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

[moelski]

Hi !

I try to get the chart width & height from a chart I load from a template. This is my code:

Code: Select all

          _t2 := TChart.Create(Self);
          _t2.Parent := NIL;
          Chart_Container.ChartMemStream.Position := 0;  // Stream auf Anfang positionieren
          LoadChartFromStream(TCustomChart(_t2), TStream(Chart_Container.ChartMemStream));
          ChartStreamWidth  := _t2.ChartRect.Bottom - _t2.ChartRect.Top;
          ChartStreamHeight := _t2.ChartRect.right  - _t2.chartrect.left;

          if _t2 <> NIL then _t2.Free;

The problem is the nonvisible chart because of parent = NIL. I get 0 as result for height und width.

If I use _t2.Parent := TestTab (TestTab is a Pagecontrol Panel) it works as I aspected.

But if I set the paranet <> NIL the chart will be painted completely?!

Is there a way to get the values with parent = NIL ?

[Narcís]

Hi Dominik,

This should work fine because when exporting a TChart to a template file or stream, its width and height are exported as well. Code below works fine for me here.

Code: Select all

uses TeeStore, TeeEditPro;

procedure TForm1.Button1Click(Sender: TObject);
var tmpChart: TChart;
    stream: TMemoryStream;
begin
  stream:=TMemoryStream.Create;
  tmpChart:=TChart.Create(self);

  try
    SaveChartToStream(Chart1,stream);
    stream.Position:=0;
    LoadChartFromStream(TCustomChart(tmpChart),stream);
  finally
    stream.Free;
  end;

  Caption:=IntToStr(tmpChart.Width) + ', ' + IntToStr(tmpChart.Height);
end;

Even the chart has no parent you could try calling its Draw method so that Width and Height properties are computed.

Hope this helps!

[moelski]

Hi Narcis,

well I can read width and height. That is no problem.
But I need only the width / height of the chart area.

Width and Height includes the axis. And that´s not what I need.

So I need something like this:
ChartStreamWidth := _t2.ChartRect.Bottom - _t2.ChartRect.Top;
ChartStreamHeight := _t2.ChartRect.right - _t2.chartrect.left;

I will test if I get useful value if I call the draw methode before. At the moment the chartrect is 0,0,0,0.

[Narcís]

Hi Dominik,

Ok, you need to set a parent for the chart to be able to draw it and obtain valid values. This works fine for me here:

Code: Select all

uses TeeStore, TeeEditPro;

procedure TForm1.Button1Click(Sender: TObject);
var tmpChart: TChart;
    stream: TMemoryStream;
    RectWidth, RectHeight: Integer;
begin
  stream:=TMemoryStream.Create;
  tmpChart:=TChart.Create(self);

  try
    SaveChartToStream(Chart1,stream);
    stream.Position:=0;
    LoadChartFromStream(TCustomChart(tmpChart),stream);
  finally
    stream.Free;
  end;

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

  RectWidth:=tmpChart.ChartRect.Right-tmpChart.ChartRect.Left;
  RectHeight:=tmpChart.ChartRect.Bottom-tmpChart.ChartRect.Top;
  Caption:=IntToStr(RectWidth) + ', ' + IntToStr(RectHeight);
end;

[moelski]

Hi Narcis,

I tried your solution but this works not really good.

What I need is the original ChartRect size. The problem in your code is the following:
You save a Chart to a stream. Then resize the Form and do this:

Code: Select all

          Chart_Container.ChartMemStream.Position := 0;  // Stream auf Anfang positionieren
          LoadChartFromStream(TCustomChart(_t2), TStream(Chart_Container.ChartMemStream));
          _t2.Parent := Self;
          _t2.Draw;
          _t2.Parent := nil;

The first thing what happens is a resize of _t2. And if I read the ChartRect values in the next step I don´t get the correct values.

I want to use these values for calculate the correct positions for callouts. You know that the position is saved in pixel values. And if you load a chart from a stream and your form size has changed the callouts will be placed wrong.

My idea was to read the saved ChartRect information and do some calculations like this:

Code: Select all

Left  := Trunc(Left  * (Width  / ChartStreamWidth));

Width = actual ChartRect Width
ChartStreamWidth = saved ChartRect Width

This would result in correct callout positions. But with your code I won´t get the correct ChartStreamWidth value and in the end I have the callouts at the wrong position, too.

Any further idea?

[Narcís]

Hi Dominik,

I want to use these values for calculate the correct positions for callouts. You know that the position is saved in pixel values. And if you load a chart from a stream and your form size has changed the callouts will be placed wrong.

Chart's dimensions are independent to form's dimensions, moreover if it's a chart with its Parent set to nil.

Could you please send us a simple example project we can run "as-is" and let us know the exact steps we should follow to reproduce your problem here?

Thanks in advance.

[moelski]

Hi Narcis,

I have done a small example and uploaded it to your server:
Received CallOutPos After Load.zip Content Type application/x-zip-compressed Length 21703

Just run it and click the Button from 1 to 4.

You will see that the callout is at the wrong position. That´s because the position is stored in pixel.

The simple question is ...
How can I set the callout to the correct position after loading the TEE file?

[Narcís]

Hi Dominik,

Thanks for the example project. I've just sent it back to you modified doing what I already suggested you:

1. Using relative position for the rectangle tool.
2. Refreshing its position after loading the template file.

[moelski]

Hi Narcis,

thx for the example but that won´t fix my problem.

You do this:

Code: Select all

  x := Chart1[0].CalcXPos(6);
  y := Chart1[0].CalcYPos(5);
  Annotacion.Callout.XPosition := x;
  Annotacion.Callout.YPosition := y;

You set the position always to the same position.

