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Diffstat (limited to 'docview/src/docdump/iterator_impl.pas')
-rw-r--r-- | docview/src/docdump/iterator_impl.pas | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/docview/src/docdump/iterator_impl.pas b/docview/src/docdump/iterator_impl.pas new file mode 100644 index 00000000..4ad88052 --- /dev/null +++ b/docview/src/docdump/iterator_impl.pas @@ -0,0 +1,480 @@ +unit iterator_impl; + +{$mode objfpc}{$H+} + +interface + +uses + Classes + ,SysUtils + ,Regex { to be used with filtered string iterator } + ,iterator_intf + ,contnrs + ; + +type + + TTBStringsIterator = class(TInterfacedObject, ITBStringIterator, ITBStringAndObjectIterator) + private + FStrings: TStrings; + FCursor: Integer; + { Interface methods should always be private because + we will only ever access them via an Interface, + never via an Object instance } + + { Interface: ITBStringIterator and ITBStringAndObjectIterator } + function HasNext: Boolean; + function Next: string; + function HasPrevious: Boolean; + function Previous: string; + { Interface: ITBStringAndObjectIterator } + function HasNextObject: Boolean; + function NextObject: TObject; + function HasPreviousObject: Boolean; + function PreviousObject: TObject; + public + constructor CreateCustom(const ASource: TStrings); virtual; + end; + + + TTBListIterator = class(TInterfacedObject, ITBIterator) + private + FList: TList; + FCursor: Integer; + { Interface: ITBIterator } + function HasNext: Boolean; + function Next: TObject; + function HasPrevious: Boolean; + function Previous: TObject; + public + constructor CreateCustom(const ASource: TList); virtual; + end; + + + TTBCollectionIterator = class(TInterfacedObject, ITBIterator) + private + FCollection: TCollection; + FCursor: Integer; + { Interface: ITBIterator } + function HasNext: Boolean; + function Next: TObject; + function HasPrevious: Boolean; + function Previous: TObject; + public + constructor CreateCustom(const ASource: TCollection); virtual; + end; + + + TTBInterfaceListIterator = class(TInterfacedObject, ITBInterfaceIterator) + private + FList: TInterfaceList; + FCursor: integer; + { Interface: ITBinterfaceIterator } + function HasNext: Boolean; + function Next: IInterface; + function HasPrevious: Boolean; + function Previous: IInterface; + public + constructor CreateCustom(const ASource: TInterfaceList); virtual; + end; + + + TTBFilteredStringsIterator = class(TTBStringsIterator, ITBFilteredStringIterator) + private + FNextIndex: Integer; + FRegex: TRegexEngine; + { Interface: ITBFilteredStringIterator } + function GetFilter: string; + procedure SetFilter(const AValue: string); + { Interface: ITBStringIterator and ITBStringAndObjectIterator } + function HasNext: Boolean; + function Next: string; + function HasPrevious: Boolean; + function Previous: string; + public + constructor CreateCustom(const ASource: TStrings); override; + destructor Destroy; override; + end; + + + TTBObjectListIterator = class(TInterfacedObject, ITBIterator) + private + FList: TObjectList; + FCursor: Integer; + { Interface: ITBIterator } + function HasNext: Boolean; + function Next: TObject; + function HasPrevious: Boolean; + function Previous: TObject; + public + constructor CreateCustom(const ASource: TObjectList); virtual; + end; + + + +implementation + + +{ TTBStringsIterator } + +function TTBStringsIterator.HasNext: Boolean; +begin + Result := False; + if Assigned(FStrings) then + if FCursor < FStrings.Count - 1 then + Result := True; +end; + +function TTBStringsIterator.Next: string; +begin + Result := ''; + if HasNext then + begin + Inc(FCursor, 1); + Result := FStrings.Strings[FCursor]; + end; +end; + +function TTBStringsIterator.HasPrevious: Boolean; +begin + Result := False; + if Assigned(FStrings) then + if FCursor > 0 then + Result := True; +end; + +function TTBStringsIterator.Previous: string; +begin + Result := ''; + if HasPrevious then + begin + Dec(FCursor, 1); + Result := FStrings.Strings[FCursor]; + end; +end; + +function TTBStringsIterator.HasNextObject: Boolean; +begin + Result := False; + if Assigned(FStrings) then + if FCursor < FStrings.Count - 1 then + Result := FStrings.Objects[FCursor] <> nil; +end; + +function TTBStringsIterator.NextObject: TObject; +begin + Result := nil; + if HasNextObject then + // Note that Next(...) increments the FCursor + Result := FStrings.Objects[FCursor]; +end; + +function TTBStringsIterator.HasPreviousObject: Boolean; +begin + Result := False; + if Assigned(FStrings) then + if FCursor > 0 then + Result := FStrings.Objects[FCursor] <> nil; +end; + +function TTBStringsIterator.PreviousObject: TObject; +begin + Result := nil; + if HasPreviousObject then + // Note that Previous(...) decrements the FCursor + Result := FStrings.Objects[FCursor]; +end; + +constructor TTBStringsIterator.CreateCustom(const ASource: TStrings); +begin + inherited Create; + FStrings := ASource; + FCursor := -1; +end; + + +{ TTBListIterator } + +function TTBListIterator.HasNext: Boolean; +begin + Result := False; + if Assigned(FList) then + if FCursor < FList.Count - 1 then + Result := True; +end; + +function TTBListIterator.Next: TObject; +begin + Result := nil; + if HasNext then + begin + Inc(FCursor, 1); + result := TObject(FList.Items[FCursor]); + end; +end; + +function