Displaying charts on TeePreviewPanel

[Metek]

Hi,
to print several charts on one page I have a form containing a TeePreviewPanel.
In my MainForm I have the following code to show the print preview:

Code: Select all

procedure TMainForm.ShowPrintPreview(Sender: TObject);
begin
  Chart1.PrintProportional:=False;
  Chart2.PrintProportional:=False;
  Chart3.PrintProportional:=False;
  Chart4.PrintProportional:=False;

  Chart1.PrintMargins:=Rect(2,2,2,76);
  Chart2.PrintMargins:=Rect(2,25,2,51);
  Chart3.PrintMargins:=Rect(2,50,2,26);
  Chart4.PrintMargins:=Rect(2,75,2,2);

  with frmPrintPreview.TeePreviewPanel1 do begin
    Panels.Clear;
    Panels.Add(Chart1);
    Panels.Add(Chart2);
    Panels.Add(Chart3);
    Panels.Add(Chart4);
  end;

   frmPrintPreview.ShowModal;
end;

When the preview form is shown only one chart is visible. Only when i move the window or change its size the charts will be displayed correctly. I have tried to call Repaint and Refresh with no success. How can I solve the problem?

A second question: How can I insert a text on top of the panel? I want to insert a title before printing and tried the following:

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  with TeePreviewPanel1.DelphiCanvas do begin
    Font.Height := 10;
    Font.Color := clBlack;
    TextOut(50,10,'My Title here');
  end;

but the text is not visible. What is the correct code to do this?

Thank you in advance
Metek

[Yeray]

Hello,

The following simple example seems to work fine for me here:

Code: Select all

uses Chart, Series, TeePrevi, TeePreviewPanel;

var Charts: array of TChart;

procedure TForm1.BPrintPreviewClick(Sender: TObject);
var preview: TChartPreview;
begin
  Charts[0].PrintProportional:=False;
  Charts[1].PrintProportional:=False;
  Charts[2].PrintProportional:=False;
  Charts[3].PrintProportional:=False;

  Charts[0].PrintMargins:=Rect(2,2,2,76);
  Charts[1].PrintMargins:=Rect(2,25,2,51);
  Charts[2].PrintMargins:=Rect(2,50,2,26);
  Charts[3].PrintMargins:=Rect(2,75,2,2);

  preview:=TChartPreview.Create(Self);
  with preview.TeePreviewPanel1 do begin
    Panels.Clear;
    Panels.Add(Charts[0]);
    Panels.Add(Charts[1]);
    Panels.Add(Charts[2]);
    Panels.Add(Charts[3]);
  end;

  preview.ShowModal;
end;

procedure TForm1.FormCreate(Sender: TObject);

  function CreateChart: TChart;
  begin
    Result:=TChart.Create(Self);

    with Result do
    begin
      Parent:=Self;
      Color:=clWhite;
      Gradient.Visible:=False;
      Walls.Back.Color:=clWhite;
      Walls.Back.Gradient.Visible:=False;
      Legend.Hide;
      View3D:=False;
    end;

    Result.AddSeries(TBarSeries).FillSampleValues;
  end;

var i: Integer;
begin
  SetLength(Charts, 4);
  for i:=0 to 3 do
  begin
    Charts[i]:=CreateChart;
    with Charts[i] do
    begin
      Left:=i mod 2 * Width;
      Top:=(i div 2 * Height) + Panel1.Height;
    end;
  end;

  Width:=(Charts[0].Width*2) + 15;
  Height:=(Charts[0].Height*2) + Panel1.Height + 38;
end;

PrintPreview.png (50.22 KiB) Viewed 14531 times

Could you please modify it so we can reproduce the problem here?
Thanks in advance.

[Yeray]

Regarding the second question, you could implement the OnAfterDraw of the TeePreviewPanel1 as follows:

Code: Select all

  with preview.TeePreviewPanel1 do begin
    //...
    OnAfterDraw:=PreviewAfterDraw;
  end;

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procedure TForm1.PreviewAfterDraw(Sender: TObject);
begin
  with TTeePreviewPanel(Sender).Canvas do
  begin
    Font.Height := -10;
    Font.Color := clBlack;
    TextOut(50, 10, 'My Title here');
  end;
end;

[Metek]

Hello Yeray,
i was close to desperation to locate the problem in my application, but now I can reproduce it.
In my application each of the 4 charts is assigned to separate page of a PageControl.
If I start the application and immediately call up the print preview before all pages have been displayed once, the print preview does not work. This only happens the first time I call it up.

