TParadoxDataset: Add filtering support.
git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6908 8e941d3f-bd1b-0410-a28a-d453659cc2b4
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@ -4,7 +4,7 @@
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<PathDelim Value="\"/>
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<Name Value="lazparadoxpkg"/>
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<Type Value="RunAndDesignTime"/>
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<Author Value="Christian Ulrich"/>
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<Author Value="Christian Ulrich, Werner Pamler"/>
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<CompilerOptions>
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<Version Value="11"/>
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<PathDelim Value="\"/>
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@ -22,8 +22,8 @@
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</Debugging>
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</Linking>
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</CompilerOptions>
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<Description Value="Dataset for Paradox database files
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Read-only
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<Description Value="Dataset for Paradox database files; support of blobs, bookmarks and filtering
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Read-only, no indexes
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Tested on Win and Linux gtk2/qt (32bit/64bit)"/>
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<License Value="LGPL"/>
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<Version Minor="2"/>
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@ -10,28 +10,28 @@ unit paradoxds;
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interface
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uses
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Classes, SysUtils, db, lconvencoding;
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Classes, SysUtils, db, lconvencoding, bufdataset_parser;
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const
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{ Paradox codes for field types }
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pxfAlpha = $01;
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pxfDate = $02;
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pxfShort = $03;
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pxfLong = $04;
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pxfCurrency = $05;
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pxfNumber = $06;
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pxfLogical = $09;
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pxfMemoBLOb = $0C;
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pxfBLOb = $0D;
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pxfFmtMemoBLOb = $0E;
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pxfOLE = $0F;
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pxfGraphic = $10;
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pxfTime = $14;
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pxfTimestamp = $15;
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pxfAutoInc = $16;
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pxfBCD = $17;
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pxfBytes = $18;
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{ Paradox codes for field types }
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pxfAlpha = $01;
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pxfDate = $02;
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pxfShort = $03;
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pxfLong = $04;
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pxfCurrency = $05;
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pxfNumber = $06;
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pxfLogical = $09;
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pxfMemoBLOb = $0C;
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pxfBLOb = $0D;
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pxfFmtMemoBLOb = $0E;
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pxfOLE = $0F;
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pxfGraphic = $10;
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pxfTime = $14;
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pxfTimestamp = $15;
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pxfAutoInc = $16;
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pxfBCD = $17;
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pxfBytes = $18;
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type
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@ -166,11 +166,15 @@ type
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FInputEncoding: String;
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FTargetEncoding: String;
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FPxFields: Array of TPxField;
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FFilterBuffer : TRecordBuffer;
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FParser: TBufDatasetParser;
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function GetEncrypted: Boolean;
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function GetInputEncoding: String; inline;
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function GetTargetEncoding: String; inline;
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function GetVersion: String;
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function IsStoredTargetEncoding: Boolean;
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function PxFilterRecord(Buffer: TRecordBuffer): Boolean;
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function PxGetActiveBuffer(var Buffer: TRecordBuffer): Boolean;
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procedure ReadBlock;
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procedure ReadNextBlockHeader;
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procedure ReadPrevBlockHeader;
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@ -198,8 +202,11 @@ type
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procedure InternalPost; override;
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procedure InternalSetToRecord(Buffer: PChar); override;
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function IsCursorOpen: Boolean; override;
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procedure ParseFilter(const AFilter: string);
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procedure SetBookmarkData(Buffer: PChar; Data: Pointer); override;
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procedure SetBookmarkFlag(Buffer: PChar; Value: TBookmarkFlag); override;
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procedure SetFiltered(Value: Boolean); override;
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procedure SetFilterText(const Value: String); override;
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procedure SetRecNo(Value: Integer); override;
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public
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constructor Create(AOwner: TComponent); override;
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@ -217,6 +224,7 @@ type
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property Active;
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property AutoCalcFields;
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property FieldDefs;
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property Filter;
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property Filtered;
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property BeforeOpen;
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property AfterOpen;
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@ -268,7 +276,7 @@ end;
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function TParadoxDataset.BookmarkValid(ABookmark: TBookmark): Boolean;
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begin
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Result := Assigned(ABookmark) and (Length(ABookMark) <> 0);
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Result := Assigned(ABookmark) and (Length(ABookmark) <> 0);
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end;
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function TParadoxDataset.CompareBookmarks(Bookmark1, Bookmark2: TBookmark): Longint;
