Steema Central

Barry wrote:I have a candlestick chart which users use to view and correct financial data (pls see attached jpg). The Marks on the chart show where there are corporate actions 'C' or name changes 'N'. I currently use cross hairs and allow users to click and drag a rectangle to zoom into the chart to see the candle bars in more detail and then when a candle is clicked on using the OnClickSeries event I display the candle data for a user to edit.

What the users are asking for is when they click on a candle for a vertical line to be drawn on the chart so they can easily see where they have clicked. They also want this line to move when they click on another candle - all this needs to happen without losing any of the existing functionality.

I have read the various posts and tried a number of different things and none of these seem to display a vertical line and I wondered if you could help.

uses CandleCh, TeeTools;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Chart1.View3D:=false;
  Chart1.Legend.Visible:=false;

  with Chart1.Tools.Add(TColorLineTool) as TColorLineTool do
  begin
    Axis:=Chart1.Axes.Bottom;
    AllowDrag:=false;
    Active:=false;
  end;

  with Chart1.AddSeries(TCandleSeries) as TCandleSeries do
  begin
    FillSampleValues;
    OnClick:=CandleClick;
  end;
end;

procedure TForm1.CandleClick(Sender:TChartSeries; ValueIndex:Integer; Button:TMouseButton;
                             Shift: TShiftState; X, Y: Integer);
begin
  with Chart1.Tools[0] as TColorLineTool do
  begin
    Value:=Sender.XValue[ValueIndex];
    Active:=true;
  end;
end;

Barry wrote:The final question from the users is its quite tricky to actually click on a candle so can they click anywhere on the chart and pickup the candle above or below where they click.

uses CandleCh, TeeTools;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Chart1.View3D:=false;
  Chart1.Legend.Visible:=false;

  with Chart1.Tools.Add(TColorLineTool) as TColorLineTool do
  begin
    Axis:=Chart1.Axes.Bottom;
    AllowDrag:=false;
    Active:=false;
  end;

  Chart1.AddSeries(TCandleSeries).FillSampleValues;

  Chart1.OnMouseDown:=Chart1MouseDown;
end;

procedure TForm1.Chart1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var ValueIndex: Integer;
begin
  ValueIndex:=Chart1[0].Clicked(X,Y);
  if ValueIndex>-1 then
    SetColorLine(true, Chart1[0].XValue[ValueIndex])
  else
  begin
    if Chart1.Tools[0].Active then
      SetColorLine(false)
    else
    begin
      ValueIndex:=TNearestTool.GetNearestPoint(Chart1[0], X, Y);
      if ValueIndex>-1 then
        SetColorLine(true, Chart1[0].XValue[ValueIndex]);
    end;
  end;
end;

procedure TForm1.SetColorLine(AActive: boolean; AValue: Double=-1);
begin
  with Chart1.Tools[0] as TColorLineTool do
  begin
    Active:=AActive;
    if AValue>-1then
      Value:=AValue;
  end;
end;

Barry wrote:1. I assume you meant

with Chart1.Tools.Add(TColorLineTool) as TColorLineTool do
begin
Axis:=Chart1.Axes.Bottom;
AllowDrag:=true;
Active:=true;
end;

not setting them to false as per your example.

Barry wrote:How do I get the values of the candle under the line, as the line moves I want to see the values reflected in a table. I do this today by clicking on a point, but users want something more dynamic

Barry wrote:Please see attached sample which doesn't seem to work

  with Chart1.AddSeries(TCandleSeries) as TCandleSeries do
  begin
    OnClick:=CandleClick;
  end;

  Series1.OnClick:=CandleClick;

Barry wrote:If you run your demo and then select Editor then

Tools -> Color line - > Options and click "allow Drag" (I also made mine Red so I could see it better)

Barry wrote:The final question from the users is its quite tricky to actually click on a candle so can they click anywhere on the chart and pickup the candle above or below where they click.

  ColorLine1:=Chart1.Tools.Add(TColorLineTool) as TColorLineTool;
  with ColorLine1 do
  begin
    Axis:=Chart1.Axes.Bottom;
    AllowDrag:=true;
    Active:=false;
    Pen.Color:=clRed;
  end;

Barry wrote:Now you can drag it left and right, what I want is the values in the string grid to change as I drag the color line over them - as it stands I still have to click on the Candle - This is already build into my code and I know how to do this, pls see the better screenshot

Barry wrote:Also the

Tools -> Color line - > Options and click "allow Drag"

Is not available at design time, is there any reason for this please ?

Barry wrote:Many thanks - especially for the demo code which allows me to explain the issue much better