreator(const Value: string);
 begin
   FData.AddItem('Creator', TPdfText.CreateText(Value));
 end;
 
 // SetTitle
-procedure TPdfInfo.SetTitle(Value: string);
+procedure TPdfInfo.SetTitle(const Value: string);
 begin
   FData.AddItem('Title', TPdfText.CreateText(Value));
 end;
 
 // SetSubject
-procedure TPdfInfo.SetSubject(Value: string);
+procedure TPdfInfo.SetSubject(const Value: string);
 begin
   FData.AddItem('Subject', TPdfText.CreateText(Value));
 end;
 
 // SetKeywords
-procedure TPdfInfo.SetKeywords(Value: string);
+procedure TPdfInfo.SetKeywords(const Value: string);
 begin
   FData.AddItem('Keywords', TPdfText.CreateText(Value));
 end;
@@ -2653,13 +2651,13 @@ begin
 end;
 
 // GetCharWidth
-function TPdfFont.GetCharWidth(AText: string; APos: integer): integer;
+function TPdfFont.GetCharWidth(const AText: string; APos: integer): integer;
 begin
   result := 0;
 end;
 
 // Create
-constructor TPdfFont.Create(AXref: TPdfXref; AName: string);
+constructor TPdfFont.Create(AXref: TPdfXref; const AName: string);
 begin
   inherited Create;
   FName := AName;
diff --git a/components/powerpdf/PdfFonts.pas b/components/powerpdf/PdfFonts.pas
index 8f1369ecf..86be45c74 100644
--- a/components/powerpdf/PdfFonts.pas
+++ b/components/powerpdf/PdfFonts.pas
@@ -500,78 +500,78 @@ type
     FArray: array[0..255] of Word;
   public
     procedure SetData(Value: TPdfDictionary); override;
-    function GetCharWidth(AText: string; APos: integer): integer; override;
+    function GetCharWidth(const AText: string; APos: integer): integer; override;
   end;
 
   TPdfFixedWidth = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfFixedWidthBold = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfFixedWidthItalic = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfFixedWidthBoldItalic = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfArial = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfArialBold = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfArialItalic = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfArialBoldItalic = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfTimesRoman = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfTimesBold = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfTimesItalic = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfTimesBoldItalic = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfScript = class(TPdfType1Font)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
 implementation
 
 { TPdfType1Font }
-function TPdfType1Font.GetCharWidth(AText: string; APos: integer): integer;
+function TPdfType1Font.GetCharWidth(const AText: string; APos: integer): integer;
 begin
   result := FArray[ord(AText[APos])];
 end;
@@ -604,7 +604,7 @@ begin
 end;
 
 { FixedWidth }
-constructor TPdfFixedWidth.Create(AXref: TPdfXref; AName: string);
+constructor TPdfFixedWidth.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -628,7 +628,7 @@ begin
 end;
 
 { FixedWidthBold }
-constructor TPdfFixedWidthBold.Create(AXref: TPdfXref; AName: string);
+constructor TPdfFixedWidthBold.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -648,7 +648,7 @@ begin
 end;
 
 { FixedWidthItalic }
-constructor TPdfFixedWidthItalic.Create(AXref: TPdfXref; AName: string);
+constructor TPdfFixedWidthItalic.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -668,7 +668,7 @@ begin
 end;
 
 { FixedWidthBoldItalic }
-constructor TPdfFixedWidthBoldItalic.Create(AXref: TPdfXref; AName: string);
+constructor TPdfFixedWidthBoldItalic.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -688,7 +688,7 @@ begin
 end;
 
 { Arial }
-constructor TPdfArial.Create(AXref: TPdfXref; AName: string);
+constructor TPdfArial.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -710,7 +710,7 @@ begin
 end;
 
 { Arial-Bold }
-constructor TPdfArialBold.Create(AXref: TPdfXref; AName: string);
+constructor TPdfArialBold.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -733,7 +733,7 @@ begin
 end;
 
 { Arial-Italic }
-constructor TPdfArialItalic.Create(AXref: TPdfXref; AName: string);
+constructor TPdfArialItalic.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -755,7 +755,7 @@ begin
 end;
 
