How to read chart width & height from a non visible char

[Narcís]

Hi Dominik,

Thanks for the information, I understand your problem.

In that case you could try using a temporary chart with no parent for retrieving original chart width and height, for example:

Code: Select all

procedure TForm16.Button2Click(Sender: TObject);
var tmpChart: TChart;
begin
  Form16.Width  := 640;
  Form16.Height := 480;

  tmpChart:=TChart.Create(self);

  LoadChartFromFile(TCustomChart(tmpChart), 'Test.tee');

  tmpWidth:=tmpChart.Width;
  tmpHeight:=tmpChart.Height;

  tmpChart.Free;

  LoadChartFromFile(TCustomChart(Chart1), 'Test.tee');

  SetAnnotationPosition(Chart1.Tools.Items[0] as TRectangleTool);
end;

I've also sent you the project modified.

[moelski]

Hi Narcis,

ok we come closer and closer

But there is still a small problem ...

You used this code:

Code: Select all

  tmpChart:=TChart.Create(self);

  LoadChartFromFile(TCustomChart(tmpChart), 'Test.tee');

  tmpWidth:=tmpChart.Width;
  tmpHeight:=tmpChart.Height;

  tmpChart.Free;

But width and height includes the axis. So what we need is something like this:

Code: Select all

  tmpChart:=TChart.Create(self);

  LoadChartFromFile(TCustomChart(tmpChart), 'Test.tee');

  tmpWidth  := tmpChart.chartRect.Right  - tmpChart.chartRect.Left;   //tmpChart.Width;
  tmpHeight := tmpChart.chartRect.Bottom - tmpChart.chartRect.Top;

  tmpChart.Free;

But if I debug this code I get 0 for tmpWidth and tmpHeight.

And if I use your code, the callout is not at the correct position after loading in a resized chart.

[Narcís]

Hi Dominik,

Ok, in that case you need to draw tmpChart and use tmpWidht and tmpHeight like this:

Code: Select all

procedure TForm16.Button4Click(Sender: TObject);
begin
  SaveChartToFile(Chart1, 'Test.tee', True, True);
  tmpWidth  := Chart1.chartRect.Right  - Chart1.chartRect.Left;   //tmpChart.Width;
  tmpHeight := Chart1.chartRect.Bottom - Chart1.chartRect.Top;
end;

procedure TForm16.Button2Click(Sender: TObject);
var tmpChart: TChart;
begin
  Form16.Width  := 640;
  Form16.Height := 480;

  tmpChart:=TChart.Create(self);

  LoadChartFromFile(TCustomChart(tmpChart), 'Test.tee');

  tmpChart.Parent:=self;
  tmpChart.Draw;
  tmpChart.Parent:=nil;

  tmpWidth  := tmpChart.chartRect.Right  - tmpChart.chartRect.Left;   //tmpChart.Width;
  tmpHeight := tmpChart.chartRect.Bottom - tmpChart.chartRect.Top;

  tmpChart.Free;

  LoadChartFromFile(TCustomChart(Chart1), 'Test.tee');

  SetAnnotationPosition(Chart1.Tools.Items[0] as TRectangleTool);
end;

And then implement SetAnnotationPosition this way:

Code: Select all

procedure TForm16.SetAnnotationPosition(Annotacion: TRectangleTool);
var w,h: Double;
    RectWidth, RectHeight: Integer;
begin
  Chart1.Draw;

  Annotacion.Shape.Left := Chart1.ChartRect.Left  + (150 - Chart1.Left);
  Annotacion.Shape.Top :=  Chart1.ChartRect.Top + (100 - Chart1.Top);

  if tmpWidth=0 then
    Annotacion.Callout.XPosition := Chart1.ChartRect.Left  + (250 - Chart1.Left)
  else
  begin
    RectWidth := Chart1.ChartRect.Right - Chart1.ChartRect.Left;
    w := RectWidth / tmpWidth;
    Annotacion.Callout.XPosition := Round(Annotacion.Callout.XPosition * w);
  end;

  if tmpHeight=0 then
    Annotacion.Callout.YPosition := Chart1.ChartRect.Top + (180 - Chart1.Top)
  else
  begin
    RectHeight := Chart1.ChartRect.Bottom - Chart1.ChartRect.Top;
    h:= RectHeight / tmpHeight;
    Annotacion.Callout.YPosition := Round(Annotacion.Callout.YPosition * h);
  end;
end;

[moelski]

Hi Narcis,

ok the calculation of tmpWidth and tmpHeight works now. But I think there is still something wrong.