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@ -399,13 +407,15 @@ var
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int: LongInt absolute s;
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d: Double absolute s;
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str: String;
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buf: TRecordBuffer = nil;
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begin
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Result := False;
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if (RecordCount = 0) then
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exit;
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PXGetActiveBuffer(Buf);
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p := buf + FPxFields[Field.FieldNo - 1].Offset;
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F := FPxFields[Field.FieldNo - 1].Info;
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p := ActiveBuffer + FPxFields[Field.FieldNo - 1].Offset;
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size := F^.fSize;
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// These numeric fields are stored as big endian --> swap bytes
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@ -484,59 +494,63 @@ end;
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function TParadoxDataset.GetRecord(Buffer: PChar; GetMode: TGetMode; DoCheck: Boolean): TGetResult;
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var
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L: Longword;
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accepted: Boolean;
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begin
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Result := grOK;
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case GetMode of
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gmNext:
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begin
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inc(FaRecord);
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if (FaBlockIdx = FHeader^.lastBlock) and
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(FaRecord > FaBlockStart + FaBlock^.addDataSize div FHeader^.recordSize + 1)
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then
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Result := grEOF
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else
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accepted := false;
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repeat
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case GetMode of
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gmNext:
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begin
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inc(FaRecord);
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if (FaBlockIdx = FHeader^.lastBlock) and
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(FaRecord > FaBlockStart + FaBlock^.addDataSize div FHeader^.recordSize + 1)
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then
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Result := grEOF
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else
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if FaRecord > FaBlockStart+1+(FaBlock^.addDataSize div FHeader^.recordSize) then
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ReadNextBlockHeader;
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end;
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end;
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gmPrior:
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begin
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dec(FaRecord);
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if (FaBlockIdx = FHeader^.firstBlock) and (FaRecord < 1) then
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Result := grBOF
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else
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gmPrior:
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begin
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dec(FaRecord);
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if (FaBlockIdx = FHeader^.firstBlock) and (FaRecord < 1) then
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Result := grBOF
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else
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if FaRecord <= FaBlockStart then
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begin
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ReadPrevBlockHeader;
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FaRecord := FaBlockStart+(FaBlock^.addDataSize div FHeader^.recordSize)+1;
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end;
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begin
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ReadPrevBlockHeader;
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FaRecord := FaBlockStart+(FaBlock^.addDataSize div FHeader^.recordSize)+1;
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end;
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end;
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gmCurrent:
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if (FaRecord > RecordCount) or (FaRecord < 1) then
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result := grError;
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end;
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gmCurrent:
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begin
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if (FaRecord > RecordCount) or (FaRecord < 1) then
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result := grError;
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end;
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end;
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if Result = grOK then
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begin
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if not FBlockreaded then
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if Result = grOK then begin
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if not FBlockReaded then
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ReadBlock;
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L := ((faRecord-(FaBlockstart+1))*FHeader^.recordSize)+6;
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if (faRecord-(FaBlockstart+1)) >= 0 then
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begin
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Move(PChar(FaBlock)[L],Buffer[0],FHeader^.recordSize);
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end
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L := ((faRecord - (FaBlockstart + 1))*FHeader^.recordSize) + 6;
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if (faRecord - (FaBlockstart + 1)) >= 0 then
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Move(PChar(FaBlock)[L],Buffer[0],FHeader^.recordSize)
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else
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result := grError;
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with PRecInfo(Buffer + FHeader^.recordSize)^ do
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begin
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BookmarkFlag := bfCurrent;
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RecordNumber := FaRecord;
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end;
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Result := grError;
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with PRecInfo(Buffer + FHeader^.recordSize)^ do begin
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BookmarkFlag := bfCurrent;
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RecordNumber := FaRecord;
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end;
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// Filtering
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if Filtered then
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accepted := PXFilterRecord(Buffer)
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else
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accepted := True;
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if (GetMode = gmCurrent) and not accepted then
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Result := grError;
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end;
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until (Result <> grOK) or Accepted;
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end;