 { Arial-BoldItalic }
-constructor TPdfArialBoldItalic.Create(AXref: TPdfXref; AName: string);
+constructor TPdfArialBoldItalic.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -778,7 +778,7 @@ begin
 end;
 
 { TPdfTimesRoman }
-constructor TPdfTimesRoman.Create(AXref: TPdfXref; AName: string);
+constructor TPdfTimesRoman.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -798,7 +798,7 @@ begin
 end;
 
 { TPdfTimesBold }
-constructor TPdfTimesBold.Create(AXref: TPdfXref; AName: string);
+constructor TPdfTimesBold.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -818,7 +818,7 @@ begin
 end;
 
 { TPdfTimesItalic }
-constructor TPdfTimesItalic.Create(AXref: TPdfXref; AName: string);
+constructor TPdfTimesItalic.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -838,7 +838,7 @@ begin
 end;
 
 { TPdfTimesBoldItalic }
-constructor TPdfTimesBoldItalic.Create(AXref: TPdfXref; AName: string);
+constructor TPdfTimesBoldItalic.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFont: TPdfDictionary;
@@ -858,7 +858,7 @@ begin
 end;
 
 { TPdfScript }
-constructor TPdfScript.Create(AXref: TPdfXref; AName: string);
+constructor TPdfScript.Create(AXref: TPdfXref; const AName: string);
 var
   FWidths: TPdfArray;
   FFontDescriptor: TPdfDictionary;
diff --git a/components/powerpdf/PdfGBFonts.pas b/components/powerpdf/PdfGBFonts.pas
index 678d1ffc4..53d765d73 100644
--- a/components/powerpdf/PdfGBFonts.pas
+++ b/components/powerpdf/PdfGBFonts.pas
@@ -65,14 +65,14 @@ type
     procedure AddDescendantFontItem(ADescendantFont: TPdfDictionary); virtual;
     function GetFontName: string; virtual;
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfGBFixedFont = class(TPdfGBFont)
   protected
     procedure AddDescendantFontItem(ADescendantFont: TPdfDictionary); override;
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfChinese = class(TPdfGBFixedFont)
@@ -115,7 +115,7 @@ begin
 end;
 
 // Create
-constructor TPdfGBFont.Create(AXref: TPdfXref; AName: string);
+constructor TPdfGBFont.Create(AXref: TPdfXref; const AName: string);
 var
   FFontDescriptor: TPdfDictionary;
   FFont: TPdfDictionary;
@@ -179,7 +179,7 @@ begin
   ADescendantFont.AddItem('W', FWidths);
 end;
 
-constructor TPdfGBFixedFont.Create(AXref: TPdfXref; AName: string);
+constructor TPdfGBFixedFont.Create(AXref: TPdfXref; const AName: string);
 begin
   inherited Create(AXref, AName);
   AddStrElements(Data, TYPE0_GB_FONT_STR_TABLE);
diff --git a/components/powerpdf/PdfJPFonts.pas b/components/powerpdf/PdfJPFonts.pas
index 71d4421fe..bc029b884 100644
--- a/components/powerpdf/PdfJPFonts.pas
+++ b/components/powerpdf/PdfJPFonts.pas
@@ -223,7 +223,7 @@ type
   TPdfType0Font = class(TPdfFont)
   private
     FCharToCMap: TCharToCMap;
-    FArray: TList;
+    FArray: TFpList;
     FDW: Word;
     FMissingWidth: Word;
   protected
@@ -232,7 +232,7 @@ type
     destructor Destroy; override;
     procedure SetData(AData: TPdfDictionary); override;
     procedure SetCharToCMap(AFunc: TCharToCMap); virtual;
-    function GetCharWidth(AText: string; APos: integer): integer; override;
+    function GetCharWidth(const AText: string; APos: integer): integer; override;
   end;
 
