fpspreadsheet: Implement TsWorksheet.Clear (removes all content from sheet). Called by new TsWorksheetGrid.Clear.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@4674 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/fpspreadsheet.pas

@@ -400,6 +400,7 @@ type
     procedure CopyValue(AFromCell, AToCell: PCell); overload;
     procedure CopyValue(AValueCell: PCell; AToRow, AToCol: Cardinal); overload;
 
+    procedure Clear;
     procedure DeleteCell(ACell: PCell);
     procedure EraseCell(ACell: PCell);
 
@@ -1855,6 +1856,20 @@ begin
   CopyValue(AValueCell, GetCell(AToRow, AToCol));
 end;
 
+procedure TsWorksheet.Clear;
+begin
+  FCells.Clear;
+  FComments.Clear;
+  FHyperlinks.Clear;
+  FMergedCells.Clear;
+
+  RemoveAllImages;
+  RemoveAllRows;
+  RemoveAllCols;
+
+  ChangedCell(0, 0);
+end;
+
 {@@ ----------------------------------------------------------------------------
   Deletes a specified cell. If the cell belongs to a merged block its content
   and formatting is erased. Otherwise the cell is destroyed and its memory is

components/fpspreadsheet/fpspreadsheetgrid.pas

@@ -274,6 +274,7 @@ type
 
     procedure BeginUpdate;
     function CellRect(ACol1, ARow1, ACol2, ARow2: Integer): TRect; overload;
+    procedure Clear;
     procedure DefaultDrawCell(ACol, ARow: Integer; var ARect: TRect; AState: TGridDrawState); override;
     procedure DeleteCol(AGridCol: Integer); reintroduce;
     procedure DeleteRow(AGridRow: Integer); reintroduce;
@@ -1373,6 +1374,14 @@ begin
   end;
 end;
 
+{@@ ----------------------------------------------------------------------------
+  Clears the grid contents
+-------------------------------------------------------------------------------}
+procedure TsCustomWorksheetGrid.Clear;
+begin
+  if (Worksheet <> nil) then Worksheet.Clear;
+end;
+
 {@@ ----------------------------------------------------------------------------
   Converts a spreadsheet font to a font used for painting (TCanvas.Font).
 
@@ -4322,11 +4331,11 @@ begin
 
   if FLockSetup > 0 then
     exit;
-
+  {
   if not HandleAllocated then
     //Avoid crash when accessing the canvas, e.g. in GetDefaultHeaderColWidth
     exit;
-
+   }
   if (Worksheet = nil) or (Worksheet.GetCellCount = 0) then begin
     FixedCols := FFrozenCols + FHeaderCount;
     FixedRows := FFrozenRows + FHeaderCount;