TPad::WaitPrimitive comments

From: Maxim Nikulin <nikulin_at_gorodok.net>
Date: Mon, 24 Apr 2006 10:31:43 +0700

Hi,

I faced several problems during my attempts to use the TPad::WaitPrimitive() method and I think these issues should be mentioned in the documentation. I've written a script demonstrating a possible solution, I hope it will be useful for someone.

{

    h = new TH1F ("h", "h", 10, 0, 1);
    h->Draw();
    t = new TText(0.5, 0.5, "Text");

    t->SetName("t");  // otherwise it has empty name ""


                      // and WaitPrimitive() returns immediately

                      // TText is not the only class having the empty

                      // name by default

    t->Draw();
    for (Int_t i = 0; i < 10; ++i)
    {
       h->Fill(i/10. + 0.01);
       c1->Modified();
       c1->Update();
       c1->WaitPrimitive();
       c1->HandleInput(kNoEvent, 0, 0); // next call of WaitPrimitive()
                                        // often receives the same event
                                        // so no pause happens
       cout << i << endl;

    }
}

Another point is that the canvas can be closed while WaitPrimitive() is executed. Probably the code should handle this case.

I don't think input event processing significantly varies for different window managers, but just to be precise. I use Black box window manager, ROOT 5.10/00 and Fedora Core 2 on a Pentium 4 box.

-- 
Maxim Nikulin

Received on Mon Apr 24 2006 - 05:31:50 MEST