   TPdfJpFont = class(TPdfType0Font)
@@ -241,14 +241,14 @@ type
     procedure AddDescendantFontItem(ADescendantFont: TPdfDictionary); virtual;
     function GetFontName: string; virtual;
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfJpFixedFont = class(TPdfJpFont)
   protected
     procedure AddDescendantFontItem(ADescendantFont: TPdfDictionary); override;
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfGothic = class(TPdfJpFixedFont)
@@ -301,7 +301,7 @@ type
 
   TPdfJpProportionalFont = class(TPdfJpFont)
   public
-    constructor Create(AXref: TPdfXref; AName: string); override;
+    constructor Create(AXref: TPdfXref; const AName: string); override;
   end;
 
   TPdfPGothic = class(TPdfJpProportionalFont)
@@ -380,7 +380,7 @@ begin
   FDW := DescendantFont.PdfNumberByName('DW').Value;
   Discriptor := DescendantFont.PdfDictionaryByName('FontDescriptor');
   FMissingWidth := Discriptor.PdfNumberByName('MissingWidth').Value;
-  FArray := TList.Create;
+  FArray := TFpList.Create;
   WidthsRoot := DescendantFont.PdfArrayByName('W');
 
   // create widths array from "W"attribute.
@@ -451,7 +451,7 @@ begin
 end;
 
 // GetCharWidth
-function TPdfType0Font.GetCharWidth(AText: string; APos: integer): integer;
+function TPdfType0Font.GetCharWidth(const AText: string; APos: integer): integer;
 var
   CID: integer;
 begin
@@ -506,7 +506,7 @@ begin
 end;
 
 // Create
-constructor TPdfJpFont.Create(AXref: TPdfXref; AName: string);
+constructor TPdfJpFont.Create(AXref: TPdfXref; const AName: string);
 var
   FFontDescriptor: TPdfDictionary;
   FFont: TPdfDictionary;
@@ -570,7 +570,7 @@ begin
   ADescendantFont.AddItem('W', FWidths);
 end;
 
-constructor TPdfJpFixedFont.Create(AXref: TPdfXref; AName: string);
+constructor TPdfJpFixedFont.Create(AXref: TPdfXref; const AName: string);
 begin
   inherited Create(AXref, AName);
   AddStrElements(Data, TYPE0_JP_FONT_STR_TABLE);
@@ -765,7 +765,7 @@ end;
 { TPdfJpProportionalFont }
 
 // Create
-constructor TPdfJpProportionalFont.Create(AXref: TPdfXref; AName: string);
+constructor TPdfJpProportionalFont.Create(AXref: TPdfXref; const AName: string);
 begin
   inherited Create(AXref, AName);
   AddStrElements(Data, TYPE0_JPP_FONT_STR_TABLE);
diff --git a/components/powerpdf/PdfTypes.pas b/components/powerpdf/PdfTypes.pas
index 6b01fdf76..da5d1395b 100644
--- a/components/powerpdf/PdfTypes.pas
+++ b/components/powerpdf/PdfTypes.pas
@@ -160,7 +160,7 @@ type
    protected
     procedure InternalWriteStream(const AStream: TStream); override;
   public
-    constructor CreateString(AValue: string);
+    constructor CreateString(const AValue: string);
     property Value: string read FValue write FValue;
   end;
 
@@ -170,7 +170,7 @@ type
   protected
     procedure InternalWriteStream(const AStream: TStream); override;
   public
-    constructor CreateText(AValue: string);
+    constructor CreateText(const AValue: string);
     property Value: String read FValue write FValue;
   end;
 