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function TParadoxDataset.GetRecordCount: Integer;
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@ -584,6 +598,7 @@ begin
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DestroyFields;
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FreeMem(FHeader);
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FreeMem(FaBlock);
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FreeAndNil(FParser);
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FreeAndNil(FBlobStream);
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FreeAndNil(FStream);
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FActive := False;
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@ -730,6 +745,13 @@ begin
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if DefaultFields then CreateFields;
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BindFields(True);
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FActive := True;
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try
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ParseFilter(Filter);
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except
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on E: Exception do
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Filter := '';
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end;
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end;
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procedure TParadoxDataset.InternalPost;
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@ -737,9 +759,13 @@ begin
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end;
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procedure TParadoxDataset.InternalSetToRecord(Buffer: PChar);
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var
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bm: LongWord;
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begin
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if (State <> dsInsert) then
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InternalGotoBookmark(@PRecInfo(Buffer + FHeader^.RecordSize)^.RecordNumber);
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if (State <> dsInsert) then begin
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bm := PRecInfo(Buffer + FHeader^.RecordSize)^.RecordNumber;
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InternalGotoBookmark(@bm);
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end;
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end;
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function TParadoxDataset.IsCursorOpen: Boolean;
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@ -752,6 +778,59 @@ begin
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Result := not SameText(FTargetEncoding, EncodingUTF8);
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end;
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procedure TParadoxDataset.ParseFilter(const AFilter: string);
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begin
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if Length(AFilter) > 0 then
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begin
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if (FParser = nil) and IsCursorOpen then
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FParser := TBufDatasetParser.Create(Self);
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if FParser <> nil then
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begin
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FParser.PartialMatch := not (foNoPartialCompare in FilterOptions);
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FParser.CaseInsensitive := foCaseInsensitive in FilterOptions;
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FParser.ParseExpression(AFilter);
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end;
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end;
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end;
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function TParadoxDataset.PxFilterRecord(Buffer: TRecordBuffer): Boolean;
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var
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SaveState: TDatasetState;
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begin
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Result := True;
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if not Assigned(OnFilterRecord) and not Filtered then
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Exit;
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SaveState := SetTempState(dsFilter);
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Try
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FFilterBuffer := Buffer;
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If Assigned(OnFilterRecord) then
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OnFilterRecord(Self, Result);
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If Result and Filtered and (Filter <> '') then
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Result := Boolean((FParser.ExtractFromBuffer(FFilterBuffer))^);
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Finally
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RestoreState(SaveState);
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end;
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end;
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function TParadoxDataset.PxGetActiveBuffer(var Buffer: TRecordBuffer): Boolean;
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begin
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case State of
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dsBrowse:
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if IsEmpty then
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Buffer := nil
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else
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Buffer := ActiveBuffer;
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dsEdit,
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dsInsert:
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Buffer := ActiveBuffer;
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dsFilter:
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Buffer := FFilterBuffer;
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else
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Buffer := nil;
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end;
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Result := (Buffer <> nil);
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end;
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procedure TParadoxDataset.ReadBlock;
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var
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L : longint;
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@ -822,6 +901,25 @@ begin
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FFilename := AValue;
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end;
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procedure TParadoxDataset.SetFiltered(Value: Boolean);
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begin
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if (Value <> Filtered) then begin
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inherited;
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if IsCursorOpen then
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Refresh;
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end;
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end;
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procedure TParadoxDataset.SetFilterText(const Value: String);
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begin
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if (Value <> Filter) then begin
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ParseFilter(Value);
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inherited;
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if IsCursorOpen and Filtered then
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Refresh;
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end;
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end;
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procedure TParadoxDataset.SetRecNo(Value: Integer);
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begin
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if Value < FaRecord then
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