{
  Int_t w = 800;
  Int_t h = 600;
  TCanvas *c;
  gROOT->SetBatch(kFALSE);
  c = new TCanvas("c", "c", w, h); c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  c->SetWindowSize(w + (w - c->GetWw()), h + (h - c->GetWh()));
  c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  delete c;
  c = new TCanvas("c", "c", w, h); c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  c->SetCanvasSize(w, h);
  c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  delete c;
  gROOT->SetBatch(kTRUE);
  c = new TCanvas("c", "c", w, h); c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  c->SetWindowSize(w + (w - c->GetWw()), h + (h - c->GetWh()));
  c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  delete c;
  c = new TCanvas("c", "c", w, h); c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
  c->SetCanvasSize(w, h);
  c->Modified(); c->Update();
  std::cout << c->GetWw() << " " << c->GetWh() << std::endl;
}