@@ -187,7 +187,7 @@ type
 
   TPdfArray = class(TPdfObject)
   private
-    FArray: TList;
+    FArray: TFpList;
     FObjectMgr: TPdfObjectMgr;
     function GetItems(Index: integer): TPdfObject;
     function GetItemCount: integer;
@@ -198,8 +198,8 @@ type
     constructor CreateNumArray(AObjectMgr: TPdfObjectMgr; AArray: array of Integer);
     destructor Destroy; override;
     procedure AddItem(AItem: TPdfObject);
-    function FindName(AName: string): TPdfName;
-    function RemoveName(AName: string): boolean;
+    function FindName(const AName: string): TPdfName;
+    function RemoveName(const AName: string): boolean;
     property Items[Index: integer]: TPdfObject read GetItems;
     property ItemCount: integer read GetItemCount;
     property ObjectMgr: TPdfObjectMgr read FObjectMgr;
@@ -212,8 +212,8 @@ type
     FIsInternal: boolean;
     function GetKey: string;
   public
-    constructor Create(AKey: string; AValue: TPdfObject);
-    constructor CreateAsInternal(AKey: string; AValue: TPdfObject; AVoid: Pointer);
+    constructor Create(const AKey: string; AValue: TPdfObject);
+    constructor CreateAsInternal(const AKey: string; AValue: TPdfObject; AVoid: Pointer);
     destructor Destroy; override;
     property Key: string read GetKey;
     property Value: TPdfObject read FValue;
@@ -222,7 +222,7 @@ type
 
   TPdfDictionary = class(TPdfObject)
   private
-    FArray: TList;
+    FArray: TFpList;
     FObjectMgr: TPdfObjectMgr;
     function GetItems(Index: integer): TPdfDictionaryElement;
     function GetItemCount: integer;
@@ -231,20 +231,20 @@ type
   public
     constructor CreateDictionary(AObjectMgr: TPdfObjectMgr);
     destructor Destroy; override;
-    function ValueByName(AKey: string): TPdfObject;
-    function PdfBooleanByName(AKey: string): TPdfBoolean;
-    function PdfNumberByName(AKey: string): TPdfNumber;
-    function PdfTextByName(AKey: string): TPdfText;
-    function PdfRealByName(AKey: string): TPdfReal;
-    function PdfStringByName(AKey: string): TPdfString;
-    function PdfNameByName(AKey: string): TPdfName;
-    function PdfDictionaryByName(AKey: string): TPdfDictionary;
-    function PdfArrayByName(AKey: string): TPdfArray;
-    procedure AddItem(AKey: string; AValue: TPdfObject);
-    procedure AddNumberItem(AKey: string; AValue: Integer);
-    procedure AddNameItem(AKey: string; AValue: string);
-    procedure AddInternalItem(AKey: string; AValue: TPdfObject);
-    procedure RemoveItem(AKey: string);
+    function ValueByName(const AKey: string): TPdfObject;
+    function PdfBooleanByName(const AKey: string): TPdfBoolean;
+    function PdfNumberByName(const AKey: string): TPdfNumber;
+    function PdfTextByName(const AKey: string): TPdfText;
+    function PdfRealByName(const AKey: string): TPdfReal;
+    function PdfStringByName(const AKey: string): TPdfString;
+    function PdfNameByName(const AKey: string): TPdfName;
+    function PdfDictionaryByName(const AKey: string): TPdfDictionary;
+    function PdfArrayByName(const AKey: string): TPdfArray;
+    procedure AddItem(const AKey: string; AValue: TPdfObject);
+    procedure AddNumberItem(const AKey: string; AValue: Integer);
+    procedure AddNameItem(const AKey: string; AValue: string);
+    procedure AddInternalItem(const AKey: string; AValue: TPdfObject);
+    procedure RemoveItem(const AKey: string);
     property Items[Index: integer]: TPdfDictionaryElement read GetItems;
     property ItemCount: integer read GetItemCount;
     property ObjectMgr: TPdfObjectMgr read FObjectMgr;
@@ -298,13 +298,13 @@ type
   function _FloatToStrR(Value: Extended): string;
   function _GetUnicodeHeader: string;
   function _PdfRect(Left, Top, Right, Bottom: Single): TPdfRect;
-  function _GetCharCount(Text: string): integer;
+  function _GetCharCount(const Text: string): integer;
 
