Revision 60ec740a0e8fd4c1c281e66c78eab6eb38d6e32b authored by Axel Naumann on 26 February 2020, 16:07:10 UTC, committed by Axel Naumann on 26 February 2020, 16:38:23 UTC
1 parent d645438
hworld2.cxx
// @(#)root/test:$Id$
// Author: Fons Rademakers 04/04/97
// This small demo shows the traditional "Hello World". Its main use is
// to show how to use ROOT graphics and how to enter the eventloop to
// be able to interact with the graphics.
#include "TApplication.h"
#include "TCanvas.h"
#include "TLine.h"
#include "TPaveLabel.h"
int main(int argc, char **argv)
{
TApplication theApp("App", &argc, argv);
TCanvas *c = new TCanvas("c", "The Hello Canvas", 400, 400);
TPaveLabel *hello = new TPaveLabel(0.2,0.4,0.8,0.6,"Hello World");
hello->Draw();
TPaveLabel *quit = new TPaveLabel(0.2,0.2,0.8,0.3,"Close via menu File/Quit");
quit->Draw();
c->Update();
// Enter event loop, one can now interact with the objects in
// the canvas. Select "Exit ROOT" from Canvas "File" menu to exit
// the event loop and execute the next statements.
theApp.Run(kTRUE);
TLine *l = new TLine(0.1,0.2,0.5,0.9);
l->Draw();
quit->SetLabel("Select File/Quit again to exit app");
c->Update();
// Here we don't return from the eventloop. "Exit ROOT" will quit the app.
theApp.Run();
return 0;
}
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