TChart : The check/unchecked event not working in ExtraLegendTool - delphi-xe2

Question

I displayed an ExtraLegendTool with checkboxes but the checkbox event is not working.
Here is the code to display the ExtraLegend:
procedure TFRChart.TCChartAfterDraw(Sender: TObject);
begin
if CKDisplay.Checked then
begin
with ExtraLegend do
begin
Active:= True;
Series := TBarSeries(Self.FindComponent('SeriesTotal'));
with Legend do
begin
LegendStyle := lsAuto;
CheckBoxes := True;
//MaxNumRows := 3;
CustomPosition := True;
Left:= TCChart.Legend.Left;
Top:= TCChart.Legend.ShapeBounds.Bottom + 10;
Width := TCChart.Legend.Width;
ShapeBounds.Right := TCChart.Legend.ShapeBounds.Bottom;
DrawLegend;
end;
end;
end;
end;
Please check the folowing image for more details :
As you can see in the image, I have 2 legends one of type 'Chart1.Legend.LegendStyle := lsSeriesGroups' and the other one is an ExtraLegend.
How can I NOT display all the blue bars for all the series groups when I uncheck the blue series in the Extralegend?

Answer 1

You can use the ExtraLegendTool Clicked() function at the chart OnClick event to get the item of the legend that has been clicked. Then, you can activate/deactivate any series you desire.
This simple example seems to work fine for me here:
procedure TForm1.Chart1Click(Sender: TObject);
var MousePos: TPoint;
index: Integer;
begin
MousePos:=Chart1.GetCursorPos;
index:=ChartTool1.Legend.Clicked(MousePos);
while (index>-1) and (index<Chart1.SeriesCount) do
begin
Chart1[index].Active:=not Chart1[index].Active;
index:=index+3;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
Chart1.SeriesGroups.Add;
Chart1.SeriesGroups.Add;
Chart1.SeriesGroups[0].Name:='This is Group 1';
Chart1.SeriesGroups[1].Name:='This is Group 2';
for i:=0 to 9 do
with Chart1.AddSeries(TBarSeries) as TBarSeries do
begin
FillSampleValues(5);
if (i<3) then
begin
Chart1.SeriesGroups[0].Add(Chart1[i]);
StackGroup:=0;
end
else
begin
Chart1.SeriesGroups[1].Add(Chart1[i]);
StackGroup:=1;
end;
MultiBar:=mbStacked;
end;
Chart1.Legend.LegendStyle := lsSeriesGroups;
Chart1.Draw;
with ChartTool1 do
begin
Active:= True;
//Series := TBarSeries(Self.FindComponent('SeriesTotal'));
Series := Chart1[0];
with Legend do
begin
LegendStyle := lsAuto;
CheckBoxes := True;
MaxNumRows := 3;
CustomPosition := True;
Left:= Chart1.Legend.Left;
Top:= Chart1.Legend.ShapeBounds.Bottom + 10;
Width := Chart1.Legend.Width;
ShapeBounds.Right := Chart1.Legend.ShapeBounds.Bottom;
DrawLegend;
end;
end;
end;