{
* This Source Code Form is subject to the terms of the Mozilla Public License,
* v. 2.0. If a copy of the MPL was not distributed with this file, You can
* obtain one at http://mozilla.org/MPL/2.0/
*
* Copyright (C) 2009-2012, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Defines a record that uniquely indentifies a snippet in the database, along
* with an object that maintains a list of snippet ID records.
}
unit USnippetIDs;
interface
uses
// Delphi
Generics.Collections,
// Project
IntfCommon;
type
/// <summary>Record that uniquely identifies a code snippet. Specifies name
/// and flag indicating whether snippet is user-defined.</summary>
TSnippetID = record
strict private
var
/// <summary>Value of Name property.</summary>
fName: string;
/// <summary>Value of UserDefined property.</summary>
fUserDefined: Boolean;
public
/// <summary>Name of snippet.</summary>
property Name: string read fName write fName;
/// <summary>Whether snippet is user defined.</summary>
property UserDefined: Boolean read fUserDefined write fUserDefined;
/// <summary>Creates a record with given property values.</summary>
constructor Create(const AName: string; const AUserDefined: Boolean);
/// <summary>Creates copy of given snippet ID</summary>
constructor Clone(const Src: TSnippetID);
/// <summary>Compares this record with another.</summary>
/// <param name="SID">TSnippetID [in] Snippet ID to compare with.</param>
/// <returns>Integer. 0 if records are same, -ve if this record less than
/// SID or +ve if this record greater than SID.</returns>
function CompareTo(const SID: TSnippetID): Integer;
/// <summary>Compares two snippet names.</summary>
/// <param name="Left">string [in] First name.</param>
/// <param name="Right">string [in] Second name.</param>
/// <result>Integer. 0 if names are same, -ve if Left is less than Right or
/// +ve Left is greater than Right.</result>
class function CompareNames(const Left, Right: string): Integer; static;
/// <summary>Overload of equality operator for two TSnippetIDs.</summary>
class operator Equal(const SID1, SID2: TSnippetID): Boolean;
/// <summary>Overload of inequality operator for two TSnippetIDs.</summary>
class operator NotEqual(const SID1, SID2: TSnippetID): Boolean;
end;
type
/// <summary>Interface supported by objects that implement a list of
/// TSnippetID records.</summary>
ISnippetIDList = interface(IInterface)
['{238CFDCC-E84E-4D29-9BC6-10FBCECBC4FA}']
/// <summary>Gets new list enumerator.</summary>
function GetEnumerator: TEnumerator<TSnippetID>;
/// <summary>Clears the list.</summary>
procedure Clear;
/// <summary>Adds given snippet ID to list and returns its index in list.
/// </summary>
function Add(const SnippetID: TSnippetID): Integer;
/// <summary>Checks if list contains given snippet ID.</summary>
function Contains(const SnippetID: TSnippetID): Boolean;
/// <summary>Returns number of snippet ID records in list.</summary>
function Count: Integer;
/// <summary>Gets snippet ID record from list by index.</summary>
function GetItem(Idx: Integer): TSnippetID;
/// <summary>Stores snippet ID record in list at specified index.</summary>
procedure SetItem(Idx: Integer; const Value: TSnippetID);
/// <summary>Provides read/write access to snippet IDs by index.</summary>
property Items[Idx: Integer]: TSnippetID
read GetItem write SetItem; default;
end;
type
/// <summary>Implements a list of snippet identification records.</summary>
TSnippetIDList = class(TInterfacedObject, ISnippetIDList, IAssignable)
strict private
var
/// <summary>Internal list if snippet ID records.</summary>
fList: TList<TSnippetID>;
public
/// <summary>Constructs empty list object.</summary>
constructor Create;
/// <summary>Destroys object.</summary>
destructor Destroy; override;
/// <summary>Gets new list enumerator.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function GetEnumerator: TEnumerator<TSnippetID>;
/// <summary>Clears the list.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
procedure Clear;
/// <summary>Adds given snippet ID to list and returns its index in list.
/// </summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function Add(const SnippetID: TSnippetID): Integer;
/// <summary>Checks if list contains given snippet ID.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function Contains(const SnippetID: TSnippetID): Boolean;
/// <summary>Returns number of snippet ID records in list.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function Count: Integer;
/// <summary>Gets snippet ID record from list by index.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
function GetItem(Idx: Integer): TSnippetID;
/// <summary>Stores snippet ID record in list at specified index.</summary>
/// <remarks>Method of ISnippetIDList.</remarks>
procedure SetItem(Idx: Integer; const Value: TSnippetID);
/// <summary>Copies properties of given list to this one.</summary>
/// <param name="Src">IInterface [in] List whose properties are to be
/// copied. Src must support ISnippetIDList.</param>
/// <remarks>Method of IAssignable.</remarks>
procedure Assign(const Src: IInterface);
end;
implementation
uses
// Delphi
SysUtils, Generics.Defaults,
// Project
UStrUtils;
{ TSnippetID }
constructor TSnippetID.Clone(const Src: TSnippetID);
begin
Create(Src.Name, Src.UserDefined);
end;
class function TSnippetID.CompareNames(const Left, Right: string): Integer;
begin
Result := StrCompareText(Left, Right);
end;
function TSnippetID.CompareTo(const SID: TSnippetID): Integer;
begin
Result := CompareNames(Name, SID.Name);
if Result = 0 then
Result := Ord(UserDefined) - Ord(SID.UserDefined);
end;
constructor TSnippetID.Create(const AName: string; const AUserDefined: Boolean);
begin
fName := AName;
fUserDefined := AUserDefined;
end;
class operator TSnippetID.Equal(const SID1, SID2: TSnippetID): Boolean;
begin
Result := SID1.CompareTo(SID2) = 0;
end;
class operator TSnippetID.NotEqual(const SID1, SID2: TSnippetID): Boolean;
begin
Result := not (SID1 = SID2);
end;
{ TSnippetIDList }
function TSnippetIDList.Add(const SnippetID: TSnippetID): Integer;
begin
Result := fList.Add(SnippetID);
end;
procedure TSnippetIDList.Assign(const Src: IInterface);
var
SrcID: TSnippetID; // references each ID in source
begin
Assert(Supports(Src, ISnippetIDList),
ClassName + '.Assign: Src must support ISnippetIDList');
Clear;
for SrcID in (Src as ISnippetIDList) do
Add(TSnippetID.Clone(SrcID));
end;
procedure TSnippetIDList.Clear;
begin
fList.Clear;
end;
function TSnippetIDList.Contains(const SnippetID: TSnippetID): Boolean;
begin
Result := fList.Contains(SnippetID);
end;
function TSnippetIDList.Count: Integer;
begin
Result := fList.Count;
end;
constructor TSnippetIDList.Create;
begin
inherited;
fList := TList<TSnippetID>.Create(
TDelegatedComparer<TSnippetID>.Create(
function(const Left, Right: TSnippetID): Integer
begin
Result := Left.CompareTo(Right);
end
)
);
end;
destructor TSnippetIDList.Destroy;
begin
fList.Free;
inherited;
end;
function TSnippetIDList.GetEnumerator: TEnumerator<TSnippetID>;
begin
Result := fList.GetEnumerator;
end;
function TSnippetIDList.GetItem(Idx: Integer): TSnippetID;
begin
Result := fList[Idx];
end;
procedure TSnippetIDList.SetItem(Idx: Integer; const Value: TSnippetID);
begin
fList[Idx] := Value;
end;
end.
