fpspreadsheet: Add TsClearFormatAction to clear a cell format.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6492 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/source/common/fpspreadsheet.pas

@@ -9255,6 +9255,11 @@ end;
 -------------------------------------------------------------------------------}
 function TsWorkbook.GetPointerToCellFormat(AIndex: Integer): PsCellFormat;
 begin
+  if FCellFormatList.Count = 0 then
+    raise Exception.Create('[TsWorkbook.GetPointerToCellFormat]: No format items.');
+
+  if (AIndex < 0) or (AIndex >= FCellFormatList.Count) then
+    AIndex := 0;  // 0 is default format
   Result := FCellFormatList.Items[AIndex];
 end;
 

components/fpspreadsheet/source/design/fpsvisualreg.pas

@@ -42,6 +42,7 @@ begin
     TsWorksheetZoomAction,
     // Cell or cell range formatting actions
     TsCopyAction,
+    TsClearFormatAction,
     TsFontStyleAction, TsFontDialogAction, TsBackgroundColorDialogAction,
     TsHorAlignmentAction, TsVertAlignmentAction,
     TsTextRotationAction, TsWordWrapAction,

components/fpspreadsheet/source/visual/fpsactions.pas

@@ -180,6 +180,12 @@ type
     property Visible;
   end;
 
+  { TsClearFormatAction }
+  TsClearFormatAction = class(TsAutoFormatAction)
+  protected
+    procedure ApplyFormatToCell(ACell: PCell); override;
+  end;
+
   { TsFontStyleAction }
   TsFontStyleAction = class(TsAutoFormatAction)
   private
@@ -928,6 +934,18 @@ begin
 end;
 
 
+{ TsClearFormatAction }
+
+procedure TsClearFormatAction.ApplyFormatToCell(ACell: PCell);
+begin
+  if ACell <> nil then
+  begin
+    ACell^.FormatIndex := 0;  // Default format
+    Worksheet.ChangedCell(ACell^.Row, ACell^.Col);
+  end;
+end;
+
+
 { TsFontStyleAction }
 
 constructor TsFontStyleAction.Create(AOwner: TComponent);