Changeset 344 for trunk/ItemList.pas

Timestamp:

Dec 23, 2024, 8:16:05 AM (10 hours ago)

Author:

chronos

Message:

• Modified: Improved implementation of TItemList class to be generic class to avoid explicit typecasting.

File:

• trunk/ItemList.pas (modified) (21 diffs)

trunk/ItemList.pas

@@ -7 +7 @@
 
 type
-  TItemList = class;
+  //TItemList<T> = class;
   TUndefinedEnum = (eeNone);
 
@@ -34 +34 @@
     function AddField(Index: Integer; SysName, Name: string; DataType: TDataType): TItemField;
     function SearchByIndex(Index: Integer): TItemField;
+  end;
+
+  { IList }
+
+  IList<T> = interface
+    function GetName: string;
+    function GetCount: SizeInt;
+    function GetItem(Index: SizeInt): T;
+    function Remove(constref AValue: T): SizeInt;
+    function Add(constref AValue: T): SizeInt;
+    function CreateBaseItem(Name: string = ''): T;
+    function GetNextAvailableName(Name: string): string;
+    function GetItemFields: TItemFields;
+    procedure SetItem(Index: SizeInt; AValue: T);
+    property Count: SizeInt read GetCount;
+    property Items[Index: SizeInt]: T read GetItem write SetItem; default;
   end;
 
@@ -71 +87 @@
     class function GetClassSysName: string; virtual;
     class function GetClassName: string; virtual;
-    function GetReferenceList(Index: Integer): TItemList; virtual;
+    function GetReferenceList(Index: Integer): IList<TItem>; virtual;
     constructor Create; virtual;
   end;
@@ -77 +93 @@
   TItemClass = class of TItem;
 
+  IItemList = interface(IList<TItem>)
+  end;
+
   { TItemList }
 
-  TItemList = class(TObjectList<TItem>)
+  TItemList<T: TItem> = class(TObjectList<T>, IList<TItem>)
   private
     procedure RecalculateNewId(Reset: Boolean);
     procedure RecalculateItemsId;
+    function GetItem(Index: SizeInt): TItem;
+    procedure SetItem(Index: SizeInt; AValue: TItem);
+  protected
+    function GetCount: SizeInt; override;
   public
+  type
+  var
     NewId: Integer;
-    class function GetItemClass: TItemClass; virtual;
+    function GetName: string;
+    function GetItemFields: TItemFields;
+    function Remove(constref AValue: TItem): SizeInt;
+    function Add(constref AValue: TItem): SizeInt;
+    function CreateItem(Name: string = ''): T; virtual;
+    function CreateBaseItem(Name: string = ''): TItem;
     function IncrementName(Name: string): string;
     function GetNextAvailableName(Name: string): string;
-    function FindById(Id: Integer): TItem;
-    function FindByName(Name: string): TItem;
+    function FindById(Id: Integer): T;
+    function FindByName(Name: string): T;
     function GetNewId: Integer;
     function ToString: string; override;
-    procedure Assign(Source: TItemList); virtual;
-    function Compare(ItemList: TItemList): Boolean; virtual;
-    function AddItem(Name: string = ''): TItem; virtual;
-    function CreateItem(Name: string = ''): TItem; virtual;
+    procedure Assign(Source: TItemList<T>); virtual;
+    function Compare(ItemList: TItemList<T>): Boolean; virtual;
+    function AddItem(Name: string = ''): T; virtual;
     procedure LoadFromNode(Node: TDOMNode); virtual;
     procedure SaveToNode(Node: TDOMNode); virtual;
     constructor Create(FreeObjects: Boolean = True);
+    function QueryInterface({$IFDEF FPC_HAS_CONSTREF}constref{$ELSE}const{$ENDIF} iid : tguid;out obj) : longint;{$IFNDEF WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
+    function _AddRef: Longint;{$IFNDEF WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
+    function _Release: Longint;{$IFNDEF WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
   end;
 
@@ -145 +177 @@
 { TItemList }
 
-procedure TItemList.Assign(Source: TItemList);
+procedure TItemList<T>.Assign(Source: TItemList<T>);
 var
   I: Integer;
@@ -155 +187 @@
 end;
 
-function TItemList.Compare(ItemList: TItemList): Boolean;
+function TItemList<T>.Compare(ItemList: TItemList<T>): Boolean;
 var
   I: Integer;
@@ -167 +199 @@
 end;
 
-function TItemList.AddItem(Name: string): TItem;
-begin
-  Result := CreateItem(Name);
+function TItemList<T>.AddItem(Name: string): T;
+begin
+  Result := T.Create;
+  Result.Name := Name;
   Result.Id := GetNewId;
   Add(Result);
 end;
 
-function TItemList.CreateItem(Name: string): TItem;
-begin
-  Result := GetItemClass.Create;
+function TItemList<T>.CreateItem(Name: string): T;
+begin
+  Result := T.Create;
   Result.Name := Name;
 end;
 