 {$IFDEF LAZ_POWERPDF}
   function _UTF8StrToUnicodeHex(const Value:string): string;
   function _UTF8ToWinAnsi(const value:string; InvalidChar:char='?'): string;
-  procedure PdfLazRegisterClassAlias(aClass: TPersistentClass; Alias: string);
-  function  PdfLazFindClass(aClassName: string):TPersistentClass;
+  procedure PdfLazRegisterClassAlias(aClass: TPersistentClass; const Alias: string);
+  function  PdfLazFindClass(const aClassName: string):TPersistentClass;
 {$ENDIF}
 
 implementation
@@ -470,7 +470,7 @@ begin
 end;
 
 // CreateString
-constructor TPdfString.CreateString(AValue: string);
+constructor TPdfString.CreateString(const AValue: string);
 begin
   Create;
   Value := AValue;
@@ -493,7 +493,7 @@ begin
 end;
 
 // CreateText
-constructor TPdfText.CreateText(AValue: string);
+constructor TPdfText.CreateText(const AValue: string);
 begin
   Create;
   Value := AValue;
@@ -575,7 +575,7 @@ end;
 constructor TPdfArray.CreateArray(AObjectMgr: TPdfObjectMgr);
 begin
   inherited Create;
-  FArray := TList.Create;
+  FArray := TFpList.Create;
   FObjectMgr := AObjectMgr;
 end;
 
@@ -585,7 +585,7 @@ var
   i: integer;
 begin
   inherited Create;
-  FArray := TList.Create;
+  FArray := TFpList.Create;
   FObjectMgr := AObjectMgr;
 
   for i := 0 to High(AArray) do
@@ -621,7 +621,7 @@ begin
 end;
 
 // FindName
-function TPdfArray.FindName(AName: string): TPdfName;
+function TPdfArray.FindName(const AName: string): TPdfName;
 var
   i: integer;
   FPdfName: TPdfName;
@@ -641,7 +641,7 @@ begin
 end;
 
 // RemoveName
-function TPdfArray.RemoveName(AName: string): boolean;
+function TPdfArray.RemoveName(const AName: string): boolean;
 var
   AObject: TPdfObject;
 begin
@@ -665,7 +665,7 @@ begin
 end;
 
 // Create
-constructor TPdfDictionaryElement.Create(AKey: string; AValue: TPdfObject);
+constructor TPdfDictionaryElement.Create(const AKey: string; AValue: TPdfObject);
 begin
   FKey := TPdfName.Create;
   FKey.Value := AKey;
@@ -676,7 +676,7 @@ begin
 end;
 
 // CreateAsInternal
-constructor TPdfDictionaryElement.CreateAsInternal(AKey: string; AValue: TPdfObject; AVoid: Pointer);
+constructor TPdfDictionaryElement.CreateAsInternal(const AKey: string; AValue: TPdfObject; AVoid: Pointer);
 begin
   Create(AKey, AValue);
   FIsInternal := true;
@@ -729,7 +729,7 @@ end;
 constructor TPdfDictionary.CreateDictionary(AObjectMgr: TPdfObjectMgr);
 begin
   inherited Create;
-  FArray := TList.Create;
+  FArray := TFpList.Create;
   FObjectMgr := AObjectMgr;
 end;
 
@@ -751,7 +751,7 @@ begin
 end;
 
 // ValueByName
-function TPdfDictionary.ValueByName(AKey: string): TPdfObject;
+function TPdfDictionary.ValueByName(const AKey: string): TPdfObject;
 var
   i: integer;
   FElement: TPdfDictionaryElement;
@@ -774,55 +774,55 @@ begin
 end;
 
 // PdfNumberByName
-function TPdfDictionary.PdfNumberByName(AKey: string): TPdfNumber;
+function TPdfDictionary.PdfNumberByName(const AKey: string): TPdfNumber;
 begin
   result := TPdfNumber(ValueByName(AKey));
 end;
 
 // PdfTextByName
-function TPdfDictionary.PdfTextByName(AKey: string): TPdfText;
+function TPdfDictionary.PdfTextByName(const AKey: string): TPdfText;
 begin
   result := TPdfText(ValueByName(AKey));
 end;
 
 // PdfRealByName
-function TPdfDictionary.PdfRealByName(AKey: string): TPdfReal;
+function TPdfDictionary.PdfRealByName(const AKey: string): TPdfReal;
 begin
   result := TPdfReal(ValueByName(AKey));
 end;
 
