How a TRootEmbeddeCanvas should adopt an existent canvas?

ROOT
1

Hello,
I’m developing an application that use TGMainFrame and TRootEmbeddedCanvas. I would like to use only one TRootEmbeddedCanvas that show all the TCanvases that I need.
In addition, I would like to store all the canvases that are created into a root file.
I have added a simple script that do this. Use to button Add to add canvases and the combo box to show a canvas that is stored into the root file.
The AddCanvas() method add a new canvas. If a current canvas is present, store the current canvas into the file and create a new canvas (line 91-93).
When an entry into the combo box is selected, (DoSelection() slot), write the current canvas into a file and load, from file, a canvas already stored. The problem is in the lines 69-70, because I’m not able to associate the canvas loaded from file with the TRootEmbeddedCanvas object. How is possible to do this?
An additional question. Why if a run the script two times in the same root session I get an error about TQObject::CheckConnectArgs?

Thank you very much for the help.

Best regards
Andrea Bulgarelli
multicanvas_file.c (4.85 KB)

2

Hi Andrea,

How to embed a canvas in an TRootEmbedded canvas is written in the ROOT reference guide available on web. Here is the the text :

To embed a canvas derived from a TCanvas do the following:

TRootEmbeddedCanvas *embedded = new TRootEmbeddedCanvas(0, p, w, h);
      [note name must be 0, not null string ""]
 Int_t wid = embedded->GetCanvasWindowId();
 TMyCanvas *myc = new TMyCanvas("myname", 10, 10, wid);
 embedded->AdoptCanvas(myc);

Did you try it? I am going to see how the macro you have attached works.

Best regards, Ilka

3

Yes, I have seen the code but maybe I have not understand how it work, because my problem is to get a canvas from a root file and show it into the TRootEmbeddedCanvas of my application.
For example, in the example that I have sent I load a canvas from a root file with the following line of code:

TCanvas* fCurrentCanvas = file->Get(padname);

and after this I try to associate the fCurrentCanvas with the TRootEmbeddedCanvas (fEcan):

fEcan->AdoptCanvas(fCurrentCanvas);

but this don’t work.
The question is: how is possible to get a canvas from a file and associate the wid of the TRootEmbeddedCanvas to this canvas?

Thank you very much
Best regards
Andrea Bulgarelli

4

Hi Andrea,

The current CVS version allow to do it now.
This code works :

[code] TCanvas* oldCanvas = fEmbeddedCanvas->GetCanvas();
if (oldCanvas) {
delete oldCanvas;
}
//Get a canvas from the file -----------------------
fCurrentCanvas = (TCanvas *)file->Get(CanvasName);
if(fCurrentCanvas == 0) return;
fEmbeddedCanvas->AdoptCanvas(fCurrentCanvas);

fCurrentCanvas->Draw();
fCurrentCanvas->Modified();
fCurrentCanvas->Update();
[/code]
Cheers,
Bertrand.

5

Thank you. It work.

Best regards
Andrea Bulgarelli