To demonstrate the effect, I have modified your example programm a little:

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unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, VclTee.TeeGDIPlus, VCLTee.TeEngine,
  Vcl.ExtCtrls, VCLTee.TeeProcs, VCLTee.Chart, Vcl.StdCtrls, VCLTee.Series,
  VclTee.TeePrevi, Vcl.ComCtrls;

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    BPrintPreview: TButton;
    PageControl1: TPageControl;
    TabSheet1: TTabSheet;
    TabSheet2: TTabSheet;
    TabSheet3: TTabSheet;
    TabSheet4: TTabSheet;
    procedure FormCreate(Sender: TObject);
    procedure BPrintPreviewClick(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;
  Charts: array of TChart;

implementation

{$R *.dfm}

procedure TForm1.BPrintPreviewClick(Sender: TObject);
var preview: TChartPreview;
begin
  Charts[0].PrintProportional:=False;
  Charts[1].PrintProportional:=False;
  Charts[2].PrintProportional:=False;
  Charts[3].PrintProportional:=False;

  Charts[0].PrintMargins:=Rect(2,2,2,76);
  Charts[1].PrintMargins:=Rect(2,25,2,51);
  Charts[2].PrintMargins:=Rect(2,50,2,26);
  Charts[3].PrintMargins:=Rect(2,75,2,2);

  preview:=TChartPreview.Create(Self);
  with preview.TeePreviewPanel1 do begin
    Panels.Clear;
    Panels.Add(Charts[0]);
    Panels.Add(Charts[1]);
    Panels.Add(Charts[2]);
    Panels.Add(Charts[3]);
  end;

  preview.ShowModal;
  preview.Free;
end;

procedure TForm1.FormCreate(Sender: TObject);

  function CreateChart(aParent: TWinControl): TChart;
  begin
    Result:=TChart.Create(Self);
    with Result do
    begin
      Parent:=aParent;
      Color:=clWhite;
      Gradient.Visible:=False;
      Walls.Back.Color:=clWhite;
      Walls.Back.Gradient.Visible:=False;
      Legend.Hide;
      View3D:=False;
    end;
    Result.AddSeries(TLineSeries).FillSampleValues;
  end;

var i: Integer;
begin
  SetLength(Charts, 4);
  for i:=0 to 3 do
  begin
    Charts[i]:=CreateChart(PageControl1.Pages[i]);
    with Charts[i] do Align := alClient;
  end;
end;

end.

(The second problem (with the print title) we should perhaps discuss in a separate thread. I wanted to have the print title printed on the paper as well, not only on the preview panel)

Regards
Metek

[Metek]

Does anyone have a solution or workaround for the prolem?

[Marc]

Hello Metek,

I'm checking what repaint method can force the render but haven't found one yet other than CopyToClipboard, which works but, as the name implies, leaves a chart on the clipboard.

ie.
Charts.CopyToClipboardBitmap;

Regards,
Marc Meumann

[Metek]

Hello Marc,
thanks for the workaround, it works well.
The clipboard can then simply be deleted with Clipboard.Clear

[Yeray]

Hello,

As an alternative to that workaround, forcing the charts to be drawn works fine for me:

Code: Select all

procedure TForm1.BPrintPreviewClick(Sender: TObject);
var preview: TChartPreview;
    i: Integer;
begin
  Charts[0].PrintMargins:=Rect(2,2,2,76);
  Charts[1].PrintMargins:=Rect(2,25,2,51);
  Charts[2].PrintMargins:=Rect(2,50,2,26);
  Charts[3].PrintMargins:=Rect(2,75,2,2);

  preview:=TChartPreview.Create(Self);
  with preview.TeePreviewPanel1 do begin
    Panels.Clear;
    for i:=0 to High(Charts) do begin
      Charts[i].Draw;
      Charts[i].PrintProportional:=False;
      Panels.Add(Charts[i]);
    end;
  end;

  preview.ShowModal;
  preview.Free;
end;