[ROOT] Problems with GUI

From: cstrato@EUnet.at
Date: Sat Sep 01 2001 - 23:15:48 MEST


Dear Rooters

Since Rene and Fons are not available, maybe someone else has an
answer to my questions, thank you.

I have wrapped my program in a GUI, with identical code running
either within root or compiled as standalone program.

1, Rotating a histogram:
I have created a TRootEmbeddedCanvas where I define:
   vH2 = new TH2F(...);
   vH2->Draw("SURF2Z");
Running the program within root, I am able to rotate the histogram,
however, when compiled as standalone program I can no longer rotate it.
Why is this the case?
Do I have to initialize something?

2, Filling TGListBox:
I fill fListBox with data from a tree in this way:
   vCount = 0;
   vNEntries = 250;
   for (Int_t id=0;id<vNEntries;id++) {
      vTree->GetEntry(id);
      TString vName = vBranchItem->FGetName();
      vCount++;
      fListBox->AddEntry(vName, vCount);
   }
   fListBox->MapSubwindows();
   fListBox->Layout();
For a test tree with 250 entries (vNEntries=250) everything works
fine, however, for a tree with 10,000 entries (vNEntries=10000),
fListBox displays only part of the entries, and seems to scramble
memory since, when I access a different tree, I get the error:
"Error in <TFile::TFile>: file "vName_xxx" does not exist"
Why does TGListBox not display all entries?
Is TGListBox able to handle 10,000 entries?
Is there a better way to display a list with 10,000 entries?

3, Calling main destructor:
When I exit the GUI by closing the main window, the main destructor
is called. Sometimes, I get the following message:
"Warning in <TObjectTable::Remove>: 0x108d50a8 not found at 7872"
What does this mean?
What does the number 7872 (or a different number) mean?
Can I use this information somehow to find the bug?

Thank you very much for your help.

Best regards
Christian
----------------------------------
C.h.r.i.s.t.i.a.n  S.t.r.a.t.o.w.a
V.i.e.n.n.a,  A.u.s.t.r.i.a



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