 // PdfStringByName
-function TPdfDictionary.PdfStringByName(AKey: string): TPdfString;
+function TPdfDictionary.PdfStringByName(const AKey: string): TPdfString;
 begin
   result := TPdfString(ValueByName(AKey));
 end;
 
 // PdfNameByName
-function TPdfDictionary.PdfNameByName(AKey: string): TPdfName;
+function TPdfDictionary.PdfNameByName(const AKey: string): TPdfName;
 begin
   result := TPdfName(ValueByName(AKey));
 end;
 
 // PdfDictionaryByName
-function TPdfDictionary.PdfDictionaryByName(AKey: string): TPdfDictionary;
+function TPdfDictionary.PdfDictionaryByName(const AKey: string): TPdfDictionary;
 begin
   result := TPdfDictionary(ValueByName(AKey));
 end;
 
 // PdfArrayByName
-function TPdfDictionary.PdfArrayByName(AKey: string): TPdfArray;
+function TPdfDictionary.PdfArrayByName(const AKey: string): TPdfArray;
 begin
   result := TPdfArray(ValueByName(AKey));
 end;
 
 // PdfBooleanByName
-function TPdfDictionary.PdfBooleanByName(AKey: string): TPdfBoolean;
+function TPdfDictionary.PdfBooleanByName(const AKey: string): TPdfBoolean;
 begin
   result := TPdfBoolean(ValueByName(AKey));
 end;
 
 // AddItem
-procedure TPdfDictionary.AddItem(AKey: string; AValue: TPdfObject);
+procedure TPdfDictionary.AddItem(const AKey: string; AValue: TPdfObject);
 var
   FItem: TPdfDictionaryElement;
   FTmpObject: TPdfVirtualObject;
@@ -841,19 +841,19 @@ begin
 end;
 
 // AddNumberItem
-procedure TPdfDictionary.AddNumberItem(AKey: string; AValue: Integer);
+procedure TPdfDictionary.AddNumberItem(const AKey: string; AValue: Integer);
 begin
   AddItem(AKey, TPdfNumber.CreateNumber(AValue));
 end;
 
 // AddNameItem
-procedure TPdfDictionary.AddNameItem(AKey: string; AValue: string);
+procedure TPdfDictionary.AddNameItem(const AKey: string; AValue: string);
 begin
   AddItem(AKey, TPdfName.CreateName(AValue));
 end;
 
 // AddInternalItem
-procedure TPdfDictionary.AddInternalItem(AKey: string; AValue: TPdfObject);
+procedure TPdfDictionary.AddInternalItem(const AKey: string; AValue: TPdfObject);
 var
   FItem: TPdfDictionaryElement;
   FTmpObject: TPdfVirtualObject;
@@ -872,7 +872,7 @@ begin
 end;
 
 // RemoveItem
-procedure TPdfDictionary.RemoveItem(AKey: string);
+procedure TPdfDictionary.RemoveItem(const AKey: string);
 var
   i: integer;
   FElement: TPdfDictionaryElement;
@@ -1178,7 +1178,7 @@ begin
 end;
 
 // _GetCharCount
-function _GetCharCount(Text: string): integer;
+function _GetCharCount(const Text: string): integer;
 var
   i: integer;
 begin
@@ -1214,7 +1214,7 @@ begin
     result := result + CP1252(word(w[i]), InvalidChar);
 end;
 
-procedure PdfLazRegisterClassAlias(aClass: TPersistentClass; Alias: string);
+procedure PdfLazRegisterClassAlias(aClass: TPersistentClass; const Alias: string);
 begin
   Classes.RegisterClass(aClass);
   if AliasList=nil then
@@ -1222,7 +1222,7 @@ begin
   AliasList.AddObject(Alias, TObject(aClass));
 end;
 
-function PdfLazFindClass(aClassName: String): TPersistentClass;
+function PdfLazFindClass(const aClassName: String): TPersistentClass;
 var
   i: Integer;
 begin