TTBListIterator.HasPrevious: Boolean; +begin + Result := False; + if Assigned(FList) then + begin + if FCursor > 0 then + Result := True; + end; +end; + +function TTBListIterator.Previous: TObject; +begin + Result := nil; + if HasPrevious then + begin + Dec(FCursor, 1); + Result := TObject(FList.Items[FCursor]); + end; +end; + +constructor TTBListIterator.CreateCustom(const ASource: TList); +begin + inherited Create; + FList := ASource; + FCursor := -1; +end; + + +{ TTBCollectionIterator } + +function TTBCollectionIterator.HasNext: Boolean; +begin + Result := False; + if Assigned(FCollection) then + if FCursor < FCollection.Count - 1 then + Result := True; +end; + +function TTBCollectionIterator.Next: TObject; +begin + Result := nil; + if HasNext then + begin + Inc(FCursor, 1); + result := FCollection.Items[FCursor]; + end; +end; + +function TTBCollectionIterator.HasPrevious: Boolean; +begin + Result := False; + if Assigned(FCollection) then + if FCursor > 0 then + Result := True; +end; + +function TTBCollectionIterator.Previous: TObject; +begin + Result := nil; + if HasPrevious then + begin + Dec(FCursor, 1); + Result := FCollection.Items[FCursor]; + end; +end; + +constructor TTBCollectionIterator.CreateCustom(const ASource: TCollection); +begin + inherited Create; + FCollection := ASource; + FCursor := -1; +end; + + +{ TTBFilteredStringsIterator } + +function TTBFilteredStringsIterator.GetFilter: string; +begin + Result := FRegex.RegexString; +end; + +procedure TTBFilteredStringsIterator.SetFilter(const AValue: string); +const + cFilterErr = 'Error in Filter string at position %d with ErrorCode %d. Filter string <%s>'; +var + LErrorCode: TRegexError; + LErrorPos: integer; +begin + if AValue <> FRegex.RegexString then + begin + FRegex.RegexString := AValue; + if not FRegex.Parse(LErrorPos, LErrorCode) then + raise Exception.CreateFmt(cFilterErr, [LErrorPos, Ord(LErrorCode), AValue]); + end; + FNextIndex := -1; +end; + +function TTBFilteredStringsIterator.HasNext: Boolean; +var + LIndex: integer; + LMatchPos: integer; + LOffset: integer; +begin + Result := False; + if GetFilter = '' then + begin + Result := inherited HasNext; + if Result then + FNextIndex := FCursor + 1; + end + else + begin + if FCursor < FStrings.Count - 1 then + begin + { If we haven't already calculated the next matching item } + if FNextIndex = -1 then + begin + LIndex := FCursor + 1; + { Peek ahead to find the next matching string } + while (LIndex < FStrings.Count) and (FNextIndex = -1) do + begin + { reset MatchString parameters } + LOffset := 0; + LMatchPos := 0; + if FRegex.MatchString(FStrings.Strings[LIndex], LMatchPos, LOffset) then + FNextIndex := LIndex; + Inc(LIndex); + end; + end; + if FNextIndex <> -1 then + Result := True; + end; + end; { if..else } +end; + +function TTBFilteredStringsIterator.Next: string; +begin + Result := ''; + if HasNext then + begin + FCursor := FNextIndex; + FNextIndex := -1; + Result := FStrings.Strings[FCursor]; + end; +end; + +function TTBFilteredStringsIterator.HasPrevious: Boolean; +begin + Result := False; // Filtered String is uni-directional +end; + +function TTBFilteredStringsIterator.Previous: string; +begin + Result := ''; + raise EUniDirectionalIterator.Create('Filtered String Iterator is uni-directional (forward) only.'); +end; + +constructor TTBFilteredStringsIterator.CreateCustom(const ASource: TStrings); +begin + inherited CreateCustom(ASource); + FRegex := TRegexEngine.Create(''); + FRegex.IgnoreCase := True; + FNextIndex := -1; +end; + +destructor TTBFilteredStringsIterator.Destroy; +begin + FRegex.Free; + inherited Destroy; +end; + + +{ TTBInterfaceListIterator } + +function TTBInterfaceListIterator.HasNext: Boolean; +begin + Result := False; + if Assigned(FList) then + if FCursor < FList.Count - 1 then + Result := True; +end; + +function TTBInterfaceListIterator.Next: IInterface; +begin + Result := nil; + if HasNext then + begin + Inc(FCursor, 1); + Result := FList.Items[FCursor]; + end; +end; + +function TTBInterfaceListIterator.HasPrevious: Boolean; +begin + Result := False; + if Assigned(FList) then + if FCursor > 0 then + Result := True; +end; + +function TTBInterfaceListIterator.Previous: IInterface; +begin + Result := nil; + if HasPrevious then + begin + Dec(FCursor, 1); + Result := FList.Items[FCursor]; + end; +end; + +constructor TTBInterfaceListIterator.CreateCustom(const ASource: TInterfaceList); +begin + inherited Create; + FList := ASource; + FCursor := -1; +end; + +{ TTBObjectListIterator } + +function TTBObjectListIterator.HasNext: Boolean; +begin + Result := False; + if Assigned(FList) then + if FCursor < FList.Count - 1 then + Result := True; +end; + +function TTBObjectListIterator.Next: TObject; +begin + result := nil; + if HasNext then + begin + Inc(FCursor); + result := FList.Items[FCursor]; + end; +end; + +function TTBObjectListIterator.HasPrevious: Boolean; +begin + Result := False; + if Assigned(FList) then + if FCursor > 0 then + Result := True; +end; + +function TTBObjectListIterator.Previous: TObject; +begin + result := nil; + if HasPrevious then + begin + Dec(FCursor); + result := FList.Items[FCursor]; + end; +end; + +constructor TTBObjectListIterator.CreateCustom(const ASource: TObjectList); +begin + inherited Create; + FList := ASource; + FCursor := -1; +end; + + +end. + |