Applies to
TWPPreview

Declaration
property OnCustomLinePaintBefore: TWPVirtPagePaintEvent;

Description
This event is used like OnCustomLinePaintAfter but is triggered before the text has been rendered. This makes it possible to draw to the background of the text.
This example code will draw brackets into the left margin to show how paragraphs are linked together using the KeepN property:

procedure TWPTBXForm.WPRichText1CustomLinePaintBefore(Sender: TObject; RTFEngine: TWPRTFEngineBasis; Param: TWPVirtPagePaintParam; EndOfPageRun: Boolean); var r: TRect; o: Integer; par: TParagraph; thiskeep, prevkeep, nextkeep: Boolean; begin if (Param.Par.ParentTable = nil) and (Param.PaintingInEditor) then begin if not EndOfPageRun then begin Param.CallAgainToClose := TRUE; // Make sure we get that EndOfPageRun! end else begin par := Param.Par.prev; prevkeep := (par <> nil) and (par.AGetDef(WPAT_ParKeepN, 0) = 1); thiskeep := Param.par.AGetDef(WPAT_ParKeepN, 0) = 1; nextkeep := TRUE; par := Param.Par.next; if (par = nil) or (par.AGetDef(WPAT_ParKeepN, 0) = 0) then begin nextkeep := FALSE; end; r := Param.UnionRect; o := 30; Param.Canvas.Pen.Width := 0; Param.Canvas.Pen.Color := clRed; if thiskeep and not prevkeep then begin Param.Canvas.MoveTo(r.Left, r.Top); Param.Canvas.LineTo(r.Left - o, r.Top); end; if thiskeep or prevkeep then begin Param.Canvas.MoveTo(r.Left - o, r.Top); Param.Canvas.LineTo(r.Left - o, r.Bottom); end; if not thiskeep and prevkeep and not nextkeep then begin Param.Canvas.MoveTo(r.Left - o, r.Bottom); Param.Canvas.LineTo(r.Left, r.Bottom); end; end; end; end;

Category
Paragraph-Reference