fpspreadsheet: Split chart writing code off of ods writer.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8996 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/examples/other/chart/write_chart_demo.lpr

@@ -83,7 +83,7 @@ begin
     ch.Background.Style := fsSolidFill;
     ch.Border.Style := clsSolid;
     ch.PlotArea.Background.Style := fsSolidFill;
-    ch.RotatedAxes := true;
+    //ch.RotatedAxes := true;
     ch.StackMode := csmStackedPercentage;
     //ch.Interpolation := ciCubicSpline;
 

components/fpspreadsheet/laz_fpspreadsheet.lpk

@@ -33,7 +33,7 @@
 This package is all you need if you don't want graphical components (such as grids and charts)."/>
     <License Value="LGPL with static linking exception. This is the same license as is used in the LCL (Lazarus Component Library)."/>
     <Version Major="1" Minor="17"/>
-    <Files Count="58">
+    <Files Count="59">
       <Item1>
         <Filename Value="source\fps.inc"/>
         <Type Value="Include"/>
@@ -305,6 +305,10 @@ This package is all you need if you don&apos;t want graphical components (such a
         <Filename Value="source\common\fpspreadsheet_chart.inc"/>
         <Type Value="Binary"/>
       </Item58>
+      <Item59>
+        <Filename Value="source\common\fpsopendocumentchart.pas"/>
+        <UnitName Value="fpsopendocumentchart"/>
+      </Item59>
     </Files>
     <CompatibilityMode Value="True"/>
     <i18n>

components/fpspreadsheet/source/common/fpsreaderwriter.pas

@@ -197,6 +197,19 @@ type
     property NumFormatList: TStringList read FNumFormatList;
   end;
 
+  {@@ Helper class for the spreadsheet writer to keep processing of charts
+    out of the main writer unit. }
+  TsBasicSpreadChartWriter = class
+  protected
+    FWriter: TsBasicSpreadWriter;
+  public
+    constructor Create(AWriter: TsBasicSpreadWriter); virtual;
+    procedure CreateStreams; virtual; abstract;
+    procedure DestroyStreams; virtual; abstract;
+    procedure ResetStreams; virtual; abstract;
+    procedure WriteCharts; virtual; abstract;
+    property Writer: TsBasicSpreadWriter read FWriter;
+  end;
 
 type
   TsSpreadFileAccess = (faRead, faWrite);
@@ -912,6 +925,21 @@ begin
   raise Exception.Create(rsUnsupportedWriteFormat);
 end;
 
+
+{------------------------------------------------------------------------------}
+{                           TsBasicSpreadChartWriter                           }
+{------------------------------------------------------------------------------}
+
+{@@ Constructor of the ChartWriter. It gets the main writer as parameter. }
+constructor TsBasicSpreadChartWriter.Create(AWriter: TsBasicSpreadWriter);
+begin
+  FWriter := AWriter;
+end;
+
+
+{------------------------------------------------------------------------------}
+{                          TsSpreadFormatRegistry                              }
+{------------------------------------------------------------------------------}
 type
   TsSpreadFormatData = class
   private

components/fpspreadsheet/source/common/fpsxmlcommon.pas

@@ -18,6 +18,9 @@ uses
  {$ENDIF}
   fpstypes, fpsreaderwriter;
 
+const
+  XML_HEADER = '<?xml version="1.0" encoding="utf-8" ?>';
+
 type
   TsSpreadXMLReader = class(TsCustomSpreadReader)
   protected