But I have a saved Chart which includes Rectangles with callouts. And I don´t know the positions before.

So I have to read the Chart File (TEE), get the Rectangles and set the positions of the callouts.

I have no idea how this should work with your code. The problem is the following (i think):
You have to calculate the x / y position with CalcXPos but you only have the pixel value from the Chart file. And if you resize your form / chart you won´t get the same position.

In facts ... This is what I´m doing in my application:

Code: Select all

  Annotacion.Shape.Text             := 'This is text :-)';

  Annotacion.Shape.Shadow.HorizSize := 0;
  Annotacion.Shape.Shadow.VertSize  := 0;
  Annotacion.Shape.Transparency     := 75;
  Annotacion.Shape.AutoSize         := True;
  Annotacion.Shape.Cursor           := crHandPoint;
  Annotacion.Callout.Visible        := True;
  Annotacion.Callout.Arrow.Visible  := True;
  Annotacion.Callout.Arrow.Color    := clGreen;
  Annotacion.Callout.Brush.Color    := clBlack;
  Annotacion.Callout.HorizSize      := 3;
  Annotacion.Callout.Style          := psLeftTriangle;
  Annotacion.Callout.VertSize       := 3;
  Annotacion.Callout.Visible        := True;
  Annotacion.Callout.Arrow.Visible  := True;
  Annotacion.Shape.Left := 10;
  Annotacion.Shape.Top  := 20;
  Annotacion.Callout.XPosition := 100;
  Annotacion.Callout.YPosition := 150;

And in that case your SetAnnotationPosition won´t fix my problem.

[Narcís]

Hi Dominik,

That's why I added the other alternative commented in the code. You could also add the OnResize event and do something like this:

Code: Select all

procedure TForm16.Chart1Resize(Sender: TObject);
begin
  if Chart1.Tools.Count>0 then
    SetAnnotationPosition(Chart1.Tools.Items[0] as TRectangleTool);
end;

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.ChartRect.Left  + (250 - Chart1.Left);
  Annotacion.Callout.YPosition := Chart1.ChartRect.Top + (180 - Chart1.Top);
end;

[moelski]

Hi Narcis,

Code: Select all

 Annotacion.Shape.Left := Chart1.ChartRect.Left  + (150 - Chart1.Left); 
  Annotacion.Shape.Top :=  Chart1.ChartRect.Top + (100 - Chart1.Top); 
  Annotacion.Callout.XPosition := Chart1.ChartRect.Left  + (250 - Chart1.Left); 
  Annotacion.Callout.YPosition := Chart1.ChartRect.Top + (180 - Chart1.Top); 

Sure, this will work. But you won´t read the positions from a stream (or a Tee file). You use fixed positions and that won´t solve my problem.

Keep in mind what I need to do ...
Lets say we have an annotation and a callout. We save the chart to a file. Clear the chart and resize the form / chart. If you load the chart back from the file the callout position is wrong because of resizing the chart. And that is the problem I´m trying to fix.

So I need something like this:

Code: Select all

Annotacion.Callout.XPosition := SavedPositionX * (NewChartWidth / OldChartWidth);

SavedPositionX is the X Pixel Position from the TEE file (or Stream)
NewChartWidth = actual Chart width (chartrect.right - ChartRect.Left)
OldChartWidth = Chart width from the saved chart within the TEE file
The Chart Dimensions are stored in the TEE file:

object TChart
Left = 8
Top = 39
Width = 400
Height = 239

As far as I can see your solution on ly uses fixed positions.

So what can I do to solve my problem ?

[Narcís]

Hi Dominik,

Thanks for the information.

So I need something like this:
Code:
Annotacion.Callout.XPosition := SavedPositionX * (NewChartWidth / OldChartWidth);

SavedPositionX is the X Pixel Position from the TEE file (or Stream)
NewChartWidth = actual Chart width (chartrect.right - ChartRect.Left)
OldChartWidth = Chart width from the saved chart within the TEE file
The Chart Dimensions are stored in the TEE file:
Quote:
object TChart
Left = 8
Top = 39
Width = 400
Height = 239

Ok, I think you have everything necessary then. SavedPositionX will be annotation's position after loading the .tee file, you already have NewChartWidth and OldChartWidth is saved in the .tee file as well.

[moelski]

Hi Narcis,

and OldChartWidth is saved in the .tee file as well

But there is one problem ... As soon as I create a chart Object to load the Tee temporarily the Width value is set to a new one.

So could you please give me an example (you have my small demo) which shows loading a Tee file and setting the correct callout position?

I have tried many ways now, but can´t get anything working

[Narcís]

Hi Dominik,

Yes, and I already saved that in a variable in the example I sent you some days ago.

You can do this:

Code: Select all

procedure TForm16.SetAnnotationPosition(Annotacion: TRectangleTool);
var w,h: Double;
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
    w := Chart1.Width / 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
    h:= Chart1.Height / tmpHeight;
    Annotacion.Callout.YPosition := Round(Annotacion.Callout.YPosition * h);
  end;
end;

I've sent your project modified with this code.

[moelski]

Hi Narcis,

your solution only works if you don´t close the application.

And in fact this is the most important case.
Let me show you a common usecase :

1) A user creates a chart and save it to disk.
2) He sends the file to a different user und this user opens the file. (Both have different Form / chart sizes)
3) If the second user opens the file the callouts are missplaced.

So if we could fix this issue it would be great. If it helps you I can spend a Pro Email for this because this is an important issue for us.