I uploaded the project t your server:
Received CallOutPos After Load.zip Content Type application/x-zip-compressed Length 28741

Please have a look at the following two pictures. The first one is after creation and the second one is after resize and reload of the TEE file.





As you can see the annotation is not at the correct position. Do you have any idea what causes this problem and how we can get the X / Y position calculated correct?

[Narcís]

Hi Dominik,

In your project you didn't change Button4 OnClick event implementation as I suggested in my last post. Please try using this:

Code: Select all

procedure TForm16.Button4Click(Sender: TObject);
begin
  SaveChartToFile(Chart1, 'Test.tee', True, True);
  //tmpWidth:=Chart1.Width;
  //tmpHeight:=Chart1.Height;
  tmpWidth  := Chart1.chartRect.Right  - Chart1.chartRect.Left;
  tmpHeight := Chart1.chartRect.Bottom - Chart1.chartRect.Top;
end;

[moelski]

Hi Narcis,

yes you are right.
But that button won´t be pressed if you restart the application and load the saved TEE file.

And if I use that code and don´t restart the appliaction the calculation is wrong, too.

Give it a try by doing the following steps:
1) Create Tool with Button 1
2) Save Tee
3) Clear
4) Load Tee
Now have a look where the callout is placed in X direction and keep it in mind. It should be between 13 and 14.
5) Resize the form Width and press Load Tee again
You will see that the X position has changed!

So the calculation isn´t correct at this time.

[Narcís]

Hi Dominik,

Ok, in that case you'll also need to update tmpWidth and tmpHeight in the chart OnResize event like this:

Code: Select all

procedure TForm16.Chart1Resize(Sender: TObject);
begin
  if Chart1.Tools.Count>0 then
  begin
    tmpWidth  := Chart1.chartRect.Right  - Chart1.chartRect.Left;
    tmpHeight := Chart1.chartRect.Bottom - Chart1.chartRect.Top;
    SetAnnotationPosition(Chart1.Tools.Items[0] as TRectangleTool);
  end;
end;

[moelski]

Hi Narcis,

the code you posted produces the same error as if I load the Tee file after resizing the chart.

I have created a small video (WMV Format). Please have a look and you will see the error.
http://www.logview.info/Downloads/CallOutError.zip

How can we fix this ? Maybe there is a better solution for get the CallOut stuff working ??

[moelski]

Hi Narcis,

no idea about this?

[Narcís]

Hi Dominik,

This is because of only using ChartRect dimensions. When redimensioning the chart you'll also see that margins also change and therefore you are introducing a little error here. As I told you earlier on the thread, the only way to always have an exact position for the annotation tool is setting it to a relative value to a chart element, for example this:

Code: Select all

procedure TForm16.SetAnnotationPosition(Annotacion: TRectangleTool);
begin
  Chart1.Draw;

  Annotacion.Shape.Left := Chart1.ChartRect.Left  + (150 - Chart1.Left);
  Annotacion.Shape.Top :=  Chart1.ChartRect.Top + (100 - Chart1.Top);
  Annotacion.Callout.XPosition := Chart1.Axes.Bottom.CalcXPosValue(35);
  Annotacion.Callout.YPosition := Chart1.Axes.Left.CalcYPosValue(Chart1[0].YValues[3]);
end;

[moelski]

Hi Narcis,

Annotacion.Callout.XPosition := Chart1.Axes.Bottom.CalcXPosValue(35);
Annotacion.Callout.YPosition := Chart1.Axes.Left.CalcYPosValue(Chart1[0].YValues[3]);

Are these values the stored (within the TEE file) x / y values from the callout?

[Narcís]

Hi Dominik,

No, what's stored in the tee file are the result of CalcXPosValue and CalcYPosValue calls.

[moelski]

Hi Narcis,

ok but that´s exactly my problem !

The Tee file stores a pixel Value.
And how should I get the values you are using here:
Annotacion.Callout.XPosition := Chart1.Axes.Bottom.CalcXPosValue(35);
Annotacion.Callout.YPosition := Chart1.Axes.Left.CalcYPosValue(Chart1[0].YValues[3]);

These values are not available after loading a Tee file.

[Narcís]

Hi Dominik,

No, I'm afraid there's no other option than hard coding them.

Maybe an option would be settin annotation positions to the indexes you are using, for example, setting Annotation.Callout.XPosition:=35 before exporting the file and then using this value to retrieve corresponding axis position using CalcXPosValue after the tee file has been loaded, for example:

Code: Select all

Annotacion.Callout.XPosition := Chart1.Axes.Bottom.CalcXPosValue(Annotacion.Callout.XPosition);