-procedure TItemList.LoadFromNode(Node: TDOMNode);
+function TItemList<T>.CreateBaseItem(Name: string): TItem;
+begin
+  Result := TItem(CreateItem(Name));
+end;
+
+procedure TItemList<T>.LoadFromNode(Node: TDOMNode);
 var
   Node2: TDOMNode;
-  NewItem: TItem;
+  NewItem: T;
 begin
   Count := 0;
   Node2 := Node.FirstChild;
-  while Assigned(Node2) and (Node2.NodeName = UnicodeString(GetItemClass.GetClassSysName)) do begin
+  while Assigned(Node2) and (Node2.NodeName = UnicodeString(T.GetClassSysName)) do begin
     NewItem := CreateItem;
     NewItem.LoadFromNode(Node2);
@@ -195 +233 @@
 end;
 
-procedure TItemList.SaveToNode(Node: TDOMNode);
+procedure TItemList<T>.SaveToNode(Node: TDOMNode);
 var
   I: Integer;
@@ -203 +241 @@
   for I := 0 to Count - 1 do
   with TItem(Items[I]) do begin
-    NewNode2 := Node.OwnerDocument.CreateElement(UnicodeString(GetItemClass.GetClassSysName));
+    NewNode2 := Node.OwnerDocument.CreateElement(UnicodeString(T.GetClassSysName));
     Node.AppendChild(NewNode2);
     SaveToNode(NewNode2);
@@ -209 +247 @@
 end;
 
-constructor TItemList.Create(FreeObjects: Boolean);
+constructor TItemList<T>.Create(FreeObjects: Boolean);
 begin
   inherited;
@@ -215 +253 @@
 end;
 
-procedure TItemList.RecalculateNewId(Reset: Boolean);
+function TItemList<T>.QueryInterface(constref iid: tguid; out obj): longint;
+  stdcall;
+begin
+end;
+
+function TItemList<T>._AddRef: Longint; stdcall;
+begin
+end;
+
+function TItemList<T>._Release: Longint; stdcall;
+begin
+end;
+
+function TItemList<T>.GetCount: SizeInt;
+begin
+  Result := Count;
+end;
+
+function TItemList<T>.GetName: string;
+begin
+  Result := T.GetClassName;
+end;
+
+function TItemList<T>.GetItemFields: TItemFields;
+begin
+  Result := T.GetFields;
+end;
+
+function TItemList<T>.Remove(constref AValue: TItem): SizeInt;
+begin
+  Result := inherited Remove(T(AValue));
+end;
+
+function TItemList<T>.Add(constref AValue: TItem): SizeInt;
+begin
+  Result := inherited Add(T(AValue));
+end;
+
+procedure TItemList<T>.RecalculateNewId(Reset: Boolean);
 var
   I: Integer;
@@ -226 +302 @@
 end;
 
-procedure TItemList.RecalculateItemsId;
+procedure TItemList<T>.RecalculateItemsId;
 var
   I: Integer;
@@ -235 +311 @@
 end;
 
-class function TItemList.GetItemClass: TItemClass;
-begin
-  Result := TItem;
-end;
-
-function TItemList.IncrementName(Name: string): string;
+function TItemList<T>.GetItem(Index: SizeInt): TItem;
+begin
+  Result := inherited GetItem(Index);
+end;
+
+procedure TItemList<T>.SetItem(Index: SizeInt; AValue: TItem);
+begin
+  inherited SetItem(Index, T(AValue));
+end;
+
+function TItemList<T>.IncrementName(Name: string): string;
 var
   I: Integer;
@@ -253 +334 @@
 end;
 
-function TItemList.GetNextAvailableName(Name: string): string;
+function TItemList<T>.GetNextAvailableName(Name: string): string;
 begin
   Result := Name;
@@ -260 +341 @@
 end;
 
-function TItemList.FindById(Id: Integer): TItem;
+function TItemList<T>.FindById(Id: Integer): T;
 var
   I: Integer;
@@ -270 +351 @@
 end;
 
-function TItemList.FindByName(Name: string): TItem;
+function TItemList<T>.FindByName(Name: string): T;
 var
   I: Integer;
@@ -280 +361 @@
 end;
 
-function TItemList.GetNewId: Integer;
+function TItemList<T>.GetNewId: Integer;
 begin
   Result := NewId;
@@ -286 +367 @@
 end;
 
-function TItemList.ToString: string;
+function TItemList<T>.ToString: string;
 var
   I: Integer;
@@ -370 +451 @@
 var
   ReadId: Integer;
-  ReferenceList: TItemList;
+  ReferenceList: IList<TItem>;
 begin
   if Field.DataType = dtString then begin
@@ -389 +470 @@
   if Field.DataType = dtReference then begin
     ReadId := ReadInteger(Node, Field.SysName, 0);
-    ReferenceList := GetReferenceList(Field.Index);
+    ReferenceList := IList<TItem>(GetReferenceList(Field.Index));
     if (ReadId > 0) and Assigned(ReferenceList) then
       SetValueReference(Field.Index, TItem(ReferenceList[ReadId]));
@@ -632 +713 @@
 end;
 
-function TItem.GetReferenceList(Index: Integer): TItemList;
+function TItem.GetReferenceList(Index: Integer): IList<TItem>;
 begin
   Result := nil;